scholarly journals A Genome-Wide Investigation of Effects of Aberrant DNA Methylation on the Usage of Alternative Promoters in Hepatocellular Carcinoma

2022 ◽  
Vol 11 ◽  
Author(s):  
Yuting Dong ◽  
Xiaozhao Liu ◽  
Bijun Jiang ◽  
Siting Wei ◽  
Bangde Xiang ◽  
...  

BackgroundThe alternative usage of promoters provides a way to regulate gene expression, has a significant influence on the transcriptome, and contributes to the cellular transformation of cancer. However, the function of alternative promoters (APs) in hepatocellular carcinoma (HCC) has not been systematically studied yet. In addition, the potential mechanism of regulation to the usage of APs remains unclear. DNA methylation, one of the most aberrant epigenetic modifications in cancers, is known to regulate transcriptional activity. Whether DNA methylation regulates the usage of APs needs to be explored. Here, we aim to investigate the effects of DNA methylation on usage of APs in HCC.MethodsPromoter activities were calculated based on RNA-seq data. Functional enrichment analysis was implemented to conduct GO terms. Correlation tests were used to detect the correlation between promoter activity and methylation status. The LASSO regression model was used to generate a diagnostic model. Kaplan–Meier analysis was used to compare the overall survival between high and low methylation groups. RNA-seq and whole-genome bisulfite sequencing (WGBS) in HCC samples were performed to validate the correlation of promoter activity and methylation.ResultsWe identified 855 APs in total, which could be well used to distinguish cancer from normal samples. The correlation of promoter activity and DNA methylation in APs was observed, and the APs with negative correlation were defined as methylation-regulated APs (mrAPs). Six mrAPs were identified to generate a diagnostic model with good performance (AUC = 0.97). Notably, the majority of mrAPs had CpG sites that could be used to predict clinical outcomes by methylation status. Finally, we verified 85.6% of promoter activity variation and 92.3% of methylation changes in our paired RNA-seq and WGBS samples, respectively. The negative correlation between promoter activity and methylation status was further confirmed in our HCC samples.ConclusionThe aberrant methylation status plays a critical role in the precision usage of APs in HCC, which sheds light on the mechanism of cancer development and provides a new insight into cancer screening and treatment.

2021 ◽  
pp. 1-6
Author(s):  
Ben Kang ◽  
Hyun Seok Lee ◽  
Seong Woo Jeon ◽  
Soo Yeun Park ◽  
Gyu Seog Choi ◽  
...  

BACKGROUND: Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity in the world. It is characterized by different pathways of carcinogenesis and is a heterogeneous disease with diverse molecular landscapes that reflect histopathological and clinical information. Changes in the DNA methylation status of colon epithelial cells have been identified as critical components in CRC development and appear to be emerging biomarkers for the early detection and prognosis of CRC. OBJECTIVE: To explore the underlying disease mechanisms and identify more effective biomarkers of CRC. METHODS: We compared the levels and frequencies of DNA methylation in 11 genes (Alu, APC, DAPK, MGMT, MLH1, MINT1, MINT2, MINT3, p16, RGS6, and TFPI2) in colorectal cancer and its precursor adenomatous polyp with normal tissue of healthy subjects using pyrosequencing and then evaluated the clinical value of these genes. RESULTS: Aberrant methylation of Alu, MGMT, MINT2, and TFPI2 genes was progressively accumulated during the normal-adenoma-carcinoma progression. Additionally, CGI methylation occurred either as an adenoma-associated event for APC, MLH1, MINT1, MINT31, p16, and RGS6 or a tumor-associated event for DAPK. Moreover, relatively high levels and frequencies of DAPK, MGMT, and TFPI2 methylation were detected in the peritumoral nonmalignant mucosa of cancer patients in a field-cancerization manner, as compared to normal mucosa from healthy subjects. CONCLUSION: This study identified several biomarkers associated with the initiation and progression of CRC. As novel findings, they may have important clinical implications for CRC diagnostic and prognostic applications. Further large-scale studies are needed to confirm these findings.


Epigenetics ◽  
2020 ◽  
Vol 15 (6-7) ◽  
pp. 684-701
Author(s):  
Guoqiao Chen ◽  
Xiaoxiao Fan ◽  
Yirun Li ◽  
Lifeng He ◽  
Shanjuan Wang ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chih-Hsiung Hsu ◽  
Cheng-Wen Hsiao ◽  
Chien-An Sun ◽  
Wen-Chih Wu ◽  
Tsan Yang ◽  
...  

AbstractThis study provide an insight that the panel genes methylation status in different clinical stage tended to reflect a different prognosis even in matched normal tissues, to clinical recommendation. We enrolled 153 colorectal cancer patients from a medical center in Taiwan and used the candidate gene approach to select five genes involved in carcinogenesis pathways. We analyzed the relationship between DNA methylation with different cancer stages and the prognostic outcome. There were significant trends of increasing risk of 5-year time to progression and event-free survival of subjects with raising number of hypermethylation genes both in normal tissue and tumor tissue. The group with two or more genes with aberrant methylation in the advanced cancer stages (Me/advanced) had lower 5-year event-free survival among patients with colorectal cancer in either normal or tumor tissue. The adjusted hazard ratios in the group with two or more genes with aberrant methylation with advanced cancer stages (Me/advanced) were 8.04 (95% CI, 2.80–23.1; P for trend <0.01) and 8.01 (95% CI, 1.92–33.4; P for trend <0.01) in normal and tumor tissue, respectively. DNA methylation status was significantly associated with poor prognosis outcome. This finding in the matched normal tissues of colorectal cancer patients could be an alternative source of prognostic markers to assist clinical decision making.


Author(s):  
Martin Mžik ◽  
Marcela Chmelařová ◽  
Stanislav John ◽  
Jan Laco ◽  
Ondřej Slabý ◽  
...  

AbstractBackground:Aberrant hypermethylation of tumour suppressor genes (TSGs) occurring in hepatocellular carcinoma (HCC) could provide a mean of molecular characterisation of this cancer. The aim of this study was to investigate promoter methylation and gene expression of selected TSGs in HCC to identify candidate genes for further validation as potential biomarkers.Methods:Methylation-specific multiplex ligation-dependent probe amplification method was used to measure the methylation status of 25 TSGs in 49 HCC samples and 36 corresponding non-cancerous liver tissue samples. Relative expression of the differentially methylated genes was assessed at the mRNA level using quantitative PCR.Results:We observed a significantly higher methylation in genesConclusions:HCC evince aberrant promoter methylation of


2020 ◽  
Author(s):  
Tempei Ikegame ◽  
Miki Bundo ◽  
Naohiro Okada ◽  
Yui Murata ◽  
Shinsuke Koike ◽  
...  

AbstractAssociations between altered DNA methylation of the serotonin transporter (5-HTT)-encoding gene SLC6A4 and early life adversity, mood and anxiety disorders, and amygdala reactivity have been reported. However, few studies have examined epigenetic alterations of SLC6A4 in schizophrenia (SZ). We examined CpG sites of SLC6A4, whose DNA methylation levels have been reported to be altered in bipolar disorder, using three independent cohorts of patients with SZ and age-matched controls. We found significant hypermethylation of a CpG site in SLC6A4 in male patients with SZ in all three cohorts. We showed that chronic administration of risperidone did not affect the DNA methylation status at this CpG site using common marmosets, and that in vitro DNA methylation at this CpG site diminished the promoter activity of SLC6A4. We then genotyped the 5-HTT-linked polymorphic region (5-HTTLPR) and investigated the relationship among 5-HTTLPR, DNA methylation, and amygdala volume using brain imaging data. We found that patients harboring low-activity 5-HTTLPR alleles showed hypermethylation and they showed a negative correlation between DNA methylation levels and left amygdala volumes. These results suggest that hypermethylation of the CpG site in SLC6A4 is involved in the pathophysiology of SZ, especially in male patients harboring low-activity 5-HTTLPR alleles.


2021 ◽  
Vol 11 ◽  
Author(s):  
Yu Liang ◽  
Bin Ma ◽  
Peng Jiang ◽  
Hong-Mei Yang

BackgroundIn recent years, DNA methylation modification has been shown to be a critical mechanism in the field of epigenetics.MethodsHepatocellular carcinoma (HCC) data were obtained from The Cancer Genome Atlas project, including RNA expression profiles, Illumina Human Methylation 450K BeadChip data, clinical information, and pathological features. Then, differentially expressed genes (DEGs) and differentially methylated genes were identified using R software. Methylation-regulated DEGs (MeDEGs) were further analyzed using Spearman’s correlation analysis. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using the DAVID database and ClueGO in Cytoscape software. Kaplan–Meier survival analysis explored the relationship between methylation, expression of MeDEGs, and survival time. Gene set enrichment analysis (GSEA) was conducted to predict the function of prognosis-related MeDEGs.ResultsA total of nine up-regulated and 72 down-regulated MeDEGs were identified. GO and KEGG pathway analyses results indicated that multiple cancer-related terms were enriched. Kaplan–Meier survival analysis showed that the methylation status of four MeDEGs (CTF1, FZD8, PDK4, and ZNF334) was negatively associated with overall survival. Moreover, the methylation status of CDF1 and PDK4 was identified as an independent prognostic factor. According to GSEA, hypermethylation of prognosis-related MeDEGs was enriched in pathways that included “Spliceosome”, “Cell cycle”, “RNA degradation”, “RNA polymerase”, “DNA replication”, “Mismatch repair”, “Base excision repair”, “Nucleotide excision repair”, “Homologous recombination”, “Protein export”, and “Pyrimidine metabolism”.ConclusionsAberrant DNA methylation plays a critical role in malignant progression of HCC. Prognosis-related MeDEGs identified in this research may be potential biomarkers and targets in diagnosis and treatment.


2021 ◽  
Author(s):  
Huaxiang Wang ◽  
Fengfeng Feng Xu ◽  
Lizhi Lv ◽  
Ruling Wang ◽  
Bin Jiang ◽  
...  

Abstract Background Chaperonin containing TCP1 subunit 7 (CCT7), a member of the chaperonin containing TCP1 complex (CCT), has been reported regulating the expression of many tumor-related proteins. In this study, we investigated the diagnostic and prognostic value of CCT7 expression for hepatocellular carcinoma (HCC). Methods We investigated the CCT7 expression in HCC in The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and our cohort. The diagnostic and prognostic value were verified by receiver operating characteristic curve (ROC) analysis and Kaplan-Meier analysis, respectively. The association between CCT7 expression with DNA methylation status was investigated in the TCGA database. Gene ontology (GO), The Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) analysis were employed to identify the potential pathway in which CCT7 is involved in tumorigenesis and progression. Results CCT7 expression in HCC was significantly higher than adjacent normal tissues, and elevated CCT7 expression correlated with tumor stages and tumor grade. Furthermore, the ROC curve showed CCT mRNA expression has a better diagnostic value for HCC with early-stage and low alpha-fetoprotein expression. Positive predictive value (PPV) of CCT7 was higher than alpha-fetoprotein both in the GEO and TCGA database. The Multivariate Cox Regression analysis of clinicopathologic characteristics revealed that both high mRNA and protein expression of CCT7 were independent risk factors for overall survival (OS) and recurrence-free survival (RFS). High DNA methylation of CpG site(cg19515186) was associated with low CCT7 expression and better OS in HCC. The GO, KEGG and GSEA analysis demonstrated that CCT7 mRNA expression was associated with Spliceosome signaling pathway. Conclusions The findings of this study demonstrated that CCT7 has diagnostic and prognostic value for HCC.


2021 ◽  
Vol 41 (3) ◽  
Author(s):  
Cheng Zhang ◽  
Yang Ke ◽  
Xuefen Lei ◽  
Xin Liu ◽  
Hai Li ◽  
...  

Abstract Objective: The aim of the present study was to explore the relationship among Girdin DNA methylation, its high expression, and immune infiltration in human hepatocellular carcinoma (HCC). Materials and methods: The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and International Cancer Genome Consortium (ICGC) databases were used to compare Girdin mRNA expression between HCC tissues and normal tissues, and determine the relationship between Girdin expression and HCC prognosis. TCGA database was also used to analyze the expression of Girdin and its methylation status, as well as the relationship between Girdin DNA methylation and HCC prognosis. The Tumor IMmune Estimation Resource (TIMER) database was used to explore the correlation between Girdin expression and HCC immune infiltration. Results: Girdin expression was elevated in HCC tissues compared with that in normal tissues. The degree of methylation at cg03188526, a CpG site in the Girdin gene body, was positively correlated with Girdin mRNA expression, while high Girdin expression and cg03188526 hypermethylation were both correlated with poor HCC prognosis. Additionally, HCC tissue with high Girdin expression exhibited abundant immune infiltration, and the high Girdin expression was associated with a worse prognosis in macrophage-enriched HCC specimens. Conclusion: Our findings indicated that Girdin likely functions as an oncogene in HCC and that hypermethylation at cg03188526 in the Girdin gene body may explain the high Girdin expression levels in HCC tissue. Furthermore, we report for the first time that the adverse effects of high Girdin expression in HCC patients may be partially mediated by tumor macrophage infiltration.


2021 ◽  
Vol 22 (18) ◽  
pp. 9681
Author(s):  
Morgan Bennett ◽  
Kailyn Cleaves ◽  
Tarek Hewezi

DNA methylation and demethylation precisely and effectively modulate gene expression during plant growth and development and in response to stress. However, expression profiles of genes involved in DNA methylation and demethylation during plant development and their responses to phytohormone treatments remain largely unknown. We characterized the spatiotemporal expression patterns of genes involved in de novo methylation, methyl maintenance, and active demethylation in roots, shoots, and reproductive organs using β-glucuronidase (GUS) reporter lines. Promoters of DNA demethylases were generally more highly active at the mature root tissues, whereas the promoters of genes involved in DNA methylation were more highly active at fast-growing root tissues. The promoter activity also implies that methylation status in shoot apex, leaf primordia, floral organs, and developing embryos is under tight equilibrium through the activity of genes involved in DNA methylation and demethylation. The promoter activity of DNA methylation and demethylation-related genes in response to various phytohormone treatments revealed that phytohormones can alter DNA methylation status in specific and redundant ways. Overall, our results illustrate that DNA methylation and demethylation pathways act synergistically and antagonistically in various tissues and in response to phytohormone treatments and point to the existence of hormone-linked methylome regulation mechanisms that may contribute to tissue differentiation and development.


2017 ◽  
Vol 71 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Laura C Gomez ◽  
Mayra L Sottile ◽  
Martin E Guerrero-Gimenez ◽  
Felipe C M Zoppino ◽  
Analia L Redondo ◽  
...  

AimAccumulated evidence suggests that aberrant methylation of the TP73 gene and increased levels of ΔNp73 in primary tumours correlate with poor prognosis. However, little is known regarding the transcriptional and functional regulation of the TP73 gene in breast cancer. The aim of the present study was to determine the expression of the ΔNp73 isoform, its relationship with DNA methylation of TP73 and their clinical prognostic significance in breast cancer patients.MethodsTP73 gene methylation was studied in TCGA datasets and in 70 invasive ductal breast carcinomas (IDCs). The expression of p73 isoforms was evaluated by immunohistochemistry (IHC) and Western blot and correlated with clinicopathological variables and clinical outcome.ResultsWe observed that the methylation of diverse CpG islands of TP73 differed significantly between molecular subtypes. An inverse correlation was found between p73 protein expression and the methylation status of the TP73 gene. The expression of exon 3’ of p73 (only expressed in ΔNp73) was significantly higher in patients with wild-type p53. Immunohistochemical analysis revealed that all p73 isoforms were localised in both the nuclear and cytoplasmic compartments. We confirmed a positive association between the expression of ∆Np73 and high histological grade.ConclusionsOur findings suggest that high expression of ΔNp73 could be used to determine the aggressiveness of IDCs and could be incorporated in the pathologist’s report.


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