Kinesin family member C1 accelerates bladder cancer cell proliferation and induces epithelial–mesenchymal transition via Akt/GSK3β signaling

Kinesin family member C1 (KIFC1) is implicated in the clustering of multiple centrosomes to maintain tumor survival and is thought to be an oncogene in several kinds of cancers. In our experiments, we first performed bioinformatics analysis to investigate the expression levels of KIFC1 in bladder cancer (BC) specimens and normal bladder epitheliums and then, using our samples, verified findings by quantitative real‐time PCR and western blotting assays. All data showed that KIFC1 was significantly upregulated in BC specimens at both the mRNA and protein levels. Immunohistochemical studies in a cohort of 152 paraffin‐embedded BC tissues displayed that upregulated expression of KIFC1 clearly correlated with pT status (P = .014) and recurrent status (P = .002). Kaplan‐Meier survival analysis and log‐rank test indicated that patients with BC with high KIFC1 expression had both shorter cancer‐specific survival (P < .001) and recurrence‐free survival time (P < .001) than those with low KIFC1 expression. Furthermore, ectopic downregulation of KIFC1 weakened BC cell proliferation and migration both in vitro and in vivo, whereas upregulation of KIFC1 enhanced this in vitro. Overexpression of KIFC1 phosphorylated GSK3β and promoted Snail through activating AKT (protein kinase B0) to induce proliferation and epithelial–mesenchymal transition (EMT) and, therefore, substantially promoted BC migration and metastasis. Our study revealed an oncogenic role for KIFC1 to promote BC cell proliferation and EMT via Akt/GSK3β signaling; KIFC1 might be a promising prognostic biomarker as well as a therapeutic target for BC.