DNA Methylation Change Profiling of Colorectal Disease: Screening towards Clinical Use

Increased CpG methylation at the CDH1 locus in inflamed ileal mucosa of patients with Crohn disease

BACKGROUND

E-cadherin, a major actor of cell adhesion in the intestinal barrier, is encoded by the CDH1 gene associated with susceptibility to Crohn Disease (CD) and colorectal cancer. Since epigenetic mechanisms are suspected to contribute to the multifactorial pathogenesis of CD, we studied CpG methylation at the CDH1 locus. The methylation of the CpG island (CGI) and of the 1st enhancer, two critical regulatory positions, was quantified in surgical specimens of inflamed ileal mucosa and in peripheral blood mononuclear cells (PBMC) of 21 CD patients. Sixteen patients operated on for a non-inflammatory bowel disease, although not normal controls, provided a macroscopically normal ileal mucosa and PBMC for comparison.

RESULTS

In ileal mucosa, 19/21 (90%) CD patients vs 8/16 control patients (50%) (p < 0.01) had a methylated CDH1 promoter CGI. In PBMC, CD patients with methylated CGI were 11/21 (52%) vs 7/16 controls (44%), respectively. Methylation in the 1st enhancer of CDH1 was also higher in the CD group for each of the studied CpGs and for their average value (45 ± 17% in CD patients vs 36 ± 17% in controls; p < 0.001). Again, methylation was comparable in PBMC. Methylation of CGI and 1st enhancer were not correlated in mucosa or PBMC.

CONCLUSIONS

Methylation of several CpGs at the CDH1 locus was increased in the inflamed ileal mucosa, not in the PBMC, of CD patients, suggesting the association of CDH1 methylation with ileal inflammation. Longitudinal studies will explore if this increased methylation is a risk marker for colorectal cancer.

DOK7 CpG hypermethylation in blood leukocytes as an epigenetic biomarker for acquired tamoxifen resistant in breast cancer

BACKGROUND

Breast cancer (BC) is among the most common cause of cancer 10.4% and one of the leading causes of death among 20-50 years old women in the world. Tamoxifen drug is the first line therapy for BC however tamoxifen resistance (TR) has shown in 30-50% of cases that may face BC recurrence. Hence, TR early detection reduces BC recurrence and fatalities. The epigenetic alteration that happens by hypermethylation of tumor suppressor genes and hypomethylation of oncogenes has been suggested to be useful in early cancer or drug resistance diagnosis.

METHODS

This is the first study to investigate DOK7 CpG hypermethylation in blood leukocytes of 31 TR (ER+) BC compared to 29 tamoxifen sensitive BC to evaluate DOK7 as a potential TR biomarker. DNA was extracted from blood samples of all participants and MSRE-PCR and real-time PCR were used for quantification of CpG methylation alterations.

RESULTS

The means of DOK7 CpG hypermethylation were obtained as 85.03%, 29.1% and 57.34% in TR, TS and normal control respectively. Significant hypermethylation were found among TR vs. TS (p < 0.001), TS vs. normal (p < 0.001) and TR vs. normal controls (p < 0.03). Online databases expression and survival analysis of DOK7 showed increasing expression in TS groups vs. TR groups which have consistency with our methylation alteration results. The sensitivity and specificity of the TR epigenetic test were determined using ROC analysis showed 89.66% and 96.77% respectively and showed that 37.5% above hypermethylation is at risk for TR and breast cancer recurrence.

CONCLUSION

There is a significant difference in the methylation ratio of DOK7 between tamoxifen resistant and tamoxifen sensitive groups that may be useful in the early diagnosis of tamoxifen resistance in BC cases and cancer recurrence prevention.

Genetic and Epigenetic Etiology of Inflammatory Bowel Disease: An Update

Inflammatory bowel disease (IBD) is a chronic disease with periods of exacerbation and remission of the disease. The etiology of IBD is not fully understood. Many studies point to the presence of genetic, immunological, environmental, and microbiological factors and the interactions between them in the occurrence of IBD. The review looks at genetic factors in the context of both IBD predisposition and pharmacogenetics.

GPC1 Is Associated with Poor Prognosis and Treg Infiltration in Colon Adenocarcinoma

Glypican-1 (GPC1) is a glycosylated protein recognized as a promising biomarker for cancer. Nonetheless, there have been few systematic studies on GPC1 in colon adenocarcinoma (COAD). We conducted bioinformatic analysis based on The Cancer Genome Atlas (TCGA) and used clinical samples to verify that GPC1 is overexpressed in colon adenocarcinoma. Kaplan-Meier analysis showed that higher GPC1 expression was associated with poor overall survival (OS). The Cox regression model further showed that GPC1 expression is an independent negative prognostic factor for COAD. Gene set enrichment analysis demonstrated that multiple oncogenic signaling pathways were differentially enriched in GPC1 high- versus low-expressing COAD tumors, including DNA methylation, G2/M damage checkpoint, and telomere dysfunction. We observed a positive correlation between GPC1 expression and immune cell infiltration, such as regulatory T cells (Tregs), macrophages, and mast cells, and immunohistochemistry of 50 COAD tissues revealed that GPC1 expression was positively associated with Treg enrichment. Our results provide a promising candidate gene to predict the prognosis of COAD and new insights into tumor immunity. Further research is required to validate these results.

Cancer-Associated Stromal Fibroblast-Derived Transcriptomes Predict Poor Clinical Outcomes and Immunosuppression in Colon Cancer

Background: Previous studies revealed that colonic cancer-associated fibroblasts (CAFs) are associated with the modulation of the colon tumor microenvironment (TME). However, identification of key transcriptomes and their correlations with the survival prognosis, immunosuppression, tumor progression, and metastasis in colon cancer remains lacking. Methods: We used the GSE46824, GSE70468, GSE17536, GSE35602, and the cancer genome atlas (TCGA) colon adenocarcinoma (COAD) datasets for this study. We identified the differentially expressed genes (DEGs), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, hub genes, and survival-associated genes in colon cancer. Finally, we investigated the correlation of key genes with the survival prognosis, immunosuppression, and metastasis. Results: We identified 246 common DEGs between the GSE46824 and GSE70468 datasets of colonic CAFs, which included 72 upregulated and 174 downregulated genes. The upregulated pathways are mainly involved with cancers and cellular signaling, and downregulated pathways are involved with immune regulation and cellular metabolism. The search tool for the retrieval of interacting genes (STRING)-based analysis identified 15 hub genes and 9 significant clusters in colonic CAFs. The upregulation of CTHRC1, PDGFC, PDLIM3, NTM, and SLC16A3 and downregulation of FBN2 are correlated with a shorter survival time in colon cancer. The CTHRC1, PDGFC, PDLIM3, and NTM genes are positively correlated with the infiltration of tumor-associated macrophages (TAM), macrophages, M2 macrophages, the regulatory T cells (Tregs), T cell exhaustion, and myeloid-derived suppressor cells (MDSCs), indicating the immunosuppressive roles of these transcriptomes in colon cancer. Moreover, the CTHRC1, PDGFC, PDLIM3, NTM, and SLC16A3 genes are gradually increased from normal tissue to the tumor and tumor to the metastatic tumor, and FBN2 showed the reverse pattern. Furthermore, the CTHRC1, FBN2, PDGFC, PDLIM3, and NTM genes are positively correlated with the metastatic scores in colon cancer. Then, we revealed that the expression value of CTHRC1, FBN2, PDGFC, PDLIM3, NTM, and SLC16A3 showed the diagnostic efficacy in colonic CAFs. Finally, the expression level of CTHRC1, PDGFC, and NTM genes are consistently altered in colon tumor stroma as well as in the higher CAFs-group of TCGA COAD patients. Conclusion: The identified colonic CAFs-derived key genes are positively correlated with survival prognosis, immunosuppression, tumor progression, and metastasis.

DNA Methylation Biomarkers in Colorectal Cancer: Clinical Applications for Precision Medicine

Colorectal cancer (CRC) is the second leading cause of cancer death worldwide that is attributed to gradual long-term accumulation of both genetic and epigenetic changes. To reduce the mortality rate of CRC and to improve treatment efficacy, it will be important to develop accurate noninvasive diagnostic tests for screening, acute, and personalized diagnosis. Epigenetic changes such as DNA methylation play an important role in the development and progression of CRC. Over the last decade, a panel of DNA methylation markers has been reported showing a high accuracy and reproducibility in various semi-invasive or noninvasive biosamples. Research to obtain comprehensive panels of markers allowing a highly sensitive and differentiating diagnosis of CRC is ongoing. Moreover, the epigenetic alterations for cancer therapy, as a precision medicine strategy will increase their therapeutic potential over time. Here, we discuss the current state of DNA methylation-based biomarkers and their impact on CRC diagnosis. We emphasize the need to further identify and stratify methylation-biomarkers and to develop robust and effective detection methods that are applicable for a routine clinical setting of CRC diagnostics particularly at the early stage of the disease.

Discovery of a Novel Aminocyclopropenone Compound That Inhibits BRD4-Driven Nucleoporin NUP210 Expression and Attenuates Colorectal Cancer Growth

Epigenetic deregulation plays an essential role in colorectal cancer progression. Bromodomains are epigenetic “readers” of histone acetylation. Bromodomain-containing protein 4 (BRD4) plays a pivotal role in transcriptional regulation and is a feasible drug target in cancer cells. Disease-specific elevation of nucleoporin, a component of the nuclear pore complex (NPC), is a determinant of cancer malignancy, but BRD4-driven changes of NPC composition remain poorly understood. Here, we developed novel aminocyclopropenones and investigated their biological effects on cancer cell growth and BRD4 functions. Among 21 compounds developed here, we identified aminocyclopropenone 1n (ACP-1n) with the strongest inhibitory effects on the growth of the cancer cell line HCT116. ACP-1n blocked BRD4 functions by preventing its phase separation ability both in vitro and in vivo, attenuating the expression levels of BRD4-driven MYC. Notably, ACP-1n significantly reduced the nuclear size with concomitant suppression of the level of the NPC protein nucleoporin NUP210. Furthermore, NUP210 is in a BRD4-dependent manner and silencing of NUP210 was sufficient to decrease nucleus size and cellular growth. In conclusion, our findings highlighted an aminocyclopropenone compound as a novel therapeutic drug blocking BRD4 assembly, thereby preventing BRD4-driven oncogenic functions in cancer cells. This study facilitates the development of the next generation of effective and potent inhibitors of epigenetic bromodomains and extra-terminal (BET) protein family.

Epigenetic approaches for cervical neoplasia screening (Review)

Human papillomavirus (HPV) infection is the leading cause of cervical cancer. The Papanicolaou cytology test is the usually employed type of screening for this infection; however, its sensibility is limited. Only a small percentage of women infected with high-risk HPV develop cervical cancer with an array of genetic and epigenetic modifications. Thus, it is necessary to develop rapid, reproducible and minimally invasive technologies for screening. DNA methylation has gained attention as an alternative method for molecular diagnosis and prognosis in HPV infection. The aim of the present review was to highlight the potential of DNA methylation in cervical neoplasia screening for clinical applications. It was observed that the methylation human and viral genes was correlated with high-grade lesions and cancer. Methylation biomarkers have shown a good capacity to discriminate between high-grade lesions with a transformative potential and cervical cancer, being able to detect these modifications at an early stage. With further research, the epigenetic profiles and subtypes of the tumors could be elaborated, which would aid in therapy selection by opening avenues in personalized precision medicine. Response to therapy could also be evaluated through such methods and the accessibility of liquid biopsies would allow a constant monitoring of the patient's status without invasive sampling techniques.