Clinical Significance and Prognostic Value of miR-28-5p in Colon Cancer

Epigenetic processes involved in response to pesticide exposure in human populations: a systematic review and meta-analysis

In recent decades, the use of pesticides in agriculture has increased dramatically. This has resulted in these substances being widely dispersed in the environment, contaminating both exposed workers and communities living near agricultural areas and via contaminated foodstuffs. In addition to acute poisoning, chronic exposure to pesticides can lead to molecular changes that are becoming better understood. Therefore, the aim of this study was to assess, through a systematic review of the literature, what epigenetic alterations are associated with pesticide exposure. We performed a systematic review and meta-analysis including case-control, cohort and cross-sectional observational epidemiological studies to verify the epigenetic changes, such as DNA methylation, histone modification and differential microRNA expression, in humans who had been exposed to any type of pesticide. Articles published between the years 2005 and 2020 were collected. Two different reviewers performed a blind selection of the studies using the Rayyan QCRI software. Post-completion, the data of selected articles were extracted and analyzed. Most of the 28 articles included evaluated global DNA methylation levels, and the most commonly reported epigenetic modification in response to pesticide exposure was global DNA hypomethylation. Meta-analysis revealed a significant negative correlation between Alu methylation levels and β-hexachlorocyclohexane, p,p'-dichlorodiphenyldichloroethane and p,p'-dichlorodiphenylethylene levels. In addition, some specific genes were reported to be hypermethylated in promoter regions, such as CDKN2AIGF2, WRAP53α and CDH1, while CDKN2B and H19 were hypomethylated due to pesticide exposure. The expression of microRNAs was also altered in response to pesticides, as miR-223, miR-518d-3p, miR-597, miR-517b and miR-133b that are associated with many human diseases. Therefore, this study provides evidence that pesticide exposure could lead to epigenetic modifications, possibly altering global and gene-specific methylation levels, epigenome-wide methylation and microRNA differential expression.

The importance of hsa-miR-28 in human malignancies

MicroRNA production in tumorigenesis is dysregulated by a variety of processes, such as proliferation and removal of microRNA genes, aberrant transcriptional regulation of microRNAs, disrupted epigenetic alterations, and failures in the miRNA biogenesis machinery. Under some circumstances, miRNAs may act as tumorigenic and maybe anti-oncogenes. Tumor aspects such as maintaining proliferating signals, bypassing development suppressors, delaying apoptosis, stimulating metastasis and invasion, and promoting angiogenesis have been linked to dysfunctional and dysregulated miRNAs. MiRNAs have been found as possible biomarkers for human cancer in a great deal of research, which requires additional evaluation and confirmation. It is known that hsa-miR-28 can function as an oncogene or tumor suppressor in many malignancies, and it does this by modulating the expression of several genes and the downstream signaling network. MiR-28-5p and miR-28-3p, which originate from the same RNA hairpin precursor miR-28, have essential roles in a variety of cancers. This review outlines the function and mechanisms of miR-28-3p and miR-28-5p in human cancers and illustrates the miR-28 family's potential utility as a diagnostic biomarker for prognosis and early detection of cancers.

Revisiting Inhibition Effects of miR-28 as a Metastasis Suppressor in Gastrointestinal Cancers

MicroRNAs are critical epigenetic regulators that can be used as diagnostic, prognostic, and therapeutic biomarkers for the treatment of various diseases, including gastrointestinal cancers, among a variety of cellular and molecular biomarkers. MiRNAs have also shown oncogenic or tumor suppressor roles in tumor tissue and other cell types. Studies showed that the dysregulation of miR-28 is involved in cell growth and metastasis of gastrointestinal cancers. MiR-28 plays a key role in controlling the physiological processes of cancer cells including growth and proliferation, migration, invasion, apoptosis, and metastasis. Therefore, miR-28 expression patterns can be used to distinguish patient subgroups. Based on the previous studies, miR-28 expression can be a suitable biomarker to detect tumor size and predict histological grade metastasis. In this review, we summarize the inhibitory effects of miR-28 as a metastasis suppressor in gastrointestinal cancers. miR-28 plays a role as a tumor suppressor in gastrointestinal cancers by regulating cancer cell growth, cell differentiation, angiogenesis, and metastasis. As a result, using it as a prognostic, diagnostic, and therapeutic biomarker in the treatment of gastrointestinal cancers can be a way to solve the problems in this field.

miR-876-3p suppresses the progression of colon cancer and correlates the prognosis of patients

BACKGROUND

miR-876-3p has been identified to be downregulated in colon cancer, implying the potential biological function in the progression and prognosis of colon cancer. The clinical significance and the biological function of miR-876-3p were investigated in this study to assess the potential of miR-876-3p in acting as a novel biomarker of the progression of colon cancer.

METHODS

The expression of miR-876-3p in colon cancer was evaluated by RT-qPCR. The clinical significance of miR-876-3p was assessed by associated its expression level with the clinical features and prognosis of patients. The biological function of miR-876-3p was estimated by the CCK8 and Transwell assay in vitro.

RESULTS

The significant downregulation of miR-876-3p was observed in colon cancer tissues and cells, which was closely associated with the lymph node metastasis status, TNM stage, and the perineural invasion of patients. miR-876-3p served as an independent indicator that was negatively associated with the prognosis of patients. In colon cancer cells, miR-876-3p showed significant inhibitory effects on cell proliferation, migration, and invasion, indicating its tumor suppressor role in the progression of colon cancer.

CONCLUSION

miR-876-3p might be involved in colon cancer development, which provides a potential therapeutic target for colon cancer treatment.