MiR-340 regulates the growth and metabolism of renal cell carcinoma cells by targeting frizzled class receptor 3.

MicroRNA(miR)-340 is known as a multifunctional miRNA related to various types of cancer while its role in renal cell carcinoma (RCC) remains to be further investigated. In the present study, an apparent increase in miR-340 expression was observed in both clear cell RCC tissues and RCC cell line 786-O and Caki-1. Functionally, the overexpression of miR-340 promoted cell proliferation, migration, invasion, extracellular alanine (Ala) level, and glycolysis level in 786-O cells. Then, frizzled class receptor 3 (FZD3) was determined as the target gene of miR-340 and its expression level was negatively regulated by miR-340. The FZD3 silencing abrogated the inhibitory effect of miR-340 knockdown on cell proliferation, migration, invasion, Ala level, and glycolysis level in 786-O cells. In conclusion, miR-340 promotes proliferation, migration, and invasion of RCC cells via suppressing FZD3 expression, and the promotion effect of miR-340 on RCC progression may be due to its regulatory effect on glycolysis and Ala level.