Increased KIF21B expression is a potential prognostic biomarker in hepatocellular carcinoma

BACKGROUND The kinesin superfamily protein member KIF21B plays an important role in regulating mitotic progression; however, the function and mechanisms of KIF21B in cancer, particularly in hepatocellular carcinoma (HCC), are unknown. AIM To explore the role of KIF21B in hepatocellular carcinoma and its effect on prognosis after hepatectomy. METHODS First, data on the differential expression of KIF21B in patients with HCC from The Cancer Genome Atlas database was analyzed. Subsequently, the expression levels of KIF21B in HCC cell lines and hepatocytes were detected by reverse transcription-polymerase chain reaction, and its biological effect on BEL-7404 cells was evaluated by KIF21B knockdown. Immunohistochemical analysis was used to validate the differential expression of KIF21B in HCC tissues and adjacent normal tissues from 186 patients with HCC after hepatectomy. The Kaplan-Meier method was used to assess prognosis significance. RESULTS KIF21B expression levels were significantly higher in HCC tissues than in corresponding adjacent normal tissues. The expression levels of KIF21B in four HCC cell lines were higher than that in normal liver cells. Functional experiments showed that KIF21B knockdown remarkably suppressed cell proliferation and induced apoptosis. Moreover, immunohistochemistry results are consistent with The Cancer Genome Atlas analysis, with KIF21B expression levels being increased in HCC tissues compared to adjacent normal tissues. Univariate and multivariate analyses revealed KIF21B as an independent risk factor for overall survival and disease-free survival in patients with HCC after hepatectomy. CONCLUSION Taken together, our results provide evidence that KIF21B plays an important role in HCC progression and may be a potential diagnostic and prognostic marker for HCC.