miR-429-CRKL axis regulates clear cell renal cell carcinoma malignant progression through SOS1/MEK/ERK/MMP2/MMP9 pathway.

The pathogenesis and tumorigenesis of clear cell renal cell carcinoma (ccRCC) remain unclear. The deregulations of miR-429, a member of miR-200 family, and v-crk sarcoma virus CT10 oncogene homologue (avian)-like (CRKL), an adaptor protein of CRK family, are involved in the development, metastasis and prognosis of various cancers. Current study aimed to demonstrate the differential expressions of miR-429 and CRKL with their correlationship and molecular regulation mechanism in ccRCC malignancy. miR-429 and CRKL separately showed suppressing and promoting effects in ccRCC. Lower miR-429 expression and higher CRKL expression were negatively correlated in surgical cancerous tissues by promoting the advance of ccRCC. By binding to the 3'-UTR of CRKL, miR-429 reversely regulated CRKL for its functionalities in ccRCC cells. CRKL knockdown and overexpression separately decreased and increased the in vitro migration and invasion of 786-O cells, which were consistent with the influences of miR-429 overexpression and knockdown on 786-O through respectively downregulating and upregulating CRKL via SOS1/MEK/ERK/MMP2/MMP9 pathway. The enhancements of CRKL expression, migration and invasion abilities and SOS1/MEK/ ERK/MMP2/MMP9 activation induced by TGF-β stimulation in 786-O cells could be antagonized by miR-429 overexpression. Exogenous re-expression of CRKL abrogated miR-429 suppression on the migration and invasion of 786-O cells. Collectively, miR-429 deficiency negatively correlated with CRKL overexpression promoted the aggressiveness of cancer cells and advanced the clinical progression of ccRCC patients. miR-429-CRKL axial regulation provides new clues to the fundamental research, diagnosis and treatment of ccRCC.