The value of human biospecimens available for research dramatically increases
when linked with their accumulated clinical and molecular (genomic, proteomic, subcellular modeling) data. Further, informatics tools
make it possible for researchers (both intra- and inter-institutionally) to
locate tissue needed for research faster and more reliably. We
are developing a virtual human biospecimen repository to both inventory
and link all human biospecimens with clinical and genomics data to optimize
their value for research, while satisfying all privacy and human
subjects protections regulations.
The recognition of breast cancer (BC) as a spectrum tumor in Lynch syndrome remains controversial. The aim of this study was to explore features of breast cancers arising in Lynch syndrome families.
This observational study involved 107 cases of BC identified from the Colorectal Cancer Family Registry (Colon CFR) from 90 families where 1) both breast and colon cancer co-occurred, 2) families met either modified Amsterdam criteria, or had at least one early onset (<50 years) colorectal cancer, and 3) breast tissue was available within the biospecimen repository for mismatch repair (MMR) testing. Eligibility criteria for enrolment in the Colon CFR are available online1. Breast cancers were reviewed by one pathologist. Tumor sections were stained for MLH1, PMS2, MSH2 and MSH6, and underwent MSI testing.
BC arose in 35 mutation carriers and of these, 18 (51%) demonstrated immunohistochemical absence of MMR protein corresponding to the MMR gene mutation segregating in the family. MMR-deficient BCs were more likely to be poorly differentiated (p=0.005) with a high mitotic index (p=0.002), steroid hormone receptor negative (ER p=0.031; PR p=0.022), and to have peritumoral lymphocytes (p=0.015), confluent necrosis (p=0.002), and growth in solid sheets (p<0.001) similar to their colorectal counterparts. No difference in age of onset was noted between the MMR deficient and intact groups.
MMR deficiency was identified in 51% of BC arising in known mutation carriers. BC therefore may represent a valid tissue option for the detection of MMR deficiency where spectrum tumors are lacking.
Variability of plasma sample collection and of proteomics technology platforms has been detrimental to generation of large proteomic profile datasets from human biospecimens.
We carried out a clinical trial-like protocol to standardize collection of plasma from 204 healthy and 216 breast cancer patient volunteers. The breast cancer patients provided follow up samples at 3 month intervals. We generated proteomics profiles from these samples with a stable and reproducible platform for differential proteomics that employs a highly consistent nanofabricated ChipCube™ chromatography system for peptide detection and quantification with fast, single dimension mass spectrometry (LC-MS). Protein identification is achieved with subsequent LC-MS/MS analysis employing the same ChipCube™ chromatography system.
With this consistent platform, over 800 LC-MS plasma proteomic profiles from prospectively collected samples of 420 individuals were obtained. Using a web-based data analysis pipeline for LC-MS profiling data, analyses of all peptide peaks from these plasma LC-MS profiles reveals an average coefficient of variability of less than 15%. Protein identification of peptide peaks of interest has been achieved with subsequent LC-MS/MS analyses and by referring to a spectral library created from about 150 discrete LC-MS/MS runs. Verification of peptide quantity and identity is demonstrated with several Multiple Reaction Monitoring analyses. These plasma proteomic profiles are publicly available through ProteomeCommons.
From a large prospective cohort of healthy and breast cancer patient volunteers and using a nano-fabricated chromatography system, a consistent LC-MS proteomics dataset has been generated that includes more than 800 discrete human plasma profiles. This large proteomics dataset provides an important resource in support of breast cancer biomarker discovery and validation efforts.
HER2/Neu is overexpressed in 20-30% of breast cancers and associated with aggressive phenotypes and poor prognosis. For deciphering the role of HER2/Neu in breast cancer, mouse mammary tumor virus (MMTV)-Her2/neu transgenic mice that develop mammary tumors resembling human HER2-subtype breast cancer have been established. Several recent studies have revealed that HER2/Neu is overexpressed in and regulates self renewal of breast tumor initiating cells (TICs). However, in the MMTV-Her2/neu transgenic mouse model, the identity of TICs remains elusive, despite previous studies showing supportive evidence for existence of TICs in Her2/neu-induced mammary tumors. Through systematic screening and characterization, we identified surface markers CD49f, CD61 and ESA were aberrantly overexpressed in Her2-overexpressing mammary tumor cells. Analysis of these markers as well as CD24 detected anomalous expansion of the luminal progenitor population in preneoplastic mammary glands of Her2/neu-transgenic mice, indicating that aberrant luminal progenitors originated Her2-induced mammary tumors. The combined markers, CD49f and CD61, further delineated the CD49fhighCD61high-sorted fraction as a TIC-enriched population, which displayed increased tumorsphere formation ability, enhanced tumorigenicity both in vitro and in vivo and drug resistance to pacitaxel and doxorubicin. Moreover, the TIC-enriched population manifested increased TGFβ signaling and exhibited gene expression signatures of stemness, TGFβ signaling and Epithelial-to-Mesenchymal Transition. Our findings that self-renewal and clonogenicity of TICs were suppressed by pharmacologically inhibiting the TGFβ signaling further indicate that the TGFβ pathway is vital for maintenance of the TIC population. Finally, we showed that the integrin β3 (CD61) signaling pathway was required for sustaining active TGFβ signaling and self-renewal of TICs. We for the first time developed a technique to highly enrich TICs from mammary tumors of Her2/neu-transgenic mice, unraveled their properties and identified the cooperative integrin β3-TGFβ signaling axis as a potential therapeutic target for HER2-induced TICs.
Tumor Initiating Cells; Her2/neu; mammary tumor; CD49f; CD61; ESA
Purpose. The objective of this study was to compare the salivary protein profiles from individuals diagnosed with breast cancer that were either HER2/neu receptor positive or negative. Methods. Two pooled saliva specimens underwent proteomic analysis. One pooled specimen was from women diagnosed with stage IIa HER2/neu-receptor-positive breast cancer patients (n = 10) and the other was from women diagnosed with stage IIa HER2/neu-receptor-negative cancer patients (n = 10). The pooled samples were trypsinized and the peptides labeled with iTRAQ reagent. Specimens were analyzed using an LC-MS/MS mass spectrometer. Results. The results yielded approximately 71 differentially expressed proteins in the saliva specimens. There were 34 upregulated proteins and 37 downregulated proteins.
PeptideProphet is a post-processing algorithm designed to evaluate the confidence in identifications of MS/MS spectra returned by a database search. In this manuscript we describe the "what and how" of PeptideProphet in a manner aimed at statisticians and life scientists who would like to gain a more in-depth understanding of the underlying statistical modeling. The theory and rationale behind the mixture-modeling approach taken by PeptideProphet is discussed from a statistical model-building perspective followed by a description of how a model can be used to express confidence in the identification of individual peptides or sets of peptides. We also demonstrate how to evaluate the quality of model fit and select an appropriate model from several available alternatives. We illustrate the use of PeptideProphet in association with the Trans-Proteomic Pipeline, a free suite of software used for protein identification.
For the past 20 years the mouse has served as a workhorse for studying the molecular underpinnings of human breast cancer. While some genetically engineered mouse mammary tumor models do not accurately recapitulate human disease (that is, the MMTV-Neu model and HER2-overexpressing human cancers), additional tumor models exist for studying the initiation, progression, and treatment of human breast cancer. The relationships between normal mouse mammary epithelial cells and tumor cells, however, have remained poorly defined. A recent article in Breast Cancer Research has shed light on these relationships.
Once metastasis has occurred, the possibility of completely curing breast cancer is unlikely, particularly for the 30 to 40% of cancers overexpressing the gene for HER2/neu. A vaccine targeting p185, the protein product of the HER2/neu gene, could have therapeutic application by controlling the growth and metastasis of highly aggressive HER2/neu+ cells. The purpose of this study was to determine the effectiveness of two gene vaccines targeting HER2/neu in preventive and therapeutic tumor models.
The mouse breast cancer cell line A2L2, which expresses the gene for rat HER2/neu and hence p185, was injected into the mammary fat pad of mice as a model of solid tumor growth or was injected intravenously as a model of lung metastasis. SINCP-neu, a plasmid containing Sindbis virus genes and the gene for rat HER2/neu, and Adeno-neu, an E1,E2a-deleted adenovirus also containing the gene for rat HER2/neu, were tested as preventive and therapeutic vaccines.
Vaccination with SINCP-neu or Adeno-neu before tumor challenge with A2L2 cells significantly inhibited the growth of the cells injected into the mammary fat or intravenously. Vaccination 2 days after tumor challenge with either vaccine was ineffective in both tumor models. However, therapeutic vaccination in a prime–boost protocol with SINCP-neu followed by Adeno-neu significantly prolonged the overall survival rate of mice injected intravenously with the tumor cells. Naive mice vaccinated using the same prime–boost protocol demonstrated a strong serum immunoglobulin G response and p185-specific cellular immunity, as shown by the results of ELISPOT (enzyme-linked immunospot) analysis for IFNγ.
We report herein that vaccination of mice with a plasmid gene vaccine and an adenovirus gene vaccine, each containing the gene for HER2/neu, prevented growth of a HER2/neu-expressing breast cancer cell line injected into the mammary fat pad or intravenously. Sequential administration of the vaccines in a prime–boost protocol was therapeutically effective when tumor cells were injected intravenously before the vaccination. The vaccines induced high levels of both cellular and humoral immunity as determined by in vitro assessment. These findings indicate that clinical evaluation of these vaccines, particularly when used sequentially in a prime–boost protocol, is justified.
Human epidermal growth factor receptor 2 (HER2)–positive breast cancer is highly aggressive and has higher risk of recurrence than HER2-negative cancer. With few treatment options available, new drug targets specific for HER2-positive breast cancer are needed.
We conducted a pharmacological profiling of seven genotypically distinct breast cancer cell lines using a subset of inhibitors of breast cancer cells from a screen of the Johns Hopkins Drug Library. To identify molecular targets of nelfinavir, identified in the screen as a selective inhibitor of HER2-positive cells, we conducted a genome-wide screen of a haploinsufficiency yeast mutant collection. We evaluated antitumor activity of nelfinavir with xenografts in athymic nude mouse models (n = 4–6 per group) of human breast cancer and repeated mixed-effects regression analysis. All statistical tests were two-sided.
Pharmacological profiling showed that nelfinavir, an anti-HIV drug, selectively inhibited the growth of HER2-positive breast cancer cells in vitro. A genome-wide screening of haploinsufficiency yeast mutants revealed that nelfinavir inhibited heat shock protein 90 (HSP90) function. Further characterization using proteolytic footprinting experiments indicated that nelfinavir inhibited HSP90 in breast cancer cells through a novel mechanism. In vivo, nelfinavir selectively inhibited the growth of HER2-positive breast cancer cells (tumor volume index of HCC1954 cells on day 29, vehicle vs nelfinavir, mean = 14.42 vs 5.16, difference = 9.25, 95% confidence interval [CI] = 5.93 to 12.56, P < .001; tumor volume index of BT474 cells on day 26, vehicle vs nelfinavir, mean = 2.21 vs 0.90, difference = 1.31, 95% CI = 0.83 to 1.78, P < .001). Moreover, nelfinavir inhibited the growth of trastuzumab- and/or lapatinib-resistant, HER2-positive breast cancer cells in vitro at clinically achievable concentrations.
Nelfinavir was found to be a new class of HSP90 inhibitor and can be brought to HER2-breast cancer treatment trials with the same dosage regimen as that used among HIV patients.
The capability of microarray platform to interrogate thousands of genes has led to the development of molecular diagnostic tools for cancer patients. While large-scale comparative studies of clinical samples are often limited by the access of human tissues, expression profiling databases of various human cancer types are publicly available for researchers. Given that mouse models have been instrumental to our current understanding of cancer progression, we aimed to test the hypothesis that novel gene signatures possessing predictability in clinical outcome can be derived by coupling genomic analyses in mouse models of cancer with publicly available human cancer datasets.
We established a complex series of syngeneic metastatic animal models using a murine breast cancer cell line. Tumor RNA was hybridized on Affymetrix MouseGenome-430A2.0 GeneChips. With the use of Venn logic, gene signatures that represent metastatic competency were derived and tested against publicly available human breast and lung cancer datasets.
Survival analyses showed that the spontaneous metastasis gene signature was significantly associated with metastasis-free and overall survival (p<0.0005). Consequently, the six-gene model was determined and demonstrated statistical predictability in predicting survival in breast cancer patients. In addition, the model was able to stratify poor from good prognosis for lung cancer patients in majority of the datasets analyzed.
Together, our data support that novel gene signature derived from mouse models of cancer can be utilized for predicting human cancer outcome. Our approaches set precedence that similar strategies may be used to decipher novel gene signatures for clinical utility.
Mouse model; Gene Expression; Breast Cancer; Lung Cancer; Survival; Signature
The tyrosine kinase receptor, HER2 is a crucial prognostic marker and therapeutic target for breast cancer; however, the downstream targets and biological effectors of HER2 remain unclear. We investigated the relationship between HER2 and the transcription factor FoxM1 in breast cancer. HER2 and FoxM1 expression levels were compared in breast carcinoma cell lines, paraffin embedded breast cancer patient samples and at the mRNA level in purified breast epithelial cells. To further examine the relationship between HER2 and FoxM1 expression, we either overexpressed or siRNA-mediated depleted endogenous HER2 in breast cancer cell lines. Additionally, a mammary epithelium-targeted HER2 (neu) transgenic mouse model was also used to assess the effect of HER2 on FoxM1 levels. Furthermore, the effect of the HER2-tyrosine kinase inhibitor lapatinib on FoxM1 in HER2 positive breast cancer cells was investigated. HER2 protein levels directly correlated with FoxM1 expression in both breast carcinoma cell lines and paraffin embedded breast cancer patient samples. Moreover, in purified breast epithelial cells, overexpression of HER2 was associated with high levels of FoxM1 mRNA, suggesting that the upregulation of FoxM1 expression is at least partially mediated transcriptionally. Furthermore, overexpression or ablation of endogenous HER2 resulted in parallel changes in FoxM1 expression. Critically, mammary epithelium-targeted HER2 mouse tumours also resulted in increased FoxM1 expression, suggesting that HER2 directed FoxM1 expression occurs in vivo and may be a critical downstream effector of HER2-targeting therapies. Indeed, treatment of breast cancer cells with lapatinib reduced FoxM1 expression at protein, mRNA and gene promoter levels. Moreover, analysis of normal and breast cancer patient samples revealed that elevated FoxM1 expression at protein and mRNA levels correlated with breast cancer development, but not significantly with cancer progression and survival. Our results indicate that the HER2 receptor regulates the expression of the FoxM1 transcription factor, which has a role in breast cancer development.
Tumor development relies upon essential contributions from the tumor microenvironment and host immune alterations. These contributions may inform the plasma proteome in a manner that could be exploited for cancer diagnosis and prognosis. In this study, we employed a systems biology approach to characterize the plasma proteome response in the inducible HER2/neu mouse model of breast cancer during tumor induction, progression and regression. Mass spectrometry data derived from ∼ 1.6 million spectra identified protein networks involved in wound healing, microenvironment and metabolism that coordinately changed during tumor development. The observed alterations developed prior to cancer detection, increased progressively with tumor growth, and reverted toward baseline with tumor regression. Gene expression and immunohistochemical analyses suggested that the cancer-associated plasma proteome was derived from transcriptional responses in the non-cancerous host tissues as well as the developing tumor. The proteomic signature was distinct from a non-specific response to inflammation. Overall, the developing tumor simultaneously engaged a number of innate physiological processes, including wound repair, immune response, coagulation and complement cascades, tissue remodeling and metabolic homeostasis that were all detectable in plasma. Our findings offer an integrated view of tumor development with relevance to plasma-based strategies to detect and diagnose cancer.
Carcinosarcoma of the breast, often referred to as metaplastic carcinoma of the breast, is a rare malignancy with two distinct cell lines described as a breast carcinoma of ductal type with a sarcoma-like component. Clinically, carcinosarcoma of the breast is an aggressive breast cancer. The prognosis for carcinosarcoma of the breast is less favorable compared to more common types of breast cancer such as infiltrating ductal or lobular carcinoma. Currently, the evaluation of breast carcinoma includes hormone receptor analysis of the tumor tissue, with those positive for estrogen or progesterone responding better to both hormonal and chemotherapy.
Trastuzumab (Herceptin®) is available as an adjunct treatment for tumors which over-express the HER2/neu gene. Typically, metaplastic carcinomas of the breast do not express the estrogen or progesterone receptors and do not over-express the HER2/neu oncogene. As a result of this "triple negative" phenotype, such tumors tend to be more aggressive and are unlikely to respond to targeted therapy with Herceptin. The epidermal growth factor receptor HER-1/EGFR protein is expressed in the majority of metaplastic carcinomas and thus may serve as a potential therapeutic target for EGFR inhibitors such as gefitinib and cetuximab. The two cases we describe exemplify the aggressive nature of carcinosarcoma of the breast and support the findings that this tumor type does not express the common receptors found in other breast carcinomas. These case reports also emphasize the need for investigating the role for blockade of the HER-1/EGFR receptor with targeted therapies when found to be over-expressed in the primary tumor.
MicroRNAs (miRNAs) are small, non-coding, endogenous RNAs involved in regulating gene expression and protein translation. miRNA expression profiling of human breast cancers has identified miRNAs related to the clinical diversity of the disease and potentially provides novel diagnostic and prognostic tools for breast cancer therapy. In order to further understand the associations between oncogenic drivers and miRNA expression in sub-types of breast cancer, we performed miRNA expression profiling on mammary tumors from eight well-characterized genetically engineered mouse (GEM) models of human breast cancer, including MMTV-H-Ras, -Her2/neu, -c-Myc, -PymT, -Wnt1 and C3(1)/SV40 T/t-antigen transgenic mice, BRCA1fl/fl;p53+/-;MMTV-cre knock-out mice and the p53fl/fl;MMTV-cre transplant model.
miRNA expression patterns classified mouse mammary tumors according to luminal or basal tumor subtypes. Many miRNAs found in luminal tumors are expressed during normal mammary development. miR-135b, miR-505 and miR-155 are expressed in both basal human and mouse mammary tumors and many basal-associated miRNAs have not been previously characterized. miRNAs associated with the initiating oncogenic event driving tumorigenesis were also identified. miR-10b, -148a, -150, -199a and -486 were only expressed in normal mammary epithelium and not tumors, suggesting that they may have tumor suppressor activities. Integrated miRNA and mRNA gene expression analyses greatly improved the identification of miRNA targets from potential targets identified in silico.
This is the first large-scale miRNA gene expression study across a variety of relevant GEM models of human breast cancer demonstrating that miRNA expression is highly associated with mammary tumor lineage, differentiation and oncogenic pathways.
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Central Repository makes data and biospecimens from NIDDK-funded research available to the broader scientific community. It thereby facilitates: the testing of new hypotheses without new data or biospecimen collection; pooling data across several studies to increase statistical power; and informative genetic analyses using the Repository’s well-curated phenotypic data. This article describes the initial database plan for the Repository and its revision using a simpler model. Among the lessons learned were the trade-offs between the complexity of a database design and the costs in time and money of implementation; the importance of integrating consent documents into the basic design; the crucial need for linkage files that associate biospecimen IDs with the masked subject IDs used in deposited data sets; and the importance of standardized procedures to test the integrity data sets prior to distribution. The Repository is currently tracking 111 ongoing NIDDK-funded studies many of which include genotype data, and it houses over 5 million biospecimens of more than 25 types including serum, plasma, stool, urine, DNA, red blood cells, buffy coat and tissue. Repository resources have supported a range of biochemical, clinical, statistical and genetic research (188 external requests for clinical data and 31 for biospecimens have been approved or are pending). Genetic research has included GWAS, validation studies, development of methods to improve statistical power of GWAS and testing of new statistical methods for genetic research. We anticipate that the future impact of the Repository’s resources on biomedical research will be enhanced by (i) cross-listing of Repository biospecimens in additional searchable databases and biobank catalogs; (ii) ongoing deployment of new applications for querying the contents of the Repository; and (iii) increased harmonization of procedures, data collection strategies, questionnaires etc. across both research studies and within the vocabularies used by different repositories.
Database URL: http://www.niddkrepository.org
Overexpression of the HER2/neu gene in breast cancer is associated with an increased incidence of metastatic disease and with a poor prognosis. Although passive immunotherapy with the humanized monoclonal antibody trastuzumab (Herceptin) has shown some effect, a vaccine capable of inducing T-cell and humoral immunity could be more effective.
Virus-like replicon particles (VRP) of Venezuelan equine encephalitis virus containing the gene for HER2/neu (VRP-neu) were tested by an active immunotherapeutic approach in tumor prevention models and in a metastasis prevention model.
VRP-neu prevented or significantly inhibited the growth of HER2/neu-expressing murine breast cancer cells injected either into mammary tissue or intravenously. Vaccination with VRP-neu completely prevented tumor formation in and death of MMTV-c-neu transgenic mice, and resulted in high levels of neu-specific CD8+ T lymphocytes and serum IgG.
On the basis of these findings, clinical testing of this vaccine in patients with HER2/neu+ breast cancer is warranted.
adjuvant treatment; breast cancer; gene vaccines; immunotherapy; virus-like replicon particles
We explored the association of mammographic density, a breast cancer risk factor, with hormonal and proliferation markers in benign tissue from tumor blocks of pre-and postmenopausal breast cancer cases.
Breast cancer cases were recruited from a case-control study on breast density. Mammographic density was assessed on digitized prediagnostic mammograms using a computer-assisted method. For 279 participants of the original study, we obtained tumor blocks and prepared tissue microarrays (TMA), but benign tissue cores were only available for 159 women. The TMAs were immunostained for estrogen receptor alpha (ERα) and beta (ERβ), progesterone receptor (PR), HER2/neu, Ki-67, and Proliferating Cell Nuclear Antigen (PCNA). We applied general linear models to compute breast density according to marker expression.
A substantial proportion of the samples were in the low or no staining categories. None of the results was statistically significant, but women with PR and ERβ staining had 3.4% and 2.4% higher percent density. The respective values for Caucasians were 5.7% and 11.6% but less in Japanese women (3.5% and -1.1%). Percent density was 3.4% higher in women with any Ki-67 staining and 2.2% in those with positive PCNA staining.
This study detected little evidence for an association between mammographic density and expression of steroid receptors and proliferation markers in breast tissue, but it illustrated the problems of locating tumor blocks and benign breast tissue samples for epidemiologic research. Given the suggestive findings, future studies examining estrogen effects in tissue, cell proliferation, and density in the breast may be informative.
Cancer stem cells, initiating and sustaining the tumor process, have been isolated in human and murine breast cancer using different cell markers. In the present study, we aimed to evaluate the presence and characteristics of stem/tumor-initiating cells in the model of the mouse mammary neoplasia driven by the activated form of rat Her-2/neu oncogene (BALB-neuT mice). For this purpose, we generated tumor spheres from primary spontaneous BALB-neuT tumors. Tumor sphere cultures were characterized for clonogenicity, self-renewal, and ability to differentiate in epithelial/myoepithelial cells of the mammary gland expressing basal and luminal cytokeratins and alpha-smooth muscle actin. In addition, tumor spheres were more resistant to doxorubicin compared with parental tumor cells. In the attempt to identify a selected marker for the sphere-generating cells, we found that Sca-1+ cells, present in tumors or enriched in mammospheres, and not CD24+ or CD29+ cells, were responsible for the sphere generation in vitro. Moreover, cells from the tumor spheres showed an increased tumor-generating ability in respect to the epithelial tumor cells. Sca-1+ sorted cells or clonal mammospheres derived from a Sca-1+ cell showed a superimposable tumor-initiating ability. The data of the present study indicate that a Sca-1+ population derived from mammary BALB-neuT tumors is responsible for sphere generation in culture and for initiating tumors in vivo.
Understanding the molecular pathways that contribute to the aggressive behavior of human cancers is a critical research priority. The SNF1/AMPK-related protein kinase Hunk is overexpressed in aggressive subsets of human breast, ovarian, and colon cancers. Analysis of Hunk–/– mice revealed that this kinase is required for metastasis of c-myc–induced mammary tumors but not c-myc–induced primary tumor formation. Similar to c-myc, amplification of the proto-oncogene HER2/neu occurs in 10%–30% of breast cancers and is associated with aggressive tumor behavior. By crossing Hunk–/– mice with transgenic mouse models for HER2/neu-induced mammary tumorigenesis, we report that Hunk is required for primary tumor formation induced by HER2/neu. Knockdown and reconstitution experiments in mouse and human breast cancer cell lines demonstrated that Hunk is required for maintenance of the tumorigenic phenotype in HER2/neu-transformed cells. This requirement is kinase dependent and resulted from the ability of Hunk to suppress apoptosis in association with downregulation of the tumor suppressor p27kip1. Additionally, we find that Hunk is rapidly upregulated following HER2/neu activation in vivo and in vitro. These findings provide what we believe is the first evidence for a role for Hunk in primary tumorigenesis and cell survival and identify this kinase as an essential effector of the HER2/neu oncogenic pathway.
Background & objectives:
Fluorescence in situ hybridization (FISH) is increasingly being recognized as the most accurate and predictive test for HER2/neu gene amplification and response to therapy in breast cancer. In the present study we investigated HER-2/neu gene amplification by FISH in breast carcinoma tissue specimens and compared the results with that of immunohistochemical (IHC) analysis.
A total of 90 breast carcinoma tissue samples were used for immunohistochemical (IHC) and FISH analysis. IHC was performed by using mouse monoclonal antibody to the intracellular domain of HER-2/neu protein. Each slide was scored in a blinded fashion by two pathologists according to the manufacturer's recommended criteria. FISH analysis was performed on paraffin embedded breast tumour tissue sections. The polysomy for centromere 17 (Spec green signal) was read as green signals less than 4 as moderate polysomy, and more than 4 as highly polysomy.
Thirty of the 90 patients had negative results by IHC and FISH. Of the 28 patients with the score of 2+ by IHC, 20 were FISH positive for HER-2/neu gene amplification, three were FISH negative and five patients showed equivocal (1.8-2.2) results by FISH. These five cases were retested for IHC and FISH on different paraffin embedded tissue blocks, and all five were found positive for HER-2/neu gene amplification. Twenty five patients with the score of 3+ by IHC were FISH positive for HER-2/neu gene amplification (>2.2). Seven cases with the score of 3+ by IHC were FISH negative for HER-2/neu gene amplification (>2.2), and showed polysomy of chromosome number 17 high polysomy > 4.
Interpretation & conclusions:
Our results indicated that HER-2/neu status by FISH should be performed in all cases of breast tumour with a 2+ score by IHC. Cases demonstrating a 3+ score by IHC may be subjected to FISH to rule out polysomy of chromosome 17 which could be falsely interpreted as HER-2/neu overexpression by IHC analysis. There is also a need for establishing a clinically validated cut-off value for HER-2/neu FISH amplification against IHC which may be further compared and calibrated.
Breast cancer; HER2/neu gene amplification; fluorescence in situ hybridization (FISH); immunohistochemistry (IHC)
Background & objectives:
An association between over-expression of proto-oncogene Her-2/neu and resistance to tamoxifen in estrogen receptor (ER) positive, primary and metastatic breast cancer has been suggested. HR+/Her-2/neu+ patients have a poor response to endocrine therapy, making this group a matter of debate. The present study was carried out to examin whether Her-2/neu expression in breast cancer patients predicted tamoxifen effectiveness.
An enzyme-linked immunosorbent assay (ELISA) specific for the extracellular domain of the Her-2/neuoncoprotein product was used to detect serum Her-2/neu levels in 207 patients with histological confirmed breast cancer. Tissue Her-2/neu expression was studied in 100 breast cancer patients by immunohistochemistry (IHC) and compared with serum Her-2/neu levels by ELISA.
Among 207 histologically confirmed breast cancer patients, 53 were serum Her-2/neu positive. Patients who were treated with surgery, chemotherapy, and radiotherapy showed significantly (P<0.05) reduced serum Her-2/neu levels, showing good response to treatment. Patients who were treated with tamoxifen in addition to the above regimen did not show any significant reduction in serum Her-2/neu levels showing resistance to treatment.
Interpretation & conclusions:
The present findings study support the hypothesis that Her-2/neu overexpression contributes to tamoxifen resistance. Trastuzumab or other growth factor inhibitors should be used in combination with tamoxifen, since monotherapy is not likely to be optimal in HR+/Her-2/neu+ tumours.
Breast cancer; ELISA; estrogen receptor; Her-2/neu; tamoxifen
Biodegradable nanopolymers are believed to offer great potential in cancer therapy. Here, we report the characterization of a novel, targeted, nanobiopolymeric conjugate based on biodegradable, nontoxic, and nonimmunogenic PMLA [poly(β-l-malic acid)]. The PMLA nanoplatform was synthesized for repetitive systemic treatments of HER2/neu-positive human breast tumors in a xenogeneic mouse model. Various moieties were covalently attached to PMLA, including a combination of morpholino antisense oligonucleotides (AON) directed against HER2/neu mRNA, to block new HER2/neu receptor synthesis; anti-HER2/neu antibody trastuzumab (Herceptin), to target breast cancer cells and inhibit receptor activity simultaneously; and transferrin receptor antibody, to target the tumor vasculature and mediate delivery of the nanobiopolymer through the host endothelial system. The results of the study showed that the lead drug tested significantly inhibited the growth of HER2/neu-positive breast cancer cells in vitro and in vivo by enhanced apoptosis and inhibition of HER2/neu receptor signaling with suppression of Akt phosphorylation. In vivo imaging analysis and confocal microscopy demonstrated selective accumulation of the nanodrug in tumor cells via an active delivery mechanism. Systemic treatment of human breast tumor-bearing nude mice resulted in more than 90% inhibition of tumor growth and tumor regression, as compared with partial (50%) tumor growth inhibition in mice treated with trastuzumab or AON, either free or attached to PMLA. Our findings offer a preclinical proof of concept for use of the PMLA nanoplatform for combination cancer therapy.
ErbB2 (HER2, neu) is a receptor tyrosine kinase overexpressed in about 25% of invasive breast carcinomas. Neutrophil gelatinase-associated lipocalin (NGAL) is a secreted glycoprotein expressed in a variety of cancers including breast carcinomas. NGAL can inhibit erythroid cell production leading to anemia. Anemia usually occurs in cancer patients and negatively impacts quality of life. However, current treatment for cancer-related anemia has potential complications. ErbB2, NGAL, and anemia have all been associated with increased metastasis and poor prognosis in breast cancer patients, although the relationship between ErbB2 and NGAL expression is not clear. Here, using breast cancer cell lines in vitro and transgenic mice carrying the activated c-neu oncogene driven by a mouse mammary tumor virus (MMTV-neu) in vivo, we demonstrate that ErbB2 overexpression leads to NGAL upregulation, which is dependent on nuclear factor kappa B (NF-κB) activity. MMTV-neu transgenic mice developed anemia after tumor onset, and anemia progression could be partially arrested by an NF-κB inhibitor and an ErbB2-targeted therapy. Taken together, upregulation of NGAL by ErbB2 through NF-κB activation is involved in cancer-related anemia, and ErbB2, NF-κB, NGAL pathway may serve as potential therapeutic targets for cancer-related anemia.
ErbB2; neutrophil gelatinase-associated lipocalin (NGAL); nuclear factor kappa B (NF-κB); anemia; breast cancer
Aim—To evaluate the clinical usefulness of three commercially available assays for Her-2/neu oncogene and protein measurements. The Her-2/neu protein is overexpressed, mostly as a result of gene amplification, in 20–30% of human breast cancers, and has been shown to have prognostic and predictive value for treatment with chemotherapy or the new monoclonal antibody, Herceptin.
Methods—An immunohistochemistry (IHC) assay using the Dako polyclonal antibody A0485, which measures the Her-2/neu protein, was compared with two new Food and Drug Administration (FDA) approved fluorescence in situ hybridisation (FISH) assays—INFORMTM and PathVysionTM, in a cohort of 52 formalin fixed, paraffin wax embedded breast tissues. These tissues were selected randomly from 84 consecutive infiltrating breast cancer specimens, which were first stratified according to the Her-2/neu protein levels as measured by IHC.
Results—The two FISH assays achieved a 98% concordance rate: 14 specimens (27%) showed Her-2/neu gene amplification and 37 specimens (71%) showed no Her-2/neu gene amplification. The PathVysion assay had certain advantages over the INFORM assay. In contrast, the IHC assay detected Her-2/neu overexpression in a high percentage of cases, including 13 high positive specimens (25%) and 13 medium positive specimens (25%). Although 10 of these 13 IHC high positive specimens showed gene amplification by FISH, nine of 13 IHC medium positive specimens showed no gene amplification. Statistical analyses showed that the differences between IHC and FISH assays were primarily in the specimens with medium positive IHC, but negative FISH results.
Conclusions—Because of the increasing importance of the Her-2/neu oncogene and oncoprotein in the clinical management of patients with breast cancer, the accurate and consistent evaluation of Her-2/neu status is crucial. This study suggests that the best approach is to combine both IHC and FISH assays; that is, to use the IHC assay as a triage step, followed by the PathVysion FISH assay to analyse the IHC medium and high positive cases.
Key Words: Her-2/neu • breast cancer • fluorescence in situ hybridisation
The New York University Langone Medical Center (NYULMC) has committed $15 million to ensure that researchers have access to cutting edge enabling technologies. The Office of Collaborative Science enables access to expertise and technology through the centralized administration of Shared Resource Centers. In partnership with the NYU Cancer Institute, Center for AIDS Research and Clinical and Translational Science Institute, we strive to increase collaboration among clinical, translational and basic scientists to support novel science and to classify and treat diseases not just by their phenotype, but also by their molecular profiles. Here we highlight several Core Resource Labs that support translational research at NYULMC. Human biospecimens are essential validating mechanistic insights into biological processes gleaned from cell lines, animal models of disease, and epidemiological studies. The availability of well-annotated human biospecimens is a critical link between basic science and translational research. The NYULMC Tissue Acquisition and Biorepository Core provides investigators with freshly acquired frozen, normal, and diseased tissue at the time of surgery, as well as pathology-archived, formalin fixed, paraffin-embedded (FFPE) specimens, from appropriately consented patients. The Immunohistochemistry and Histopathology Cores closely interface with the Tissue Biorepository, providing the means for clinical and basic research collaborations and the microscopic analysis of clinical research specimens. The Genome Technology Centers sequencing and microarray units are dedicated to RNA-seq of cancer patient transciptomes, array expression profiling and SNP genotyping, enabling translation research as well as the preparation of nucleic acids for molecular profiling, mutational analysis and microRNA screens. The RNAi Core provides an integrated, state-of-the-art, RNA interference (RNAi) based high-throughput screening (HTS) and offers siRNA/dsRNA screening libraries for the cross-species functional characterization of whole genomes in a systematic, comprehensive, and cost effective manner.