miR-142-5p promotes development of colorectal cancer through targeting SDHB and facilitating generation of aerobic glycolysis.

Aberrant expression of miRNAs contributes to the development of human malignancies. A recent study revealed that miR-142-5p is increased in the serum of colorectal cancer (CRC) patients compared to health people. Using starBase v2.0, we found that succinate dehydrogenase-B (SDHB) is a potential target of miR-142-5p, while SDHB is negatively correlated to cancer development through regulating energetic metabolism. Based on these information, this study further examined the expression profiles of miR-142-5p and SDHB in CRC tissues and cell lines using PCR and Western blotting. Transfection experiment and luciferase assay were performed to identify relationship between miR-142-5p and SDHB. Oxygen intake, glucose consumption and production of lactic acid were used to evaluate the influence on energetic metabolism. CRC growth and proliferation were assessed by in vitro and in vivo studies. Results showed that miR-142-5p was up-regulated in CRC, but SDHB was down-regulated. SDHB was confirmed as a target of miR-142-5p, and decreased SDHB in CRC was result from the abnormal up-regulation of miR-142-5p. Lose of SDHB by miR-142-5p inhibited oxygen intake by CRC cells, but increased glucose consumption and lactate production. These suggest miR-142-5p up-regulation in CRC probably facilitates generation of aerobic glycolysis by reducing SDHB. miR-142-5p promoted proliferation and colony formation of CRC, but inhibited apoptosis. SDHB overexpression abrogated these effect of miR-142-5p, which indicates that SDHB depletion mediates tumor-promoting actions of miR-142-5p. This study added novel insight into the CRC development regulated by miR-142-5p. It may be a promising therapy target in the future molecular therapy.