MicroRNAs (miRNAs) are small non-coding RNA molecules, approximately 22 nucleotides in length that regulate gene translation through silencing or degradation of target mRNAs. They are involved in multiple biological processes, including differentiation and proliferation, metabolism, hemostasis, apoptosis or inflammation, and in pathophysiology of many diseases. Numerous studies have suggested circulating miRNAs as promising diagnostic and prognostic biomarkers of many diseases.
MicroRNA-146a-5p acts as a tumor suppressor in various types of cancer, including hepatocellular carcinoma, esophageal squamous cell carcinoma (ESCC), non small cell lung cancer (NSCLC) and prostate cancer. On the other hand, it is upregulated in melanoma and thyroid carcinoma.
miR-146a-5p was observed to be downregulated in triple-negative breast cancer (TNBC) tissues and cell lines. Additionally, miR-146a-5p could inhibit TNBC cell proliferation, migration and invasion, suppress expression of mesenchymal markers (N-cadherin, vimentin and fibronectin) and increase epithelial marker (E-cadherin) expression.
Another study reported that miR 146a 5p was downregulated in hepatocellular carcinoma and acted as a tumor suppressor.
miR-146a-5p level was significantly decreased in ESCC tissue and serum and it could act as a promising biomarker for the prognosis and diagnosis of ESCC. It was revealed that miR 146a 5p affected ESCC by regulating epithelial mesenchymal transition (EMT) progression.
Furthermore, miR 146a 5p has been confirmed to inhibit non small cell lung cancer (NSCLC) cell proliferation and cell cycle progression. Reduced levels of miR-146-5p in serum exosomes were correlated with shorter progression-free survival and cisplatin resistance in NSCLC patients. Thus, serum exosomal miR-146a-5p may be a new biomarker predicting the efficacy of cisplatin for NSCLC patients and enabling real-time monitoring of drug resistance.
Another study indicated that miR 146a 5p could promote prostate cancer cell apoptosis by targeting ROCK1.
miR-146a-5p level was consistently increased in HCV-infected hepatocyte-like cells and primary human hepatocytes, as well as in liver tissue from HCV-infected patients.
Over-expression of miR-140-5p, miR-140-3p, and miR-146a-5p reduced induced expression of cytokines IL1β, IL6, and IL8. The anti-inflammatory effects of these microRNAs were clearly shown by down-regulation of NFκB-p65 subunit and several inflammatory components in the NFκB pathway. The protective effects of the microRNAs in chondrocytes were also exerted by up-regulation of inhibitors of the NFκB- pathway.
- References to miR-146a-5p