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1.  MYC-xing it up with PIK3CA mutation and resistance to PI3K inhibitors: summit of two giants in breast cancers 
Approximately 35% of breast cancers exhibit PIK3CA activating mutation. Since PIK3CA hotspot mutation is the most frequently mutated gene in human breast cancers and primarily overlaps in HER2+ as well as ER+ breast cancers, the subset of patients bearing PIK3CA activating mutation does not get fullest benefit from either anti-HER2 or anti-hormonal agents. Literature also suggests that these patients may have chemotherapy resistance. Indeed, multiple clinical trials are currently evaluating the efficacy of over 30 drugs targeting different nodal points in the PI3K-AKT-mTOR pathway in breast and other cancers. However, to date, responses of solid tumors to PI3K pathway inhibitor monotherapy remains modest with an accompanied rapid emergences of drug resistance. MYC elevation represents one of the potential modes of actions by which breast tumors develop resistance to the PI3K pathway-specific targeted therapies. As products of oncogenes, both MYC and PIK3CA are well-established onco-proteins which contribute to breast oncogenesis. However, their similarities out number their dissimilarities in the context of their specific oncogenic cellular signals. In this review we will describe the specific cellular signals initiated following alteration in the MYC gene and PIK3CA gene in breast cancers. We will interrogate how MYC gene alterations influence the action of PI3K pathway targeted drugs in the context of PIK3CA mutation towards the development PI3K inhibitor induced drug-resistance in breast cancers.
PMCID: PMC4300701  PMID: 25628917
Breast tumors; MYC; PIK3CA; PI3K inhibitors; resistance
2.  MicroRNA regulation and therapeutic targeting of survivin in cancer 
Survivin, the smallest member of IAP (inhibitor of apoptosis) family, is a dual functional protein acting as a critical apoptosis inhibitor and key cell cycle regulator. Survivin is usually expressed in embryonic tissues during development and undetectable in most terminally differentiated tissues. Numerous studies demonstrate that survivin is selectively upregulated in almost all types of human malignancies and its overexpression positively correlates with poor prognosis, tumor recurrence, and therapeutic resistance. This differential expression of survivin in tumors and normal tissues draws a great interest to develop survivin-targeted therapy for cancer treatment. Nonetheless, the molecular mechanisms controlling survivin expression in malignant tumor cells have not been fully understood. While aberrant activation of receptor tyrosine kinases (RTKs) and the downstream signaling, such as PI-3K/Akt, MEK/MAPK, mTOR, and STAT pathways, have frequently been shown to upregulate survivin, recent data suggest that a class of noncoding RNAs, microRNAs (miRNAs) also play an important role in survivin dysregulation in human cancers. Here, we focus on survivin expression-regulated by specific miRNAs binding to the 3’-UTR of survivin mRNA, and summarize the latest advances on survivin-targeted therapy in clinical trials and the therapeutic potential of survivin-targeting miRNAs in cancer.
PMCID: PMC4300714  PMID: 25628918
Survivin; miRNA; targeted therapy; cancer
3.  Anticancer activity of essential oils and their chemical components - a review 
Essential oils are widely used in pharmaceutical, sanitary, cosmetic, agriculture and food industries for their bactericidal, virucidal, fungicidal, antiparasitical and insecticidal properties. Their anticancer activity is well documented. Over a hundred essential oils from more than twenty plant families have been tested on more than twenty types of cancers in last past ten years. This review is focused on the activity of essential oils and their components on various types of cancers. For some of them the mechanisms involved in their anticancer activities have been carried out.
PMCID: PMC4266698  PMID: 25520854
Essential oils; anticancer activity; chemical composition
4.  Redundant kinase activation and resistance of EGFR-tyrosine kinase inhibitors 
Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have shown dramatic effects against that tumors harboring EGFR activating mutations in the EGFR intracytoplasmic tyrosine kinase domain and resulted in cell apoptosis. Unfortunately, a number of patients ultimately developed resistance by multiple mechanisms. Thus, elucidation of the mechanism of resistance to EGFR-TKIs can provide strategies for blocking or reversing the situation. Recent studies suggested that redundant kinase activation plays pivotal roles in escaping from the effects of EGFR-TKIs. Herein, we aimed to characterize several molecular events involved in the resistance to EGFR-TKIs mediated by redundant kinase activation.
PMCID: PMC4266699  PMID: 25520855
EGFR; redundant kinase activation; resistance to EGFR-TKIs
5.  EGFR-TKI resistance in NSCLC patients: mechanisms and strategies 
The epidermal growth factor receptor (EGFR) is a kind of receptor tyrosine kinase (RTK) that plays a critical role in the initiation and development of malignant tumors via modulating downstream signaling pathways. In non-small cell lung cancer (NSCLC), the activating mutations located in the tyrosine kinase domains of EGFR have been demonstrated in multiple researches as the “Achilles’ heel” of this deadly disease since they could be well-targeted by epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). However, it’s still too early to celebrate since the first-generation EGFR-TKIs such as gefitinib and erlotinib have only achieved limited clinical benefits and acquired resistance to this kind of drugs occurred inevitably in almost all the NSCLC patients. In order to make the most of EGFR-TKIs and develop more effective regimens for the NSCLC patients, researchers majoring in different aspects start a battle against EGFR-TKI resistance. Challenging as it is, we still progress stably and step firmly toward the final victory. This review will summarize the major mechanisms of acquired resistance to EGFR-TKIs, and then discuss the development of rationally designed molecular target drugs in accordance with each mechanism, in the hope of shedding light on the great achievements we have obtained and tough obstacles we have to overcome in the battle against this deadly disease.
PMCID: PMC4163608  PMID: 25232485
Non-small cell lung cancer; epithelial growth factor receptor; tyrosine kinase inhibitors; drug resistance; molecular targeted therapy
6.  A review of management strategies of malignant gliomas in the elderly population 
Glioblastoma Multiforme (GBM) is the most frequent primary malignant brain tumor in adults. It is an aggressive primary brain neoplasm, associated with a poor prognosis and median survival of less than 1 year. Approximately 50% of patients diagnosed with malignant gliomas in the United States are over the age of 65. Advancing age and poor performance status are two variables that have found to negatively affect prognosis. When compared to younger patients, not only is the treatment of elderly patients associated with decreased efficacy but also greater toxicity. As a result, elderly patients often receive less aggressive treatment and are excluded from clinical trials. There are many challenges in the treatment of elderly patients with GBM including increased surgical morbidity and mortality as well as increased toxicity to radiation and chemotherapy. As such, the optimal therapy remains unclear and controversial for the elderly malignant glioma population.
PMCID: PMC4163609  PMID: 25232486
High grade glioma; GBM; MGMT; malignant astrocytoma; elderly patients
7.  Role of SOX family of transcription factors in central nervous system tumors 
SOX genes are developmental regulators with functions in the instruction of cell fate and maintenance of progenitor’s identity during embryogenesis. They play additional roles during tissue homeostasis and regeneration in adults particularly in the Central Nervous System (CNS). In the last years a growing number of evidences has shown that mutations and dysfunction of SOX factors are implicated in several human diseases, including a variety of cancers. In this review, we will summarize the current knowledge about SOX family in CNS tumors and their role in the origin and maintenance of the subpopulation of cancer stem cells in these tumors.
PMCID: PMC4106650  PMID: 25057435
SOX; CNS tumors; glioblastoma; glioma stem cell; cell of origin; oncogenic SOX2; therapy target
8.  S100 protein family in human cancer 
S100 protein family has been implicated in multiple stages of tumorigenesis and progression. Among the S100 genes, 22 are clustered at chromosome locus 1q21, a region frequently rearranged in cancers. S100 protein possesses a wide range of intracellular and extracellular functions such as regulation of calcium homeostasis, cell proliferation, apoptosis, cell invasion and motility, cytoskeleton interactions, protein phosphorylation, regulation of transcriptional factors, autoimmunity, chemotaxis, inflammation and pluripotency. Many lines of evidence suggest that altered expression of S100 proteins was associated with tumor progression and prognosis. Therefore, S100 proteins might also represent potential tumor biomarkers and therapeutic targets. In this review, we summarize the evidence connecting S100 protein family and cancer and discuss the mechanisms by which S100 exerts its diverse functions.
PMCID: PMC3960449  PMID: 24660101
S100 proteins; proliferation; apoptosis; invasion; migration; pluripotency; biomarker
9.  Beyond laser microdissection technology: follow the yellow brick road for cancer research 
Normal biological tissues harbour different populations of cells with intricate spacial distribution patterns resulting in heterogeneity of their overall cellular composition. Laser microdissection involving direct viewing and expertise by a pathologist, enables access to defined cell populations or specific region on any type of tissue sample, thus selecting near-pure populations of targeted cells. It opens the way for molecular methods directed towards well-defined populations, and provides also a powerful tool in studies focused on a limited number of cells. Laser microdissection has wide applications in oncology (diagnosis and research), cellular and molecular biology, biochemistry and forensics for tissue selection, but other areas have been gradually opened up to these new methodological approaches, such as cell cultures and cytogenetics. In clinical oncology trials, molecular profiling of microdissected samples can yield global “omics” information which, together, with the morphological analysis of cells, can provide the basis for diagnosis, prognosis and patient-tailored treatments. This remarkable technology has brought new insights in the understanding of DNA, RNA, and the biological functions and regulation of proteins to identify molecular disease signatures. We review herein the different applications of laser microdissection in a variety of fields, and we particularly focus attention on the pre-analytical steps that are crucial to successfully perform molecular-level investigations.
PMCID: PMC3902229  PMID: 24482735
Laser microdissection; histopathology; quality control; snap-freezing; DNA; RNA; proteomics; in situ cellular and molecular analyses
10.  NFκB function and regulation in cutaneous T-cell lymphoma 
The nuclear accumulation and transcriptional activity of NFκB are constitutively increased in cutaneous T-cell lymphoma (CTCL) cells, and are responsible for their increased survival and proliferation. However, in addition to the anti-apoptotic and pro-inflammatory genes, NFκB induces expression of immunosuppressive genes, such as IL-10 and TGFβ, which inhibit the immune responses and are characteristic for the advanced stages of CTCL. While the mechanisms regulating NFκB-dependent transcription of anti-apoptotic and pro-inflammatory genes have been studied extensively, very little is known about the NFκB regulation of immunosuppressive genes. The specificity of NFκB-regulated responses is determined by the subunit composition of NFκB complexes recruited to the individual promoters, post-translational modifications of NFκB proteins, as well as by their interactions with other transcriptional factors and regulators. In this review, we discuss the mechanisms regulating the transcription of NFκB-dependent anti-apoptotic, pro-inflammatory and immunosuppressive genes in CTCL cells, as potential targets for CTCL therapies.
PMCID: PMC3816964  PMID: 24224122
Apoptosis; bortezomib; cutaneous T cell lymphoma; IκBα; IL-10; immunosuppression; NFκB; proteasome inhibition; TGFβ
11.  Nuclear transcription factor Y and its roles in cellular processes related to human disease 
Nuclear transcription factor Y (NF-Y) is an example of a transcriptional regulation factor in eukaryotes consisting of three different subunits, NF-YA, NF-YB and NF-YC, which are all necessary for formation of NF-Y complexes and binding to CCAAT boxes in promoters of its target genes. Highly conserved between human and Drosophila, NF-Y regulates transcription of various genes related to the cell cycle and various human diseases. Drosophila models have been widely used as tools for studying genetics and developmental biology and more recently for analyzing the functions of human disease genes, including those responsible for developmental and neurological disorders, cancer, cardiovascular disease and metabolic and storage diseases, as well as genes required for function of the visual, auditory and immune systems. In this review, in vivo findings from Drosophila models relevant to the roles of NF-Y in various human diseases are summarized. Recent studies have demonstrated novel contributions of dNF-Y to apoptosis and apoptosis-induced proliferation, and in photoreceptor cell differentiation during the development of the Drosophila compound eye.
PMCID: PMC3744014  PMID: 23977444
Transcription factors; NF-Y; NF-YB; apoptosis; Drosophila model
12.  BLT2 is a pro-tumorigenic mediator during cancer progression and a therapeutic target for anti-cancer drug development 
Cancer is a leading cause of death worldwide and has been linked to inflammation. Leukotriene B4 (LTB4) is synthesized from arachidonic acid via the 5-lipoxygenase pathway and is a potent chemoattractant for inflammatory cells. LTB4 was recently shown to be associated with the pathogenesis of inflammatory diseases, including cancer. Of the two known LTB4 receptors, BLT1 and BLT2, the biological roles of the low-affinity LTB4 receptor 2, BLT2, have only recently been elucidated. This review focuses on recent discoveries regarding BLT2 and its roles in cancer progression and the downstream signaling mechanisms of the BLT2-linked signaling cascade in cancer cells. We believe that these findings will facilitate the development of new cancer treatments.
PMCID: PMC3744015  PMID: 23977445
Leukotriene B4 receptor 2 (BLT2); leukotriene B4; NADPH oxidase; reactive oxygen species; nuclear factor-kB; cancer progression
13.  Mouse models for colorectal cancer 
Colorectal cancer (CRC) is the third leading cause of cancer-related death in the United States, with the number of affected people increasing. There are many risk factors that increase CRC risk, including family or personal history of CRC, smoking, consumption of red meat, obesity, and alcohol consumption. Conversely, increased screening, maintaining healthy body weight, not smoking, and limiting intake of red meat are all associated with reduced CRC morbidity and mortality. Mouse models of CRC were first used in 1928 and have played an important role in understanding CRC biology and treatment and have long been instrumental in clarifying the pathobiology of CRC formation and inhibition. This review focuses on advancements in modeling CRC in mice.
PMCID: PMC3696531  PMID: 23841024
Colorectal cancer; human; mouse models; tumorigenesis; Apc; FAP; HNPCC; stem cells
14.  Autophagy in breast cancer and its implications for therapy 
Autophagy is an evolutionarily conserved process of cellular self-digestion that serves as a mechanism to clear damaged organelles and recycle nutrients. Since autophagy can promote cell survival as well as cell death, it has been linked to different human pathologies, including cancer. Although mono-allelic deletion of autophagy-related gene BECN1 in breast tumors originally indicated a tumor suppressive role for autophagy in breast cancer, the intense research during the last decade suggests a role for autophagy in tumor progression. It is now recognized that tumor cells often utilize autophagy to survive various stresses, such as oncogene-induced transformation, hypoxia, endoplasmic reticulum (ER) stress and extracellular matrix detachment. Induction of autophagy by tumor cells may also contribute to tumor dormancy and resistance to anticancer therapies, thus making autophagy inhibitors promising drug candidates for breast cancer treatment. The scientific endeavors continue to define a precise role for autophagy in breast cancer. In this article, we review the current literature on the role of autophagy during the development and progression of breast cancer, and discuss the potential of autophagy modulators for breast cancer treatment.
PMCID: PMC3696532  PMID: 23841025
Autophagy; breast cancer; transformation; hypoxia; ER stress; tumor microenvironment; metabolism; metastasis; apoptosis; cancer therapy
15.  Leptomeningeal metastases in breast cancer 
Central nervous system (CNS) metastasis from breast cancer may be characterized as either parenchymal brain metastasis (BM) or leptomeningeal (LM) metastasis. BM are much more common (about 80% of all CNS metastases), and have been more extensively studied than LM. CNS metastasis in breast cancer has been associated with reduced overall survival, with the shortest survival generally observed in cases of LM. Here, we review the epidemiology, prognostic factors, diagnostic tools, currently available treatments, and potential future therapies for LM from breast cancer.
PMCID: PMC3623833  PMID: 23593536
Leptomeningeal metastases; intrathecal chemotherapy; breast cancer
16.  Ethnical disparities of prostate cancer predisposition: genetic polymorphisms in androgen-related genes 
Prostate cancer (PCa) is the most commonly diagnosed male malignancy and the second biggest cause of cancer death in men of the Western world. Higher incidences of PCa occur in men from North America, Oceania and Western countries, whereas men from Asia and North Africa have a much lower PCa incidence rate. Investigations into this population disparity of PCa incidence, in order to identify potential preventive factors or targets for the therapeutic intervention of PCa, have found differences in both environmental and genetic variations between these populations. Environmental variations include both diet and lifestyle, which vary widely between populations. Evidence that diet comes into play has been shown by men who immigrate from Eastern to Western countries. PCa incidence in these men is higher than men in their native countries. However the number of immigrants developing PCa still doesn’t match native black/white men, therefore genetic factors also contribute to PCa risk, which are supported by familial studies. There are a number of genetic polymorphisms that are differentially presented between Western and Eastern men, which are potentially associated with PCa incidence. Androgen and its receptor (AR) play a major role in PCa development and progression. In this study, we focus on genes involved in androgen biosynthesis and metabolism, as well as those associated with AR pathway, whose polymorphisms affect androgen level and biological or physiological functions of androgen. While many of the genetic polymorphisms in this androgen/AR system showed different frequencies between populations, contradictory evidences exist for most of these genes investigated individually as to the true contribution to PCa risk. More accurate measurements of androgen activity within the prostate are required and further studies need to include more African and Asian subjects. As many of these genetic polymorphisms may contribute to different steps in the same biological/physiological function of androgen and AR pathway, an integrated analysis considering the combined effect of all the genetic polymorphisms may be necessary to assess their contribution to PCa initiation and progression.
PMCID: PMC3623834  PMID: 23593537
Prostate cancer; ethnical disparity; risk factors; genetic polymorphism; androgen; androgen receptor
17.  Increasing frequency of reirradiation studies in radiation oncology: systematic review of highly cited articles 
Objectives: Identification of the most influential scientific publications and directions of mainstream reirradiation research. Methods: A systematic search of the database Scopus (Elsevier B.V., www.scopus.com) was performed, which focused on the time period 1998-2010. Patterns of citation were analysed (total number of citations accumulated independently of their origin and proportion of highly cited articles, arbitrarily defined as those with ≥50 citations). Results: Up to 64 articles were published each year. Numbers increased over time, especially after the year 2007. Among all 76 articles with at least 50 citations, 28 (37%) focused on head and neck cancer, 27 (36%) on brain tumours including metastases, and 5 (7%) on bone metastases. Most articles evaluated external beam approaches while 10 (13%) focused on brachytherapy. Many of the often quoted publications reported on stereotactic and/or intensity-modulated radiotherapy. Two (3%) reported on randomised clinical studies and 10 (13%) on non-randomised prospective clinical studies (single institution or cooperative group). Only two articles (3%) reported on experimental animal studies. Conclusions: The number of published reirradiation studies has increased in recent years. Many studies examined highly conformal and precise radiotherapy, in particular of brain and head and neck tumours. Given that few randomised clinical trials were published, efforts to increase this type of research activity are warranted.
PMCID: PMC3623835  PMID: 23593538
Radiotherapy; radiation oncology; radiation retreatment; reirradiation; citation; research evaluation
18.  Mastocytosis: a paradigmatic example of a rare disease with complex biology and pathology 
Mastocytosis is a rare disease characterized by abnormal expansion and accumulation of tissue mast cells (MC) in one or multiple organs. In most adult patients, systemic mastocytosis (SM) is diagnosed. Based on histopathological findings and organ damage, SM is divided into indolent SM (ISM), smoldering SM (SSM), SM with an associated hematologic non-MC-lineage disease (SM-AHNMD), aggressive SM (ASM), and MC leukemia (MCL). The clinical course and prognosis vary greatly among these groups of patients. In all variants of SM and most patients, neoplastic cells display the KIT mutation D816V. This suggests that additional KIT-independent molecular defects cause progression. Indeed, additional oncogenic lesions, including RAS- and TET2 mutations, have recently been identified in advanced SM. In patients with SM-AHNMD, such additional lesions are often detectable in the ‘AHNMD-component’ of the disease. Clinically relevant symptoms of SM result from i) malignant MC infiltration and the subsequent organ damage seen in advanced SM and/or ii) the release of pro-inflammatory and vasoactive mediators from MC, found in all disease-variants. Therapy of SM has to be adjusted to the individual situation in each patient. In ISM, the aim is to control mediator release and mediator effects. In advanced SM, a major goal is to control MC expansion by using conventional drugs or novel targeted drugs directed against mutant forms of KIT and/or other pro-oncogenic kinase-targets. In rapidly progressing ASM, MCL and drug-resistant AHNMD, chemotherapy and subsequent stem cell transplantation has to be considered.
PMCID: PMC3623836  PMID: 23593539
Mastocytosis; mast cells; rare disease; KIT mutations; targeted therapy
19.  LXR, prostate cancer and cholesterol: the Good, the Bad and the Ugly 
Cholesterol is a fundamental molecule for life. Located in the cell membrane, this sterol participates to the cell signaling of growth factors. Inside the cell it can be converted in hormones such as androgens or modulate the immune response. Such important functions could not be solely dependent of external supply by diet hence de novo synthesis could occur from acetate in almost all mammalian cells. If a deficiency in cholesterol sourcing leads to development troubles, overstocking has been associated to various diseases such as atherosclerosis and cancers. Cholesterol homeostasis should thus be tightly regulated at the uptake, de novo synthesis, storage and export processes. Various transcription factors have been described these last years as important to regulate cholesterol levels. Besides, synthetic molecules have been developed for many years to modulate cholesterol synthesis, such as statins. Many articles have associated prostate cancer, whose incidence is constantly increasing, to cholesterol disequilibrium. Targeting cholesterol could thus be a new pharmacological hit to counteract the initiation, development and/or progression of prostate cancer. Among the transcription factors regulating cholesterol homeostasis, the nuclear receptors Liver X Receptors (LXRs) control cholesterol uptake and export. Targeting the LXRs offers a new field of investigation to treat cancer. This review highlights the molecular relationships among LXRs, prostate cancer and cholesterol and why LXRs have good chance to be targeted one day in this tumor. LXRs, prostate cancer and cholesterol, more than a “Ménage à trois”, The Good, the Bad and the Ugly.
PMCID: PMC3555197  PMID: 23359865
LXR; cholesterol; prostate cancer; lipid raft; pharmacological modulation
20.  Role of heparan sulfatases in ovarian and breast cancer 
Endosulfatases HSulf-1 and -2 (also referred to as Sulf1 and -2) represent a family of enzymes that modulate heparin binding growth factor signaling. Heparan sulfatase 1 (HSulf-1) and heparan sulfatase 2 (HSulf-2) are two important 6-O endosulfatases which remove or edit 6-O sulfate residues of N-glucosamine present on highly sulfated HS. Alteration of heparan sulfatases have been identified in the context of several cancer types. Many cancer types either exhibit increased or decreased HSulfs expression at the transcript levels. Specifically, HSulf-1 was found to be downregulated in early-stage ovarian tumors, hepatocellular carcinoma, and metastatic breast cancer patients. HSulf-2 was found to be upregulated in ductal carcinoma in situ and invasive ductal carcinoma, whereas limited information is present about HSulf-2 expression in different stages of ovarian cancers. Here, we review the important role of these sulfatases play in ovarian and breast cancers in terms of tumorigenesis such as angiogenesis, chemoresistance, apoptosis, growth factor signaling, hypoxia and metastasis. These recent discoveries have added significant understanding about these sulfate editing enzymes.
PMCID: PMC3555198  PMID: 23359864
Ovarian and breast cancer; heparin binding growth factor signaling; tumorigenesis; angiogenesis; chemoresponse and metastasis
21.  The Role of chemokine receptor CXCR4 in breast cancer metastasis 
Breast cancer is one of the leading causes of cancer related deaths worldwide. Breast cancer-related mortality is associated with the development of metastatic potential of primary tumor lesions. The chemokine receptor CXCR4 has been found to be a prognostic marker in various types of cancer, including breast cancer. Recent advances in the field of cancer biology has pointed to the critical role that CXCR4 receptor and its ligand CXCL12 play in the metastasis of various types of cancer, including breast cancer. Breast tumors preferentially metastasize to the lung, bones and lymph nodes, all of which represent organs that secrete high levels of CXCL12. CXCL12 acts as a chemoattractant that drives CXCR4-positive primary tumor cells towards secondary metastatic sites leading to the onset of metastatic lesions. Since its discovery in 2001, the CXCR4 field has progressed at a very fast rate and further studies have pointed to the role of CXCR4 in dissemination of tumor cells from primary sites, transendothelial migration of tumor cells as well as the trafficking and homing of cancer stem cells. This review summarizes the information that has been obtained over the years regarding the role of CXCL12-CXCR4 signaling in breast cancer, discusses its potential application to the development of new therapeutic tools for breast cancer control, and elucidates the potential therapeutic challenges which lie ahead and the future directions that this field can take for the improvement of prognosis in breast cancer patients.
PMCID: PMC3555200  PMID: 23359227
CXCR4; CXCL12; breast cancer
22.  Life after death: targeting high mobility group box 1 in emergent cancer therapies 
High mobility group box 1 (HMGB1), an evolutionarily highly conserved and abundant nuclear protein also has roles within the cytoplasm and as an extracellular damage-associated molecular pattern (DAMP) molecule. Extracellular HMGB1 is the prototypic endogenous ‘danger signal’ that triggers inflammation and immunity. Recent findings suggest that posttranslational modifications dictate the cellular localization and secretion of HMGB1. HMGB1 is actively secreted from immune cells and stressed cancer cells, or passively released from necrotic cells. During cancer development or administration of therapeutic agents including chemotherapy, radiation, epigenetic drugs, oncolytic viruses, or immunotherapy, the released HMGB1 may either promote or limit cancer growth, depending on the state of progression and vascularization of the tumor. Extracellular HMGB1 enhances autophagy and promotes persistence of surviving cancer cells following initial activation. When oxidized, it chronically suppresses the immune system to promote cancer growth and progression, thereby enhancing resistance to cancer therapeutics. In its reduced form, it can facilitate and elicit innate and adaptive anti-tumor immunity, recruiting and activating immune cells, in conjunction with cytotoxic agents, particularly in early transplantable tumor models. We hypothesize that HMGB1 also functions as an epigenetic modifier, mainly through regulation of NF-kB-dependent signaling pathways, to modulate the behavior of surviving cancer cells as well as the immune cells found within the tumor microenvironment. This has significant implications for developing novel cancer therapeutics.
PMCID: PMC3555201  PMID: 23359863
Cancer; HMGB1; NF-kB signaling; activation; innate immunity; dendritic cells; CD8+ T cells; epigenetic pathways
23.  Obesity-driven inflammation and cancer risk: role of myeloid derived suppressor cells and alternately activated macrophages 
During carcinogenesis, tumors induce dysfunctional development of hematopoietic cells. Myeloid lineage cells, in the form of myeloid derived suppressor cells (MDSCs) and alternatively polarized M2 macrophages, influence almost all types of cancers by regulating diverse facets of immunosuppression, angiogenesis, cell proliferation, growth and metastasis. One-third of Americans are obese, and accumulating evidence suggests that obesity is a risk factor for various cancers. However, the relationship between these immune players and obesity are not well-described. In this review, we evaluate potential mechanisms through which different aspects of obesity, namely insulin resistance, increased estrogen, adiposity and low grade chronic inflammation from adipose tissue macrophages, may coalesce to promote MDSC induction and M2 macrophage polarization, thereby facilitating cancer development. Detailed understanding of the interplay between obesity and myeloid mediated immunosuppression may provide novel avenues for therapeutic targeting, with the goal to reduce the challenge obesity presents towards gains made in cancer outcomes.
PMCID: PMC3555202  PMID: 23359288
Obesity; inflammation; myeloid derived suppressor cells; alternately activated macrophage; cancer
24.  Mechanisms of action of CD20 antibodies 
Therapeutic monoclonal antibodies (mAbs) that target the CD20 antigen on B cells are successfully used in the clinic for the depletion of B cells to treat various forms of cancer and autoimmune diseases. The first CD20 mAb, approved by the FDA in 1998, was rituximab (RTX) and since then it has been widely used to treat more than one million patients thus far. The success of RTX has led to a general interest in the mechanism of action of CD20 mAbs. CD20 mAbs can induce tumor killing via various mechanisms, such as direct induction of apoptosis, antibody-dependent cell-mediated cytotoxicity (ADCC) or complement-dependent lysis (CDC). Although we now understand these mechanisms better, it is still unclear which of these mechanisms is the most important for in vivo RTX action. Not every patient respond to RTX treatment and eventually the overwhelming majority will experience a relapse. Therefore, there is an urgent need to improve the efficacy of CD20 mAbs. This review aims to summarize our current understanding on the mechanism of action of CD20 mAbs.
PMCID: PMC3512181  PMID: 23226614
Antibodies; CD20; effector mechanisms; Fc receptors; complement; complement receptors; apoptosis
25.  Regulators of gene expression as biomarkers for prostate cancer 
Recent technological advancements in gene expression analysis have led to the discovery of a promising new group of prostate cancer (PCa) biomarkers that have the potential to influence diagnosis and the prediction of disease severity. The accumulation of deleterious changes in gene expression is a fundamental mechanism of prostate carcinogenesis. Aberrant gene expression can arise from changes in epigenetic regulation or mutation in the genome affecting either key regulatory elements or gene sequences themselves. At the epigenetic level, a myriad of abnormal histone modifications and changes in DNA methylation are found in PCa patients. In addition, many mutations in the genome have been associated with higher PCa risk. Finally, over- or underexpression of key genes involved in cell cycle regulation, apoptosis, cell adhesion and regulation of transcription has been observed. An interesting group of biomarkers are emerging from these studies which may prove more predictive than the standard prostate specific antigen (PSA) serum test. In this review, we discuss recent results in the field of gene expression analysis in PCa including the most promising biomarkers in the areas of epigenetics, genomics and the transcriptome, some of which are currently under investigation as clinical tests for early detection and better prognostic prediction of PCa.
PMCID: PMC3512182  PMID: 23226612
Prostate cancer; biomarker; epigenetics; methylation; acetylation; ncRNA; genomics; SNP; transcriptomics; miRNA; lncRNA

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