Overexpression of kif11 is a poor prognostic factor in clear cell renal cell carcinoma.

Introduction: Unresectable renal cell carcinoma continues to be a great challenge due to our limited understanding of its underlying pathophysiology. We explored the relationship between KIF11 protein expression and the clinical courses of clear cell renal cell carcinoma (ccRCC) using a tissue microarray.

Material and methods: The tissue microarray contained specimens derived from 90 patients, cancer and matched adjacent non-cancerous tissue (2 cores per case), followed up for 7 years. Tumour samples were evaluated for KIF11 expression using the H-score, and their correlations with clinicopathological data and survival data were analysed.

Results: 72.7% of ccRCC tissues presented KIF11 cytoplasmic expression with a median value of 20 (interquartile range 0-200). The nuclear staining was positive in 36.36% of ccRCC tissues. Among controls, nuclear KIF11 expression was absent, but cytoplasmic expression was identified in all cases, with a median value of 230 (interquartile range 45-290). Cytoplasmic KIF11 expression in ccRCC tissues was lower than in the control tissues and was positively correlated with tumour grade and mortality (p < 0.05). KIF11 nuclear expression did not correlate with overall survival.

Conclusions: Elevated expression of KIF11 predicts poor clinical outcome in ccRCC patients. Downregulation of KIF11 may provide a new therapeutic strategy for ccRCC.