GATA4 and GATA5 are potential tumor suppressors and biomarkers in colorectal cancer

Edge-based relative entropy as a sensitive indicator of critical transitions in biological systems

BACKGROUND

Disease progression in biosystems is not always a steady process but is occasionally abrupt. It is important but challenging to signal critical transitions in complex biosystems.

METHODS

In this study, based on the theoretical framework of dynamic network biomarkers (DNBs), we propose a model-free method, edge-based relative entropy (ERE), to identify temporal key biomolecular associations/networks that may serve as DNBs and detect early-warning signals of the drastic state transition during disease progression in complex biological systems. Specifically, by combining gene‒gene interaction (edge) information with the relative entropy, the ERE method converts gene expression values into network entropy values, quantifying the dynamic change in a biomolecular network and indicating the qualitative shift in the system state.

RESULTS

The proposed method was validated using simulated data and real biological datasets of complex diseases. The applications show that for certain diseases, the ERE method helps to reveal so-called "dark genes" that are non-differentially expressed but with high ERE values and of essential importance in both gene regulation and prognosis.

CONCLUSIONS

The proposed method effectively identified the critical transition states of complex diseases at the network level. Our study not only identified the critical transition states of various cancers but also provided two types of new prognostic biomarkers, positive and negative edge biomarkers, for further practical application. The method in this study therefore has great potential in personalized disease diagnosis.

Pathogenesis and biomarkers of colorectal cancer by epigenetic alteration

Colorectal cancer (CRC) ranks third in cancer incidence and stands as the second leading cause of cancer-related deaths globally. CRC tumorigenesis results from a cumulative set of genetic and epigenetic alterations, disrupting cancer-regulatory processes like cell proliferation, metabolism, angiogenesis, cell death, invasion, and metastasis. Key epigenetic modifications observed in cancers encompass abnormal DNA methylation, atypical histone modifications, and irregularities in noncoding RNAs, such as microRNAs and long noncoding RNAs. The advancement in genomic technologies has positioned these genetic and epigenetic shifts as potential clinical biomarkers for CRC patients. This review concisely covers the fundamental principles of CRC-associated epigenetic changes, and examines in detail their emerging role as biomarkers for early detection, prognosis, and treatment response prediction.

Epigenetic signature of ionizing radiation in therapy-related AML patients

Therapy-related acute myeloid leukaemia (t-AML) is a late side effect of previous chemotherapy (ct-AML) and/or radiotherapy (rt-AML) or immunosuppressive treatment. t-AMLs, which account for ∼10-20 % of all AML cases, are extremely aggressive and have a poor prognosis compared to de novo AML. Our hypothesis is that exposure to radiation causes genome-wide epigenetic changes in rt-AML. An epigenome-wide association study was undertaken, measuring over 850K methylation sites across the genome from fifteen donors (five healthy, five de novo, and five t-AMLs). The study predominantly focussed on 94K sites that lie in CpG-rich gene promoter regions. Genome-wide hypomethylation was discovered in AML, primarily in intergenic regions. Additionally, genes specific to AML were identified with promoter hypermethylation. A two-step validation was conducted, both internally, using pyrosequencing to measure methylation levels in specific regions across fifteen primary samples, and externally, with an additional eight AML samples. We demonstrated that the MEST and GATA5 gene promoters, which were previously identified as tumour suppressors, were noticeably hypermethylated in rt-AML, as opposed to other subtypes of AML and control samples. These may indicate the epigenetic involvement in the development of rt-AML at the molecular level and could serve as potential targets for drug therapy in rt-AML.

The benign nature and rare occurrence of cardiac myxoma as a possible consequence of the limited cardiac proliferative/ regenerative potential: a systematic review

BACKGROUND

Cardiac Myxoma is a primary tumor of heart. Its origins, rarity of the occurrence of primary cardiac tumors and how it may be related to limited cardiac regenerative potential, are not yet entirely known. This study investigates the key cardiac genes/ transcription factors (TFs) and signaling pathways to understand these important questions.

METHODS

Databases including PubMed, MEDLINE, and Google Scholar were searched for published articles without any date restrictions, involving cardiac myxoma, cardiac genes/TFs/signaling pathways and their roles in cardiogenesis, proliferation, differentiation, key interactions and tumorigenesis, with focus on cardiomyocytes.

RESULTS

The cardiac genetic landscape is governed by a very tight control between proliferation and differentiation-related genes/TFs/pathways. Cardiac myxoma originates possibly as a consequence of dysregulations in the gene expression of differentiation regulators including Tbx5, GATA4, HAND1/2, MYOCD, HOPX, BMPs. Such dysregulations switch the expression of cardiomyocytes into progenitor-like state in cardiac myxoma development by dysregulating Isl1, Baf60 complex, Wnt, FGF, Notch, Mef2c and others. The Nkx2-5 and MSX2 contribute predominantly to both proliferation and differentiation of Cardiac Progenitor Cells (CPCs), may possibly serve roles based on the microenvironment and the direction of cell circuitry in cardiac tumorigenesis. The Nkx2-5 in cardiac myxoma may serve to limit progression of tumorigenesis as it has massive control over the proliferation of CPCs. The cardiac cell type-specific genetic programming plays governing role in controlling the tumorigenesis and regenerative potential.

CONCLUSION

The cardiomyocytes have very limited proliferative and regenerative potential. They survive for long periods of time and tightly maintain the gene expression of differentiation genes such as Tbx5, GATA4 that interact with tumor suppressors (TS) and exert TS like effect. The total effect such gene expression exerts is responsible for the rare occurrence and benign nature of primary cardiac tumors. This prevents the progression of tumorigenesis. But this also limits the regenerative and proliferative potential of cardiomyocytes. Cardiac Myxoma develops as a consequence of dysregulations in these key genes which revert the cells towards progenitor-like state, hallmark of CM. The CM development in carney complex also signifies the role of TS in cardiac cells.

DNA Methylation-Based Testing in Peripheral Blood Mononuclear Cells Enables Accurate and Early Detection of Colorectal Cancer

An effective blood-based method for the diagnosis of colorectal cancer has not yet been developed. Molecular alterations of immune cells occur early in tumorigenesis, providing the theoretical underpinning for early cancer diagnosis based on immune cell profiling. Therefore, we aimed to develop an effective detection method based on peripheral blood mononuclear cells (PBMC) to improve the diagnosis of colorectal cancer. Analysis of the genome-wide methylation landscape of PBMCs from patients with colorectal cancer and healthy controls by microarray, pyrosequencing, and targeted bisulfite sequencing revealed five DNA methylation markers for colorectal cancer diagnosis, especially early-stage colorectal cancer. A single-tube multiple methylation-specific quantitative PCR assay (multi-msqPCR) for simultaneous detection of five methylation markers was established, which allowed quantitative analysis of samples with as little as 0.1% PBMC DNA and had better discriminative performance than single-molecule detection. Then, a colorectal cancer diagnostic model (CDM) based on methylation markers and the multi-msqPCR method was constructed that achieved high accuracy for early-stage colorectal cancer (AUC = 0.91; sensitivity = 81.18%; specificity = 89.39%), which was improved compared with CEA (AUC = 0.79). The CDM also enabled a high degree of discrimination for advanced adenoma cases (AUC = 0.85; sensitivity = 63.04%). Follow-up data also demonstrated that the CDM could identify colorectal cancer potential up to 2 years before currently used diagnostic methods. In conclusion, the approach constructed in this study based on PBMC-derived DNA methylation markers and a multi-msqPCR method is a promising and easily implementable diagnostic method for early-stage colorectal cancer.

SIGNIFICANCE

Development of a diagnostic model for early colorectal cancer based on epigenetic analysis of PBMCs supports the utility of altered DNA methylation in immune cells for cancer diagnosis.

Targeting PI3K/Akt signaling in prostate cancer therapy

Urological cancers have obtained much attention in recent years due to their mortality and morbidity. The most common and malignant tumor of urological cancers is prostate cancer that imposes high socioeconomic costs on public life and androgen-deprivation therapy, surgery, and combination of chemotherapy and radiotherapy are employed in its treatment. PI3K/Akt signaling is an oncogenic pathway responsible for migration, proliferation and drug resistance in various cancers. In the present review, the role of PI3K/Akt signaling in prostate cancer progression is highlighted. The activation of PI3K/Akt signaling occurs in prostate cancer, while PTEN as inhibitor of PI3K/Akt shows down-regulation. Stimulation of PI3K/Akt signaling promotes survival of prostate tumor cells and prevents apoptosis. The cell cycle progression and proliferation rate of prostate tumor cells increase by PI3K/Akt signaling induction. PI3K/Akt signaling stimulates EMT and enhances metastasis of prostate tumor cells. Silencing PI3K/Akt signaling impairs growth and metastasis of prostate tumor cells. Activation of PI3K/Akt signaling mediates drug resistance and reduces radio-sensitivity of prostate tumor cells. Anti-tumor compounds suppress PI3K/Akt signaling in impairing prostate tumor progression. Furthermore, upstream regulators such as miRNAs, lncRNAs and circRNAs regulate PI3K/Akt signaling and it has clinical implications for prostate cancer patients.

The Roles of Zinc Finger Proteins in Colorectal Cancer

Despite colorectal cancer remaining a leading worldwide cause of cancer-related death, there remains a paucity of effective treatments for advanced disease. The molecular mechanisms underlying the development of colorectal cancer include altered cell signaling and cell cycle regulation that may result from epigenetic modifications of gene expression and function. Acting as important transcriptional regulators of normal biological processes, zinc finger proteins also play key roles in regulating the cellular mechanisms underlying colorectal neoplasia. These actions impact cell differentiation and proliferation, epithelial-mesenchymal transition, apoptosis, homeostasis, senescence, and maintenance of stemness. With the goal of highlighting promising points of therapeutic intervention, we review the oncogenic and tumor suppressor roles of zinc finger proteins with respect to colorectal cancer tumorigenesis and progression.

Potential Prognostic Value of GATA4 Depends on the p53 Expression in Primary Glioblastoma Patients

BACKGROUND

Primary glioblastoma is characterized by an extremely poor prognosis. The promoter methylation of GATA4 leads to the loss of its expression in many cancer types. The formation of high-grade astrocytomas can be promoted by the concurrent loss of TP53 and GATA4 in normal human astrocytes. Nevertheless, the impact of GATA4 alterations with linkage to TP53 changes in gliomagenesis is poorly understood. This study aimed to evaluate GATA4 protein expression, GATA4 promoter methylation, p53 expression, TP53 promoter methylation, and mutation status in patients with primary glioblastoma and to assess the possible prognostic impact of these alterations on overall survival.

MATERIALS AND METHODS

Thirty-one patients with primary glioblastoma were included. GATA4 and p53 expressions were determined immunohistochemically, and GATA4 and TP53 promoter methylations were analyzed via methylation-specific PCR. TP53 mutations were investigated via Sanger sequencing.

RESULTS

The prognostic value of GATA4 depends on p53 expression. Patients without GATA4 protein expression were more frequently negative for TP53 mutations and had better prognoses than the GATA4 positive patients. In patients positive for GATA4 protein expression, p53 expression was associated with the worst outcome. However, in patients positive for p53 expression, the loss of GATA4 protein expression seemed to be associated with improved prognosis. GATA4 promoter methylation was not associated with a lack of GATA4 protein expression.

CONCLUSIONS

Our data indicate that there is a possibility that GATA4 could function as a prognostic factor in glioblastoma patients, but in connection with p53 expression. A lack of GATA4 expression is not dependent on GATA4 promoter methylation. GATA4 alone has no influence on survival time in glioblastoma patients.

Colon cancer transcriptome

Over the last four decades, methodological innovations have continuously changed transcriptome profiling. It is now feasible to sequence and quantify the transcriptional outputs of individual cells or thousands of samples using RNA sequencing (RNA-seq). These transcriptomes serve as a connection between cellular behaviors and their underlying molecular mechanisms, such as mutations. This relationship, in the context of cancer, provides a chance to unravel tumor complexity and heterogeneity and uncover novel biomarkers or treatment options. Since colon cancer is one of the most frequent malignancies, its prognosis and diagnosis seem to be critical. The transcriptome technology is developing for an earlier and more accurate diagnosis of cancer which can provide better protectivity and prognostic utility to medical teams and patients. A transcriptome is a whole set of expressed coding and non-coding RNAs in an individual or cell population. The cancer transcriptome includes RNA-based changes. The combined genome and transcriptome of a patient may provide a comprehensive picture of their cancer, and this information is beginning to affect treatment decision-making in real-time. A full assessment of the transcriptome of colon (colorectal) cancer has been assessed in this review paper based on risk factors such as age, obesity, gender, alcohol use, race, and also different stages of cancer, as well as non-coding RNAs like circRNAs, miRNAs, lncRNAs, and siRNAs. Similarly, they have been examined independently in the transcriptome study of colon cancer.

Colon Cancer Screening Methods: 2023 Update

Colorectal cancer (CRC) is a significant cause of morbidity and mortality worldwide. National screening guidelines have been implemented to identify and remove precancerous polyps before they become cancer. Routine CRC screening is advised for people with average risk starting at age 45 because it is a common and preventable malignancy. Various screening modalities are currently in use, ranging from stool-based tests (fecal occult blood test (FOBT), fecal immunochemical test (FIT), and FIT-DNA test), radiologic tests (computed tomographic colonography (CTC), double contrast barium enema), and visual endoscopic examinations (flexible sigmoidoscopy (FS), colonoscopy, and colon capsule endoscopy (CCE)) with their varying sensitivity and specificity. Biomarkers also play a vital role in assessing the recurrence of CRC. This review offers a summary of the current screening options, including biomarkers available to detect CRC, highlighting the benefits and challenges encompassing each screening modality.

Expression profile and prognostic values of GATA family members in kidney renal clear cell carcinoma

To investigate the possible diagnostic and prognostic biomarkers of kidney renal clear cell carcinoma (KIRC), an integrated study of accumulated data was conducted to obtain more reliable information and more feasible measures. Using the Tumor Immune Estimation Resource (TIMER), University of Alabama at Birmingham Cancer Data Analysis Portal (UALCAN), Human Protein Atlas (HPA), Kaplan-Meier plotter database, Gene Expression Profiling Interactive Analysis (GEPIA2) database, cBioPortal, and Metascape, we analyzed the expression profiles and prognoses of six members of the GATA family in patients with KIRC. Compared to normal samples, KIRC samples showed significantly lower GATA2/3/6 mRNA and protein expression levels. KIRC's pathological grades, clinical stages, and lymph node metastases were closely related to GATA2 and GATA5 levels. Patients with KIRC and high GATA2 and GATA5 expression had better overall survival (OS) and recurrence-free survival (RFS), while those with higher expression of GATA3/4/6 had worse outcomes. The role and underlying mechanisms of the GATA family in cell cycle, cell proliferation, metabolic processes, and other aspects were evaluated based on Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses. Furthermore, we found that infiltrating immune cells were highly correlated with GATA expression profiles. These results showed that GATA family members may serve as prognostic biomarkers and therapeutic targets for KIRC.

Changes of Mutations and Copy-Number and Enhanced Cell Migration during Breast Tumorigenesis

Although cancer stem cells (CSCs) play a major role in tumorigenesis and metastasis, the role of genetic alterations in invasiveness of CSCs is still unclear. Tumor microenvironment signals, such as extracellular matrix (ECM) composition, significantly influence cell behaviors. Unfortunately, these signals are often lost in in vitro cell culture. This study determines putative CSC populations, examines genetic changes during tumorigenesis of human breast epithelial stem cells, and investigates single-cell migration properties on ECM-mimetic platforms. Whole exome sequencing data indicate that tumorigenic cells have a higher somatic mutation burden than non-tumorigenic cells, and that mutations exclusive to tumorigenic cells exhibit higher predictive deleterious scores. Tumorigenic cells exhibit distinct somatic copy number variations (CNVs) including gain of duplications in chromosomes 5 and 8. ECM-mimetic topography selectively enhances migration speed of tumorigenic cells, but not of non-tumorigenic cells, and results in a wide distribution of tumorigenic single-cell migration speeds, suggesting heterogeneity in cellular sensing of contact guidance cues. This study identifies mutations and CNVs acquired during breast tumorigenesis, which can be associated with enhanced migration of breast tumorigenic cells, and demonstrates that a nanotopographically-defined platform can be applied to recapitulate an ECM structure for investigating cellular migration in the simulated tumor microenvironment.

Identification of an Immune-Related Gene Signature Associated with Prognosis and Tumor Microenvironment in Esophageal Cancer

Background

Esophageal cancer (EC) is a common malignant tumor of the digestive system with high mortality and morbidity. Current evidence suggests that immune cells and molecules regulate the initiation and progression of EC. Accordingly, it is necessary to identify immune-related genes (IRGs) affecting the biological behaviors and microenvironmental characteristics of EC.

Methods

Bioinformatics methods, including differential expression analysis, Cox regression, and immune infiltration prediction, were conducted using R software to analyze the Gene Expression Omnibus (GEO) dataset. The Cancer Genome Atlas (TCGA) cohort was used to validate the prognostic signature. Patients were stratified into high- and low-risk groups for further analyses, including functional enrichment, immune infiltration, checkpoint relevance, clinicopathological characteristics, and therapeutic sensitivity analyses.

Results

A prognostic signature was established based on 21 IRGs (S100A7, S100A7A, LCN1, CR2, STAT4, GAST, ANGPTL5, TRAV39, F2RL2, PGLYRP3, KLRD1, TRIM36, PDGFA, SLPI, PCSK2, APLN, TICAM1, ITPR3, MAPK9, GATA4, and PLAU). Compared with high-risk patients, better overall survival rates and clinicopathological characteristics were found in low-risk patients. The areas under the curve of the two cohorts were 0.885 and 0.718, respectively. Higher proportions of resting CD4⁺ memory T lymphocytes, M2 macrophages, and resting dendritic cells and lower proportions of follicular helper T lymphocytes, plasma cells, and neutrophils were found in the high-risk tumors. Moreover, the high-risk group showed higher expression of CD44 and TNFSF4, lower expression of PDCD1 and CD40, and higher TIDE scores, suggesting they may respond poorly to immunotherapy. High-risk patients responded better to chemotherapeutic agents such as docetaxel, doxorubicin, and gemcitabine. Furthermore, IRGs associated with tumor progression, including PDGFA, ITPR3, SLPI, TICAM1, and GATA4, were identified.

Conclusion

Our immune-related signature yielded reliable value in evaluating the prognosis, microenvironmental characteristics, and therapeutic sensitivity of EC and may help with the precise treatment of this patient population.

Fecal biomarkers: Non-invasive diagnosis of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer in the world in terms of morbidity and mortality, which brings great health hazards and economic burdens to patients and society. A fecal examination is an effective method for clinical examination and the most commonly used method for the census. It is simple, non-invasive, and suitable for large-scale population screening. With the development of molecular biology, lots of efforts have been made to discover new fecal biomarkers for the early screening of colorectal cancer. In this review, we summarize and discuss the recent advances of fecal biomarkers for CRC screening or diagnosis, including DNA biomarkers, RNA biomarkers, protein biomarkers, gut microbes and volatile organic compounds focusing on their diagnostic evaluation for CRC, which can provide a basis for the further development of new and effective CRC fecal screening and early diagnosis techniques.

Novel estrogen-responsive genes (ERGs) for the evaluation of estrogenic activity

Estrogen action is mediated by various genes, including estrogen-responsive genes (ERGs). ERGs have been used as reporter-genes and markers for gene expression. Gene expression profiling using a set of ERGs has been used to examine statistically reliable transcriptomic assays such as DNA microarray assays and RNA sequencing (RNA-seq). However, the quality of ERGs has not been extensively examined. Here, we obtained a set of 300 ERGs that were newly identified by six sets of RNA-seq data from estrogen-treated and control human breast cancer MCF-7 cells. The ERGs exhibited statistical stability, which was based on the coefficient of variation (CV) analysis, correlation analysis, and examination of the functional association with estrogen action using database searches. A set of the top 30 genes based on CV ranking were further evaluated quantitatively by RT-PCR and qualitatively by a functional analysis using the GO and KEGG databases and by a mechanistic analysis to classify ERα/β-dependent or ER-independent types of transcriptional regulation. The 30 ERGs were characterized according to (1) the enzymes, such as metabolic enzymes, proteases, and protein kinases, (2) the genes with specific cell functions, such as cell-signaling mediators, tumor-suppressors, and the roles in breast cancer, (3) the association with transcriptional regulation, and (4) estrogen-responsiveness. Therefore, the ERGs identified here represent various cell functions and cell signaling pathways, including estrogen signaling, and thus, may be useful to evaluate estrogenic activity.

Epigenetic insights in the diagnosis, prognosis, and treatment selection in CRC, an updated review

BACKGROUND/AIM

The gradual accumulation of genetic and epigenetic alterations can lead to the development of colorectal cancer. In the last decade much research has been done to discover how methylation as an epigenetic alteration leads to carcinogenesis. While Methylation is a biological process, it can influence gene expression by affecting the promoter activity. This article reviews the role of methylation in critical pathways in CRC.

METHODS

In this study using appropriate keywords, all research and review articles related to the role of methylation on different cancers were collected and analyzed. Also, existing information on methylation detection methods and therapeutic sensitivity or resistance due to DNA methylation were reviewed.

RESULTS

The results of this survey revealed that while Methylation is a biological process, it can influence gene expression by affecting the promoter activity. Promoter methylation is associated with up or downregulation of genes involved in critical pathways, including cell cycle, DNA repair, and cell adherence. Hence promoter methylation can be used as a molecular tool for early diagnosis, improving treatment, and predicting treatment resistance.

CONCLUSION

Current knowledge on potential methylation biomarkers for diagnosis and prognoses of CRC has also been discussed. Our survey proposes that a multi-biomarker panel is more efficient than a single biomarker in the early diagnosis of CRC.

Overexpression of GATA5 Inhibits Prostate Cancer Progression by Regulating PLAGL2 via the FAK/PI3K/AKT Pathway

Simple Summary

Prostate cancer (PCa) has the highest incidence of malignant tumors and is the second-ranked tumor-causing death of men. GATA binding protein 5 (GATA5) belongs to the GATA gene family and we found that GATA5 was downregulated in PCa tissues, but the function of GATA5 in PCa remains elusive. We found overexpression GATA5 inhibited tumor proliferation, migration, invasion and the process of epithelial–mesenchymal transition (EMT), and upregulation of GATA5 promoted PCa cell apoptosis. In addition, we disclosed that GATA5 could interact with pleomorphic adenoma gene-like-2 (PLAGL2) to regulate PCa cell growth via FAK/PI3K/AKT signaling pathway. Hence, these findings suggested that GATA5 could serve as a new therapeutic target in the future.

Abstract

Background: Prostate cancer (PCa) is a malignancy with high incidence and the principal cause of cancer deaths in men. GATA binding protein 5 (GATA5) belongs to the GATA gene family. GATA5 has a close association with carcinogenesis, but the role of GATA5 in PCa remains poorly understood. The aim of our present study was to probe into the effect of GATA5 on PCa progression and to elucidate the involved mechanism. Methods: The expression of GATA5 was detected in both PCa samples and PCa cell lines. GATA5 overexpression, PLAGL2 knockdown, and overexpression cell models were generated, then Western blotting experiments were utilized to validate the efficiency of transfection. The effects of GATA5 on PCa cell proliferation, metastasis, apoptosis, cell cycle progression, and EMT were detected in vitro or in vivo. Furthermore, the mechanism by which GATA5 inhibits prostate cancer progression through regulating PLAGL2 via the FAK/PI3K/AKT pathway was also explored. Results: GATA5 expression was downregulated in PCa samples and cell lines. GATA5 overexpression inhibited PCa cell proliferation and metastasis but increased the rate of apoptosis. In addition, we confirmed that GATA5 inhibited prostate cancer progression, including EMT, by regulating PLAGL2 via the FAK/PI3K/AKT pathway. Conclusion: We demonstrated that GATA5, as a tumor suppressor in PCa, inhibits PCa progression by regulating PLAGL2. These results showed that the GATA5/PLAGL2/FAK/PI3K/AKT pathway may become a new therapeutic direction for the treatment of PCa.

DNA methylation-based diagnostic, prognostic, and predictive biomarkers in colorectal cancer

DNA methylation is an epigenetic mechanism regulating gene expression. Changes in DNA methylation were suggested to be useful biomarkers for diagnosis, and for the determination of prognosis and treatment response. Here, we provide an overview of methylation-based biomarkers in colorectal cancer. First, we start with the two methylation-based diagnostic biomarkers already approved for colorectal cancer, SEPT9 and the combination of NDRG4 and BMP3. Then, we provide a list-based overview of new biomarker candidates depending on the sample source including plasma, stool, urine, and surgically removed tumor tissues. The most often identified markers like SDC2, VIM, APC, MGMT, SFRP1, SFRP2, and NDRG4 have distinct functions previously linked to tumor progression. Although numerous studies have identified tumor-specific methylation changes, most of these alterations were observed in a single study only. The lack of validation in independent samples means low reproducibility and is a major limitation. The genome-wide determination of methylation status (methylome) can provide data to solve these issues. In the third section of the review, methylome studies focusing on different aspects related to CRC, including precancerous lesions, CRC-specific changes, molecular subtypes, aging, and chemotherapy response are summarized. Notably, techniques simultaneously analyzing a large set of regions can also uncover epigenetic regulation of genes which have not yet been associated with tumorigenesis previously. A remaining constraint of studies published to date is the low patient number utilized in these preventing the identification of clinically valuable biomarker candidates. Either future large-scale studies or the integration of already available methylome-level data will be necessary to uncover biomarkers sufficiently robust for clinical application.

Transcription factor GATA4 drives RNA polymerase III-directed transcription and transformed cell proliferation through a filamin A/GATA4/SP1 pathway

RNA polymerase III (pol III) products play fundamental roles in a variety of cellular processes, including protein synthesis and cancer cell proliferation. In addition, dysregulation of pol III-directed transcription closely correlates with tumorigenesis. It is therefore of interest to identify novel pathways or factors governing pol III-directed transcription. Here, we show that transcription factor (TF) GATA binding protein 4 (GATA4) expression in SaOS2 cells was stimulated by the silencing of filamin A (FLNA), a repressor of pol III-directed transcription, suggesting that GATA4 is potentially associated with the regulation of pol III-directed transcription. Indeed, we show that GATA4 expression positively correlates with pol III-mediated transcription and tumor cell proliferation. Mechanistically, we found that GATA4 depletion inhibits the occupancies of the pol III transcription machinery factors at the loci of pol III target genes by reducing expression of both TFIIIB subunit TFIIB-related factor 1 and TFIIIC subunit general transcription factor 3C subunit 2 (GTF3C2). GATA4 has been shown to activate specificity factor 1 (Sp1) gene transcription by binding to the Sp1 gene promoter, and Sp1 has been confirmed to activate pol III gene transcription by directly binding to both Brf1 and Gtf3c2 gene promoters. Thus, the findings from this study suggest that GATA4 links FLNA and Sp1 signaling to form an FLNA/GATA4/Sp1 axis to modulate pol III-directed transcription and transformed cell proliferation. Taken together, these results provide novel insights into the regulatory mechanism of pol III-directed transcription.

Novel Diagnostic Biomarkers in Colorectal Cancer

Colorectal cancer (CRC) is still a leading cause of cancer death worldwide. Less than half of cases are diagnosed when the cancer is locally advanced. CRC is a heterogenous disease associated with a number of genetic or somatic mutations. Diagnostic markers are used for risk stratification and early detection, which might prolong overall survival. Nowadays, the widespread use of semi-invasive endoscopic methods and feacal blood tests characterised by suboptimal accuracy of diagnostic results has led to the detection of cases at later stages. New molecular noninvasive tests based on the detection of CRC alterations seem to be more sensitive and specific then the current methods. Therefore, research aiming at identifying molecular markers, such as DNA, RNA and proteins, would improve survival rates and contribute to the development of personalized medicine. The identification of “ideal” diagnostic biomarkers, having high sensitivity and specificity, being safe, cheap and easy to measure, remains a challenge. The purpose of this review is to discuss recent advances in novel diagnostic biomarkers for tumor tissue, blood and stool samples in CRC patients.

A GATA4-regulated secretory program suppresses tumors through recruitment of cytotoxic CD8 T cells

The GATA4 transcription factor acts as a master regulator of development of multiple tissues. GATA4 also acts in a distinct capacity to control a stress-inducible pro-inflammatory secretory program that is associated with senescence, a potent tumor suppression mechanism, but also operates in non-senescent contexts such as tumorigenesis. This secretory pathway is composed of chemokines, cytokines, growth factors, and proteases. Since GATA4 is deleted or epigenetically silenced in cancer, here we examine the role of GATA4 in tumorigenesis in mouse models through both loss-of-function and overexpression experiments. We find that GATA4 promotes non-cell autonomous tumor suppression in multiple model systems. Mechanistically, we show that Gata4-dependent tumor suppression requires cytotoxic CD8 T cells and partially requires the secreted chemokine CCL2. Analysis of transcriptome data in human tumors reveals reduced lymphocyte infiltration in GATA4-deficient tumors, consistent with our murine data. Notably, activation of the GATA4-dependent secretory program combined with an anti-PD-1 antibody robustly abrogates tumor growth in vivo.

Transcriptomic and Proteomic Study on the High-Fat Diet Combined With AOM/DSS-Induced Adenomatous Polyps in Mice

Objective

To screen and identify molecular targets and bacteria genus leading to adenomatous polyps in mouse induced by high-fat diet (HFD) +AOM/DSS using omics technology.

Methods

The molecular targets of colorectal adenoma disease were obtained from the GeneCards and OMIM database. The SPF C57BL mice were randomly divided into blank (Control) and AOM/DSS+HFD colorectal adenoma model (ADH) groups. The ADH model group was intraperitoneally injected with AOM reagent. Then, mice were given with 2.5% DSS (in free drinking water) and high-fat diet to establish the mouse model. During this period, the changes of physical signs of mice in each group were observed. After the end of modeling, HE staining was used to evaluate the histopathological change of mice. The differentially expressed genes and proteins in the Control group and ADH group were detected by RNA-seq transcriptome sequencing and Tandem Mass Tags (TMT) quantitative proteomics. The histological results were analyzed by intersection with the intestinal adenoma molecular targets obtained from the database. Moreover, the changes of intestinal flora in the two groups were examined. The correlation between targets and differential bacteria was analyzed and verified by Parallel Reaction Monitoring (PRM) to comprehensively evaluate the mouse model of adenomatous polyp induced by AOM/DSS+HFD.

Results

The general condition and histopathological results of mice confirmed that the ADH mouse model was successfully established and tubular adenoma was formed. A total of 604 genes and 42 proteins related to intestinal adenoma were obtained by histological analysis and database intersection analysis. The intestinal microflora of ADH mice was different from that of normal mice, and the constituents and abundance of intestinal flora were similar to those of human intestinal adenoma. GATA4 and LHPP were selected as potential pathological markers of the model mice by correlation analysis of targets and intestinal flora. The results of PRM verification were highly consistent with the results of RNA-Seq transcriptome sequencing and TMT analysis.

Conclusion

The pathological results, molecular pathological markers and the changes of intestinal flora suggest that the mouse ADH model is ideal for studying the transformation of inflammatory cancer. The ADH model will be helpful for understanding the occurrence and development of human colorectal cancer at the transcriptomic and proteomic level.

Comprehensive Analysis of Expression and Prognostic Value of GATAs in Lung Cancer

GATAs are a family of transcription factors that play sophisticated and extensive roles in cell fate transitions and tissue morphogenesis during embryonic development. Emerging evidence indicate that GATAs are involved in tumorigenesis of lung cancer (LC). However, the distinct roles, diverse expression patterns and prognostic values of six GATA family members in LC have yet to be elucidated. In the present study, the diverse expression patterns, prognostic values, genetic mutations, protein-protein interaction(PPI) networks of GATAs, Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway in LC patients were analyzed using a serious of databases, including ONCOMINE database, Cancer Cell Line Encyclopedia database, the Human Protein Atlas, the Gene Expression Profiling Interactive Analysis database, the Kaplan-Meier plotter, cBioPortal, String database and database Database for Annotation, Visualization, and Integrated Discovery. The mRNA expression levels of GATA1/2/4/5/6 were downregulated, while GATA3 showed abnormal expressions of up-regulation and down-regulation in patients with LC. Aberrant GATAs mRNA expression was connected with prognosis. Furthermore, genetic alterations mainly appeared in GATA4. Gene Ontology enrichment and network analysis demonstrated that GATAs and their 50 interactors were primarily associated with positive regulation of transcription from RNA polymerase II promoter, transcription factor complex, transcription factor binding Jak-STAT signaling pathway. This comprehensive bioinformatic analysis demonstrated that GATA1/2/3/4/6 may be new prognosis factors, and GATA2/5/6 may be potential targets for personalized therapy for patients with LC, but further studies are requisite to analyze the mechanism of their carcinogenicity and investigate novel drug treatment. Finally, these findings would conduce to a better understanding of the unique roles of GATAs in LC.

Performance evaluation of stool DNA methylation tests in colorectal cancer screening: a systematic review and meta-analysis

AIM

There is not sufficient evidence about whether stool DNA methylation tests allow prioritizing patients to colonoscopy. Due to the COVID-19 pandemic, there will be a wait-list for rescheduling colonoscopies once the mitigation is lifted. The aim of this meta-analysis was to evaluate the accuracy of stool DNA methylation tests in detecting colorectal cancer.

METHODS

The PubMed, Cochrane Library and MEDLINE via Ovid were searched. Studies reporting the accuracy (Sackett phase 2 or 3) of stool DNA methylation tests to detect sporadic colorectal cancer were included. The DerSimonian-Laird method with random-effects model was utilized for meta-analysis.

RESULTS

Forty-six studies totaling 16 149 patients were included in the meta-analysis. The pooled sensitivity and specificity of all single genes and combinations was 62.7% (57.7%, 67.4%) and 91% (89.5%, 92.2%), respectively. Combinations of genes provided higher sensitivity compared to single genes (80.8% [75.1%, 85.4%] vs. 57.8% [52.3%, 63.1%]) with no significant decrease in specificity (87.8% [84.1%, 90.7%] vs. 92.1% [90.4%, 93.5%]). The most accurate single gene was found to be SDC2 with a sensitivity of 83.1% (72.6%, 90.2%) and a specificity of 91.2% (88.6%, 93.2%).

CONCLUSIONS

Stool DNA methylation tests have high specificity (92%) with relatively lower sensitivity (81%). Combining genes increases sensitivity compared to single gene tests. The single most accurate gene is SDC2, which should be considered for further research.

A pan-cancer analysis of CpG Island gene regulation reveals extensive plasticity within Polycomb target genes

CpG Island promoter genes make up more than half of human genes, and a subset regulated by Polycomb-Repressive Complex 2 (PRC2+-CGI) become DNA hypermethylated and silenced in cancer. Here, we perform a systematic analysis of CGI genes across TCGA cancer types, finding that PRC2+-CGI genes are frequently prone to transcriptional upregulation as well. These upregulated PRC2+-CGI genes control important pathways such as Epithelial-Mesenchymal Transition (EMT) and TNFα-associated inflammatory response, and have greater cancer-type specificity than other CGI genes. Using publicly available chromatin datasets and genetic perturbations, we show that transcription factor binding sites (TFBSs) within distal enhancers underlie transcriptional activation of PRC2+-CGI genes, coinciding with loss of the PRC2-associated mark H3K27me3 at the linked promoter. In contrast, PRC2-free CGI genes are predominantly regulated by promoter TFBSs which are common to most cancer types. Surprisingly, a large subset of PRC2+-CGI genes that are upregulated in one cancer type are also hypermethylated/silenced in at least one other cancer type, underscoring the high degree of regulatory plasticity of these genes, likely derived from their complex regulatory control during normal development.

Epigenetic alterations in the gastrointestinal tract: Current and emerging use for biomarkers of cancer

Colorectal cancer is a leading cause of cancer related deaths worldwide. One of the hallmarks of cancer and a fundamental trait of virtually all gastrointestinal cancers is genomic and epigenomic DNA alterations. Cancer cells acquire genetic and epigenetic alterations that drive the initiation and progression of the cancers by altering the molecular and cell biological process of the cells. These alterations, as well as other host and microenvironment factors, ultimately mediate the initiation and progression of cancers, including colorectal cancer. Epigenetic alterations, which include changes affecting DNA methylation, histone modifications, chromatin structure, and noncoding RNA expression, have emerged as a major class of molecular alteration in colon polyps and colorectal cancer. The classes of epigenetic alterations, their status in colorectal polyps and cancer, their effects on neoplasm biology, and their application to clinical care will be discussed.

Identification of prognostic immune-related genes in rhabdoid tumor of kidney based on TARGET database analysis

Background: Malignant rhabdoid tumor of the kidney (RTK) is a rare and highly aggressive pediatric malignancy. Immune system dysfunction is significantly correlated with tumor initiation and progression.

Methods: We integrated and analyzed the expression profiles of immune-related genes (IRGs) in 65 RTK patients based on the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. Prognostic related IRGs in RTK patients were analyzed using univariate and multivariate analysis, based on which a prognostic model with IRGs was constructed. Correlation analysis between the risk score of our model and tumor-infiltrating cell were also investigated.

Results: Twenty two IRGs were significantly associated with the clinical outcomes of RTK patients. Gene ontology (GO) analysis revealed that inflammatory pathways were most frequently implicated in RTK. A prognostic model was constructed using 7 IRGs (MMP9, SERPINA3, FAM19A5, CCR9, PLAUR, IL1R2, PRKCG), which were independent prognostic indices that could differentiate patients based on their survival outcomes. Furthermore, the risk scores from our prognostic model was positively associated with cancer-associated fibroblasts (CAFs).

Conclusions: We screened seven IRGs of clinical significance to distinguish patients with different survival outcomes. This may enhance our understanding of the immune microenvironment of RTK, and could use to design individualized treatments for RTK patients.

Background: Malignant rhabdoid tumor of the kidney (RTK) is a rare and highly aggressive pediatric malignancy. Immune system dysfunction is significantly correlated with tumor initiation and progression.

Methods: We integrated and analyzed the expression profiles of immune-related genes (IRGs) in 65 RTK patients based on the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. Prognostic related IRGs in RTK patients were analyzed using univariate and multivariate analysis, based on which a prognostic model with IRGs was constructed. Correlation analysis between the risk score of our model and tumor-infiltrating cell were also investigated.

Results: Twenty two IRGs were significantly associated with the clinical outcomes of RTK patients. Gene ontology (GO) analysis revealed that inflammatory pathways were most frequently implicated in RTK. A prognostic model was constructed using 7 IRGs (MMP9, SERPINA3, FAM19A5, CCR9, PLAUR, IL1R2, PRKCG), which were independent prognostic indices that could differentiate patients based on their survival outcomes. Furthermore, the risk scores from our prognostic model was positively associated with cancer-associated fibroblasts (CAFs).

Conclusions: We screened seven IRGs of clinical significance to distinguish patients with different survival outcomes. This may enhance our understanding of the immune microenvironment of RTK and could use to design individualized treatments for RTK patients.

Epigenetic Alterations in the Gastrointestinal Tract: Current and Emerging Use for Biomarkers of Cancer

Colorectal cancer, liver cancer, stomach cancer, pancreatic cancer, and esophageal cancer are leading causes of cancer-related deaths worldwide. A fundamental trait of virtually all gastrointestinal cancers is genomic and epigenomic DNA alterations. Cancer cells acquire genetic and epigenetic alterations that drive the initiation and progression of the cancers by altering the molecular and cell biological processes of the cells. These alterations, as well as other host and microenvironment factors, ultimately mediate the clinical behavior of the precancers and cancers and can be used as biomarkers for cancer risk determination, early detection of cancer and precancer, determination of the prognosis of cancer and prediction of the response to therapy. Epigenetic alterations have emerged as one of most robust classes of biomarkers and are the basis for a growing number of clinical tests for cancer screening and surveillance.

DNA methylation markers detected in blood, stool, urine, and tissue in colorectal cancer: a systematic review of paired samples

PURPOSE

Methylated cell-free DNA in liquid biopsies are promising non-invasive biomarkers for colorectal cancer (CRC). Optimal markers would have high sensitivity and specificity for early detection of CRC and could be detected in more than one type of material from the patient. We systematically reviewed the literature on DNA methylation markers of colorectal cancer, detected in more than one type of material, regarding their potential as contributors to a panel for screening and follow-up of CRC.

METHODS

The databases MEDLINE, Web of Science, and Embase were systematically searched. Data extraction and review was performed by two authors independently. Agreement between methylation status in tissue and other materials (blood/stool/urine) was analyzed using the McNemar test and Cohen's kappa.

RESULTS

From the 51 included studies, we identified seven single markers with sensitivity ≥ 75% and specificity ≥ 90% for CRC. We also identified one promising plasma panel and two stool panels. The correspondence of methylation status was evaluated as very good for four markers, but only marginal for most of the other markers investigated (12 of 21).

CONCLUSION

The included studies reported only some of the variables and markers of interest and included few patients. Hence, a meta-analysis was not possible at this point. Larger, prospective studies must be designed to study the discordant detection of markers in tissue and liquid biopsies. When reporting their findings, such studies should use a standardized format.

A multi-scale integrated analysis identifies KRT8 as a pan-cancer early biomarker

An early biomarker would transform our ability to screen and treat patients with cancer. The large amount of multi-scale molecular data in public repositories from various cancers provide unprecedented opportunities to find such a biomarker. However, despite identification of numerous molecular biomarkers using these public data, fewer than 1% have proven robust enough to translate into clinical practice. One of the most important factors affecting the successful translation to clinical practice is lack of real-world patient population heterogeneity in the discovery process. Almost all biomarker studies analyze only a single cohort of patients with the same cancer using a single modality. Recent studies in other diseases have demonstrated the advantage of leveraging biological and technical heterogeneity across multiple independent cohorts to identify robust disease biomarkers. Here we analyzed 17149 samples from patients with one of 23 cancers that were profiled using either DNA methylation, bulk and single-cell gene expression, or protein expression in tumor and serum. First, we analyzed DNA methylation profiles of 9855 samples across 23 cancers from The Cancer Genome Atlas (TCGA). We then examined the gene expression profile of the most significantly hypomethylated gene, KRT8, in 6781 samples from 57 independent microarray datasets from NCBI GEO. KRT8 was significantly over-expressed across cancers except colon cancer (summary effect size=1.05; p < 0.0001). Further, single-cell RNAseq analysis of 7447 single cells from lung tumors showed that genes that significantly correlated with KRT8 (p < 0.05) were involved in p53-related pathways. Immunohistochemistry in tumor biopsies from 294 patients with lung cancer showed that high protein expression of KRT8 is a prognostic marker of poor survival (HR = 1.73, p = 0.01). Finally, detectable KRT8 in serum as measured by ELISA distinguished patients with pancreatic cancer from healthy controls with an AUROC=0.94. In summary, our analysis demonstrates that KRT8 is (1) differentially expressed in several cancers across all molecular modalities and (2) may be useful as a biomarker to identify patients that should be further tested for cancer.

Fecal DNA methylation markers for detecting stages of colorectal cancer and its precursors: a systematic review

Background

DNA methylation biomarkers in stool may have applications in early colorectal cancer (CRC) detection; however, their association with stages of CRC carcinogenesis or their performance in detecting various stages is unclear. We aimed to systematically review the evidence for DNA methylation markers in stool for risk stratification or detection of specific CRC stages, as well as precursors of CRC.

Methods

We conducted a systematic search in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched PubMed and ISI Web of Knowledge to identify relevant studies published until 14th January 2020. Two reviewers independently extracted data on study population characteristics, candidate genes, methylation measurement methods, odds ratios (ORs), overall and stage-specific sensitivities, specificities, areas under the receiver operating characteristics curve, and p-values for statistical significance for OR and for association of methylation levels with stage.

Results

Twenty-seven studies that reported stage-specific associations or performances of fecal DNA methylation markers for detecting colorectal neoplasms were identified. All studies used methylation-specific polymerase chain reaction for assessing methylation levels in the promoter or exon 1 regions of targeted genes. However, most studies were underpowered and limited by their case-control design. Furthermore, the stage-specific associations or sensitivities were validated for two markers (hypermethylation of GATA4 and VIM) only.

Conclusion

Methylation markers in stool may be useful for detection of CRC precursors or CRC staging, but promising candidate markers need to be validated in longitudinal studies on large screening populations, performing epigenome-wide analyses. Identification of stage-specific DNA methylation biomarkers in stool could boost current strategies towards early detection and enable different approaches to precision medicine for CRC.

A novel miRNA located in the GATA4 gene regulates the expression of IGF-1R and AKT1/2 genes and controls cell proliferation

GATA4 gene is a zinc-finger transcription factor known to be involved in cardiogenesis and the progression of different cancer types. Its diverse functions might be attributed to noncoding RNAs that could be embedded within its sequence. Here, we predicted a stable RNA stem-loop structure that is located in the second intron of the GATA4 gene. Available microRNA (miRNA) sequencing data and molecular genetics tools confirmed the identity of a mature miRNA (named GATA4-miR1) originating from the predicted stem-loop. In silico analysis predicted IGF-1R and AKT1/2 genes as potential targets for GATA4-miR1. Indeed, direct interactions between GATA4-miR1 and 3' untranslated regions sequences of IGF-1R and AKT1/2 genes were documented by dual luciferase assay. In addition, overexpression of GATA4-miR1 in SW480 cells resulted in the reduction of IGF-1R and AKT1/2 genes' expression, detected by reverse transcription quantitative (RT-q) polymerase chain reaction and Western blot analysis. This observation was consistent with a deduced negative correlation between the expression patterns of GATA4-miR1 and IGF-1R genes during cardiomyocyte differentiation. Moreover, overexpressing GATA4-miR1 in SW480 and PC3 cells resulted in a significant increase of the sub-G1 population in both cell lines, as detected by propidium iodide flow cytometry. Further analysis by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay indicated a reduction in the survival and proliferation rates of SW480 cells overexpressing GATA4-miR1, but no impact was observed on apoptosis progression, as indicated by Annexin-V flow cytometry. Overall, GATA4-miR1 represents a promising candidate for further research in the fields of cancer and cardiovascular therapeutics.

The zinc finger protein GATA4 induces mesenchymal-to-epithelial transition and cellular senescence through the nuclear factor-κB pathway in hepatocellular carcinoma

BACKGROUND AND AIM

The high mortality and poor prognosis of hepatocellular carcinoma (HCC) have raised the public attention. Gene therapy is considered as a promising treatment option for cancer; thus, finding a new therapeutic target for HCC is urgently needed. GATA4 is a tumor suppressor gene in multiple cancers, but its role in HCC is unclear. In this study, we explored the function of GATA4 in HCC.

METHODS

Reverse transcription-polymerase chain reaction and quantitative polymerase chain reaction were used to detect the mRNA expression of GATA4 in HCC cells and tissues. Cell viability, transwell, colony formation, and flow cytometry assays were applied to examine different aspects of biological effects of GATA4 in vitro. Xenografts, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling assays were performed to evaluate the effect of GATA4 on tumorigenicity in vivo. Western blotting, immunofluorescence, and β-galactosidase staining were used to investigate the mechanism underlying the function of GATA4.

RESULTS

We found that GATA4 was silenced in 15/19 (79%) HCC tissues. Restoring the expression of GATA4 induced G₀ /G₁ phase arrest, promoted apoptosis, suppressed HCC proliferation in vitro, and inhibited HCC tumor growth in vivo. Our data further showed that the ectopic expression of GATA4 induced cellular senescence through regulating nuclear factor-κB and inducing mesenchymal-to-epithelial transition.

CONCLUSIONS

Our data demonstrated that by inducing cellular senescence and mesenchymal-to-epithelial transition, GATA4 plays a crucial role as a tumor suppressor in HCC. It may thus be a potential cancer therapeutic target for HCC.

Promoter hypermethylation in ductal carcinoma in situ of the male breast

Ductal carcinoma in situ (DCIS) of the male breast is very rare and has hardly been studied molecularly. In males, we compared methylation status of 25 breast cancer-related genes in pure DCIS (n = 18) and invasive breast carcinoma (IBC) with adjacent DCIS (DCIS-AIC) (n = 44) using methylation-specific multiplex ligation-dependent probe amplification. Results were compared to female breast cancer (BC). There were no significant differences in methylation features between male pure DCIS, DCIS-AIC and IBC after correction for multiple comparisons. In paired analysis of IBC and adjacent DCIS, CADM1 showed a significantly higher absolute methylation percentage in DCIS (P = 0.002). In cluster analysis, two clusters stood out with respectively infrequent and frequent methylation (GATA5, KLLN, PAX6, PAX5, CDH13, MSH6 and WT1 were frequently methylated). Compared to female DCIS, methylation was in general much less common in male DCIS, especially for VHL, ESR1, CDKN2A, CD44, CHFR, BRCA2, RB1 and STK11. In contrast, THBS1 and GATA5 were more frequently methylated in male DCIS. In conclusion, there is frequent methylation of GATA5, KLLN, PAX6, PAX5, CDH13, MSH6 and WT1 in male DCIS. Since there was little change in the methylation status for the studied genes from pure male DCIS to DCIS-AIC and IBC, methylation of these seven genes is more likely to occur early in male breast carcinogenesis. Based on the current markers male DCIS seems to be an epigenetically more advanced precursor of male BC, although in comparison to its female counterpart it appears that fewer loci harbor methylation, pointing to differences between male and female breast carcinogenesis with regard to the studied loci.

Novel roles for GATAe in growth, maintenance and proliferation of cell populations in the Drosophila renal tubule

The GATA family of transcription factors is implicated in numerous developmental and physiological processes in metazoans. In Drosophila melanogaster, five different GATA factor genes (pannier, serpent, grain, GATAd and GATAe) have been reported as essential in the development and identity of multiple tissues, including the midgut, heart and brain. Here, we present a novel role for GATAe in the function and homeostasis of the Drosophila renal (Malpighian) tubule. We demonstrate that reduced levels of GATAe gene expression in tubule principal cells induce uncontrolled cell proliferation, resulting in tumorous growth with associated altered expression of apoptotic and carcinogenic key genes. Furthermore, we uncover the involvement of GATAe in the maintenance of stellate cells and migration of renal and nephritic stem cells into the tubule. Our findings of GATAe as a potential master regulator in the events of growth control and cell survival required for the maintenance of the Drosophila renal tubule could provide new insights into the molecular pathways involved in the formation and maintenance of a functional tissue and kidney disease.

UHRF1 depletion and HDAC inhibition reactivate epigenetically silenced genes in colorectal cancer cells

BACKGROUND

Ubiquitin-like protein containing PHD and RING finger domains 1 (UHRF1) is a major regulator of epigenetic mechanisms and is overexpressed in various human malignancies. In this study, we examined the involvement of UHRF1 in aberrant DNA methylation and gene silencing in colorectal cancer (CRC).

RESULTS

CRC cell lines were transiently transfected with siRNAs targeting UHRF1, after which DNA methylation was analyzed using dot blots, bisulfite pyrosequencing, and Infinium HumanMethylation450 BeadChip assays. Gene expression was analyzed using RT-PCR and gene expression microarrays. Depletion of UHRF1 rapidly induced genome-wide DNA demethylation in CRC cells. Infinium BeadChip assays and bisulfite pyrosequencing revealed significant demethylation across entire genomic regions, including CpG islands, gene bodies, intergenic regions, and repetitive elements. Despite the substantial demethylation, however, UHRF1 depletion only minimally reversed CpG island hypermethylation-associated gene silencing. By contrast, the combination of UHRF1 depletion and histone deacetylase (HDAC) inhibition reactivated the silenced genes and strongly suppressed CRC cell proliferation. The combination of UHRF1 depletion and HDAC inhibition also induced marked changes in the gene expression profiles such that cell cycle-related genes were strikingly downregulated.

CONCLUSIONS

Our results suggest that (i) maintenance of DNA methylation in CRC cells is highly dependent on UHRF1; (ii) UHRF1 depletion rapidly induces DNA demethylation, though it is insufficient to fully reactivate the silenced genes; and (iii) dual targeting of UHRF1 and HDAC may be an effective new therapeutic strategy.

DNA Methylation of Tumor Suppressor Genes in Pituitary Neuroendocrine Tumors

CONTEXT

Epigenetic alterations may play a role in the development and behavior of pituitary neuroendocrine tumors (PitNETs).

OBJECTIVE

To evaluate the effect of methylation of tumor suppressor genes (TSGs) on their gene expression and on the behavior of PitNETs.

MATERIAL AND METHODS

We used methylation-specific multiplex ligation-dependent probe amplification and quantitative real-time PCR techniques to analyze the DNA-promoter hypermethylation and gene expression of 35 TSGs in 105 PitNETs. We defined functionality, size, and invasiveness of tumors according to their clinical manifestations, Hardy's classification, and MRI invasiveness of the cavernous sinus, respectively.

RESULTS

We observed different methylation patterns among PitNET subtypes. The methylation status of TP73 correlated negatively with its gene expression in the overall series (P = 0.013) and in some subtypes. MSH6 and CADM1 showed higher methylation frequency in macroadenomas than in microadenomas in the overall series and in corticotroph PitNETs (all P ≤ 0.053). ESR1 and RASSF1 were more highly methylated in noninvasive than in invasive tumors in the overall series (P = 0.054 and P = 0.031, respectively) and in the gonadotroph subtype (P = 0.055 and P = 0.050, respectively). ESR1 and CASP8 appeared more hypermethylated in functioning than in silent corticotroph tumors (P = 0.034 and P = 0.034, respectively).

CONCLUSIONS

DNA methylation of TSGs has a selective effect on their gene expression and on the growth and invasiveness of PitNETs. Its involvement in their functionality is biased because all silent operated tumors are macroadenomas, whereas all operated microadenomas are functioning ones. Therefore, the subtypes of PitNETs should be considered different entities.

Pioneer Factors and Architectural Proteins Mediating Embryonic Expression Signatures in Cancer

Accumulation of mutations causing aberrant changes in the genome promotes cancer. However, mutations do not occur in every cancer subtype, suggesting additional events that trigger cancer. Chromatin rearrangements initiated by pioneer factors and architectural proteins are key events occurring before cancer-related genes are expressed. Both protein groups are also master regulators of important processes during embryogenesis. Several publications demonstrated that embryonic gene expression signatures are reactivated during cancer. This review article highlights current knowledge on pioneer factors and architectural proteins mediating chromatin rearrangements, which are the backbone of embryonic expression signatures promoting malignant transformation. Understanding chromatin rearrangements inducing embryonic expression signatures in adult cells might be the key to novel therapeutic approaches against cancers subtypes that arise without genomic mutations.

GATA5 inhibits hepatocellular carcinoma cells malignant behaviours by blocking expression of reprogramming genes

Evidence indicated that GATA5 may suppress hepatocellular carcinoma (HCC) cell malignant transformation, but the mechanism of how GATA5 affects cancer cell reprogramming to inhibit HCC malignant behaviour is still unclear. In this study, we report that the expression of β‐catenin and reprogramming genes p‐Oct4, Nanog, Klf4, c‐myc and EpCAM was significantly higher in HCC tissues compared to normal liver tissues. In contrast, the expression of GATA5 was significantly lower in HCC tissues compared to normal liver tissues. Transfection of CDH‐GATA5 vectors into HCC cells (HLE, Bel 7402 and PLC/PRF/5 cells) increased the GATA5 expression and decreased the expression of β‐catenin and reprogramming genes p‐Oct4, Nanog, Klf4, c‐myc and EpCAM. Increased GATA5 expression by transfection with its expression vectors was also able to inhibit the cell growth, colony formation and capability of migration, invasion, while promoting apoptosis in HCC cells. Results revealed that GATA5 co‐localization with β‐catenin in the cytoplasm, preventing β‐catenin from entering the nucleus. Treatment with the specific Wnt/β‐catenin pathway inhibitor salinomycin was able to reduce the expression of β‐catenin and reprogramming genes. Salinomycin exerted a similar influence as GATA5, and siRNA‐GATA5 restored β‐catenin and reprogramming gene expression. This study demonstrates that an increase in the expression of GATA5 inhibits the expression of β‐catenin and reprogramming genes and suppresses tumour growth, colony formation, metastasis and invasion, while promoting apoptosis in HCC cells. The mechanism of GATA5 inhibiting the malignant behaviours of HCC cells may involve in the disruption of the Wnt/β‐catenin pathway and the reduction of reprogramming gene expression.

A systematic review and quantitative assessment of methylation biomarkers in fecal DNA and colorectal cancer and its precursor, colorectal adenoma

Colorectal cancer (CRC) arises from accumulated genetic and epigenetic alterations, which provide the possibility to identify tumor-specific biomarkers by analyzing fecal DNA. Methylation status in human genes from tumor tissue is highlighted as promising biomarker in the early detection of CRC. A number of studies have documented altered methylation levels in DNA extracted from stool samples, but generated heterogeneous results. We performed a systematic review and quantitative assessment of existing studies to compare levels of DNA methylation in most frequently studied genes and their diagnostic value in CRC and its precursor, colorectal adenoma, with their counterparts in healthy subjects. Robust searches of the literature were performed in our study with explicit strategies and definite inclusion/exclusion criteria. Pooled data revealed that methylation levels of SFRP2, SFRP1, TFPI2, BMP3, NDRG4, SPG20, and BMP3 plus NDRG4 genes exceeded a sensitivity of 70% and a specificity of 80% for CRC detection. The DOR of the seven candidate biomarkers ranged from 19.80 to 334.33, indicating a good diagnostic power in discriminating cancer from normal tissues. The AUC range was from 0.88 to 0.95, indicating a good or very good discriminatory performance. When test results for BMP3 and NDRG4 were combined, the DOR of CRC detection was 98.36, which was higher than that for BMP3 and NDRG4 separately. As for adenoma detection, the DOR of methylated NDRG4 is higher than that for CRC (CRC vs. adenoma: 54.86 vs. 57.22). Both the sensitivity and specificity of NDRG4 for adenoma detection exceeded 70%. These findings demonstrate the eligibility and feasibility of DNA methylation as a minimally invasive biomarker in feces in the diagnosis of CRC and adenoma. The use of DNA from human stools has the potential to be readily applicable to detect aberrant DNA methylation levels among many subjects for CRC early screening.

Testicular Cancer: Genes, Environment, Hormones

Testicular cancer (TC) represents one of the most peculiar clinical challenges at present. In fact, currently treatments are so effective ensuring a 5 years disease-free survival rate in nearly 95% of patients. On the other hand however, TC represents the most frequent newly diagnosed form of cancer in men between the ages of 14 and 44 years, with an incidence ranging from <1 to 9.9 affected individuals per 100,000 males across countries, while the overall incidence is also increasing worldwide. Furthermore, cancer survivors show a 2% risk of developing cancer in the contralateral testis within 15 years of initial diagnosis. This complex and multifaceted scenario requires a great deal of effort to understand the clinical base of available evidence. It is now clear that genetic, environmental and hormonal risk factors concur and mutually influence both the development of the disease and its prognosis, in terms of response to treatment and the risk of recurrence. In this paper, the most recent issues describing the relative contribution of the aforementioned risk factors in TC development are discussed. In addition, particular attention is paid to the exposure to environmental chemical substances and thermal stress, whose role in cancer development and progression has recently been investigated at the molecular level.

Prognostic Values of EPDR1 Hypermethylation and Its Inhibitory Function on Tumor Invasion in Colorectal Cancer

Aberrant DNA methylation is a potential mechanism underlying the development of colorectal cancer (CRC). Thus, identification of prognostic DNA methylation markers and understanding the related molecular functions may offer a new perspective on CRC pathogenesis. To that end, we explored DNA methylation profile changes in CRC subtypes based on the microsatellite instability (MSI) status through genome-wide DNA methylation profiling analysis. Of 34 altered genes, three hypermethylated (epidermal growth factor, EGF; carbohydrate sulfotransferase 10, CHST10; ependymin related 1, EPDR1) and two hypomethylated (bone marrow stromal antigen 2, BST2; Rac family small GTPase 3, RAC3) candidates were further validated in CRC patients. Based on quantitative methylation-specific polymerase chain reaction (Q-MSP), EGF, CHST10 and EPDR1 showed higher hypermethylated levels in CRC tissues than those in adjacent normal tissues, whereas BST2 showed hypomethylation in CRC tissues relative to adjacent normal tissues. Additionally, among 75 CRC patients, hypermethylation of CHST10 and EPDR1 was significantly correlated with the MSI status and a better prognosis. Moreover, EPDR1 hypermethylation was significantly correlated with node negativity and a lower tumor stage as well as with mutations in B-Raf proto-oncogene serine/threonine kinase (BRAF) and human transforming growth factor beta receptor 2 (TGFβR2). Conversely, a negative correlation between the mRNA expression and methylation levels of EPDR1 in CRC tissues and cell lines was observed, revealing that DNA methylation has a crucial function in modulating EPDR1 expression in CRC cells. EPDR1 knockdown by a transient small interfering RNA significantly suppressed invasion by CRC cells, suggesting that decreased EPDR1 levels may attenuate CRC cell invasion. These results suggest that DNA methylation-mediated EPDR1 epigenetic silencing may play an important role in preventing CRC progression.

Restoration of GATA4 expression impedes breast cancer progression by transcriptional repression of ReLA and inhibition of NF-κB signaling

There are increasing reports of aberrant expression of GATA4, correlated with oncogenesis and malignant progression in some solid tumors, but whether GATA4 functions as an oncogenic driver or a tumor suppressor in carcinogenesis remains controversial. Because the role and mechanism of GATA4 in breast cancer (BrCa) remain poorly understood, we focused on the expression of GATA4 in BrCa cell lines and tissues and its mechanism in breast oncogenesis. Semiquantitative real-time polymerase chain reaction (RT-PCR), quantitative RT-PCR, Western blot analysis, and immunohistochemistry were used to detect expression of GATA4 in BrCa cell lines and adjacent breast tissues. Methylation statuses of the GATA4 promoter were studied using methylation-specific PCR in BrCa cell lines.The effects of GATA4 on proliferation, invasion, and cell cycle were also analyzed. Compared with adjacent breast tissue, GATA4 expression in BrCa tissue and cell lines was obviously lower and low expression levels of GATA4 predicted poor outcome. Methylation of GATA4 occurred in almost all of BrCa cell lines . GATA4 overexpression decreased viability, invasion, migration, and epithelial-to-mesenchymal transition of MB-231 and BT549 cells, and markedly induced cell cycle arrest and apoptosis. Exogenous expression GATA4 accompanied a significant alteration of MMP2, MMP3, E-cadherin, and N-cadherin expression and induction of the caspase-8 pathway. Moreover, GATA4 could directly repress RelA (p65) transcription, reduce the nuclear phosphorylation-p65 and upregulate inhibitor kappa B expression. Altogether, GATA4 plays a tumor-suppressive role via repression of NF-κB signaling in BrCa cells. Our findings suggest that GATA4 is a potential prognostic biomarker and gene therapeutic target for human BrCa.

GATA4 inhibits cell differentiation and proliferation in pancreatic cancer

Pancreatic ductal carcinoma (PDAC) is a common malignant tumor of the digestive system. GATA4 is one of the transcriptional regulatory factors, which regulates the development of endoderm-derived organs, including heart and gut. GATA4 may act as a putative tumor suppressor gene. However, the role of GATA4 in pancreatic carcinogenesis is not yet clarified. This study showed that GATA4 was highly expressed in pancreatic cancer tissues, and its expression level was positively related to the grade of pathological differentiation, suggesting that it may contribute to the progression of pancreatic neoplasia. Ectopic expression of GATA4 gene reduced cell viability and interference of GATA4 expression significantly increased the colony formation ability of pancreatic cancer cells. Furthermore, GATA4 inhibited tumor growth in xenograft mice. Agilent expression microarray profiling analysis indicated that the genes with significant levels of differential expression in GATA4 over-expressing cells were enriched in the cell differentiation process. Analysis of KEGG signaling pathway demonstrated that the regulated genes were partially enriched in MAPK and JAK-STAT signaling pathways. Re-expression of GATA4 up-regulated P53 gene expression. Our data indicate that GATA4 gene might play a role in cell proliferation and differentiation during the progression of pancreatic cancer.

The importance of stool DNA methylation in colorectal cancer diagnosis: A meta-analysis

A large number of tumor-related methylated genes have been suggested to be of diagnostic and prognostic values for CRC when analyzed in patients' stool samples; however, reported sensitivities and specificities have been inconsistent and widely varied. This meta-analysis was conducted to assess the detection accuracy of stool DNA methylation assay in CRC, early stages of CRC (advanced adenoma, non-advanced adenomas) and hyperplastic polyps, separately. We searched MEDLINE, Web of Science, Scopus and Google Scholar databases until May 1, 2016. From 469 publications obtained in the initial literature search, 38 studies were included in the final analysis involving 4867 individuals. The true positive, false positive, true negative and false negative of a stool-based DNA methylation biomarker using all single-gene tests considering a certain gene; regardless of a specific gene were pooled and studied in different categories. The sensitivity of different genes in detecting different stages of CRC ranged from 0% to 100% and the specificities ranged from 73% to 100%. Our results elucidated that SFRP1 and SFRP2 methylation possessed promising accuracy for detection of not only CRC (DOR: 31.67; 95%CI, 12.31-81.49 and DOR: 35.36; 95%CI, 18.71-66.84, respectively) but also the early stages of cancer, adenoma (DOR: 19.72; 95%CI, 6.68-58.25 and DOR: 13.20; 95%CI, 6.01-28.00, respectively). Besides, NDRG4 could be also considered as a significant diagnostic marker gene in CRC (DOR: 24.37; 95%CI, 10.11-58.73) and VIM in adenoma (DOR: 15.21; 95%CI, 2.72-85.10). In conclusion, stool DNA hypermethylation assay based on the candidate genes SFRP1, SFRP2, NDRG4 and VIM could offer potential diagnostic value for CRC based on the findings of this meta-analysis.

Methylation-Mediated Silencing of GATA5 Gene Suppresses Cholangiocarcinoma Cell Proliferation and Metastasis

Cholangiocarcinoma (CCA) is one of the most common hepatic and biliary malignancies, accounting for about 3% of all gastrointestinal tumors. GATA5 is a transcription factor capable of suppressing the development of various human cancer types. Transcriptional inactivation and CpG island (CGI) methylation of GATA3 and GATA5, two members of the GATA family of transcription factors, have been observed in some human cancers. But whether high-density CGI methylation of GATA5 is associated with the clinical course of CCA patients has not been clarified. Herein, we observed reduced expression of GATA5 in CCA tissues compared with noncancerous tissues. Treatment with the demethylating agent 5-aza-2'-deoxycytidine restored GATA5 expression in CCA cell lines. Furthermore, GATA5 expression was downregulated after treatment with IL-6 in human intrahepatic biliary epithelial cells. Upregulated GATA5 inhibited CCA cell growth and metastasis. Mechanistically, GATA5 suppressed CCA cell growth and metastasis via Wnt/β-catenin pathway. Specific β-catenin inhibitor or siRNA abolished the discrepancy of the proliferation and metastasis capacity between GATA5-overexpression CCA cells and their control cells, which further confirmed that Wnt/β-catenin was required in GATA5-inhibited CCA cell growth and metastasis.

ADAM17 is required for EGF-R-induced intestinal tumors via IL-6 trans-signaling

Schmidt et al. show that loss of the membrane-bound metalloprotease ADAM17 led to impaired intestinal cancer development in the murine APC^min/+ model, which also depended on IL-6 trans-signaling via the soluble IL-6R and could be blocked by the specific IL-6 trans-signaling inhibitor sgp130Fc.

Colorectal cancer is treated with antibodies blocking epidermal growth factor receptor (EGF-R), but therapeutic success is limited. EGF-R is stimulated by soluble ligands, which are derived from transmembrane precursors by ADAM17-mediated proteolytic cleavage. In mouse intestinal cancer models in the absence of ADAM17, tumorigenesis was almost completely inhibited, and the few remaining tumors were of low-grade dysplasia. RNA sequencing analysis demonstrated down-regulation of STAT3 and Wnt pathway components. Because EGF-R on myeloid cells, but not on intestinal epithelial cells, is required for intestinal cancer and because IL-6 is induced via EGF-R stimulation, we analyzed the role of IL-6 signaling. Tumor formation was equally impaired in IL-6^−/− mice and sgp130Fc transgenic mice, in which only trans-signaling via soluble IL-6R is abrogated. ADAM17 is needed for EGF-R–mediated induction of IL-6 synthesis, which via IL-6 trans-signaling induces β-catenin–dependent tumorigenesis. Our data reveal the possibility of a novel strategy for treatment of colorectal cancer that could circumvent intrinsic and acquired resistance to EGF-R blockade.

Methylation markers differentiate thyroid cancer from benign nodules

PURPOSE

The incidence of thyroid cancer (TC) is increasing. Cytology by itself cannot distinguish TC from some benign nodules especially in certain subtypes of TC. Our immediate goal is to identify DNA methylation markers for early detection of TC and to molecularly differentiate TC subtypes from benign nodules.

METHODS

Promoter methylation status of 21 candidate genes was examined on formalin-fixed paraffin-embedded tissue (FFPE) utilizing quantitative methylation-specific polymerase chain reaction (QMSP) in a retrospective cohort of 329 patients (56% white, 29% African American, 61% female) comprising 71 normal thyroid, 83 benign nodules [follicular adenomas (FA)], 90 follicular TC (FTC) and 85 papillary TC (PTC). All genes were analyzed individually (Kruskal-Wallis and Wilcoxon rank sum tests) and in combination (logistic regression models) to identify genes whose methylation levels might best separate groups.

RESULTS

Combination gene panels TPO and UCHL1 (ROC = 0.607, sensitivity 78%) discriminated FTC from FA, and RASSF1 and TPO (ROC = 0.881, sensitivity 78%) discriminated FTC from normal. Methylation of TSHR distinguished PTC from FTC (ROC = 0.701, sensitivity 84%) and PTC from FA (ROC = 0.685, sensitivity 70%). The six gene panel of TIMP3, RARB2, SERPINB5, RASSF1, TPO and TSHR, which differentiates PTC from normal thyroid, had the best combination sensitivity (91%) and specificity (81%) of the panels addressing discrimination of cancer tissue.

CONCLUSIONS

Aberrant gene methylation used in combination panels may be useful clinically in differentiating FTC and PTC from benign nodules. If confirmed in additional studies, these findings could help reduce the over diagnosis of thyroid cancer and surgeries related to over diagnosis.

Aberrant DNA Methylation in Colorectal Cancer: What Should We Target?

Colorectal cancers (CRCs) are characterized by global hypomethylation and promoter-specific DNA methylation. A subset of CRCs with extensive and co-ordinate patterns of promoter methylation has also been identified, termed the CpG-island methylator phenotype. Some genes methylated in CRC are established tumor suppressors; however, for the majority, direct roles in disease initiation or progression have not been established. Herein, we examine functional evidence of specific methylated genes contributing to CRC pathogenesis, focusing on components of commonly deregulated signaling pathways. We also review current knowledge of the mechanisms underpinning promoter methylation in CRC, including genetic events, altered transcription factor binding, and DNA damage. Finally, we summarize clinical trials of DNA methyltransferase inhibitors in CRC, and propose strategies for enhancing their efficacy.