Elevated expression of KIF18A enhances cell proliferation and predicts poor survival in human clear cell renal carcinoma.

The function of kinesin family member 18A (KIF18A) in human renal cell carcinoma (RCC) is unclear. The purpose of the current study was to determine the expression and prognostic significance of KIF18A in RCC. Specimens from 273 RCC patients undergoing nephrectomies were studied. Expression of KIF18A mRNA was examined by reverse transcription-polymerase chain reaction (RT-PCR) or quantitative PCR, and the expression of KIF18A protein was examined by immunohistochemistry and western blotting. The expression of KIF18A in clear-cell RCC cell lines was decreased using small interfering RNA targeting KIF18A, and increased by transfection with KIF18A cDNA. The proliferative ability of RCC cells in vitro and in vivo was detected by WST-1 assay and an animal xenograft model with BALB/c nude mice, respectively. The association between KIF18A expression and overall survival was calculated using Kaplan-Meier analysis. The results showed that KIF18A expression was significantly increased in RCC tissues compared with normal kidney tissues. The level of KIF18A expression was significantly associated with tumor stage, histological grade, metastasis and tumor size. Moreover, KIF18A increased the proliferation of RCC cells in vitro and in vivo. KIF18A expression was upregulated in RCC and enhanced the proliferation of RCC cells. Therefore, it appears that KIF18A plays a key role in the carcinogenesis and progression of RCC, and is a novel candidate prognostic marker for RCC patients. Furthermore, silencing KIF18A expression may serve as a new therapeutic strategy against RCC.