Downregulation of E-cadherin expression in breast cancer by promoter hypermethylation and its relation with progression and prognosis of tumor

Decoding the Epigenome of Breast Cancer

Breast cancer (BC) is the most prevalent malignancy among women, characterized by extensive heterogeneity stemming from molecular and genetic alterations. This review explores the intricate epigenetic landscape of BC, highlighting the significant role of epigenetic modifications-particularly DNA methylation, histone modifications, and the influence of non-coding RNAs-in the initiation, progression, and prognosis of the disease. Epigenetic alterations drive crucial processes, including gene expression regulation, cell differentiation, and tumor microenvironment interactions, contributing to tumorigenesis and metastatic potential. Notably, aberrations in DNA methylation patterns, including global hypomethylation and hypermethylation of CpG islands, have been associated with distinct BC subtypes, with implications for early detection and risk assessment. Furthermore, histone modifications, such as acetylation and methylation, affect cancer cell plasticity and aggressiveness by profoundly influencing chromatin dynamics and gene transcription. Finally, non-coding RNAs contribute by modulating epigenetic machinery and gene expression. Despite advances in our knowledge, clinical application of epigenetic therapies in BC is still challenging, often yielding limited efficacy when used alone. However, combining epi-drugs with established treatments shows promise for enhancing therapeutic outcomes. This review underscores the importance of integrating epigenetic insights into personalized BC treatment strategies, emphasizing the potential of epigenetic biomarkers for improving diagnosis, prognosis, and therapeutic response in affected patients.

Metastasis and chemoresistance in breast cancer: Crucial function of ZEB1/2 proteins

Breast cancer remains one of the leading causes of mortality worldwide. While advancements in chemotherapy, immunotherapy, radiotherapy, and targeted therapies have significantly improved breast cancer treatment, many patients are diagnosed at advanced stages, where tumor cells exhibit aggressive behavior and therapy resistance. Understanding the mechanisms driving breast cancer progression is therefore critical. Metastasis is a major factor that drastically reduces patient prognosis and survival, accounting for most breast cancer-related deaths. ZEB proteins have emerged as key regulators of cancer metastasis. Beyond their role in metastasis, ZEB proteins also influence drug resistance. This review focuses on the role of ZEB1 and ZEB2 in regulating breast cancer metastasis. These proteins interact with components of the tumor microenvironment (TME) to drive cancer progression and metastasis. Additionally, ZEB proteins regulate angiogenesis through interactions with VEGF. Targeting ZEB proteins offers potential therapeutic benefits, particularly for aggressive breast cancer subtypes such as triple-negative breast cancer (TNBC), which often show poor therapeutic response. ZEB proteins also influence the sensitivity of breast cancer cells to chemotherapy, making them promising targets for enhancing treatment efficacy. Given their upregulation in breast cancer, ZEB proteins can serve as valuable diagnostic and prognostic markers.

Hypomethylating agents as emerging therapeutics for triple-negative breast cancer

Triple-negative breast cancer (TNBC) is recognized as the most aggressive subtype of breast cancer. Epigenetic silencing, such as DNA methylation mediated by DNA methyltransferases (DNMTs) plays key roles in TNBC tumorigenesis. Hypomethylating agents (HMAs) such as azacitidine, decitabine, and guadecitabine are key inhibitors of DNMTs, and accumulating evidence has shown their immunogenicity properties. In this review, the efficacy and anti-tumor immune responses triggered by HMAs in TNBC are presented and discussed. Essentially, overexpression of DNMTs is associated with poor prognosis and reduced TNBC survival rates, and these effects are negated by HMAs. In particular, HMAs could reverse epigenetic silencing of tumor suppressor genes and enhance immune recognition of TNBC cells. Clinical trials of HMAs in TNBCs are limited but early-stage trials indicate that HMAs are safe and tolerable. More clinical studies are required to establish the effectiveness of HMAs against the disease, as supported by preclinical data substantiating their effectiveness especially guadecitabine. Future research should focus on optimizing dosing and exploring combinations with immunotherapies to maximize the potential of HMAs in TNBC treatment.

E-cadherin staining in the diagnosis of lobular versus ductal neoplasms of the breast: the emperor has no clothes

Categorizing breast neoplasia as ductal or lobular is a daily exercise that relies on a combination of histologic and immunohistochemical tools. The historically robust link between loss of the E-cadherin molecule and lobular neoplasia has rendered staining for E-cadherin by immunohistochemistry a staple of this diagnostic process. Unfortunately, discordances between E-cadherin expression and histomorphology, and variations in E-cadherin staining patterns and intensities abound in clinical practice, but are often neglected in favour of a binary interpretation of the E-cadherin result. In this article, we highlight the complexities of E-cadherin expression through a review of the E-cadherin protein and its associated gene (CDH1), the mechanisms leading to aberrant/absent E-cadherin expression, and the implications of these factors on the reliability of the E-cadherin immunohistochemical stain in the classification of ductal versus lobular mammary neoplasia.

An update on existing therapeutic options and status of novel anti-metastatic agents in breast cancer: Elucidating the molecular mechanisms underlying the pleiotropic action of Withania somnifera (Indian ginseng) in breast cancer attenuation

Major significant advancements in pharmacology and drug technology have been made to heighten the impact of cancer therapies, improving the life expectancy of subjects diagnosed with malignancy. Statistically, 99% of breast cancers occur in women while 0.5-1% occur in men, the female gender being the strongest breast cancer risk factor. Despite several breakthroughs, breast cancer continues to have a worldwide impact and is one of the leading causes of mortality. Additionally, resistance to therapy is a crucial factor enabling cancer cell persistence and resurgence. As a result, the search and discovery of novel modulatory agents and effective therapies capable of controlling tumor progression and cancer cell proliferation is critical. Withania somnifera (L.) Dunal (WS), commonly known as Indian ginseng, has long been used traditionally for the treatment of several ailments in the Indian context. Recently, WS and its phytoconstituents have shown promising anti-breast cancer properties and, as such, can be employed as prophylactic as well as therapeutic adjuncts to the main line of breast cancer treatment. The present review is an attempt to explore and provide experimental evidences in support of the prophylactic and therapeutic potential of WS in breast cancer, along with a deeper insight into the multiple molecular mechanisms and novel targets through which it acts against breast and other hormonally-induced cancers viz. ovarian, uterine and cervical. This exploration might prove crucial in providing better understanding of breast cancer progression and metastasis and its use as an adjunct in improving disease prognosis and therapeutic outcome.

Epigenetic regulation of breast cancer metastasis

Breast cancer is the most frequently diagnosed malignancy and the second leading cause of cancer-related mortality among women worldwide. Recurrent metastasis is associated with poor patient outcomes and poses a significant challenge in breast cancer therapies. Cancer cells adapting to a new tissue microenvironment is the key event in distant metastasis development, where the disseminating tumor cells are likely to acquire genetic and epigenetic alterations during the process of metastatic colonization. Despite several decades of research in this field, the exact mechanisms governing metastasis are not fully understood. However, emerging body of evidence indicates that in addition to genetic changes, epigenetic reprogramming of cancer cells and the metastatic niche are paramount toward successful metastasis. Here, we review and discuss the latest knowledge about the salient attributes of metastasis and epigenetic regulation in breast cancer and crucial research domains that need further investigation.

Epigenetic modulations in triple-negative breast cancer: Therapeutic implications for tumor microenvironment

Triple-negative breast cancer (TNBC) is an aggressive subtype lacking estrogen receptors, progesterone receptors and lacks HER2 overexpression. This absence of critical molecular targets poses significant challenges for conventional therapies. Immunotherapy, remarkably immune checkpoint blockade, offers promise for TNBC treatment, but its efficacy remains limited. Epigenetic dysregulation, including altered DNA methylation, histone modifications, and imbalances in regulators such as BET proteins, plays a crucial role in TNBC development and resistance to treatment. Hypermethylation of tumor suppressor gene promoters and the imbalance of histone methyltransferases such as EZH2 and histone deacetylases (HDACs) profoundly influence tumor cell proliferation, survival, and metastasis. In addition, epigenetic alterations critically shape the tumor microenvironment (TME), including immune cell composition, cytokine signaling, and immune checkpoint expression, ultimately contributing to immune evasion. Targeting these epigenetic mechanisms with specific inhibitors such as EZH2 and HDAC inhibitors in combination with immunotherapy represents a compelling strategy to remodel the TME, potentially overcoming immune evasion and enhancing therapeutic outcomes in TNBC. This review aims to comprehensively elucidate the current understanding of epigenetic modulation in TNBC, its influence on the TME, and the potential of combining epigenetic therapies with immunotherapy to overcome the challenges posed by this aggressive breast cancer subtype.

MicroRNA-561-3p indirectly regulates the PD-L1 expression by targeting ZEB1, HIF1A, and MYC genes in breast cancer

Globally, breast cancer is the second most common cause of cancer-related deaths among women. In breast cancer, microRNAs (miRNAs) are essential for both the initiation and development of tumors. It has been suggested that the tumor suppressor microRNA-561-3p (miR-561-3p) is crucial in arresting the growth of cancer cells. Further research is necessary to fully understand the role and molecular mechanism of miR-561 in human BC. The aim of this study was to investigate the inhibitory effect of miR-561-3p on ZEB1, HIF1A, and MYC expression as oncogenes that have the most impact on PD-L1 overexpression and cellular processes such as proliferation, apoptosis, and cell cycle in breast cancer (BC) cell lines. The expression of ZEB1, HIF1A, and MYC genes and miR-561-3p were measured in BC clinical samples and cell lines via qRT-PCR. The luciferase assay, MTT, Annexin-PI staining, and cell cycle experiments were used to assess the effect of miR-561-3p on candidate gene expression, proliferation, apoptosis, and cell cycle progression. Flow cytometry was used to investigate the effects of miR-561 on PD-L1 suppression in the BC cell line. The luciferase assay showed that miRNA-561-3p targets the 3'-UTRs of ZEB1, HIF1A and MYC genes significantly. In BC tissues, the qRT-PCR results demonstrated that miR-561-3p expression was downregulated and the expression of ZEB1, HIF1A and MYC genes was up-regulated. It was shown that overexpression of miR-561-3p decreased PD-L1 expression and BC cell proliferation, and induced apoptosis and cell cycle arrest through downregulation of candidate oncogenes. Furthermore, inhibition of candidate genes by miR-561-3p reduced PD-L1 at both mRNA and protein levels. Our research investigated the impact of miR-561-3p on the expression of ZEB1, HIF1A and MYC in breast cancer cells for the first time. Our findings may help clarify the role of miR-561-3p in PD-L1 regulation and point to this miR as a potential biomarker and novel therapeutic target for cancer immunotherapy.

A journey from omics to clinicomics in solid cancers: Success stories and challenges

The word 'cancer' encompasses a heterogenous group of distinct disease types characterized by a spectrum of pathological features, genetic alterations and response to therapies. According to the World Health Organization, cancer is the second leading cause of death worldwide, responsible for one in six deaths and hence imposes a significant burden on global healthcare systems. High-throughput omics technologies combined with advanced imaging tools, have revolutionized our ability to interrogate the molecular landscape of tumors and has provided unprecedented understanding of the disease. Yet, there is a gap between basic research discoveries and their translation into clinically meaningful therapies for improving patient care. To bridge this gap, there is a need to analyse the vast amounts of high dimensional datasets from multi-omics platforms. The integration of multi-omics data with clinical information like patient history, histological examination and imaging has led to the novel concept of clinicomics and may expedite the bench-to-bedside transition in cancer. The journey from omics to clinicomics has gained momentum with development of radiomics which involves extracting quantitative features from medical imaging data with the help of deep learning and artificial intelligence (AI) tools. These features capture detailed information about the tumor's shape, texture, intensity, and spatial distribution. Together, the related fields of multiomics, translational bioinformatics, radiomics and clinicomics may provide evidence-based recommendations tailored to the individual cancer patient's molecular profile and clinical characteristics. In this chapter, we summarize multiomics studies in solid cancers with a specific focus on breast cancer. We also review machine learning and AI based algorithms and their use in cancer diagnosis, subtyping, prognosis and predicting treatment resistance and relapse.

Tumor Microenvironment and Epigenetic Implications in Breast Cancer Progression

Breast cancer (BC) poses significant challenges, driven by its diverse nature and intricate dynamics. Epigenetic modifications, such as DNA methylation, histone modifications, and noncoding RNAs, have emerged as key regulators of gene expression and BC metastasis plasticity or therapeutic resistance. Targeting epigenetic regulators and pathways associated with therapeutic resistance holds promise for overcoming treatment obstacles and enhancing treatment efficacy.

The Epigenesis of Salivary Glands Carcinoma: From Field Cancerization to Carcinogenesis

Salivary gland carcinomas (SGCs) are a diverse collection of malignant tumors with marked differences in biological activity, clinical presentation and microscopic appearance. Although the etiology is varied, secondary radiation, oncogenic viruses as well as chromosomal rearrangements have all been linked to the formation of SGCs. Epigenetic modifications may also contribute to the genesis and progression of SGCs. Epigenetic modifications are any heritable changes in gene expression that are not caused by changes in DNA sequence. It is now widely accepted that epigenetics plays an important role in SGCs development. A basic epigenetic process that has been linked to a variety of pathological as well as physiological conditions including cancer formation, is DNA methylation. Transcriptional repression is caused by CpG islands hypermethylation at gene promoters, whereas hypomethylation causes overexpression of a gene. Epigenetic changes in SGCs have been identified, and they have been linked to the genesis, progression as well as prognosis of these neoplasms. Thus, we conduct a thorough evaluation of the currently known evidence on the involvement of epigenetic processes in SGCs.

Epigenetics and environment in breast cancer: New paradigms for anti-cancer therapies

Breast cancer remains the most frequently diagnosed cancer in women worldwide. Delayed presentation of the disease, late stage at diagnosis, limited therapeutic options, metastasis, and relapse are the major factors contributing to breast cancer mortality. The development and progression of breast cancer is a complex and multi-step process that incorporates an accumulation of several genetic and epigenetic alterations. External environmental factors and internal cellular microenvironmental cues influence the occurrence of these alterations that drives tumorigenesis. Here, we discuss state-of-the-art information on the epigenetics of breast cancer and how environmental risk factors orchestrate major epigenetic events, emphasizing the necessity for a multidisciplinary approach toward a better understanding of the gene-environment interactions implicated in breast cancer. Since epigenetic modifications are reversible and are susceptible to extrinsic and intrinsic stimuli, they offer potential avenues that can be targeted for designing robust breast cancer therapies.

Pleomorphic Adenoma of the Salivary Glands and Epithelial–Mesenchymal Transition

Pleomorphic adenoma (PA) is a localized tumor that presents pleomorphic or mixed characteristics of epithelial origin and is interwoven with mucoid tissue, myxoid tissue, and chondroid masses. The literature reported that PA most often occurs in adults aged 30–60 years and is a female predilection; the exact etiology remains unclear. Epithelial–mesenchymal transition (EMT) is the transdifferentiation of stationary epithelial cells primarily activated by a core set of transcription factors (EMT-TFs) involved in DNA repair and offers advantages under various stress conditions. Data have suggested that EMTs represent the basic principle of tissue heterogeneity in PAs, demonstrating the potential of adult epithelial cells to transdifferentiate into mesenchymal cells. It has also been reported that multiple TFs, such as TWIST and SLUG, are involved in EMT in PA and that SLUG could play an essential role in the transition from myoepithelial to mesenchymal cells. Given this background, this review aims to summarize and clarify the involvement of EMT in the development of PA, chondrocyte differentiation, and malignant transformation to contribute to the fundamental elucidation of the mechanisms underlying EMT.

Identification of Potential Core Genes Between Primary and Metastatic Malignant Melanoma and Analysis of Their Immune Correlation

Purpose

To identify the potential differential genes between primary and metastatic melanoma, screen out immune-related genes in core genes and analyze their immune correlation, thus searching for the early diagnostic biomarkers of cutaneous malignant melanoma (CMM) and the targets of curbing metastasis.

Materials and Methods

We analyzed two microarray datasets (GSE8401 and GSE46517) derived from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between primary and metastatic melanoma were screened out using the GEO2R tool. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed to identify the functions and pathways of DEGs. We analyzed protein–protein interaction of these DEGs based on the Search Tool for the Retrieval of Interacting Genes database and showed by Cytoscape software. In addition, the online Gene Expression Profiling Interactive Analysis tool (GEPIA) was used to analyze the prognostic value of hub genes expressed in metastatic melanoma patients. Immune-related genes in hub genes were screened and further analyzed.

Results

A total of 178 upregulated DEGs and 4 downregulated DEGs were identified. 23 terms and 4 pathways were confirmed related to metastatic melanoma. Ten hub genes with a high degree of connectivity were found. Overexpression of three hub genes (DSG1, FLG, PKP1) (P<0.01) was associated with metastasis and poor prognosis of CMM. Among them, the patients with overexpression of PKP1 suffered shorter survival. In addition, 2 immune-related genes (EGFR and CDH1) in hub genes were screened out and both of them were related to anti-tumor immunity, although their expression level did not affect the overall survival of CMM patients significantly.

Conclusion

Our study suggests that DSG1, FLG and PKP1 were overexpressed in metastatic melanoma compared with primary melanoma, and overexpression of these three genes was an unfavorable prognostic factor ifor CMM patients, which may indicate that they are associated with promoting metastasis of malignant melanoma. EGFR and CDH1 play a crucial role in anti-tumor immunity for CMM. Further research is needed to explore the value of these genes in the inhibition of metastasis and treatment of CMM.

DNA methylation and breast cancer: A way forward (Review)

The current management of breast cancer (BC) lacks specific non‑invasive biomarkers able to provide an early diagnosis of the disease. Epigenetic‑sensitive signatures are influenced by environmental exposures and are mediated by direct molecular mechanisms, mainly guided by DNA methylation, which regulate the interplay between genetic and non‑genetic risk factors during cancerogenesis. The inactivation of tumor suppressor genes due to promoter hypermethylation is an early event in carcinogenesis. Of note, targeted tumor suppressor genes are frequently hypermethylated in patient‑derived BC tissues and peripheral blood biospecimens. In addition, epigenetic alterations in triple‑negative BC, as the most aggressive subtype, have been identified. Thus, detecting both targeted and genome‑wide DNA methylation changes through liquid‑based assays appears to be a useful clinical strategy for early detection, more accurate risk stratification and a personalized prediction of therapeutic response in patients with BC. Of note, the DNA methylation profile may be mapped by isolating the circulating tumor DNA from the plasma as a more accessible biospecimen. Furthermore, the sensitivity to treatment with chemotherapy, hormones and immunotherapy may be altered by gene‑specific DNA methylation, suggesting novel potential drug targets. Recently, the use of epigenetic drugs administered alone and/or with anticancer therapies has led to remarkable results, particularly in patients with BC resistant to anticancer treatment. The aim of the present review was to provide an update on DNA methylation changes that are potentially involved in BC development and their putative clinical utility in the fields of diagnosis, prognosis and therapy.

Seeding metastases: The role and clinical utility of circulating tumour cells

Peripheral human blood is a readily-accessible source of patient material in which circulating tumour cells (CTCs) can be found. Their isolation and characterization holds the potential to provide prognostic value for various solid cancers. Enumeration of CTCs from blood is becoming a common practice in informing prognosis and may guide therapy decisions. It is further recognized that enumeration alone does not capture perspective on the heterogeneity of tumours and varying functional abilities of the CTCs to interact with the secondary microenvironment. Characterizing the isolated CTCs further, in particular assessing their functional abilities, can track molecular changes in the disease progress. As a step towards identifying a suite of functional features of CTCs that could aid in clinical decisions, developing a CTC isolation technique based on extracellular matrix (ECM) interactions may provide a more solid foundation for isolating the cells of interest. Techniques based on size, charge, density, and single biomarkers are not sufficient as they underutilize other characteristics of cancer cells. The ability of cancer cells to interact with ECM proteins presents an opportunity to utilize their full character in capturing, and also allows assessment of the features that reveal how cells might behave at secondary sites during metastasis. This article will review some common techniques and recent advances in CTC capture technologies. It will further explore the heterogeneity of the CTC population, challenges they experience in their metastatic journey, and the advantages of utilizing an ECM-based platform for CTC capture. Lastly, we will discuss how tailored ECM approaches may present an optimal platform to capture an influential heterogeneous population of CTCs.

Gene-associated methylation status of ST14 as a predictor of survival and hormone receptor positivity in breast Cancer

Background

Genomic profiles of specific gene sets have been established to guide personalized treatment and prognosis for patients with breast cancer (BC). However, epigenomic information has not yet been applied in a clinical setting. ST14 encodes matriptase, a proteinase that is widely expressed in BC with reported prognostic value.

Methods

In this present study, we evaluated the effect of ST14 DNA methylation (DNAm) on overall survival (OS) of patients with BC as a representative example to promote the use of the epigenome in clinical decisions. We analyzed publicly available genomic and epigenomic data from 1361 BC patients. Methylation was characterized by the β-value from CpG probes based on sequencing with the Illumina Human 450 K platform.

Results

A high mean DNAm (β > 0.6779) across 34 CpG probes for ST14, as the gene-associated methylation (GAM) pattern, was associated with a longer OS after adjusting age, stage, histology and molecular features in Cox model (p value < 0.001). A high GAM status was also associated with a higher XBP1 expression level and higher proportion of hormone-positive BC (p value < 0.001). Pathway analysis revealed that altered GAM was related to matrisome-associated pathway.

Conclusions

Here we show the potential role of ST14 DNAm in BC prognosis and warrant further study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08645-3.

Obscurin: A multitasking giant in the fight against cancer

Giant obscurins (720-870 kDa), encoded by OBSCN, were originally discovered in striated muscles as cytoskeletal proteins with scaffolding and regulatory roles. Recently though, they have risen to the spotlight as key players in cancer development and progression. Herein, we provide a timely prudent synopsis of the expanse of OBSCN mutations across 16 cancer types. Given the extensive work on OBSCN's role in breast epithelium, we summarize functional studies implicating obscurins as potent tumor suppressors in breast cancer and delve into an in silico analysis of its mutational profile and epigenetic (de)regulation using different dataset platforms and sophisticated computational tools. Lastly, we formally describe the OBSCN-Antisense-RNA-1 gene, which belongs to the long non-coding RNA family and discuss its potential role in modulating OBSCN expression in breast cancer. Collectively, we highlight the escalating involvement of obscurins in cancer biology and outline novel potential mechanisms of OBSCN (de)regulation that warrant further investigation.

Emerging Role and Clinicopathological Significance of AEG-1 in Different Cancer Types: A Concise Review

Tumor breakthrough is driven by genetic or epigenetic variations which assist in initiation, migration, invasion and metastasis of tumors. Astrocyte elevated gene-1 (AEG-1) protein has risen recently as the crucial factor in malignancies and plays a potential role in diverse complex oncogenic signaling cascades. AEG-1 has multiple roles in tumor growth and development and is found to be involved in various signaling pathways of: (i) Ha-ras and PI3K/AKT; (ii) the NF-κB; (iii) the ERK or mitogen-activated protein kinase and Wnt or β-catenin and (iv) the Aurora-A kinase. Recent studies have confirmed that in all the hallmarks of cancers, AEG-1 plays a key functionality including progression, transformation, sustained angiogenesis, evading apoptosis, and invasion and metastasis. Clinical studies have supported that AEG-1 is actively intricated in tumor growth and progression which includes esophageal squamous cell, gastric, colorectal, hepatocellular, gallbladder, breast, prostate and non-small cell lung cancers, as well as renal cell carcinomas, melanoma, glioma, neuroblastoma and osteosarcoma. Existing studies have reported that AEG-1 expression has been induced by Ha-ras through intrication of PI3K/AKT signaling. Conversely, AEG-1 also activates PI3K/AKT pathway and modulates the defined subset of downstream target proteins via crosstalk between the PI3K/AKT/mTOR and Hedgehog signaling cascade which further plays a crucial role in metastasis. Thus, AEG-1 may be employed as a biomarker to discern the patients of those who are likely to get aid from AEG-1-targeted medication. AEG-1 may play as an effective target to repress tumor development, occlude metastasis, and magnify the effectiveness of treatments. In this review, we focus on the molecular mechanism of AEG-1 in the process of carcinogenesis and its involvement in regulation of crosstalk between the PI3K/AKT/mTOR and Hedgehog signaling. We also highlight the multifaceted functions, expression, clinicopathological significance and molecular inhibitors of AEG-1 in various cancer types.

Methylation as a critical epigenetic process during tumor progressions among Iranian population: an overview

Cancer is one of the main health challenges and leading causes of deaths in the world. Various environmental and genetic risk factors are associated with tumorigenesis. Epigenetic deregulations are also important risk factors during tumor progression which are reversible transcriptional alterations without any genomic changes. Various mechanisms are involved in epigenetic regulations such as DNA methylation, chromatin modifications, and noncoding RNAs. Cancer incidence and mortality have a growing trend during last decades among Iranian population which are significantly related to the late diagnosis. Therefore, it is required to prepare efficient molecular diagnostic panels for the early detection of cancer in this population. Promoter hyper methylation is frequently observed as an inhibitory molecular mechanism in various genes associated with DNA repair, cell cycle regulation, and apoptosis during tumor progression. Since aberrant promoter methylations have critical roles in early stages of neoplastic transformations, in present review we have summarized all of the aberrant methylations which have been reported during tumor progression among Iranian cancer patients. Aberrant promoter methylations are targetable and prepare novel therapeutic options for the personalized medicine in cancer patients. This review paves the way to introduce a non-invasive methylation specific panel of diagnostic markers for the early detection of cancer among Iranians.

Long non-coding (lnc)RNA profiling and the role of a key regulator lnc-PNRC2-1 in the transforming growth factor-1-induced epithelial-mesenchymal transition of CNE1 nasopharyngeal carcinoma cells

Objectives

To identify key long non-coding (lnc)RNAs responsible for the epithelial–mesenchymal transition (EMT) of CNE1 nasopharyngeal carcinoma cells and to investigate possible regulatory mechanisms in EMT.

Methods

CNE1 cells were divided into transforming growth factor (TGF)-β1-induced EMT and control groups. The mRNA and protein expression of EMT markers was determined by real-time quantitative PCR and western blotting. Differentially expressed genes (DEGs) between the two groups were identified by RNA sequencing analysis, and DEG functions were analyzed by gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses. EMT marker expression was re-evaluated by western blotting after knockdown of a selected lncRNA.

Results

TGF-β1-induced EMT was characterized by decreased E-cadherin and increased vimentin, N-cadherin, and Twist expression at both mRNA and protein levels. Sixty lncRNA genes were clustered in a heatmap, and mRNA expression of 14 dysregulated lncRNAs was consistent with RNA sequencing. Knockdown of lnc-PNRC2-1 increased expression of its antisense gene MYOM3 and reduced expression of EMT markers, resembling treatment with the TGF-β1 receptor inhibitor LY2109761.

Conclusion

Various lncRNAs participated indirectly in the TGF-β1-induced EMT of CNE1 cells. Lnc-PNRC2-1 may be a key regulator of this and is a potential target to alleviate CNE1 cell EMT.

Effect of Epigenetic Drug Candidate Olsalazine on the Expression of CDH1 and uPA Genes in MCF-7 Breast Cancer Cell Line

Background: A main epigenetic change in cancer is DNA methylation, which leads to the inactivation of tumor suppressor genes. Due to its reversible nature, many studies have focused on how to correct epigenetic imbalances via inhibiting DNA methyltransferases (DNMTs). Recent studies have shown that olsalazine can be a potent candidate for DNMT inhibition. Objectives: The current study aimed to assess the cytotoxic effect of olsalazine on MCF-7 cells and the expression of CDH1 and uPA, as cancer-related genes, compared to decitabine. Methods: The cytotoxicity of olsalazine and decitabine on MCF-7 cells was assessed by MTT assay. To evaluate the effect of drugs on the expression of CDH1 and uPA genes, MCF-7 cells were treated with olsalazine and decitabine in concentrations below their IC50 values. After 24 h, RNA of treated cells was extracted and then subjected to a quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR). Results: The MTT assay showed that olsalazine was more toxic (IC50 = 1.75 mM) in MCF-7 cells than decitabine (IC50 = 3mM). Q-RT-PCR analysis showed that olsalazine can significantly increase uPA expression along with a non-significant increase in CDH1 expression. Meanwhile, no significant change was found in gene expression after treatment with decitabine. Conclusions: This study demonstrated that olsalazine was more cytotoxic than decitabine on MCF-7 cells. Also, compared to decitabine, olsalazine could increase the expression of CDH1 and uPA genes. It suggests that olsalazine might be more potent than decitabine in inhibiting DNMTs, although further studies are needed.

MicroRNAs and Their Influence on the ZEB Family: Mechanistic Aspects and Therapeutic Applications in Cancer Therapy

Molecular signaling pathways involved in cancer have been intensively studied due to their crucial role in cancer cell growth and dissemination. Among them, zinc finger E-box binding homeobox-1 (ZEB1) and -2 (ZEB2) are molecules that play vital roles in signaling pathways to ensure the survival of tumor cells, particularly through enhancing cell proliferation, promoting cell migration and invasion, and triggering drug resistance. Importantly, ZEB proteins are regulated by microRNAs (miRs). In this review, we demonstrate the impact that miRs have on cancer therapy, through their targeting of ZEB proteins. MiRs are able to act as onco-suppressor factors and inhibit the malignancy of tumor cells through ZEB1/2 down-regulation. This can lead to an inhibition of epithelial-mesenchymal transition (EMT) mechanism, therefore reducing metastasis. Additionally, miRs are able to inhibit ZEB1/2-mediated drug resistance and immunosuppression. Additionally, we explore the upstream modulators of miRs such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), as these regulators can influence the inhibitory effect of miRs on ZEB proteins and cancer progression.

E-cadherin immunohistochemical expression in invasive lobular carcinoma of the breast: correlation with morphology and CDH1 somatic alterations

E-cadherin (ECAD) immunohistochemical (IHC) expression is lost in ∼90% of invasive lobular carcinomas (ILCs) owing to genomic alterations of CDH1. We examined morphologic features and ECAD IHC expression in invasive breast carcinomas (BCs) with known CDH1 alterations. Between January 2014 and May 2018, 202 cases of BC with a CDH1 somatic alteration were identified. ECAD expression was lost in 77% (155/202) of cases and was retained in 23% (47/202) cases. Most (90%, 139/155) ECAD-negative cases were morphologically classified as ILC, while the remaining (10%, 16/155) were invasive mammary carcinoma with mixed ductal and lobular features (IMC). Of 47 cases with ECAD staining, 62% (29/47) were classified as ILC, 23% (11/47) were classified as IMC, and 15% (7/47) were classified as invasive ductal carcinoma (IDC). Of note, 51% (24/47) of ECAD-positive cases were initially diagnosed as IDC or IMC based on ECAD expression alone. For ECAD-negative BCs, 98% (152/155) of CDH1 alterations were truncating, and 2% (3/155) were variants of unknown significance (VUS). Truncating CDH1 alterations were identified in the majority of ECAD-positive BCs (72%, 34/47); however, VUS-type CDH1 alterations were more prevalent (28%, 13/47) in ECAD-positive BCs than in ECAD-negative BCs. Although 90% of ECAD-negative tumors were compatible with ILC in this study, 17% (29/168) of ILC cases were ECAD positive. In addition, CDH1 truncating alterations were seen in ECAD-positive ILC, supporting the notion of aberrant ECAD staining. Therefore, ECAD IHC expression must be interpreted in conjunction with morphology, and BC with classic histologic features of ILC should not be reclassified as IDC/IMC based solely on the status of ECAD IHC expression.

Understanding the Mechanisms by Which Epigenetic Modifiers Avert Therapy Resistance in Cancer

The development of resistance to anti-cancer therapeutics remains one of the core issues preventing the improvement of survival rates in cancer. Therapy resistance can arise in a multitude of ways, including the accumulation of epigenetic alterations in cancer cells. By remodeling DNA methylation patterns or modifying histone proteins during oncogenesis, cancer cells reorient their epigenomic landscapes in order to aggressively resist anti-cancer therapy. To combat these chemoresistant effects, epigenetic modifiers such as DNA hypomethylating agents, histone deacetylase inhibitors, histone demethylase inhibitors, along with others have been used. While these modifiers have achieved moderate success when used either alone or in combination with one another, the most positive outcomes were achieved when they were used in conjunction with conventional anti-cancer therapies. Epigenome modifying drugs have succeeded in sensitizing cancer cells to anti-cancer therapy via a variety of mechanisms: disrupting pro-survival/anti-apoptotic signaling, restoring cell cycle control and preventing DNA damage repair, suppressing immune system evasion, regulating altered metabolism, disengaging pro-survival microenvironmental interactions and increasing protein expression for targeted therapies. In this review, we explore different mechanisms by which epigenetic modifiers induce sensitivity to anti-cancer therapies and encourage the further identification of the specific genes involved with sensitization to facilitate development of clinical trials.

E-cadherin deregulation in breast cancer

E‐cadherin protein (CDH1 gene) integrity is fundamental to the process of epithelial polarization and differentiation. Deregulation of the E‐cadherin function plays a crucial role in breast cancer metastases, with worse prognosis and shorter overall survival. In this narrative review, we describe the inactivating mechanisms underlying CDH1 gene activity and its possible translation to clinical practice as a prognostic biomarker and as a potential targeted therapy.

Decitabine Response in Breast Cancer Requires Efficient Drug Processing and Is Not Limited by Multidrug Resistance

Dysregulation of DNA methylation is an established feature of breast cancers. DNA demethylating therapies like decitabine are proposed for the treatment of triple-negative breast cancers (TNBC) and indicators of response need to be identified. For this purpose, we characterized the effects of decitabine in a panel of 10 breast cancer cell lines and observed a range of sensitivity to decitabine that was not subtype specific. Knockdown of potential key effectors demonstrated the requirement of deoxycytidine kinase (DCK) for decitabine response in breast cancer cells. In treatment-naïve breast tumors, DCK was higher in TNBCs, and DCK levels were sustained or increased post chemotherapy treatment. This suggests that limited DCK levels will not be a barrier to response in patients with TNBC treated with decitabine as a second-line treatment or in a clinical trial. Methylome analysis revealed that genome-wide, region-specific, tumor suppressor gene-specific methylation, and decitabine-induced demethylation did not predict response to decitabine. Gene set enrichment analysis of transcriptome data demonstrated that decitabine induced genes within apoptosis, cell cycle, stress, and immune pathways. Induced genes included those characterized by the viral mimicry response; however, knockdown of key effectors of the pathway did not affect decitabine sensitivity suggesting that breast cancer growth suppression by decitabine is independent of viral mimicry. Finally, taxol-resistant breast cancer cells expressing high levels of multidrug resistance transporter ABCB1 remained sensitive to decitabine, suggesting that the drug could be used as second-line treatment for chemoresistant patients.

Osteoglycin (OGN) Inhibits Cell Proliferation and Invasiveness in Breast Cancer via PI3K/Akt/mTOR Signaling Pathway

Introduction

Previous studies have indicated that the small leucine-rich proteoglycan (SLR) osteoglycin (OGN) is downregulated in various cancers, including squamous cervical carcinoma, gastric cancer, and colorectal adenoma, indicating that OGN is a putative tumor suppressor. However, its exact role in the pathology of human cancers, especially breast cancer (BC), is not clear.

Methods

The expression of OGN in BC tissues was examined using qRT-PCR. Online databases were employed to analyze the correlation between OGN expression and clinicopathological characteristics. CCK-8 assay, colony formation assay, transwell migration and invasion assays were applied to detect cell proliferation, colony formation, migration and invasion of BC cells, respectively. Xenograft tumor models were constructed to explore the role of OGN on tumor growth in vivo.

Results

OGN expression was reduced in 24 paired BC samples compared with normal tissue. Decreased expression of OGN was correlated with greater pathological grade, a more aggressive tumor subtype, and poor overall survival. In vitro experiments showed that OGN overexpressed by plasmid transfection significantly inhibited cell proliferation, colony formation, migration, and invasion of BC cell lines. In xenograft tumor models, overexpression of OGN repressed the growth of MCF-7 cells in vivo and alleviated the compression of the tumor on surrounding structures. We also observed that OGN expression reversed EMT via repressing the PI3K/Akt/mTOR pathway.

Conclusion

This study revealed that OGN could function as a tumor suppressor during breast carcinogenesis, and we contribute new evidence to the body of research on the SLRP family.

Functional roles of fucosylated and O-glycosylated cadherins during carcinogenesis and metastasis

Reduced cellular adhesiveness as a result of cadherin dysfunction is a defining feature of cancer and the mechanism involved in many aspects. Glycosylation is one of the most important post-translational modifications to cadherin. Major changes of glycosylation on cadherins can affect its stability, trafficking, and cell-adhesion properties. It has been reported that the different glycoforms of cadherins are promising biomarkers in cancer, with potential clinical application to constitute targets for the development of new therapies. Among the various glycoforms of cadherins, fucosylated and O-glycosylated cadherins are attracting more attention for their important roles in regulating cadherin functions during carcinogenesis. This review will discuss the most recent insights of the functional roles of fucosylated and O-glycosylated cadherins and their regulation mechanisms during carcinogenesis and metastasis. In summary, more understanding of fucosylated and O-glycosylated cadherins will lead to development of novel therapeutic approaches targeted to cancer.

Roadmap of DNA methylation in breast cancer identifies novel prognostic biomarkers

BACKGROUND

Breast cancer is a highly heterogeneous disease resulting in diverse clinical behaviours and therapeutic responses. DNA methylation is a major epigenetic alteration that is commonly perturbed in cancers. The aim of this study is to characterize the relationship between DNA methylation and aberrant gene expression in breast cancer.

METHODS

We analysed DNA methylation and gene expression profiles from breast cancer tissue and matched normal tissue in The Cancer Genome Atlas (TCGA). Genome-wide differential methylation analysis and methylation-gene expression correlation was performed. Gene expression changes were subsequently validated in the METABRIC dataset. The Oncoscore tool was used to identify genes that had previously been associated with cancer in the literature. A subset of genes that had not previously been studied in cancer was chosen for further analysis.

RESULTS

We identified 368 CpGs that were differentially methylated between tumor and normal breast tissue (∆β > 0.4). Hypermethylated CpGs were overrepresented in tumor tissue and were found predominantly (56%) in upstream promoter regions. Conversely, hypomethylated CpG sites were found primarily in the gene body (66%). Expression analysis revealed that 209 of the differentially-methylated CpGs were located in 169 genes that were differently expressed between normal and breast tumor tissue. Methylation-expression correlations were predominantly negative (70%) for promoter CpG sites and positive (74%) for gene body CpG sites. Among these differentially-methylated and differentially-expressed genes, we identified 7 that had not previously been studied in any form of cancer. Three of these, TDRD10, PRAC2 and TMEM132C, contained CpG sites that showed diagnostic and prognostic value in breast cancer, particularly in estrogen-receptor (ER)-positive samples. A pan-cancer analysis confirmed differential expression of these genes together with diagnostic and prognostic value of their respective CpG sites in multiple cancer types.

CONCLUSION

We have identified 368 DNA methylation changes that characterize breast cancer tumor tissue, of which 209 are associated with genes that are differentially-expressed in the same samples. Novel DNA methylation markers were identified, of which cg12374721 (PRAC2), cg18081940 (TDRD10) and cg04475027 (TMEM132C) show promise as diagnostic and prognostic markers in breast cancer as well as other cancer types.

The roles of ZEB1 in tumorigenic progression and epigenetic modifications

Highly expressed Zinc-finger E-box binding protein 1 (ZEB1) is significantly associated with the malignancy of various cancers. Signal transduction and activation of ZEB1 play important roles in cancer transformation and epithelial-mesenchymal transition (EMT). Emerging evidence suggests that ZEB1 drives the induction of EMT with activation of stem cell traits, immune evasion and epigenetic reprogramming. As an ideal target for EMT research, ZEB1 has been extensively studied for decades. However, the link between ZEB1 and epigenetic regulation of EMT has only recently been discovered. ZEB1 facilitates the epigenetic silencing of E-cadherin by recruiting multiple chromatin enzymes of E-cadherin promoter, such as histone deacetylases (HDACs), DNA methyltransferase (DNMT) and ubiquitin ligase. Destruction of the connection between ZEB1 and these chromatin-modifying enzymes may represent an efficient for treating cancer. In this review, we outlined the biological function of ZEB1 in tumorigenic progression and epigenetic modifications and elucidate its transcriptional network, which is a suitable potential target for the design of novel anticancer drugs.

Epigenetic silencing of RNF144A expression in breast cancer cells through promoter hypermethylation and MBD4

Emerging evidence shows that ring finger protein 144A (RNF144A), a poorly characterized member of the Ring-between-Ring (RBR) family of E3 ubiquitin ligases, is a potential tumor suppressor gene. However, its regulatory mechanism in breast cancer remains undefined. Here, we report that RNF144A promoter contains a putative CpG island and the methylation levels of RNF144A promoter are higher in primary breast tumors than those in normal breast tissues. Consistently, RNF144A promoter methylation levels are associated with its transcriptional silencing in breast cancer cells, and treatment with DNA methylation inhibitor 5-Aza-2-deoxycytidine (AZA) reactivates RNF144A expression in cells with RNF144A promoter hypermethylation. Furthermore, genetic knockdown or pharmacological inhibition of endogenous methyl-CpG-binding domain 4 (MBD4) results in increased RNF144A expression. These findings suggest that RNF144A is epigenetically silenced in breast cancer cells by promoter hypermethylation and MBD4.

Influence of the Twist gene on the invasion and metastasis of colon cancer

The present study investigated the role of the Twist gene in epithelial-mesenchymal transition (EMT) and its effects on the invasion and metastasis of malignant tumors. In vitro, we transfected SW480, HCT116 and HT29 cells with recombinant plasmids, pTracer-CMV/BSD-Twist and pGenesil1.2-Twist-shRNA, to influence expression of Twist. The transfection efficacy of the plasmids in the cell lines was confirmed by flow cytometry. The relative mRNA and protein expression levels of Twist, E-cadherin and vimentin in the transfected cells were detected by RT-PCR and western blotting, respectively. In addition, migration and invasion were assessed by Transwell assays. In vivo, we established a xenogenic liver metastasis mouse model by intrasplenic injection with transfected SW480, HCT116 or HT29 human colon cancer cells and used hematoxylin and eosin (H&E) staining to demonstrate the effective establishment of the model. The relative mRNA levels of Twist and vimentin were detected by RT-PCR. In vitro, RT-PCR and western blotting showed higher relative mRNA and protein expression levels of Twist and vimentin in cell lines transfected with the recombinant, highly expressed Twist plasmid than in non-transfected cell lines (P<0.05), while E-cadherin was inhibited (P<0.05). After transfection with the plasmid pGenesil1.2-Twist-shRNA, the relative mRNA and protein levels of Twist and vimentin were markedly inhibited in the HCT116 cells (P<0.05), and the levels of E-cadherin were not changed (P>0.05), along with inhibition of the migration and invasion abilities of the cell line (P<0.01). In vivo, relative mRNA levels of Twist and vimentin in both the liver and spleen of the mouse model were higher in the groups that were injected with one of the three cell lines transfected with pTracer-CMV/BSD-Twist than in the groups injected with cells transfected with pGenesil1.2-Twist-shRNA (P<0.05). In conclusion, upregulation of Twist gene expression can promote EMT molecular events. Interfering with the Twist gene can effectively silence Twist gene expression in HCT116 cells and consequently inhibit colon cancer cell migration and invasion.

Promoter hypermethylation may contribute to E‑cadherin repression in the human salivary carcinoma ex pleomorphic adenoma

The role of promoter methylation in the inactivation of E‑cadherin (CDH1) in salivary carcinoma ex pleomorphic adenoma (CXPA) is unknown. The objective of this study was to determine the role and potential clinical implications of CDH1 promoter methylation in salivary CXPA. The CDH1 promoter methylation status was determined by bisulfite sequencing PCR in 37 primary CXPA tissues and 2 CXPA cell lines. E‑cadherin expression levels were determined by immunohistochemical analysis of each tumor. E‑cadherin protein levels and CDH1 mRNA levels were examined by immunoblotting and quantitative real-time PCR, respectively, in 2 CXPA cell lines. Cells were treated with 5‑Aza-dC or TGF‑β1 to test the influence of promoter methylation on CDH1 mRNA and protein expression. Associations between CDH1 molecular alterations and patients' clinicopathologic characteristics and prognosis were statistically evaluated. CDH1 promoter hypermethylation was detected in 21 of 37 tumors (56.76%). Of these 37 tumors, 13 tumors (35.14%) showed low E‑cadherin expression. Tumors that had CDH1 promoter methylation had a histological tendency toward luminal differentiation (P=0.004), high tumor grade (P=0.005), high T stage (P=0.024) and high TNM stage (P=0.038) compared with tumors that did not. The two CXPA cell lines exhibited an inverse relationship between CDH1 promoter methylation status and CDH1 mRNA and protein expression. Treatment of the hypermethylated cell line with 5‑Aza-dC restored CDH1 mRNA and E‑cadherin protein expression. The induction of hypermethylation by TGF‑β1 resulted in the repression of CDH1 mRNA and protein expression. CDH1 is commonly silenced in CXPA through promoter methylation. CDH1 methylation is closely related to tumor cell differentiation, histological grade, lymph node metastasis and advanced TNM stage, indicating that CDH1 methylation may play a role in the initiation and progression of CXPA.

Astrocyte elevated gene-1 promotes the proliferation and invasion of breast cancer cells by activating the Wnt/β-catenin signaling pathway

Astrocyte elevated gene-1 (AEG1) was identified to be overexpressed in breast cancer, and to be associated with the development of breast cancer. In the present study, AEG1 was identified as highly expressed in the MCF-7, MDA-MB-231 and SK-BR-3 breast cancer cell lines and was detected in the MCF-10A normal breast epithelial cell line. The present study established an AEG1-knockdown MCF-7 cell line to investigate the expression status of certain cancer-associated proteins. Western blotting demonstrated that AEG1 may affect cancer cell proliferation and invasion via activating the Wnt/β-catenin signaling pathway, a hypothesis that has been supported by cell function tests. The results of the present study demonstrated that when AEG1 was significantly overexpressed in breast cancer cells it promoted cell proliferation and invasion via activating the Wnt/β-catenin signaling pathway. Therefore, AEG1 may serve as a novel therapeutic target in breast cancer.

Lack of Altered BECN1 Gene Expression in Iranian Patients with Acute Myeloid Leukemia

Acute myeloid leukemia (AML), one of the most prevalent leukemia types in adults, demonstrates great heterogeneity in molecular and clinical terms. Hence, there is a necessity to the mechanisms involved in AML generation in order to determine optimal treatment. This cross sectional study aimed to assess changes in BECN1 gene expression in with blood samples from 30 AML patients, compared with samples from 15 healthy persons. RNA was extracted and cDNA was synthesized and Real Time PCR applied to determine BECN1 gene expression. The results showed no significant differences in BECN1 gene expression between patients with AML and normal controls (P > 0.05). It appears that expression of BECN1 does not play a significant role in genesis of AML leukemia.

Prognostic Value of E-Cadherin and β-Catenin in Triple-Negative Breast Cancer

OBJECTIVES

To analyze the expression of E-cadherin and β-catenin in triple-negative breast cancer (TNBC) to assess their prognostic significance.

METHODS

The expression of E-cadherin and β-catenin was examined semiquantitatively and correlated with other pathologic factors and survival outcomes.

RESULTS

Of 72 consecutive TNBCs, 56% showed reduced membranous expression of E-cadherin or β-catenin, with a strong correlation to each other. Of the clinicopathologic factors analyzed, tumor size and nodal status were significantly associated with overall survival and disease-specific survival, while the latter remained an independent factor by multivariate analysis. Reduced E-cadherin and β-catenin were both significantly associated with a poor overall survival and disease-specific survival by univariate and multivariate analyses.

CONCLUSIONS

E-cadherin and β-catenin expression provides discriminative prognostic power independent of conventional pathologic factors, thus further reinforcing the important role of cell adhesion molecules in the process of tumor metastasis, especially in TNBC.

Cadherins Glycans in Cancer: Sweet Players in a Bitter Process

Cadherins are key components in tissue morphogenesis and architecture, contributing to the establishment of cohesive cell adhesion. Reduced cellular adhesiveness as a result of cadherin dysfunction is a defining feature of cancer. During tumor development and progression, major changes in the glycan repertoire of cancer cells take place, affecting the stability, trafficking, and cell-adhesion properties of cadherins. Importantly, the different glycoforms of cadherins are promising biomarkers, with potential clinical application to improve the management of patients, and constitute targets for the development of new therapies. This review discusses the most recent insights on the impact of glycan structure on the regulation of cadherin function in cancer, and provides a perspective on how cadherin glycans constitute tumor biomarkers and potential therapeutic targets.

miR-200c Regulation of Metastases in Ovarian Cancer: Potential Role in Epithelial and Mesenchymal Transition

Among the gynecological malignancies, ovarian cancer is the most fatal due to its high mortality rate. Most of the identified cases are epithelial ovarian cancer (EOC) with five distinct subtypes: high-grade serous carcinoma, low-grade serous carcinoma, mucinous carcinoma, endometrioid carcinoma, and clear-cell carcinoma. Lack of an early diagnostic approach, high incidence of tumor relapse and the heterogenous characteristics between each EOC subtypes contribute to the difficulties in developing precise intervention and therapy for the patients. MicroRNAs (miRNAs) are single-stranded RNAs that have been shown to function as tumor suppressors or oncomiRs. The miR-200 family, especially miR-200c, has been shown to be implicated in the metastasis and invasion of ovarian carcinoma due to its functional regulation of epithelial-to-mesenchymal transition (EMT). This mini review is aimed to summarize the recent findings of the miR-200c functional role as well as its validated targets in the metastasis cascade of ovarian cancer, with a focus on EMT regulation. The potential of this miRNA in early diagnosis and its dual expression status are also discussed.

Overview of major molecular alterations during progression from Barrett's esophagus to esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) develops in the sequential transformation of normal epithelium into metaplastic epithelium, called Barrett's esophagus (BE), then to dysplasia, and finally cancer. BE is a common condition in which normal stratified squamous epithelium of the esophagus is replaced with an intestine-like columnar epithelium, and it is the most prominent risk factor for EAC. This review aims to impartially systemize the knowledge from a large number of publications that describe the molecular and biochemical alterations occurring over this progression sequence. In order to provide an unbiased extraction of the knowledge from the literature, a text-mining methodology was used to select genes that are involved in the BE progression, with the top candidate genes found to be TP53, CDKN2A, CTNNB1, CDH1, GPX3, and NOX5. In addition, sample frequencies across analyzed patient cohorts at each stage of disease progression are summarized. All six genes are altered in the majority of EAC patients, and accumulation of alterations correlates well with the sequential progression of BE to cancer, indicating that the text-mining method is a valid approach for gene prioritization. This review discusses how, besides being cancer drivers, these genes are functionally interconnected and might collectively be considered a central hub of BE progression.

Application of multiplex PCR for Rapid and sensitive detection of human papillomaviruses in cervical cancer

Objectives:

Reffering to an increase in cervical cancer in the recent years, rapid, sensitive and economical detection of human papillomaviruses (HPVs) as causative agents of cervical cancer is important. The traditional methods for the detection of HPVs in cervical cancer, such as pap smear, suffer from limitation and PCR has a potential to overcome the limitaitons. The purpose of present research work was to identify the five important strains of HPV (16, 18, 31, 33 and 45) simultaneously by Multiplex PCR application.

Methods:

Study was done on 100 cervical lesions of women. DNA was extracted from specimens by a genomic DNA purification kit. A 5-plex PCR was developed for the simultaneous detection of major HPV. Five pair of new primers was designed for detection of HPV 16, 18, 31, 33 and 45 by Multiplex PCR.

Results:

Among the 100 evaluated samples, 82 were found positive to HPVs. In the meantime the highest rate of infection was for HPV 16. Also 30 of HPV positive samples had infections with two or more HPV types.

Conclusion:

Multiplex PCR assay used in present study can provide a rapid, sensitive and economical method for detection of viral infections and is applicable to small volumes of vaginal samples.

Differentially Expressed MicroRNAs in Meningiomas Grades I and II Suggest Shared Biomarkers with Malignant Tumors

Meningiomas represent the most common primary tumors of the central nervous system, but few microRNA (miRNA) profiling studies have been reported so far. Deep sequencing of small RNA libraries generated from two human meningioma biopsies WHO grades I (benign) and II (atypical) were compared to excess dura controls. Nineteen differentially expressed miRNAs were validated by RT-qPCR using tumor RNA from 15 patients and 5 meninges controls. Tumor suppressor miR-218 and miR-34a were upregulated relative to normal controls, however, miR-143, miR-193b, miR-451 and oncogenic miR-21 were all downregulated. From 10 selected putative mRNA targets tested by RT-qPCR only four were differentially expressed relative to normal controls. PTEN and E-cadherin (CDH1) were upregulated, but RUNX1T1 was downregulated. Proliferation biomarker p63 was upregulated with nuclear localization, but not detected in most normal arachnoid tissues. Immunoreactivity of E-cadherin was detected in the outermost layer of normal arachnoids, but was expressed throughout the tumors. Nuclear Cyclin D1 expression was positive in all studied meningiomas, while its expression in arachnoid was limited to a few trabecular cells. Meningiomas of grades I and II appear to share biomarkers with malignant tumors, but with some additional tumor suppressor biomarkers expression. Validation in more patients is of importance.

Promoter methylation and expression of CDH1 and susceptibility and prognosis of eyelid squamous cell carcinoma

Eyelid skin tumors are the most frequent type of cancer in ophthalmology. And, eyelid squamous cell carcinoma (SCC) accounts for a large part of it. CDH1 encodes E-cadherin, a glycoprotein that plays an important part in cell-cell interaction. Loss of CDH1 function was suspected to be associated with tumorigenesis. Methylation of CDH1 promotors can alter the expression of its protein and is also considered as a contributor to various cancers. In this study, CDH1 methylation and expression profile as well as prognosis of 38 cases of eyelid SCC and the corresponding adjacent tissues were analyzed to clarify the role of CDH1 methylation in SCC carcinogenesis and prognosis. Methylation was detected by PCR, and CDH1 expression was evaluated by immunohistochemistry. We observed that CDH1 methylation is significantly correlated with decreased CDH1 protein expression in eyelid SCC patients. Patients with methylation and low expression of CDH1 are significantly associated with advanced and aggressive phenotypes. Therefore, CDH1 methylation and CDH1 expression are both independent prognostic factors for prognosis of eyelid SCC patients.

CDH1/E-cadherin and solid tumors. An updated gene-disease association analysis using bioinformatics tools

Cancer is a group of diseases that causes millions of deaths worldwide. Among cancers, Solid Tumors (ST) stand-out due to their high incidence and mortality rates. Disruption of cell-cell adhesion is highly relevant during tumor progression. Epithelial-cadherin (protein: E-cadherin, gene: CDH1) is a key molecule in cell-cell adhesion and an abnormal expression or/and function(s) contributes to tumor progression and is altered in ST. A systematic study was carried out to gather and summarize current knowledge on CDH1/E-cadherin and ST using bioinformatics resources. The DisGeNET database was exploited to survey CDH1-associated diseases. Reported mutations in specific ST were obtained by interrogating COSMIC and IntOGen tools. CDH1 Single Nucleotide Polymorphisms (SNP) were retrieved from the dbSNP database. DisGeNET analysis identified 609 genes annotated to ST, among which CDH1 was listed. Using CDH1 as query term, 26 disease concepts were found, 21 of which were neoplasms-related terms. Using DisGeNET ALL Databases, 172 disease concepts were identified. Of those, 80 ST disease-related terms were subjected to manual curation and 75/80 (93.75%) associations were validated. On selected ST, 489 CDH1 somatic mutations were listed in COSMIC and IntOGen databases. Breast neoplasms had the highest CDH1-mutation rate. CDH1 was positioned among the 20 genes with highest mutation frequency and was confirmed as driver gene in breast cancer. Over 14,000 SNP for CDH1 were found in the dbSNP database. This report used DisGeNET to gather/compile current knowledge on gene-disease association for CDH1/E-cadherin and ST; data curation expanded the number of terms that relate them. An updated list of CDH1 somatic mutations was obtained with COSMIC and IntOGen databases and of SNP from dbSNP. This information can be used to further understand the role of CDH1/E-cadherin in health and disease.

IL-8 suppresses E-cadherin expression in nasopharyngeal carcinoma cells by enhancing E-cadherin promoter DNA methylation

Nasopharyngeal carcinoma (NPC) has the highest metastasis potential among head and neck cancers. Distant metastasis is the major cause of treatment failure. Recent studies from our laboratory have revealed that IL-8 promotes NPC metastasis via activation of AKT signaling and induction of epithelial-mesenchymal transition (EMT) in the cells. In the present study, we found that IL-8 treatment for NPC cells resulted in an accumulation of DNMT1 protein through activating AKT1 pathway and consequent DNMT1 protein stabilization. Then DNMT1 suppressed E-cadherin expression by increasing the methylation of its promoter region. LY-294002 blocked IL-8-induced p-AKT1 activation resulting in reduction of DNMT1 and increase of E-cadherin expression, whereas forced demethylation using 5-aza-2'-deoxycytidine restored E-cadherin expression. In conclusion, our study, for the first time, shows that the IL-8/AKT1 signaling pathway stabilizes DNMT1 protein, consequently enhancing hypermethylation of E-cadherin promoter regions and downregulating E-cadherin protein level in NPC cells. Upon blockage of the IL-8/AKT pathway and inhibition of DNMT1, E-cadherin expression can be reversed. These data suggest that targeting the IL-8/AKT1 signaling pathway and DNMT1 may provide a potential therapeutic approach for blocking NPC metastasis.

Clinicopathological significance and potential drug target of CDH1 in breast cancer: a meta-analysis and literature review

CDH1, as a tumor suppressor gene, contributes sporadic breast cancer (BC) progression. However, the association between CDH1 hypermethylation and BC, and its clinicopathological significance remains unclear. We conducted a meta-analysis to investigate the relationship between the CDH1 methylation profile and the major clinicopathological features. A detailed literature was searched through the electronic databases PubMed, Web of Science™, and EMBASE™ for related research publications. The data were extracted and assessed by two reviewers independently. Odds ratios (ORs) with corresponding confidence intervals (CIs) were calculated and summarized respectively. The frequency of CDH1 methylation was significantly higher in invasive ductal carcinoma than in normal breast tissues (OR =5.83, 95% CI 3.76-9.03, P<0.00001). CDH1 hypermethylation was significantly higher in estrogen receptor (ER)-negative BC than in ER-positive BC (OR =0.62, 95% CI 0.43-0.87, P=0.007). In addition, we found that the CDH1 was significantly methylated in HER2-negative BC than in HER2-positive BC (OR =0.26, 95% CI 0.15-0.44, P<0.00001). However, CDH1 methylation frequency was not associated with progesterone receptor (PR) status, or with grades, stages, or lymph node metastasis of BC patients. Our results indicate that CDH1 hypermethylation is a potential novel drug target for developing personalized therapy. CDH1 hypermethylation is strongly associated with ER-negative and HER2-negative BC, respectively, suggesting CDH1 methylation status could contribute to the development of novel therapeutic approaches for the treatment of ER-negative or HER2-negative BC with aggressive tumor biology.