Capn4 induces human renal cancer cell proliferation by activating NF-κB signaling pathway through FAK phosphorylation.

Previous study found that higher Capn4 mRNA level is observed in patients with more advanced pathological stage of ccRCC and is also associated with decreased overall survival of patients with ccRCC. However, the mechanism by which Capn4 promotes progression of RCC is not understood. In the present study, we found that over-expression of Capn4 in RCC cells enhances tumor cell growth and down-regulation of Capn4 in RCC cells decreases tumor cell growth in vitro. Interestingly, Capn4 was found to increase phosphorylation of specific tyrosine residues of FAK and subsequent activate NF-κB p65 phosphorylation. Furthermore, Capn4-mediated cell proliferation of RCC cells required up-regulation of NF-κB p65 phosphorylation through activation of FAK signaling pathway. Taken together, our data showed that Capn4 can contribute to RCC growth via activation of the FAK and the downstream signaling pathways leading to the activation of NF-κB. IJCEP