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.
miR-29a are encoded on human chromosome 7q32.3 known as the miR-29a/b-1 cluster. miR-29a-3p has been reported to function as a tumor suppressor in several cancers including colorectal cancer (CRC), hepatocellular carcinoma (HCC), pancreatic cancer, breast cancer and ovarian cancer. miR-29a was down-regulated in metastatic prostate cancer, lung cancer, breast cancer, myeloid leukemias, oral squamous carcinoma and glioblastoma.
The expression of miR-29a and three other miRNAs in serum of patients with advanced stages of CRC was compared to a group of healthy volunteers. Levels of miR-29a were correlated with the clinical stage of CRC.
miR-29a-3p has been shown to act as a regulator of insulin-like growth factor 1 receptor (IGF1R) in (HCC). High expression of miR-29a-3p in HCC tissues provided better prognosis. Thus, restoration of miR-29a-3p expression in HCC cells could reduce cell proliferation and suppress cell migration and tumor formation. miR-29a-3p was also found to be significantly down-regulated in HCC tissues compared to adjacent non-tumor tissues. miR-29a-3p participates in the HCC progression (suppresses cell proliferation) by regulation of NF-κB pathway via targeting PTEN.
Another study showed that inhibition of miR-29a-3p decreased activation of Akt and p38, Inhibition of miR-29a-3p increased cardiomyocyte apoptosis. The level of miR-29a-3p was measured in plasma of acute myocardial infarction (AMI) patients. The circulating miR-29a-3p was significantly decreased in AMI patients compared to healthy controls. ROC curve analysis demonstrated that plasma miR-29a-3p has a considerable diagnostic efficiency, which is comparable to cTnI and CK-MB.
miR-29a was observed in kinds of non-malignant diseases, like Alzheimer’s disease, atherosclerosis, atrial fibrillation, diabetes, active pulmonary tuberculosis, hepatic fibrosis, cholestatic pediatric liver disease, fatty liver disease and scleroderma.
Up-regulation of several miRNAs was observed in gestational hypertension (GH) and preeclampsia (PE). GH and late PE showed up-regulation of miR-17-5p, miR-20b-5p and miR-29a-3p.
- References to miR-29a-3p