Epigenetic Alteration by DNA Methylation of ESR1, MYOD1 and hTERT Gene Promoters is Useful for Prediction of Response in Patients of Locally Advanced Invasive Cervical Carcinoma Treated by Chemoradiation

An epigenomic landscape of cervical intraepithelial neoplasia and cervical cancer using single-base resolution methylome and hydroxymethylome

BACKGROUND

Cervical cancer (CC) is the second leading cause of cancer death among women worldwide. Epigenetic regulation of gene expression through DNA methylation and hydroxymethylation plays a pivotal role during tumorigenesis. In this study, to analyze the epigenomic landscape and identify potential biomarkers for CCs, we selected a series of samples from normal to cervical intra-epithelial neoplasia (CINs) to CCs and performed an integrative analysis of whole-genome bisulfite sequencing (WGBS-seq), oxidative WGBS, RNA-seq, and external histone modifications profiling data.

RESULTS

In the development and progression of CC, there were genome-wide hypo-methylation and hypo-hydroxymethylation, accompanied by local hyper-methylation and hyper-hydroxymethylation. Hydroxymethylation prefers to distribute in the CpG islands and CpG shores, as displayed a trend of gradual decline from health to CIN2, while a trend of increase from CIN3 to CC. The differentially methylated and hydroxymethylated region-associated genes both enriched in Hippo and other cancer-related signaling pathways that drive cervical carcinogenesis. Furthermore, we identified eight novel differentially methylated/hydroxymethylated-associated genes (DES, MAL, MTIF2, PIP5K1A, RPS6KA6, ANGEL2, MPP, and PAPSS2) significantly correlated with the overall survival of CC. In addition, no any correlation was observed between methylation or hydroxymethylation levels and somatic copy number variations in CINs and CCs.

CONCLUSION

Our current study systematically delineates the map of methylome and hydroxymethylome from CINs to CC, and some differentially methylated/hydroxymethylated-associated genes can be used as the potential epigenetic biomarkers in CC prognosis.

miR-130a-3p promotes cell proliferation and invasion by targeting estrogen receptor α and androgen receptor in cervical cancer

Cervical cancer is the most common gynecological cancer in women worldwide. Human papillomavirus (HPV) is required but not sufficient for developing cervical cancer. HPV E6 and E7 proteins are able to directly interact with certain nuclear receptors; however, whether steroid hormone receptors mediate cervical carcinogenesis is not completely understood. The present study demonstrated via immunohistochemistry that estrogen receptor α (ERα) and androgen receptor (AR) expression were decreased in a sequential manner from healthy cervical tissues to cervical intraepithelial neoplasia tissues and further to cervical cancer (CC) tissues, whereas microRNA (miR)-130a-3p expression levels were higher in CC tissues compared with healthy tissues. Both ERα and AR were direct targets of miR-130a-3p, as determined by performing luciferase reporter assays and western blotting. Functionally, compared with the corresponding control groups, miR-130a-3p knockdown, ERα overexpression and AR overexpression significantly inhibited CC cell proliferation and invasion, as demonstrated by the results obtained from the Cell Counting Kit-8 and Transwell assays in vitro. In addition, antagomiR-130a decreased tumor size and weight in vivo compared with control antagomiR as determined via the xenograft tumor growth assay. Therefore, the results suggested that miR-130a-3p might contribute to tumor progression by suppressing ERα and AR, and serve as a promising candidate target for the treatment of patients with CC.

An initiative to assess the quality of Tanzanian cervical cancer specimens for HPV and telomerase detection

The aim of our study was to assess the quality of Tanzanian cervical cancer specimens, evaluating telomerase alterations and human papilloma virus (HPV) infection in relation to histopathological characteristics since these biomarkers are not routinely analyzed. Thirty-two Tanzanian women with invasive cervical cancer were included in the study. Histopathological classification and all the analyses on tissue, including TERT immunohistochemistry, were performed at IRST IRCCS (Meldola, Italy). HPV typization was performed by pyrosequencing. FHACT™ was used to identify chromosomal aberrations. Nonparametric ranking statistics were used. The majority (75 %) of the cases analyzed were squamous carcinoma, while 12.5 % were adenocarcinoma. The presence of HPV infection was confirmed in 26/27 (96.3 %) cases. A high percentage of patients (88 %) were infected with HPV16 of whom 12 (44.4 %) with African type 1, and 4 (14.8 %) with African type 2. TERT expression evaluated in the entire case series showed a median H-score of 130 (range 3-270), with only one negative case. 88 % of the FISH-evaluable samples showed an amplification of the chromosomal region 3q26 (TERC) and/or 5p15, and 20q13, associated with a higher median expression of TERT (P = 0.0226). Despite pre-analytical problems in terms of sample fixation, we showed that the search for biomarkers such as HPV and telomerase is feasible in Tanzanian tissue. These markers could be important risk-stratification tools in this population.

Marek's Disease Virus (Gallid alphaherpesvirus 2)-Encoded miR-M2-5p Simultaneously Promotes Cell Proliferation and Suppresses Apoptosis Through RBM24 and MYOD1-Mediated Signaling Pathways

MicroRNAs (miRNAs) have been demonstrated for their involvement in virus biology and pathogenesis, including functioning as key determinants of virally-induced cancers. As an important oncogenic α-herpesvirus affecting poultry health, Marek’s disease virus serotype 1 [Gallid alphaherpesvirus 2 (GaHV-2)] induces rapid-onset T-cell lymphomatous disease commonly referred to as Marek’s disease (MD), an excellent biological model for the study of virally-induced cancer in the natural hosts. Previously, we have demonstrated that GaHV-2-encoded miRNAs (especially those within the Meq-cluster) have the potential to act as critical regulators of multiple processes such as virus replication, latency, pathogenesis, and/or oncogenesis. In addition to miR-M4-5p (miR-155 homolog) and miR-M3-5p, we have recently found that miR-M2-5p possibly participate in inducing MD lymphomagenesis. Here, we report the identification of two tumor suppressors, the RNA-binding protein 24 (RBM24) and myogenic differentiation 1 (MYOD1), being two biological targets for miR-M2-5p. Our experiments revealed that as a critical miRNA, miR-M2-5p promotes cell proliferation via regulating the RBM24-mediated p63 overexpression and MYOD1-mediated IGF2 signaling and suppresses apoptosis by targeting the MYOD1-mediated Caspase-3 signaling pathway. Our data present a new strategy of a single viral miRNA exerting dual role to potentially participate in the virally-induced T-cell lymphomagenesis by simultaneously promoting the cell proliferation and suppressing apoptosis.

The variable association between expression and methylation of estrogen receptors and the survival of patients with different tumors

BACKGROUND

Estrogen receptor (ER) is essential in reproductive development and is also the primary driver of breast cancers. Deregulation of ER may also be involved in tumorigenesis of other organs. To understand the role of ER in different tumor types, pan-cancer analysis of estrogen receptor alpha (ESR1) and estrogen receptor beta (ESR2) in various tumors and association with patients' survival were conducted using The Cancer Genome Atlas (TCGA) data.

RESULTS

Gene methylation level was evaluated by the mean methylation level of CpG sites in the promoter region. The significant different DNA methylation between tumor and healthy tissues was shown in 10 tumor types for ESR1 and eight tumor types for ESR2. The methylation pattern was also varied across different TCGA tumors. The pan-cancer analysis showed significantly different mRNA expression of ESR1 in nine tumor types and ESR2 in four tumor types. Survival analysis showed that the effects of ERs expression on survival are diverse in different tumors. The expression of ERs was associated with tumor molecular subtypes and various clinical characteristics. ER correlated genes were mainly enriched in cancer and immune-related pathways.

CONCLUSIONS

Our pan-cancer analysis data indicated that ERs might be significantly associated with carcinogenesis and progression of some tumors, which may be potential therapeutic targets and prognosis biomarkers.

Aberrant hTERT promoter methylation predicts prognosis in Chinese patients with acral and mucosal melanoma: A CONSORT-compliant article

BACKGROUND

To evaluate the methylation levels of human telomerase reverse transcriptase (hTERT) promoter three CpG island (CGIs) regions and its prognostic impact in Chinese patients with acral and mucosal melanoma.

METHODS

Bioinformatics software was used to analyze hTERT gene promoter. Fresh frozen tissues were taken from 14 patients with melanoma (6 acral melanoma and 8 mucosal melanoma) and 14 pigmented nevus as control subjects (14 acral pigmented nevus). Bisulfite sequencing PCR (BSP) combined TA clone sequencing was used to assess the methylation levels of hTERT promoter CGIs regions. The relative expression level of hTERT mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

CGIs-1 (-1392--1098 bp), CGIs-2 (-945--669 bp), and CGIs-3 (-445--48 bp) were selected for our study. Our results indicated that the methylation levels of hTERT promotor CGIs regions in melanoma were greater than pigmented nevus (CGIs-1: 69.3 ± 18.7% vs 46.8 ± 20.4%, t = 3.048 P = .005; CGIs-2: 73.8 ± 14.7% vs 55.6 ± 16.0%, t = 3.120 P = .004; CGIs-3: 5.8 ± 2.2% vs 2.2 ± 1.3%, t = 5.164 P < .001). The relative expression level of hTERT in melanoma was greater than in pigmented nevus (50.39 ± 9.16 vs 26.10 ± 7.25, t = 7.778, P < .001). Linear regression analysis showed that the methylation level of CGIs-2 in melanoma was positively correlated with the relative expression level of hTERT mRNA (R = .490, F = 13.478, P = .003). Combined with the analysis of clinicopathological features, the methylation level of CGIs-2 in melanoma with lymph node metastasis was greater than in melanoma without lymph node metastasis, and the methylation level of CGIs-2 increased with TNM staging.

CONCLUSION

CGIs-2 methylation level was associated with the relative expression level of hTERT mRNA, lymph node metastasis and TNM staging, suggesting that CGIs-2 hypermethylation might be used to evaluate the prognosis in Chinese patients with acral and mucosal melanoma.

FIGO 2018 stage IB2 (2-4 cm) Cervical cancer treated with Neo-adjuvant chemotherapy followed by fertility Sparing Surgery (CONTESSA); Neo-Adjuvant Chemotherapy and Conservative Surgery in Cervical Cancer to Preserve Fertility (NEOCON-F). A PMHC, DGOG, GCIG/CCRN and multicenter study

BACKGROUND

There are limited data regarding the optimal management of pre-menopausal women with cervical lesions measuring 2-4 cm who desire to preserve fertility.

PRIMARY OBJECTIVES

To evaluate the feasibility of preserving fertility.

STUDY HYPOTHESIS

Neo-adjuvant chemotherapy will be effective in reducing the size of the tumor and will enable fertility-sparing surgery without compromising oncologic outcome.

TRIAL DESIGN

Pre-menopausal women diagnosed with stage International Federation of Gynecology and Obstetrics (FIGO) IB2, 2-4 cm cervical cancer who wish to preserve fertility will receive three cycles of platinum/paclitaxel chemotherapy. Patients with complete/partial response will undergo fertility-sparing surgery. Patients will be followed for 3 years to monitor outcome. Patients with suboptimal response (residual lesion ≥2 cm) will receive definitive radical hysterectomy and/or chemoradiation.

MAJOR ELIGIBILITY CRITERIA

Patients must have histologically confirmed invasive cervical cancer, 2-4 cm lesion, by clinical examination and magnetic resonance imaging (MRI), negative node, and pre-menopausal (≤40 years old). Following three cycles of neo-adjuvant chemotherapy, patients must achieve a complete/partial response (residual lesion <2 cm). Exclusion criteria include high-risk histology, tumor extension to uterine corpus/isthmus (as per MRI), and suboptimal response/progression following neo-adjuvant chemotherapy.

PRIMARY ENDPOINTS

Assess the rate of functional uterus defined as successful fertility-sparing surgery and no adjuvant therapy.

SAMPLE SIZE

A total of 90 evaluable patients will be needed to complete the study.

ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS

Expected complete accrual in 2022 with presentation of results by 2025.

TRIAL REGISTRATION NUMBER

Pending ethics submission.

Chemoradiation therapy induces in vivo changes in gene promoter methylation & gene transcript expression in patients with invasive cervical cancer

Background & objectives:

Invasive cervical cancer patients are primarily treated with chemoradiation therapy. The overall and disease-free survival in these patients is variable and depends on the tumoral response apart from the tumour stage. This study was undertaken to assess whether in vivo changes in gene promoter methylation and transcript expression in invasive cervical cancer were induced by chemoradiation. Hence, paired pre- and post-treatment biopsy samples were evaluated for in vivo changes in promoter methylation and transcript expression of 10 genes (ESR1, BRCA1, RASSF1A, MYOD1, MLH1, hTERT, MGMT, DAPK1, BAX and BCL2L1) in response to chemoradiation therapy.

Methods:

In patients with locally advanced invasive cervical cancer, paired pre- and post-treatment biopsies after 10 Gy chemoradiation were obtained. DNA/RNA was extracted and gene promoter methylation status was evaluated by custom-synthesized methylation PCR arrays, and the corresponding gene transcript expression was determined by absolute quantification method using quantitative reverse transcription PCR.

Results:

Changes in the gene promoter methylation as well as gene expression following chemoradiation therapy were observed. BAX promoter methylation showed a significant increase (P< 0.01) following treatment. There was a significant increase in the gene transcript expression of BRCA1 (P< 0.01), DAPK1 and ESR1 (P< 0.05), whereas MYOD1 and MLH1 gene transcript expression was significantly decreased (P< 0.05) following treatment.

Interpretation & conclusions:

The findings of our study show that chemoradiation therapy can induce epigenetic alterations as well as affect gene expression in tissues of invasive cervical cancer which may have implications in determining radiation response.

Adaptations of hepatic lipid metabolism and mitochondria in dairy cows with mild fatty liver

The inevitable deficiency in nutrients and energy at the onset of lactation requires an optimal adaptation of the hepatic metabolism to overcome metabolic stress. Fatty liver is one of the main health disorders after parturition. Therefore, to investigate changes in hepatic lipid metabolic status and mitochondria in dairy cows with mild fatty liver, liver and blood samples were collected from healthy cows (n = 15) and cows with mild fatty liver (n = 15). To determine the effects of palmitic acids (PA), one of the major component of fatty acids, on lipid metabolism and mitochondria in vitro, calf hepatocytes were isolated from healthy calves and treated with various concentrations of PA (0, 50, 100, and 200 μM). Dairy cows with mild fatty liver displayed hepatic lipid accumulation. The protein levels of sterol regulatory element-binding protein 1c (SREBP-1c) and peroxisome proliferator-activated receptor-α (PPARα) and mRNA levels of acetyl CoA carboxylase 1 (ACC1), fatty acid synthase (FAS), acyl-CoA oxidase (ACO), and carnitine palmitoyltransferase 1A (CPT1A) were significantly higher in dairy cows with mild fatty liver than in control cows. The hepatic mitochondrial DNA content, mRNA levels of oxidative phosphorylation complexes I to V (CO 1-V), protein levels of cytochrome c oxidase subunit IV (COX IV), voltage dependent anion channel 1 (VDAC1), peroxisome proliferator activated receptor-γ coactivator-1α (PGC-1α) and nuclear respiratory factor 1 (NRF1), and adenosine triphosphate (ATP) content were all markedly increased in the liver of dairy cows with mild fatty liver compared with healthy cows. The PA treatment significantly increased lipid accumulation; protein levels of SREBP-1c and PPARα; and mRNA levels of ACC1, FAS, ACO, and CPT1A in calf hepatocytes. Moreover, the mitochondrial DNA content, mRNA levels of CO 1-V, protein levels of COX IV, VDAC1, PGC-1α, NRF1, mitochondrial transcription factor A, and ATP content were significantly increased in PA-treated hepatocytes compared with control hepatocytes. The protein level of mitofusin-2 was significantly decreased in PA-treated groups. In conclusion, lipid synthesis and oxidation, number of mitochondria, and ATP production were increased in the liver of dairy cows with mild fatty liver and PA-treated calf hepatocytes. These changes in hepatic mitochondria and lipid metabolism may be the adaptive mechanism of dairy cows with mild fatty liver.

The Progress of Methylation Regulation in Gene Expression of Cervical Cancer

Cervical cancer is one of the most common gynecological tumors in females, which is closely related to high-rate HPV infection. Methylation alteration is a type of epigenetic decoration that regulates the expression of genes without changing the DNA sequence, and it is essential for the progression of cervical cancer in pathogenesis while reflecting the prognosis and therapeutic sensitivity in clinical practice. Hydroxymethylation has been discovered in recent years, thus making 5-hmC, the more stable marker, attract more attention in the field of methylation research. As markers of methylation, 5-hmC and 5-mC together with 5-foC and 5-caC draw the outline of the reversible cycle, and 6-mA takes part in the methylation of RNA, especially mRNA. Furthermore, methylation modification participates in ncRNA regulation and histone decoration. In this review, we focus on recent advances in the understanding of methylation regulation in the process of cervical cancer, as well as HPV and CIN, to identify the significant impact on the prospect of overcoming cervical cancer.

ESR1 Methylation: A Liquid Biopsy-Based Epigenetic Assay for the Follow-up of Patients with Metastatic Breast Cancer Receiving Endocrine Treatment

Purpose: Liquid biopsy provides real-time monitoring of tumor evolution and response to therapy through analysis of circulating tumor cells (CTCs) and plasma-circulating tumor DNA (ctDNA). ESR1 epigenetic silencing potentially affects response to endocrine treatment. We evaluated ESR1 methylation in CTCs and paired plasma ctDNA. We evaluated ESR1 methylation in CTCs and paired plasma ctDNA as a potential biomarker for response to everolimus/exemestane treatment.Experimental Design: A highly sensitive and specific real-time MSP assay for ESR1 methylation was developed and validated in (i) 65 primary breast tumors formalin-fixed paraffin-embedded (FFPE), (ii) EpCAM⁺ CTC fractions (122 patients and 30 healthy donors; HD), (iii) plasma ctDNA (108 patients and 30HD), and (iv) in CTCs (CellSearch) and in paired plasma ctDNA for 58 patients with breast cancer. ESR1 methylation status was investigated in CTCs isolated from serial peripheral blood samples of 19 patients with ER⁺/HER2^- advanced breast cancer receiving everolimus/exemestane.Results:ESR1 methylation was detected in: (i) 25/65 (38.5%) FFPEs, (ii) EpCAM⁺ CTC fractions: 26/112 (23.3%) patients and 1/30 (3.3%) HD, and (iii) plasma ctDNA: 8/108 (7.4%) patients and 1/30 (3.3%) HD. ESR1 methylation was highly concordant in 58 paired DNA samples, isolated from CTCs (CellSearch) and corresponding plasma. In serial peripheral blood samples of patients treated with everolimus/exemestane, ESR1 methylation was observed in 10/36 (27.8%) CTC-positive samples, and was associated with lack of response to treatment (P = 0.023, Fisher exact test).Conclusions: We report for the first time the detection of ESR1 methylation in CTCs and a high concordance with paired plasma ctDNA. ESR1 methylation in CTCs was associated with lack of response to everolimus/exemestane regimen. ESR1 methylation should be further evaluated as a potential liquid biopsy-based biomarker. Clin Cancer Res; 24(6); 1500-10. ©2017 AACR.

Putative biomarkers for cervical cancer: SNVs, methylation and expression profiles

Cervical cancer is primarily caused by Human papillomavirus (HPV) infection, but other factors such as smoking habits, co-infections and genetic background, can also contribute to its development. Although this cancer is avoidable, it is the fourth most frequent type of cancer in females worldwide and can only be treated with chemotherapy and radical surgery. There is a need for biomarkers that will enable early diagnosis and targeted therapy for this type of cancer. Therefore, a systems biology pipeline was applied in order to identify potential biomarkers for cervical cancer, which show significant reports in three molecular aspects: DNA sequence variants, DNA methylation pattern and alterations in mRNA/protein expression levels. CDH1, CDKN2A, RB1 and TP53 genes were selected as putative biomarkers, being involved in metastasis, cell cycle regulation and tumour suppression. Other ten genes (CDH13, FHIT, PTEN, MLH1, TP73, CDKN1A, CACNA2D2, TERT, WIF1, APC) seemed to play a role in cervical cancer, but the lack of studies prevented their inclusion as possible biomarkers. Our results highlight the importance of these genes. However, further studies should be performed to elucidate the impact of DNA sequence variants and/or epigenetic deregulation and altered expression of these genes in cervical carcinogenesis and their potential as biomarkers for cervical cancer diagnosis and prognosis.

Global analysis of H3K27me3 as an epigenetic marker in prostate cancer progression

BACKGROUND

H3K27me3 histone marks shape the inhibition of gene transcription. In prostate cancer, the deregulation of H3K27me3 marks might play a role in prostate tumor progression.

METHODS

We investigated genome-wide H3K27me3 histone methylation profile using chromatin immunoprecipitation (ChIP) and 2X400K promoter microarrays to identify differentially-enriched regions in biopsy samples from prostate cancer patients. H3K27me3 marks were assessed in 34 prostate tumors: 11 with Gleason score > 7 (GS > 7), 10 with Gleason score ≤ 7 (GS ≤ 7), and 13 morphologically normal prostate samples.

RESULTS

Here, H3K27me3 profiling identified an average of 386 enriched-genes on promoter regions in healthy control group versus 545 genes in GS ≤ 7 and 748 genes in GS > 7 group. We then ran a factorial discriminant analysis (FDA) and compared the enriched genes in prostate-tumor biopsies and normal biopsies using ANOVA to identify significantly differentially-enriched genes. The analysis identified ALG5, EXOSC8, CBX1, GRID2, GRIN3B, ING3, MYO1D, NPHP3-AS1, MSH6, FBXO11, SND1, SPATS2, TENM4 and TRA2A genes. These genes are possibly associated with prostate cancer. Notably, the H3K27me3 histone mark emerged as a novel regulatory mechanism in poor-prognosis prostate cancer.

CONCLUSIONS

Our findings point to epigenetic mark H3K27me3 as an important event in prostate carcinogenesis and progression. The results reported here provide new molecular insights into the pathogenesis of prostate cancer.

Investigation of differentially-expressed microRNAs and genes in cervical cancer using an integrated bioinformatics analysis

Cervical cancer is one of the most common types of cancer among women worldwide. In order to identify the microRNAs (miRNAs/miRs) and mRNAs associated with the carcinogenesis of cervical cancer, and to investigate the molecular mechanisms of cervical cancer, an miRNA microarray, GSE30656, and 3 mRNA microarrays, GSE63514, GSE39001 and GSE9750, for cervical cancer were retrieved from Gene Expression Omnibus. These datasets were analyzed in order to obtain differentially-expressed genes (DEGs) and miRNAs using the GEO2R tool. Gene Ontology (GO) and pathway enrichment analysis for DEGs were performed using the Database for Annotation, Visualization and Integrated Discovery. Protein-protein interaction (PPI) analysis for DEGs was conducted using The Search Tool for the Retrieval of Interacting Genes software and visualized using Cytoscape, followed by hub gene identification, and biological process and pathway enrichment analysis of the module selected from the PPI network using the Molecular Complex Detection plugin. In addition, miRecords was applied to predict the targets of differentially-expressed miRNAs. A total of 44 DEGs and 15 differentially-expressed miRNAs were identified. These DEGs were mainly enriched in GO terms associated with the cell cycle. In the PPI network, cyclin-dependent kinase 1, topoisomerase DNA IIα, aurora kinase A (AURKA) and minichromosome maintenance complex component 2 (MCM2) had higher degrees of connectivity. A significant module was detected from the PPI network. AURKA, MCM2 and kinesin family member 20A exhibited higher degrees in this module, while the genes in the module were mainly involved in the cell cycle and the DNA replication pathway. In addition, estrogen receptor 1 was predicted as the potential target of 13 miRNAs. A total of 10 DEGs were identified as potential targets of miR-203. In conclusion, the results indicated that microarray dataset analysis may provide a useful method for the identification of key genes and patterns to successfully identify determinants of the carcinogenesis of cervical cancer. The functional studies of candidate genes and miRNAs from these databases may lead to an increased understanding of the development of cervical cancer.

MeCP2 Promotes Gastric Cancer Progression Through Regulating FOXF1/Wnt5a/β-Catenin and MYOD1/Caspase-3 Signaling Pathways

Methyl-CpG binding protein 2 (MeCP2) has recently been characterized as an oncogene frequently amplified in several types of cancer. However, its precise role in gastric cancer (GC) and the molecular mechanism of MeCP2 regulation are still largely unknown. Here we report that MeCP2 is highly expressed in primary GC tissues and the expression level is correlated with the clinicopathologic features of GC. In our experiments, knockdown of MeCP2 inhibited tumor growth. Molecular mechanism of MeCP2 regulation was investigated using an integrated approach with combination of microarray analysis and chromatin immunoprecipitation sequencing (ChIP-Seq). The results suggest that MeCP2 binds to the methylated CpG islands of FOXF1 and MYOD1 promoters and inhibits their expression at the transcription level. Furthermore, we show that MeCP2 promotes GC cell proliferation via FOXF1-mediated Wnt5a/β-Catenin signaling pathway and suppresses apoptosis through MYOD1-mediated Caspase-3 signaling pathway. Due to its high expression level in GC and its critical function in driving GC progression, MeCP2 represents a promising therapeutic target for GC treatment.

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MeCP2 inhibits FOXF1 and MYOD1 transcription by binding to their promoter regions.

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MeCP2 promotes GC cell proliferation via FOXF1-mediated Wnt/β-Catenin signaling pathway.

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MeCP2 suppresses GC cell apoptosis through MYOD1-mediated Caspase-3 signaling pathway.

Gastric cancer is the fourth most common malignant cancer and the third most frequent cause of cancer-related deaths worldwide. The molecular mechanism underlying gastric carcinogenesis and progression is still unknown. Methyl-CpG binding protein 2 (MeCP2) has recently been characterized as an oncogene frequently amplified in several types of cancer. However, its precise role and the molecular mechanism of MeCP2 regulation in gastric cancer are largely unknown. Our results show that MeCP2 promotes gastric cancer cell proliferation via FOXF1-mediated Wnt5a/β-Catenin signaling pathway and suppresses cell apoptosis through MYOD1-mediated Caspase-3 signaling pathway. MeCP2 represents a promising therapeutic target for gastric cancer treatment.

Identification of key genes associated with cervical cancer by comprehensive analysis of transcriptome microarray and methylation microarray

Cervical cancer is the second most commonly diagnosed type of cancer and the third leading cause of cancer-associated mortality in women. The current study aimed to determine the genes associated with cervical cancer development. Microarray data (GSE55940 and GSE46306) were downloaded from Gene Expression Omnibus. Overlapping genes between the differentially expressed genes (DEGs) in GSE55940 (identified by Limma package) and the differentially methylated genes were screened. Gene Ontology (GO) enrichment analysis was subsequently performed for these genes using the ToppGene database. In GSE55940, 91 downregulated and 151 upregulated DEGs were identified. In GSE46306, 561 overlapping differentially methylated genes were obtained through the differential methylation analysis at the CpG site level, CpG island level and gene level. A total of 5 overlapping genes [dipeptidyl peptidase 4 (DPP4); endothelin 3 (EDN3); fibroblast growth factor 14 (FGF14); tachykinin, precursor 1 (TAC1); and wingless-type MMTV integration site family, member 16 (WNT16)] between the 561 overlapping differentially methylated genes and the 242 DEGs were identified, which were downregulated and hypermethylated simultaneously in cervical cancer samples. Enriched GO terms were receptor binding (involving DPP4, EDN3, FGF14, TAC1 and WNT16), ameboidal-type cell migration (DPP4, EDN3 and TAC1), mitogen-activated protein kinase cascade (FGF14, EDN3 and WNT16) and cell proliferation (EDN3, WNT16, DPP4 and TAC1). These results indicate that DPP4, EDN3, FGF14, TAC1 and WNT16 may be involved in the pathogenesis of cervical cancer.