[Clinical significance of methylation of a group of miRNA genes in patients with ovarian cancer.]

Oncogenes and tumor suppressor genes: functions and roles in cancers

Cancer, being the most formidable ailment, has had a profound impact on the human health. The disease is primarily associated with genetic mutations that impact oncogenes and tumor suppressor genes (TSGs). Recently, growing evidence have shown that X-linked TSGs have specific role in cancer progression and metastasis as well. Interestingly, our genome harbors around substantial portion of genes that function as tumor suppressors, and the X chromosome alone harbors a considerable number of TSGs. The scenario becomes even more compelling as X-linked TSGs are adaptive to key epigenetic processes such as X chromosome inactivation. Therefore, delineating the new paradigm related to X-linked TSGs, for instance, their crosstalk with autosome and involvement in cancer initiation, progression, and metastasis becomes utmost importance. Considering this, herein, we present a comprehensive discussion of X-linked TSG dysregulation in various cancers as a consequence of genetic variations and epigenetic alterations. In addition, the dynamic role of X-linked TSGs in sex chromosome-autosome crosstalk in cancer genome remodeling is being explored thoroughly. Besides, the functional roles of ncRNAs, role of X-linked TSG in immunomodulation and in gender-based cancer disparities has also been highlighted. Overall, the focal idea of the present article is to recapitulate the findings on X-linked TSG regulation in the cancer landscape and to redefine their role toward improving cancer treatment strategies.

miR-203a-A multifaceted regulator modulating cancer hallmarks and therapy response

MicroRNAs (miRNAs) are a class of noncoding RNAs of about 19-25 nucleotides, which serve as critical modulators of various cellular and biological processes by target gene regulation. Dysregulated expression of miRNAs modulates the pathophysiology of various human diseases, including cancer. Among miRNAs, miR-203a is one of the most extensively researched dysregulated miRNAs in different cancers. Our review investigated the roles of miR-203a in the hallmarks of cancer modulating different pathways through target gene regulations, chemoresistance, its crosstalk with other ncRNAs or genes in terms of ceRNAs impacting oncogenesis, and its potential applications in the diagnosis, prognosis, and chemotherapeutic responses in different cancer types. miR-203a impacts cancer cell behavior by regulating these exclusive hallmarks- sustaining proliferation, cell growth, invasion and metastasis, cell death, and angiogenesis. Besides, miR-203a is found in human circulating biofluids like plasma or serum of colorectal cancer, cervical cancer, and hepatocellular carcinoma, hinting at its potential as a biomarker. Further, miR-203a is involved in enhancing the chemosensitivity of cisplatin, docetaxel, paclitaxel, doxorubicin, and 5-fluorouracil in a variety of malignancies through their cognate target genes. These results suggest that miR-203a is a crucial multifaceted miRNA that controls cancer cell proliferation, metastasis, and chemotherapy response, shedding new light on its possible application.

Synergy between the Levels of Methylation of microRNA Gene Sets in Primary Tumors and Metastases of Ovarian Cancer Patients

We studied the correlations between the levels of methylation of a group of 21 microRNA genes in 99 primary tumors and 29 macroscopic peritoneal metastases of ovarian cancer. Analysis of the level of methylation by quantitative methylation-specific PCR showed that co-methylation was detected for 13 pairs of microRNA genes in primary tumors and for 22 pairs in metastases. Pairs of microRNA genes that have shown significant co-methylation can be involved in common processes and pathways of gene regulation and interaction and can have common target genes. The results are highly significant and pairs of microRNA genes can be proposed as new potential markers for the diagnosis and prognosis of ovarian cancer metastasis.