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1.  Integrative Genomic Analyses Identify BRF2 as a Novel Lineage-Specific Oncogene in Lung Squamous Cell Carcinoma 
PLoS Medicine  2010;7(7):e1000315.
William Lockwood and colleagues show that the focal amplification of a gene, BRF2, on Chromosome 8p12 plays a key role in squamous cell carcinoma of the lung.
Traditionally, non-small cell lung cancer is treated as a single disease entity in terms of systemic therapy. Emerging evidence suggests the major subtypes—adenocarcinoma (AC) and squamous cell carcinoma (SqCC)—respond differently to therapy. Identification of the molecular differences between these tumor types will have a significant impact in designing novel therapies that can improve the treatment outcome.
Methods and Findings
We used an integrative genomics approach, combing high-resolution comparative genomic hybridization and gene expression microarray profiles, to compare AC and SqCC tumors in order to uncover alterations at the DNA level, with corresponding gene transcription changes, which are selected for during development of lung cancer subtypes. Through the analysis of multiple independent cohorts of clinical tumor samples (>330), normal lung tissues and bronchial epithelial cells obtained by bronchial brushing in smokers without lung cancer, we identified the overexpression of BRF2, a gene on Chromosome 8p12, which is specific for development of SqCC of lung. Genetic activation of BRF2, which encodes a RNA polymerase III (Pol III) transcription initiation factor, was found to be associated with increased expression of small nuclear RNAs (snRNAs) that are involved in processes essential for cell growth, such as RNA splicing. Ectopic expression of BRF2 in human bronchial epithelial cells induced a transformed phenotype and demonstrates downstream oncogenic effects, whereas RNA interference (RNAi)-mediated knockdown suppressed growth and colony formation of SqCC cells overexpressing BRF2, but not AC cells. Frequent activation of BRF2 in >35% preinvasive bronchial carcinoma in situ, as well as in dysplastic lesions, provides evidence that BRF2 expression is an early event in cancer development of this cell lineage.
This is the first study, to our knowledge, to show that the focal amplification of a gene in Chromosome 8p12, plays a key role in squamous cell lineage specificity of the disease. Our data suggest that genetic activation of BRF2 represents a unique mechanism of SqCC lung tumorigenesis through the increase of Pol III-mediated transcription. It can serve as a marker for lung SqCC and may provide a novel target for therapy.
Please see later in the article for the Editors' Summary
Editors' Summary
Lung cancer is the commonest cause of cancer-related death. Every year, 1.3 million people die from this disease, which is mainly caused by smoking. Most cases of lung cancer are “non-small cell lung cancers” (NSCLCs). Like all cancers, NSCLC starts when cells begin to divide uncontrollably and to move round the body (metastasize) because of changes (mutations) in their genes. These mutations are often in “oncogenes,” genes that, when activated, encourage cell division. Oncogenes can be activated by mutations that alter the properties of the proteins they encode or by mutations that increase the amount of protein made from them, such as gene amplification (an increase in the number of copies of a gene). If NSCLC is diagnosed before it has spread from the lungs (stage I disease), it can be surgically removed and many patients with stage I NSCLC survive for more than 5 years after their diagnosis. Unfortunately, in more than half of patients, NSCLC has metastasized before it is diagnosed. This stage IV NSCLC can be treated with chemotherapy (toxic chemicals that kill fast-growing cancer cells) but only 2% of patients with stage IV lung cancer are alive 5 years after diagnosis.
Why Was This Study Done?
Traditionally, NSCLC has been regarded as a single disease in terms of treatment. However, emerging evidence suggests that the two major subtypes of NSCLC—adenocarcinoma and squamous cell carcinoma (SqCC)—respond differently to chemotherapy. Adenocarcinoma and SqCC start in different types of lung cell and experts think that for each cell type in the body, specific combinations of mutations interact with the cell type's own unique characteristics to provide the growth and survival advantage needed for cancer development. If this is true, then identifying the molecular differences between adenocarcinoma and SqCC could provide targets for more effective therapies for these major subtypes of NSCLC. Amplification of a chromosome region called 8p12 is very common in NSCLC, which suggests that an oncogene that drives lung cancer development is present in this chromosome region. In this study, the researchers investigate this possibility by looking for an amplified gene in the 8p12 chromosome region that makes increased amounts of protein in lung SqCC but not in lung adenocarcinoma.
What Did the Researchers Do and Find?
The researchers used a technique called comparative genomic hybridization to show that focal regions of Chromosome 8p are amplified in about 40% of lung SqCCs, but that DNA loss in this region is the most common alteration in lung adenocarcinomas. Ten genes in the 8p12 chromosome region were expressed at higher levels in the SqCC samples that they examined than in adenocarcinoma samples, they report, and overexpression of five of these genes correlated with amplification of the 8p12 region in the SqCC samples. Only one of the genes—BRF2—was more highly expressed in squamous carcinoma cells than in normal bronchial epithelial cells (the cell type that lines the tubes that take air into the lungs and from which SqCC develops). Artificially induced expression of BRF2 in bronchial epithelial cells made these normal cells behave like tumor cells, whereas reduction of BRF2 expression in squamous carcinoma cells made them behave more like normal bronchial epithelial cells. Finally, BRF2 was frequently activated in two early stages of squamous cell carcinoma—bronchial carcinoma in situ and dysplastic lesions.
What Do These Findings Mean?
Together, these findings show that the focal amplification of chromosome region 8p12 plays a role in the development of lung SqCC but not in the development of lung adenocarcinoma, the other major subtype of NSCLC. These findings identify BRF2 (which encodes a RNA polymerase III transcription initiation factor, a protein that is required for the synthesis of RNA molecules that help to control cell growth) as a lung SqCC-specific oncogene and uncover a unique mechanism for lung SqCC development. Most importantly, these findings suggest that genetic activation of BRF2 could be used as a marker for lung SqCC, which might facilitate the early detection of this type of NSCLC and that BRF2 might provide a new target for therapy.
Additional Information
Please access these Web sites via the online version of this summary at
The US National Cancer Institute provides detailed information for patients and professionals about all aspects of lung cancer, including information on non-small cell carcinoma (in English and Spanish)
Cancer Research UK also provides information about lung cancer and information on how cancer starts
MedlinePlus has links to other resources about lung cancer (in English and Spanish)
PMCID: PMC2910599  PMID: 20668658
2.  Transcriptomic changes in human breast cancer progression as determined by serial analysis of gene expression 
Breast Cancer Research  2004;6(5):R499-R513.
Genomic and transcriptomic alterations affecting key cellular processes such us cell proliferation, differentiation and genomic stability are considered crucial for the development and progression of cancer. Most invasive breast carcinomas are known to derive from precursor in situ lesions. It is proposed that major global expression abnormalities occur in the transition from normal to premalignant stages and further progression to invasive stages. Serial analysis of gene expression (SAGE) was employed to generate a comprehensive global gene expression profile of the major changes occurring during breast cancer malignant evolution.
In the present study we combined various normal and tumor SAGE libraries available in the public domain with sets of breast cancer SAGE libraries recently generated and sequenced in our laboratory. A recently developed modified t test was used to detect the genes differentially expressed.
We accumulated a total of approximately 1.7 million breast tissue-specific SAGE tags and monitored the behavior of more than 25,157 genes during early breast carcinogenesis. We detected 52 transcripts commonly deregulated across the board when comparing normal tissue with ductal carcinoma in situ, and 149 transcripts when comparing ductal carcinoma in situ with invasive ductal carcinoma (P < 0.01).
A major novelty of our study was the use of a statistical method that correctly accounts for the intra-SAGE and inter-SAGE library sources of variation. The most useful result of applying this modified t statistics beta binomial test is the identification of genes and gene families commonly deregulated across samples within each specific stage in the transition from normal to preinvasive and invasive stages of breast cancer development. Most of the gene expression abnormalities detected at the in situ stage were related to specific genes in charge of regulating the proper homeostasis between cell death and cell proliferation. The comparison of in situ lesions with fully invasive lesions, a much more heterogeneous group, clearly identified as the most importantly deregulated group of transcripts those encoding for various families of proteins in charge of extracellular matrix remodeling, invasion and cell motility functions.
PMCID: PMC549167  PMID: 15318932
breast cancer; gene expression profiling; serial analysis of gene expression
3.  Molecular pathways undergoing dramatic transcriptomic changes during tumor development in the human colon 
BMC Cancer  2012;12:608.
The malignant transformation of precancerous colorectal lesions involves progressive alterations at both the molecular and morphologic levels, the latter consisting of increases in size and in the degree of cellular atypia. Analyzing preinvasive tumors of different sizes can therefore shed light on the sequence of these alterations.
We used a molecular pathway-based approach to analyze transcriptomic profiles of 59 colorectal tumors representing early and late preinvasive stages and the invasive stage of tumorigenesis. Random set analysis was used to identify biological pathways enriched for genes differentially regulated in tumors (compared with 59 samples of normal mucosa).
Of the 880 canonical pathways we investigated, 112 displayed significant tumor-related upregulation or downregulation at one or more stages of tumorigenesis. This allowed us to distinguish between pathways whose dysregulation is probably necessary throughout tumorigenesis and those whose involvement specifically drives progression from one stage to the next. We were also able to pinpoint specific changes within each gene set that seem to play key roles at each transition. The early preinvasive stage was characterized by cell-cycle checkpoint activation triggered by DNA replication stress and dramatic downregulation of basic transmembrane signaling processes that maintain epithelial/stromal homeostasis in the normal mucosa. In late preinvasive lesions, there was also downregulation of signal transduction pathways (e.g., those mediated by G proteins and nuclear hormone receptors) involved in cell differentiation and upregulation of pathways governing nuclear envelope dynamics and the G2>M transition in the cell cycle. The main features of the invasive stage were activation of the G1>S transition in the cell cycle, upregulated expression of tumor-promoting microenvironmental factors, and profound dysregulation of metabolic pathways (e.g., increased aerobic glycolysis, downregulation of pathways that metabolize drugs and xenobiotics).
Our analysis revealed specific pathways whose dysregulation might play a role in each transition of the transformation process. This is the first study in which such an approach has been used to gain further insights into colorectal tumorigenesis. Therefore, these data provide a launchpad for further exploration of the molecular characterization of colorectal tumorigenesis using systems biology approaches.
PMCID: PMC3541196  PMID: 23253212
Colorectal adenoma; Colorectal cancer; Transcriptomics; Molecular pathways; Cell cycle pathways; Random set method
4.  Nuclear Receptor Expression Defines a Set of Prognostic Biomarkers for Lung Cancer 
PLoS Medicine  2010;7(12):e1000378.
David Mangelsdorf and colleagues show that nuclear receptor expression is strongly associated with clinical outcomes of lung cancer patients, and this expression profile is a potential prognostic signature for lung cancer patient survival time, particularly for individuals with early stage disease.
The identification of prognostic tumor biomarkers that also would have potential as therapeutic targets, particularly in patients with early stage disease, has been a long sought-after goal in the management and treatment of lung cancer. The nuclear receptor (NR) superfamily, which is composed of 48 transcription factors that govern complex physiologic and pathophysiologic processes, could represent a unique subset of these biomarkers. In fact, many members of this family are the targets of already identified selective receptor modulators, providing a direct link between individual tumor NR quantitation and selection of therapy. The goal of this study, which begins this overall strategy, was to investigate the association between mRNA expression of the NR superfamily and the clinical outcome for patients with lung cancer, and to test whether a tumor NR gene signature provided useful information (over available clinical data) for patients with lung cancer.
Methods and Findings
Using quantitative real-time PCR to study NR expression in 30 microdissected non-small-cell lung cancers (NSCLCs) and their pair-matched normal lung epithelium, we found great variability in NR expression among patients' tumor and non-involved lung epithelium, found a strong association between NR expression and clinical outcome, and identified an NR gene signature from both normal and tumor tissues that predicted patient survival time and disease recurrence. The NR signature derived from the initial 30 NSCLC samples was validated in two independent microarray datasets derived from 442 and 117 resected lung adenocarcinomas. The NR gene signature was also validated in 130 squamous cell carcinomas. The prognostic signature in tumors could be distilled to expression of two NRs, short heterodimer partner and progesterone receptor, as single gene predictors of NSCLC patient survival time, including for patients with stage I disease. Of equal interest, the studies of microdissected histologically normal epithelium and matched tumors identified expression in normal (but not tumor) epithelium of NGFIB3 and mineralocorticoid receptor as single gene predictors of good prognosis.
NR expression is strongly associated with clinical outcomes for patients with lung cancer, and this expression profile provides a unique prognostic signature for lung cancer patient survival time, particularly for those with early stage disease. This study highlights the potential use of NRs as a rational set of therapeutically tractable genes as theragnostic biomarkers, and specifically identifies short heterodimer partner and progesterone receptor in tumors, and NGFIB3 and MR in non-neoplastic lung epithelium, for future detailed translational study in lung cancer.
Please see later in the article for the Editors' Summary
Editors' Summary
Lung cancer, the most common cause of cancer-related death, kills 1.3 million people annually. Most lung cancers are “non-small-cell lung cancers” (NSCLCs), and most are caused by smoking. Exposure to chemicals in smoke causes changes in the genes of the cells lining the lungs that allow the cells to grow uncontrollably and to move around the body. How NSCLC is treated and responds to treatment depends on its “stage.” Stage I tumors, which are small and confined to the lung, are removed surgically, although chemotherapy is also sometimes given. Stage II tumors have spread to nearby lymph nodes and are treated with surgery and chemotherapy, as are some stage III tumors. However, because cancer cells in stage III tumors can be present throughout the chest, surgery is not always possible. For such cases, and for stage IV NSCLC, where the tumor has spread around the body, patients are treated with chemotherapy alone. About 70% of patients with stage I and II NSCLC but only 2% of patients with stage IV NSCLC survive for five years after diagnosis; more than 50% of patients have stage IV NSCLC at diagnosis.
Why Was This Study Done?
Patient responses to treatment vary considerably. Oncologists (doctors who treat cancer) would like to know which patients have a good prognosis (are likely to do well) to help them individualize their treatment. Consequently, the search is on for “prognostic tumor biomarkers,” molecules made by cancer cells that can be used to predict likely clinical outcomes. Such biomarkers, which may also be potential therapeutic targets, can be identified by analyzing the overall pattern of gene expression in a panel of tumors using a technique called microarray analysis and looking for associations between the expression of sets of genes and clinical outcomes. In this study, the researchers take a more directed approach to identifying prognostic biomarkers by investigating the association between the expression of the genes encoding nuclear receptors (NRs) and clinical outcome in patients with lung cancer. The NR superfamily contains 48 transcription factors (proteins that control the expression of other genes) that respond to several hormones and to diet-derived fats. NRs control many biological processes and are targets for several successful drugs, including some used to treat cancer.
What Did the Researchers Do and Find?
The researchers analyzed the expression of NR mRNAs using “quantitative real-time PCR” in 30 microdissected NSCLCs and in matched normal lung tissue samples (mRNA is the blueprint for protein production). They then used an approach called standard classification and regression tree analysis to build a prognostic model for NSCLC based on the expression data. This model predicted both survival time and disease recurrence among the patients from whom the tumors had been taken. The researchers validated their prognostic model in two large independent lung adenocarcinoma microarray datasets and in a squamous cell carcinoma dataset (adenocarcinomas and squamous cell carcinomas are two major NSCLC subtypes). Finally, they explored the roles of specific NRs in the prediction model. This analysis revealed that the ability of the NR signature in tumors to predict outcomes was mainly due to the expression of two NRs—the short heterodimer partner (SHP) and the progesterone receptor (PR). Expression of either gene could be used as a single gene predictor of the survival time of patients, including those with stage I disease. Similarly, the expression of either nerve growth factor induced gene B3 (NGFIB3) or mineralocorticoid receptor (MR) in normal tissue was a single gene predictor of a good prognosis.
What Do These Findings Mean?
These findings indicate that the expression of NR mRNA is strongly associated with clinical outcomes in patients with NSCLC. Furthermore, they identify a prognostic NR expression signature that provides information on the survival time of patients, including those with early stage disease. The signature needs to be confirmed in more patients before it can be used clinically, and researchers would like to establish whether changes in mRNA expression are reflected in changes in protein expression if NRs are to be targeted therapeutically. Nevertheless, these findings highlight the potential use of NRs as prognostic tumor biomarkers. Furthermore, they identify SHP and PR in tumors and two NRs in normal lung tissue as molecules that might provide new targets for the treatment of lung cancer and new insights into the early diagnosis, pathogenesis, and chemoprevention of lung cancer.
Additional Information
Please access these Web sites via the online version of this summary at
The Nuclear Receptor Signaling Atlas (NURSA) is consortium of scientists sponsored by the US National Institutes of Health that provides scientific reagents, datasets, and educational material on nuclear receptors and their co-regulators to the scientific community through a Web-based portal
The Cancer Prevention and Research Institute of Texas (CPRIT) provides information and resources to anyone interested in the prevention and treatment of lung and other cancers
The US National Cancer Institute provides detailed information for patients and professionals about all aspects of lung cancer, including information on non-small-cell carcinoma and on tumor markers (in English and Spanish)
Cancer Research UK also provides information about lung cancer and information on how cancer starts
MedlinePlus has links to other resources about lung cancer (in English and Spanish)
Wikipedia has a page on nuclear receptors (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
PMCID: PMC3001894  PMID: 21179495
5.  Preneoplasia of lung cancer 
As with other epithelial cancers, lung cancer develops over a period of several years or decades via a series of progressive morphological changes accompanied by molecular alterations that commence in histologically normal epithelium. However the development of lung cancer presents certain unique features that complicates this evaluation. Anatomically the respiratory tree may be divided into central and peripheral compartments having different gross and histological anatomies as well as different functions. In addition, there are three major forms of lung cancer and many minor forms. Many of these forms arise predominantly in either the central or peripheral compartments. Squamous cell and small cell carcinomas predominantly arise in the central compartment, while adenocarcinomas predominantly arise peripherally. Large cell carcinomas are not a single entity but consist of poorly differentiated forms of the other types and, possibly, some truly undifferentiated “stem cell like” tumors. The multistage origin of squamous cell carcinomas, because of their central location, can be followed more closely than the peripherally arising adenocarcinomas. Squamous cell carcinomas arise after a series of reactive, metaplastic, premalignant and preinvasive changes. However, long term observations indicate that not all tumors follow a defined histologic course, and the clinical course, especially of early lesions, is difficult to predict. Peripheral adenocarcinomas are believed to arise from precursor lesions known as atypical adenomatous hyperplasias and may have extensive in situ growth before becoming invasive. Small cell carcinomas are believed to arise from severely molecularly damaged epithelium without going through recognizable preneoplastic changes. The molecular changes that occur prior to the onset on invasive cancers are extensive. As documented in this chapter, they encompass all of the six classic Hallmarks of Cancer other than invasion and metastasis, which by definition occur beyond preneoplasia. A study of preinvasive lung cancer has yielded much valuable biologic information that impacts on clinical management.
PMCID: PMC3428013  PMID: 22112486
Lung cancer; squamous cell carcinoma; adenocarcinomas; small cell lung carcinoma; preneoplasia; carcinoma in situ; atypical adenomatous hyperplasia; tumor suppressor genes; oncogenes; apoptosis; telomerase; angiogenesis
6.  Sex Determining Region Y-Box 2 (SOX2) Is a Potential Cell-Lineage Gene Highly Expressed in the Pathogenesis of Squamous Cell Carcinomas of the Lung 
PLoS ONE  2010;5(2):e9112.
Non-small cell lung cancer (NSCLC) represents the majority (85%) of lung cancers and is comprised mainly of adenocarcinomas and squamous cell carcinomas (SCCs). The sequential pathogenesis of lung adenocarcinomas and SCCs occurs through dissimilar phases as the former tumors typically arise in the lung periphery whereas the latter normally arise near the central airway.
Methodology/Principal Findings
We assessed the expression of SOX2, an embryonic stem cell transcriptional factor that also plays important roles in the proliferation of basal tracheal cells and whose expression is restricted to the main and central airways and bronchioles of the developing and adult mouse lung, in NSCLC by various methodologies. Here, we found that SOX2 mRNA levels, from various published datasets, were significantly elevated in lung SCCs compared to adenocarcinomas (all p<0.001). Moreover, a previously characterized OCT4/SOX2/NANOG signature effectively separated lung SCCs from adenocarcinomas in two independent publicly available datasets which correlated with increased SOX2 mRNA in SCCs. Immunohistochemical analysis of various histological lung tissue specimens demonstrated marked nuclear SOX2 protein expression in all normal bronchial epithelia, alveolar bronchiolization structures and premalignant lesions in SCC development (hyperplasia, dysplasia and carcinoma in situ) and absence of expression in all normal alveoli and atypical adenomatous hyperplasias. Moreover, SOX2 protein expression was greatly higher in lung SCCs compared to adenocarcinomas following analyses in two independent large TMA sets (TMA set I, n = 287; TMA set II, n = 511 both p<0.001). Furthermore, amplification of SOX2 DNA was detected in 20% of lung SCCs tested (n = 40) and in none of the adenocarcinomas (n = 17).
Our findings highlight a cell-lineage gene expression pattern for the stem cell transcriptional factor SOX2 in the pathogenesis of lung SCCs and suggest a differential activation of stem cell-related pathways between squamous cell carcinomas and adenocarcinomas of the lung.
PMCID: PMC2817751  PMID: 20161759
7.  Pulmonary preinvasive neoplasia 
Journal of Clinical Pathology  2001;54(4):257-271.
Advances in molecular biology have increased our knowledge of the biology of preneoplastic lesions in the human lung. The recently published WHO lung tumour classification defines three separate lesions that are regarded as preinvasive neoplasia. These are (1) squamous dysplasia and carcinoma in situ (SD/CIS), (2) atypical adenomatous hyperplasia (AAH), and (3) diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH). SD/CIS is graded in four stages (mild, moderate, severe, and CIS), based upon the distribution of atypical cells and mitotic figures. Most airways showing SD/CIS demonstrate a range of grades; many epithelia are hard to assess and the reproducibility of this complex system remains to be established. Detailed criteria are, however, welcome and provide an objective framework on which to compare various molecular changes. Alterations in gene expression and chromosome structure known to be associated with malignant transformation can be demonstrated in CIS, less so in dysplasias, but also in morphologically normal epithelium. The changes might be sequential, and their frequency and number increase with atypia. Less is known of the "risk of progression" of SD/CIS to invasive "central" bronchial carcinoma. It may take between one and 10 years for invasion to occur, yet the lesion(s) may be reversible if carcinogen exposure ceases.
AAH may be an important precursor lesion for peripheral "parenchymal" adenocarcinoma of the lung: the "adenoma" in an adenoma–carcinoma sequence. There is good morphological evidence that AAH may progress from low to high grade to bronchioloalveolar carcinoma (BAC; a non-invasive lesion by definition). Invasion then develops within BAC and peripheral lung adenocarcinoma evolves. The molecular events associated with this progression are not well understood and studies are hampered by a lack of clear criteria to distinguish high grade AAH from BAC. Nonetheless, as with SD/CIS, the patterns of expression of tumour associated genes are consistent with neoplastic progression. We have little idea of the incidence of AAH in the normal or "smoking" populations. It is found more frequently in cancer bearing lungs, especially in those with adenocarcinoma, and is more common in women. No data are available on the risk of progression of AAH. DIPNECH is an exceptionally rare lesion associated with the development of multiple carcinoid tumours. Almost nothing is known of its biology.
Knowledge of these lesions will be crucial in the design and understanding of lung cancer screening programmes, where it is likely that the morphological and, more importantly perhaps, the molecular characteristics of these lesions will provide useful targets for detection and possibly even treatment.
Key Words: lung cancer • preneoplasia • carcinogenesis
PMCID: PMC1731391  PMID: 11304841
8.  Cell migration leads to spatially distinct but clonally related airway cancer precursors 
Thorax  2014;69(6):548-557.
Squamous cell carcinoma of the lung is a common cancer with 95% mortality at 5 years. These cancers arise from preinvasive lesions, which have a natural history of development progressing through increasing severity of dysplasia to carcinoma in situ (CIS), and in some cases, ending in transformation to invasive carcinoma. Synchronous preinvasive lesions identified at autopsy have been previously shown to be clonally related.
Using autofluorescence bronchoscopy that allows visual observation of preinvasive lesions within the upper airways, together with molecular profiling of biopsies using gene sequencing and loss-of-heterozygosity analysis from both preinvasive lesions and from intervening normal tissue, we have monitored individual lesions longitudinally and documented their visual, histological and molecular relationship.
We demonstrate that rather than forming a contiguous field of abnormal tissue, clonal CIS lesions can develop at multiple anatomically discrete sites over time. Further, we demonstrate that patients with CIS in the trachea have invariably had previous lesions that have migrated proximally, and in one case, into the other lung over a period of 12 years.
Molecular information from these unique biopsies provides for the first time evidence that field cancerisation of the upper airways can occur through cell migration rather than via local contiguous cellular expansion as previously thought. Our findings urge a clinical strategy of ablating high-grade premalignant airway lesions with subsequent attentive surveillance for recurrence in the bronchial tree.
PMCID: PMC4033139  PMID: 24550057
Lung Cancer; Airway Epithelium
9.  Integrated molecular portrait of non-small cell lung cancers 
BMC Medical Genomics  2013;6:53.
Non-small cell lung cancer (NSCLC), a leading cause of cancer deaths, represents a heterogeneous group of neoplasms, mostly comprising squamous cell carcinoma (SCC), adenocarcinoma (AC) and large-cell carcinoma (LCC). The objectives of this study were to utilize integrated genomic data including copy-number alteration, mRNA, microRNA expression and candidate-gene full sequencing data to characterize the molecular distinctions between AC and SCC.
Comparative genomic hybridization followed by mutational analysis, gene expression and miRNA microarray profiling were performed on 123 paired tumor and non-tumor tissue samples from patients with NSCLC.
At DNA, mRNA and miRNA levels we could identify molecular markers that discriminated significantly between the various histopathological entities of NSCLC. We identified 34 genomic clusters using aCGH data; several genes exhibited a different profile of aberrations between AC and SCC, including PIK3CA, SOX2, THPO, TP63, PDGFB genes. Gene expression profiling analysis identified SPP1, CTHRC1and GREM1 as potential biomarkers for early diagnosis of the cancer, and SPINK1 and BMP7 to distinguish between AC and SCC in small biopsies or in blood samples. Using integrated genomics approach we found in recurrently altered regions a list of three potential driver genes, MRPS22, NDRG1 and RNF7, which were consistently over-expressed in amplified regions, had wide-spread correlation with an average of ~800 genes throughout the genome and highly associated with histological types. Using a network enrichment analysis, the targets of these potential drivers were seen to be involved in DNA replication, cell cycle, mismatch repair, p53 signalling pathway and other lung cancer related signalling pathways, and many immunological pathways. Furthermore, we also identified one potential driver miRNA hsa-miR-944.
Integrated molecular characterization of AC and SCC helped identify clinically relevant markers and potential drivers, which are recurrent and stable changes at DNA level that have functional implications at RNA level and have strong association with histological subtypes.
PMCID: PMC4222074  PMID: 24299561
NSCLC; AC; SCC; LCC; Systems biology
10.  Down-regulation of ANAPC13 and CLTCL1: Early Events in the Progression of Preinvasive Ductal Carcinoma of the Breast12 
Translational Oncology  2012;5(2):113-123.
Alterations in the gene expression profile in epithelial cells during breast ductal carcinoma (DC) progression have been shown to occur mainly between pure ductal carcinoma in situ (DCIS) to the in situ component of a lesion with coexisting invasive ductal carcinoma (DCIS-IDC) implying that the molecular program for invasion is already established in the preinvasive lesion. For assessing early molecular alterations in epithelial cells that trigger tumorigenesis and testing them as prognostic markers for breast ductal carcinoma progression, we analyzed, by reverse transcription-quantitative polymerase chain reaction, eight genes previously identified as differentially expressed between epithelial tumor cells populations captured from preinvasive lesions with distinct malignant potential, pure DCIS and the in situ component of DCIS-IDC. ANAPC13 and CLTCL1 down-regulation revealed to be early events of DC progression that anticipated the invasiveness manifestation. Further down-regulation of ANAPC13 also occurred after invasion appearance and the presence of the protein in invasive tumor samples was associated with higher rates of overall and disease-free survival in breast cancer patients. Furthermore, tumors with low levels of ANAPC13 displayed increased copy number alterations, with significant gains at 1q (1q23.1–1q32.1), 8q, and 17q (17q24.2), regions that display common imbalances in breast tumors, suggesting that down-regulation of ANAPC13 contributes to genomic instability in this disease.
PMCID: PMC3323933  PMID: 22496928
11.  Surveillance for the detection of early lung cancer in patients with bronchial dysplasia 
Thorax  2006;62(1):43-50.
The natural history of bronchial preinvasive lesions and the risk of developing lung cancer in patients with these lesions are not clear. Previous studies have treated severe dysplasia and carcinoma in situ (CIS) on the assumption that most will progress to invasive carcinoma.
To define the natural history of preinvasive lesions and assess lung cancer risk in patients with these lesions.
Most preinvasive lesions will not progress to invasive carcinoma but patients with these lesions will be at high risk.
A cohort of patients with preinvasive lesions underwent fluorescence bronchoscopy every 4–12 months and computed tomography of the chest annually. The main end point was the development of invasive carcinoma.
22 patients with 53 lesions were followed up for 12–85 months. 11 cancers were diagnosed in 9 patients. Of the 36 high‐grade lesions (severe dysplasia and CIS), 6 progressed to invasive cancers. 5 separate cancers developed at remote sites in patients with high‐grade lesions. All cancers were N0M0 and curative treatment was given to 8 of the 9 patients. The cumulative risk of developing lung cancer in a patient with a high‐grade lesion was 33% and 54% at 1 and 2 years, respectively. Of the 17 low‐grade lesions, none progressed to invasive carcinoma.
Although the risk of malignant progression of individual preinvasive lesions is relatively small, patients with high‐grade lesions are at high risk of lung cancer. Surveillance facilitated early detection and treatment with curative intent in most patients.
PMCID: PMC2111271  PMID: 16825337
12.  Differential expression and distribution of epithelial adhesion molecules in non‐small cell lung cancer and normal bronchus 
Journal of Clinical Pathology  2006;60(6):608-614.
Changes in epithelial cell interactions have been implicated in carcinogenesis, tumour invasion and metastasis.
To screen for altered expression of epithelial adhesion genes in lung cancer development.
Gene expression profiles were assessed with cDNA expression arrays in eight non‐small cell lung cancer (NSCLC) and eight normal bronchi obtained from the same patient. Immunohistochemistry (IHC) and RNA in situ hybridisation (ISH) were used to confirm the most prominently expressed adhesion molecules and to investigate their distribution at protein and mRNA levels.
43 differentially expressed cancer‐related genes were identified in adenocarcinoma, squamous cell carcinoma (SCC) and normal bronchus. Five of these genes are related to epithelial adhesion—that is, integrin α3 (ITGA3), integrin β4 (ITGB4), desmoplakin I and II (DSP), plakoglobin, and desmocollin 3 (DSC3). ITGA3 and ITGB4, showing predominantly cell–matrix staining, were up regulated in adenocarcinoma and SCC, respectively. ITGB4 also showed strong staining in SCC with IHC and ISH. Components of the desmosome adhesion complex DSP, plakoglobin and DSC3 were strongly up regulated in SCC and showed a distinct cell–cell staining pattern. DSP and plakoglobin were predominantly present at central, more differentiated tumour cells, whereas DSC3 showed a stronger staining in the peripheral basal cells of SCC tumour areas.
Lack of cellular adhesion may have an important role in the metastatic potency of a primary tumour. A possible association of strong presence and normal‐distributed desmosomal molecules in SCC with the less frequent and late pattern of metastasis in SCC as compared with adenocarcinoma is suggested.
PMCID: PMC1955047  PMID: 16489176
13.  Natural history of bronchial preinvasive lesions 
Cancer metastasis reviews  2010;29(1):5-14.
Preinvasive bronchial lesions defined as dysplasia and carcinoma in situ (CIS) have been considered as precursors of squamous cell carcinoma of the lung. The risk and rate of progression of preinvasive lesions to invasive squamous cell carcinoma as well as the mechanism of progression or regression are incompletely understood. While the evidence for the multistage, stepwise progression model is weak with relatively few documented lesions that progress through various grades of dysplasia to CIS and then to invasive carcinoma, the concept of field carcinogenesis is strongly supported. The presence of high-grade dysplasia or CIS is a risk marker for lung cancer both in the central airways and peripheral lung. Genetic alterations such as loss of heterozygosity in chromosome 3p or chromosomal aneusomy as well as host factors such as the inflammatory load and levels of anti-inflammatory proteins in the lung influence the progression or regression of preinvasive lesions. CIS is different than severe dysplasia at the molecular level and has different clinical outcome. Molecular analysis of dysplastic lesions that progress to CIS or invasive cancer and rare lesions that progress rapidly from hyperplasia or metaplasia to CIS or invasive cancer will shed light on the key molecular determinants driving development to an invasive phenotype versus those associated with tobacco smoke damage.
PMCID: PMC3417071  PMID: 20112052
Preinvasive lesions; Natural history; Lung cancer
14.  Extensive areas of aneuploidy are present in the respiratory epithelium of lung cancer patients. 
British Journal of Cancer  1996;73(2):203-209.
According to the field cancerisation theory the entire upper aerodigestive tract has been mutagenised, thereby placing the affected individual at risk for the development of one or more cancers. To investigate this concept we studied the respiratory epithelium in lungs bearing cancer, including bronchi, bronchioles and alveoli. After identifying preneoplastic and preinvasive lesions by light microscopy, we determined the DNA content of their nuclei in Feulgen-stained sections using a high-performance digitised image analyser. Archival material from 35 resected cases of non-small-cell lung cancer (NSCLC) was selected, including 16 central tumours (mainly squamous cell carcinomas) and 19 peripheral tumours (mainly adenocarcinomas) and five resected cases of metastatic tumour from extrathoracic primary sites. Of the NSCLCs, 31/35 (89%) were aneuploid, as were 60% of the metastases from extrathoracic sites. Multiple, focal areas of preneoplasia or preinvasive carcinoma were present in the selected cases. The lesions ranged in severity from hyperplasia through metaplasia and dysplasia to carcinoma in situ. Aneuploid preinvasive lesions were not noted in association with the four diploid tumours but were present only when the accompanying NSCLC was aneuploid. With both central and peripheral tumours, aneuploid preneoplastic lesions were more frequent in the peripheral parts of the lung (bronchioles or alveoli) than in the central bronchi. Both the degree and incidence of aneuploidy increased with progressive severity of morphological change. Aneuploidy was not found in preinvasive lesions accompanying the five metastatic cases. Our findings provide strong support for the concept of field cancerisation.
PMCID: PMC2074321  PMID: 8546907
15.  MicroRNA-31 Is Overexpressed in Cutaneous Squamous Cell Carcinoma and Regulates Cell Motility and Colony Formation Ability of Tumor Cells 
PLoS ONE  2014;9(7):e103206.
Cutaneous squamous cell carcinoma (cSCC) is a malignancy of epidermal keratinocytes that is responsible for approximately 20% of skin cancer-related death yearly. We have previously compared the microRNA (miRNA) expression profile of cSCC to healthy skin and found the dysregulation of miRNAs in human cSCC. In this study we show that miR-31 is overexpressed in cSCC (n = 68) compared to healthy skin (n = 34) and precancerous skin lesions (actinic keratosis, n = 12). LNA in situ hybridization revealed that miR-31 was specifically up-regulated in tumor cells. Mechanistic studies of inhibition of endogenous miR-31 in human metastatic cSCC cells revealed suppressed migration, invasion and colony forming ability, whereas overexpression of miR-31 induced these phenotypes. These results indicate that miR-31 regulates cancer-associated phenotypes of cSCC and identify miR-31 as a potential target for cSCC treatment.
PMCID: PMC4113372  PMID: 25068518
16.  A Human Breast Cell Model of Preinvasive to Invasive Transition 
Cancer research  2008;68(5):1378-1387.
A crucial step in human breast cancer progression is the acquisition of invasiveness. There is a distinct lack of human cell culture models to study the transition from preinvasive to invasive phenotype as it may occur “spontaneously” in vivo. To delineate molecular alterations important for this transition, we isolated human breast epithelial cell lines that showed partial loss of tissue polarity in three-dimensional reconstituted basement membrane cultures. These cells remained noninvasive; however, unlike their nonmalignant counterparts, they exhibited a high propensity to acquire invasiveness through basement membrane in culture. The genomic aberrations and gene expression profiles of the cells in this model showed a high degree of similarity to primary breast tumor profiles. The xenograft tumors formed by the cell lines in three different microenvironments in nude mice displayed metaplastic phenotypes, including squamous and basal characteristics, with invasive cells exhibiting features of higher-grade tumors. To find functionally significant changes in transition from preinvasive to invasive phenotype, we performed attribute profile clustering analysis on the list of genes differentially expressed between preinvasive and invasive cells. We found integral membrane proteins, transcription factors, kinases, transport molecules, and chemokines to be highly represented. In addition, expression of matrix metalloproteinases MMP9, MMP13, MMP15, and MMP17 was up-regulated in the invasive cells. Using small interfering RNA–based approaches, we found these MMPs to be required for the invasive phenotype. This model provides a new tool for dissection of mechanisms by which preinvasive breast cells could acquire invasiveness in a metaplastic context.
PMCID: PMC2662716  PMID: 18316601
17.  Evidence that molecular changes in cells occur before morphological alterations during the progression of breast ductal carcinoma 
Ductal carcinoma in situ (DCIS) of the breast includes a heterogeneous group of preinvasive tumors with uncertain evolution. Definition of the molecular factors necessary for progression to invasive disease is crucial to determining which lesions are likely to become invasive. To obtain insight into the molecular basis of DCIS, we compared the gene expression pattern of cells from the following samples: non-neoplastic, pure DCIS, in situ component of lesions with co-existing invasive ductal carcinoma, and invasive ductal carcinoma.
Forty-one samples were evaluated: four non-neoplastic, five pure DCIS, 22 in situ component of lesions with co-existing invasive ductal carcinoma, and 10 invasive ductal carcinoma. Pure cell populations were isolated using laser microdissection. Total RNA was purified, DNase treated, and amplified using the T7-based method. Microarray analysis was conducted using a customized cDNA platform. The concept of molecular divergence was applied to classify the sample groups using analysis of variance followed by Tukey's test.
Among the tumor sample groups, cells from pure DCIS exhibited the most divergent molecular profile, consequently identifying cells from in situ component of lesions with co-existing invasive ductal carcinoma as very similar to cells from invasive lesions. Additionally, we identified 147 genes that were differentially expressed between pure DCIS and in situ component of lesions with co-existing invasive ductal carcinoma, which can discriminate samples representative of in situ component of lesions with co-existing invasive ductal carcinoma from 60% of pure DCIS samples. A gene subset was evaluated using quantitative RT-PCR, which confirmed differential expression for 62.5% and 60.0% of them using initial and partial independent sample groups, respectively. Among these genes, LOX and SULF-1 exhibited features that identify them as potential participants in the malignant process of DCIS.
We identified new genes that are potentially involved in the malignant transformation of DCIS, and our findings strongly suggest that cells from the in situ component of lesions with co-existing invasive ductal carcinoma exhibit molecular alterations that enable them to invade the surrounding tissue before morphological changes in the lesion become apparent.
PMCID: PMC2614523  PMID: 18928525
18.  mRNA expression of the DNA replication-initiation proteins in epithelial dysplasia and squamous cell carcinoma of the tongue 
BMC Cancer  2008;8:395.
The tongue squamous cell carcinomas (SCCs) are characterized by high mitotic activity, and early detection is desirable. Overexpression of the DNA replication-initiation proteins has been associated with dysplasia and malignancy. Our aim was to determine whether these proteins are useful biomarkers for assessing the development of tongue SCC.
We analyzed the mRNA expression of CDC6, CDT1, MCM2 and CDC45 in formalin-fixed, paraffin-embedded benign and malignant tongue tissues using quantitative real-time PCR followed by statistical analysis.
We found that the expression levels are significantly higher in malignant SCC than mild precancerous epithelial dysplasia, and the expression levels in general increase with increasing grade of precancerous lesions from mild, moderate to severe epithelial dysplasia. CDC6 and CDC45 expression is dependent of the dysplasia grade and lymph node status. CDT1 expression is higher in severe dysplasia than in mild and moderate dysplasia. MCM2 expression is dependent of the dysplasia grade, lymph node status and clinical stage. The expression of the four genes is independent of tumor size or histological grade. A simple linear regression analysis revealed a linear increase in the mRNA levels of the four genes from the mild to severe dysplasia and SCC. A strong association was established between CDC6 and CDT1, and between MCM2 and CDC45 expression. The nonparametric receiver operating characteristic analysis suggested that MCM2 and CDC45 had a higher accuracy than CDC6 and CDT1 for distinguishing dysplasia from tongue SCC.
These proteins can be used as biomarkers to distinguish precancerous dysplasia from SCC and are useful for early detection and diagnosis of SCC as an adjunct to clinicopathological parameters.
PMCID: PMC2648984  PMID: 19116018
19.  A Gene Expression Signature Predicts Survival of Patients with Stage I Non-Small Cell Lung Cancer 
PLoS Medicine  2006;3(12):e467.
Lung cancer is the leading cause of cancer-related death in the United States. Nearly 50% of patients with stages I and II non-small cell lung cancer (NSCLC) will die from recurrent disease despite surgical resection. No reliable clinical or molecular predictors are currently available for identifying those at high risk for developing recurrent disease. As a consequence, it is not possible to select those high-risk patients for more aggressive therapies and assign less aggressive treatments to patients at low risk for recurrence.
Methods and Findings
In this study, we applied a meta-analysis of datasets from seven different microarray studies on NSCLC for differentially expressed genes related to survival time (under 2 y and over 5 y). A consensus set of 4,905 genes from these studies was selected, and systematic bias adjustment in the datasets was performed by distance-weighted discrimination (DWD). We identified a gene expression signature consisting of 64 genes that is highly predictive of which stage I lung cancer patients may benefit from more aggressive therapy. Kaplan-Meier analysis of the overall survival of stage I NSCLC patients with the 64-gene expression signature demonstrated that the high- and low-risk groups are significantly different in their overall survival. Of the 64 genes, 11 are related to cancer metastasis (APC, CDH8, IL8RB, LY6D, PCDHGA12, DSP, NID, ENPP2, CCR2, CASP8, and CASP10) and eight are involved in apoptosis (CASP8, CASP10, PIK3R1, BCL2, SON, INHA, PSEN1, and BIK).
Our results indicate that gene expression signatures from several datasets can be reconciled. The resulting signature is useful in predicting survival of stage I NSCLC and might be useful in informing treatment decisions.
Meta-analysis of several lung cancer gene expression studies yields a set of 64 genes whose expression profile is useful in predicting survival of patients with early-stage lung cancer and possibly informing treatment decisions.
Editors' Summary
Lung cancer is the commonest cause of cancer-related death worldwide. Most cases are of a type called non-small cell lung cancer (NSCLC) and are mainly caused by smoking. Like other cancers, how NSCLC is treated depends on the “stage” at which it is detected. Stage IA NSCLCs are small and confined to the lung and can be removed surgically; patients with slightly larger stage IB tumors often receive chemotherapy after surgery. In stage II NSCLC, cancer cells may be present in lymph nodes near the tumor. Surgery plus chemotherapy is the usual treatment for this stage and for some stage III NSCLCs. However, in this stage, the tumor can be present throughout the chest and surgery is not always possible. For such cases and in stage IV NSCLC, where the tumor has spread throughout the body, patients are treated with chemotherapy alone. The stage at which NSCLC is detected also determines how well patients respond to treatment. Those who can be treated surgically do much better than those who can't. So, whereas only 2% of patients with stage IV lung cancer survive for 5 years after diagnosis, about 70% of patients with stage I or II lung cancer live at least this long.
Why Was This Study Done?
Even stage I and II lung cancers often recur and there is no accurate way to identify the patients in which this will happen. If there was, these patients could be given aggressive chemotherapy, so the search is on for a “molecular signature” to help identify which NSCLCs are likely to recur. Unlike normal cells, cancer cells divide uncontrollably and can move around the body. These behavioral differences are caused by changes in their genetic material that alter their patterns of RNA transcription and protein expression. In this study, the researchers have investigated whether data from several microarray studies (a technique used to catalog the genes expressed in cells) can be pooled to construct a gene expression signature that predicts the survival of patients with stage I NSCLC.
What Did the Researchers Do and Find?
The researchers took the data from seven independent microarray studies (including a new study of their own) that recorded gene expression profiles related to survival time (less than 2 years and greater than 5 years) for stage I NSCLC. Because these studies had been done in different places with slightly different techniques, the researchers applied a statistical tool called distance-weighted discrimination to smooth out any systematic differences among the studies before identifying 64 genes whose expression was associated with survival. Most of these genes are involved in cell adhesion, cell motility, cell proliferation, and cell death, all processes that are altered in cancer cells. The researchers then developed a statistical model that allowed them to use the gene expression and survival data to calculate risk scores for nearly 200 patients in five of the datasets. When they separated the patients into high and low risk groups on the basis of these scores, the two groups were significantly different in terms of survival time. Indeed, the gene expression signature was better at predicting outcome than routine staging. Finally, the researchers validated the gene expression signature by showing that it predicted survival with more than 85% accuracy in two independent datasets.
What Do These Findings Mean?
The 64 gene expression signature identified here could help clinicians prepare treatment plans for patients with stage I NSCLC. Because it accurately predicts survival in patients with adenocarcinoma or squamous cell cancer (the two major subtypes of NSCLC), it potentially indicates which of these patients should receive aggressive chemotherapy and which can be spared this unpleasant treatment. Previous attempts to establish gene expression signatures to predict outcome have used data from small groups of patients and have failed when tested in additional patients. In contrast, this new signature seems to be generalizable. Nevertheless, its ability to predict outcomes must be confirmed in further studies before it is routinely adopted by oncologists for treatment planning.
Additional Information.
Please access these Web sites via the online version of this summary at
US National Cancer Institute information on lung cancer for patients and health professionals.
MedlinePlus encyclopedia entries on small-cell and non-small-cell lung cancer.
Cancer Research UK, information on patients about all aspects of lung cancer.
Wikipedia pages on DNA microarrays and expression profiling (note that Wikipedia is a free online encyclopedia that anyone can edit).
PMCID: PMC1716187  PMID: 17194181
20.  Difference of Genome-Wide Copy Number Alterations between High-Grade Squamous Intraepithelial Lesions and Squamous Cell Carcinomas of the Uterine Cervix 
Korean Journal of Pathology  2012;46(2):123-130.
About 10% of high-grade squamous intraepithelial lesions (HSILs) progress to invasive carcinomas within 2-10 years. By delineating the events that occur in the early stage of the invasion, the pathogenesis of cervical cancer could be better understood. This will also propose the possible methods for inhibiting the tumor invasion and improving the survival of patients.
We compared the genomic profiles between the HSIL and the invasive squamous cell carcinoma (SCC) using an array comparative genomic hybridization. Using recurrently altered genes, we performed a principal component analysis to see variation of samples in both groups. To find possibly affected pathways by altered genes, we analyzed genomic profiles with the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database and GOEAST software.
We found 11q12.3 and 2p24.1 regions have recurrent copy number gains in both groups. 16p12-13 and 20q11-13 regions showed an increased copy number only in cases of HSIL. 1q25.3 and 3q23-29 regions showed copy number gains only in cases of SCC. Altered genes in the SCC group were related to the mitogen-activated protein kinase signaling pathway and the RNA transport. Altered genes in the HSIL group were related to the ubiquitin mediated proteolysis and cell adhesion molecules.
Our results showed not only that gains in 11q12.3 and 2p24.1 were early events occurring in the premalignant lesions and then maintained in cases of SCC but also that gains in 1q25.3 and 3q23-29 were late events occurring after invasion in those of SCC.
PMCID: PMC3479789  PMID: 23109991
Gene dosage; DNA copy number variations; Carcinoma, squamous cell; Cervical intraepithelial neoplasia
21.  Detection and minimally invasive treatment of early squamous lung cancer 
Non-small cell lung cancer (NSCLC) is the most common cause of cancer deaths worldwide. The majority of patents presenting with NSCLC have advanced disease, which precludes curative treatment. Early detection and treatment might result in the identification of more patients with early central lung cancer and improve survival. In addition, the study of early lung cancer improves understanding of lung carcinogenesis and might also reveal new treatment targets for advanced lung cancer. Bronchoscopic investigation of the central airways can reveal both early central lung cancer in situ (stage 0) and other preinvasive lesions such as dysplasia. In the current review we discuss the detection of early squamous lung cancer, the natural history of preinvasive lesions and whether biomarkers can be used to predict progression to cancer. Finally we will review the staging and management of preinvasive lung cancer lesions and the different therapeutic modalities that are available.
PMCID: PMC3707338  PMID: 23858332
biomarkers; diagnosis; non-small cell lung cancer; treatment
22.  Downregulation of transforming growth factor ß type II receptor in laryngeal carcinogenesis 
Journal of Clinical Pathology  2001;54(3):201-204.
Aims—To investigate whether anomalies of transforming growth factor ß type II receptor (TGF-ß RII) expression occur in the early stages of laryngeal carcinogenesis and to assess their importance in the development of laryngeal squamous cell carcinoma. TGF-ß RII status was examined in laryngeal premalignant lesions coupled with malignant evolution and compared with a control group of similar lesions without progression to cancer.
Methods—Immunohistochemical staining for TGF-ß RII was performed on 15 paraffin wax embedded biopsies from patients with precancerous laryngeal lesions who subsequently developed invasive squamous cell carcinoma of the larynx, and on 30 control biopsies from patients who did not develop cancer in a comparable follow up period. In addition, DNA extracted from 18 preneoplastic lesions and eight squamous cell carcinomas was amplified by the polymerase chain reaction at the poly A and the poly GT regions of the TGF-ß RII gene.
Results—In the group of lesions with progression to carcinoma, 11 of 15 cases showed loss (< 20% of epithelial cells) of TGF-ß RII immunoreactivity, whereas among non-evolved lesions only five of 30 had similar altered expression of the receptor (p < 0.001, two tailed Fisher's exact test). All squamous cell carcinomas showed a degree of receptor expression comparable with that of the corresponding preneoplastic lesion, with the exception of one case, in which loss of the receptor was evident only in invasive cancer. Mutation of the poly A sequence of the TGF-ß RII gene was identified in only one precancerous lesion and in the subsequent squamous cell carcinoma.
Conclusions—These findings indicate that the downregulation of TGF-ß RII is an early event in laryngeal carcinogenesis, which may result in the loss of TGF-ß mediated growth inhibition, thereby facilitating the progression of laryngeal precancerous lesions to squamous cell carcinoma.
Key Words: laryngeal cancer • transforming growth factor-ß type II receptor
PMCID: PMC1731366  PMID: 11253131
23.  Palladin Mutation Causes Familial Pancreatic Cancer and Suggests a New Cancer Mechanism 
PLoS Medicine  2006;3(12):e516.
Pancreatic cancer is a deadly disease. Discovery of the mutated genes that cause the inherited form(s) of the disease may shed light on the mechanism(s) of oncogenesis. Previously we isolated a susceptibility locus for familial pancreatic cancer to chromosome location 4q32–34. In this study, our goal was to discover the identity of the familial pancreatic cancer gene on 4q32 and determine the function of that gene.
Methods and Findings
A customized microarray of the candidate chromosomal region affecting pancreatic cancer susceptibility revealed the greatest expression change in palladin (PALLD), a gene that encodes a component of the cytoskeleton that controls cell shape and motility. A mutation causing a proline (hydrophobic) to serine (hydrophilic) amino acid change (P239S) in a highly conserved region tracked with all affected family members and was absent in the non-affected members. The mutational change is not a known single nucleotide polymorphism. Palladin RNA, measured by quantitative RT-PCR, was overexpressed in the tissues from precancerous dysplasia and pancreatic adenocarcinoma in both familial and sporadic disease. Transfection of wild-type and P239S mutant palladin gene constructs into HeLa cells revealed a clear phenotypic effect: cells expressing P239S palladin exhibited cytoskeletal changes, abnormal actin bundle assembly, and an increased ability to migrate.
These observations suggest that the presence of an abnormal palladin gene in familial pancreatic cancer and the overexpression of palladin protein in sporadic pancreatic cancer cause cytoskeletal changes in pancreatic cancer and may be responsible for or contribute to the tumor's strong invasive and migratory abilities.
The presence of abnormalpalladin in familial pancreatic cancer and its overexpression in sporadic pancreatic cancer leads to cytoskeletal changes and may be responsible for the tumor's invasive and migratory abilities.
Editors' Summary
Pancreatic cancer is a leading cause of cancer-related death in the US. Because it causes few symptoms in its early stages, pancreatic cancer is rarely detected until it has spread (metastasized) around the body. Pancreatic tumors can occasionally be removed surgically but the usual treatment is radio- or chemotherapy, and neither of these is curative; most patients die within a year of diagnosis. As in other cancers, the cells in pancreatic tumors have acquired genetic changes (mutations) that allow them to divide uncontrollably (normal cells divide only to repair damaged tissue). Other mutations alter the shape of the cells and allow them to migrate into (invade) other areas of the body. These mutations usually arise randomly—the cells in the human body are bombarded by chemicals and other agents that can damage their DNA—and cause “sporadic” pancreatic cancer. But some people inherit mutated genes that increase their susceptibility to pancreatic cancer. These people are recognizable because pancreatic cancer is more common in their families than in the general population.
Why Was This Study Done?
The identification of the genes that are mutated in familial pancreatic cancer might provide insights into how both inherited and sporadic cancer develops in the pancreas. Such information could suggest ways to detect pancreatic cancers earlier than is currently possible and could identify new therapeutic targets for this deadly disease. Previous work by the researchers who did this study localized a gene responsible for inherited pancreatic cancer to a small region of Chromosome 4 in a family in which pancreatic cancer is very common (Family X). In this study, the researchers identified which of the genes in this region is likely to be responsible for the susceptibility to pancreatic cancer of Family X.
What Did the Researchers Do and Find?
The researchers made a DNA microarray (a small chip spotted with DNA sequences) of the 243 genes in the chromosomal region linked to pancreatic cancer in Family X. They used this to examine gene expression in dysplastic pancreatic tissue from a Family X member (pancreatic dysplasia is a precancerous lesion that precedes cancer), in normal pancreatic tissue, and in samples from sporadic pancreatic cancers. The most highly overexpressed (compared to normal tissue) gene in both the Family X tissue and the sporadic cancers encoded a protein called palladin. Palladin is a component of the cytoskeleton (a structure that helps to control cell shape and motility) and it organizes other cytoskeletal components. Next, the researchers quantified the expression of palladin RNA in an independent set of normal and cancerous pancreatic samples, and in precancerous pancreatic tissue taken from Family X members and from people who inherit pancreatic cancer but who were not in Family X. This analysis indicated that palladin was overexpressed early in sporadic and inherited pancreatic cancer development. Sequencing of the palladin gene then uncovered a mutation in palladin that was present in Family X members with pancreatic cancer or precancerous lesions but not in unaffected members. This specific mutation, which probably affects palladin's interaction with another cytoskeletal protein called alpha-actinin, was not found in sporadic cancers although many sporadic cancer cell lines had abnormal expression of alpha-actinin protein in addition to palladin protein. Finally, the researchers showed that the introduction of mutated palladin into a human cell line growing in the laboratory increased its migration rate and disrupted its cytoskeleton.
What Do These Findings Mean?
These results strongly suggest that mutated palladin is involved in the development of familial pancreatic cancer. Because genes tend to be inherited in groups, there is still chance that a mutation in a nearby gene could be responsible for the increased susceptibility to pancreatic cancer in Family X. However, the data showing palladin overexpression in sporadic tumors and alterations of cell behavior in the laboratory after introduction of the mutated gene make this unlikely. To prove the involvement of palladin in pancreatic cancer, palladin mutations must now be identified in other familial cases and the overexpression of palladin in sporadic cancers must be explained. The results here nevertheless provide an intriguing glimpse into a potential new mechanism for cancer development in the pancreas and possibly other tissues, one in which abnormalities in palladin function or expression (or in the proteins with which it associates) drive some of the changes in cell migration, shape, and size that characterize cancer cells.
Additional Information.
Please access these Web sites via the online version of this summary at
US National Cancer Institute, information on pancreatic cancer for patients and health professionals
MedlinePlus encyclopedia entry on pancreatic carcinoma
Cancer Research UK, information for patients about pancreatic cancer
Johns Hopkins University, information on pancreatic cancer that includes details on familial cancer
CancerQuest, information provided by Emory University about how cancer develops
PMCID: PMC1751121  PMID: 17194196
24.  Aberrant DNA Methylation of OLIG1, a Novel Prognostic Factor in Non-Small Cell Lung Cancer 
PLoS Medicine  2007;4(3):e108.
Lung cancer is the leading cause of cancer-related death worldwide. Currently, tumor, node, metastasis (TNM) staging provides the most accurate prognostic parameter for patients with non-small cell lung cancer (NSCLC). However, the overall survival of patients with resectable tumors varies significantly, indicating the need for additional prognostic factors to better predict the outcome of the disease, particularly within a given TNM subset.
Methods and Findings
In this study, we investigated whether adenocarcinomas and squamous cell carcinomas could be differentiated based on their global aberrant DNA methylation patterns. We performed restriction landmark genomic scanning on 40 patient samples and identified 47 DNA methylation targets that together could distinguish the two lung cancer subgroups. The protein expression of one of those targets, oligodendrocyte transcription factor 1 (OLIG1), significantly correlated with survival in NSCLC patients, as shown by univariate and multivariate analyses. Furthermore, the hazard ratio for patients negative for OLIG1 protein was significantly higher than the one for those patients expressing the protein, even at low levels.
Multivariate analyses of our data confirmed that OLIG1 protein expression significantly correlates with overall survival in NSCLC patients, with a relative risk of 0.84 (95% confidence interval 0.77–0.91, p < 0.001) along with T and N stages, as indicated by a Cox proportional hazard model. Taken together, our results suggests that OLIG1 protein expression could be utilized as a novel prognostic factor, which could aid in deciding which NSCLC patients might benefit from more aggressive therapy. This is potentially of great significance, as the addition of postoperative adjuvant chemotherapy in T2N0 NSCLC patients is still controversial.
Christopher Plass and colleagues find thatOLIG1 expression correlates with survival in lung cancer patients and suggest that it could be used in deciding which patients are likely to benefit from more aggressive therapy.
Editors' Summary
Lung cancer is the commonest cause of cancer-related death worldwide. Most cases are of a type called non-small cell lung cancer (NSCLC). Like other cancers, treatment of NCSLC depends on the “TNM stage” at which the cancer is detected. Staging takes into account the size and local spread of the tumor (its T classification), whether nearby lymph nodes contain tumor cells (its N classification), and whether tumor cells have spread (metastasized) throughout the body (its M classification). Stage I tumors are confined to the lung and are removed surgically. Stage II tumors have spread to nearby lymph nodes and are treated with a combination of surgery and chemotherapy. Stage III tumors have spread throughout the chest, and stage IV tumors have metastasized around the body; patients with both of these stages are treated with chemotherapy alone. About 70% of patients with stage I or II lung cancer, but only 2% of patients with stage IV lung cancer, survive for five years after diagnosis.
Why Was This Study Done?
TNM staging is the best way to predict the likely outcome (prognosis) for patients with NSCLC, but survival times for patients with stage I and II tumors vary widely. Another prognostic marker—maybe a “molecular signature”—that could distinguish patients who are likely to respond to treatment from those whose cancer will inevitably progress would be very useful. Unlike normal cells, cancer cells divide uncontrollably and can move around the body. These behavioral changes are caused by alterations in the pattern of proteins expressed by the cells. But what causes these alterations? The answer in some cases is “epigenetic changes” or chemical modifications of genes. In cancer cells, methyl groups are aberrantly added to GC-rich gene regions. These so-called “CpG islands” lie near gene promoters (sequences that control the transcription of DNA into mRNA, the template for protein production), and their methylation stops the promoters working and silences the gene. In this study, the researchers have investigated whether aberrant methylation patterns vary between NSCLC subtypes and whether specific aberrant methylations are associated with survival and can, therefore, be used prognostically.
What Did the Researchers Do and Find?
The researchers used “restriction landmark genomic scanning” (RLGS) to catalog global aberrant DNA methylation patterns in human lung tumor samples. In RLGS, DNA is cut into fragments with a restriction enzyme (a protein that cuts at specific DNA sequences), end-labeled, and separated using two-dimensional gel electrophoresis to give a pattern of spots. Because methylation stops some restriction enzymes cutting their target sequence, normal lung tissue and lung tumor samples yield different patterns of spots. The researchers used these patterns to identify 47 DNA methylation targets (many in CpG islands) that together distinguished between adenocarcinomas and squamous cell carcinomas, two major types of NSCLCs. Next, they measured mRNA production from the genes with the greatest difference in methylation between adenocarcinomas and squamous cell carcinomas. OLIG1 (the gene that encodes a protein involved in nerve cell development) had one of the highest differences in mRNA production between these tumor types. Furthermore, three-quarters of NSCLCs had reduced or no expression of OLIG1 protein and, when the researchers analyzed the association between OLIG1 protein expression and overall survival in patients with NSCLC, reduced OLIG1 protein expression was associated with reduced survival.
What Do These Findings Mean?
These findings indicate that different types of NSCLC can be distinguished by examining their aberrant methylation patterns. This suggests that the establishment of different DNA methylation patterns might be related to the cell type from which the tumors developed. Alternatively, the different aberrant methylation patterns might reflect the different routes that these cells take to becoming tumor cells. This research identifies a potential new prognostic marker for NSCLC by showing that OLIG1 protein expression correlates with overall survival in patients with NSCLC. This correlation needs to be tested in a clinical setting to see if adding OLIG1 expression to the current prognostic parameters can lead to better treatment choices for early-stage lung cancer patients and ultimately improve these patients' overall survival.
Additional Information.
Please access these Web sites via the online version of this summary at
Patient and professional information on lung cancer, including staging (in English and Spanish), is available from the US National Cancer Institute
The MedlinePlus encyclopedia has pages on non-small cell lung cancer (in English and Spanish)
Cancerbackup provides patient information on lung cancer
CancerQuest, provided by Emory University, has information about how cancer develops (in English, Spanish, Chinese and Russian)
Wikipedia pages on epigenetics (note that Wikipedia is a free online encyclopedia that anyone can edit)
The Epigenome Network of Excellence gives background information and the latest news about epigenetics (in several European languages)
PMCID: PMC1831740  PMID: 17388669
25.  TGFβ1 and HGF protein secretion by esophageal squamous epithelial cells and stromal fibroblasts in oesophageal carcinogenesis 
Oncology Letters  2013;6(2):401-406.
Esophageal squamous cell carcinoma (ESCC) is an aggressive cancer with a poor prognosis. Cancer-associated fibroblasts (CAFs) affect tumorigenesis by creating an environment primed for growth and invasion through the secretion of factors, including hepatocyte growth factor (HGF) and transforming growth factor β1 (TGFβ1). In the present study, the levels of α-smooth muscle actin (α-SMA), TGFβ1 and HGF were determined immunohistochemically in oesophageal precancerous lesions (low- and high-grade intraepithelial neoplasia; LGIEN and HGIEN, respectively), carcinoma in situ (CIS) and squamous cell carcinoma (SCC). Immunoreactivity was observed in the cytoplasm of oesophageal epithelial cells and stromal fibroblasts. Expression levels of α-SMA, TGFβ1 and HGF increased significantly in the following order: normal, LGIEN, HGIEN, CIS and SCC. In addition, linear correlations between the expression of α-SMA, TGFβ1 and HGF and different lesions were observed. Microvessel density (MVD) was measured in all specimens and increased gradually in the normal, LGIEN, HGIEN, CIS and SCC specimens, successively. A linear correlation between MVD and pathological grade was also observed and the MVD in α-SMA-, HGF- and TGFβ1-positive groups was higher when compared with that of their negative counterparts. The results of the present study indicated that the frequent overexpression of TGFβ1 and HGF proteins, secreted by oesophageal epithelium and stromal fibroblasts, promoted the progression of oesophageal precancerous lesions via the proliferation of epithelial cells and angiogenesis, through the upregulation of vascular endothelial growth factor (VEGF) expression.
PMCID: PMC3789106  PMID: 24137336
esophageal squamous cell carcinoma; fibroblast; transforming growth factor-β1; α-smooth muscle actin; hepatocyte growth factor

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