Mir-26 microRNA precursor family


Origins

The miR-26 microRNA is a small non-coding RNA that is involved in regulating gene expression. The miR-26 family is composed of miR-26a-1, miR-26a-2 and miR-26b located in chromosomes 3, 12 and 2, respectively. Pre-miR-26 with stem-loop structure is processed into mature miR-26 by a series of enzymes of intranuclear and intracytoplasm. The mature miRNA of miR-26a-1 and miR-26a-2 possesses the same sequence, with the exception of 2 different nucleotides in mature miR-26b. miR-26 appears to be a vertebrate specific microRNA and has now been predicted or experimentally validated in many vertebrate species.

Expressions

miR-26 expression is induced in response to hypoxia and upregulated during smooth muscle cell differentiation and neurogenesis. Moreover,miR-26 is consistently down-regulated in a wide range of malignant tumors, such as hepatocellular carcinoma, nasopharyngeal carcinoma, lung cancer, and breast cancer. On the contrary, miR-26a is overexpressed in high-grade glioma and cholangiocarcinoma. Elevated expression of miR-26b has been reported in pituitary tumor and bladder cancer. miR-26 is emerging as critical regulators in carcinogenesis and tumor progression by acting either as oncogenes or tumor suppressor genes in various cancers.

miR-26a roles

miR-26b roles