KIFC1, a novel potential prognostic factor and therapeutic target in hepatocellular carcinoma

Kinesin family member C1 (KIFC1, also known as HSET) is a minus end-directed motor protein, which is critical in centrosome clustering. The present study investigated the expression of KIFC1 in paired hepatocellular carcinoma (HCC) tissues and adjacent non-cancerous tissues from 91 patients by immunohistochemical analysis; clinical data were concomitantly collected. KIFC1 was expressed at high levels in HCC tissues, compared with that in peritumoral tissues (54.9 vs. 14.3%; P<0.01), and its expression correlated with tumor emboli, metastasis, recurrence and time of recurrence. Kaplan-Meier analysis showed that the expression of KIFC1 was significantly associated with tumor-free survival rates. In addition, multivariate analyses revealed that the overexpression of KIFC1was an independent predictive marker in patients with HCC. Consistently, data derived from GEPIA was in agreement with the results. In vitro, KIFC1 knockdown effectively decreased HCC cell viability, and induced apoptosis and cell death. KIFC1 knockdown also significantly suppressed tumor cell migration and invasion in vitro. Mechanistically, the apoptosis-related protein, B-cell lymphoma-2 (Bcl-2), was downregulated in KIFC1 small interfering RNA-treated groups, whereas thee levels of Bcl-2-associated X protein and p53 were upregulated. In addition, the expression levels of phosphorylated phosphoinositide 3-kinase and phosphorylated AKT were decreased significantly when KIFC1 was silenced. The epithelial-mesenchymal transition-related proteins, N-cadherin, matrix metalloproteinase-2 (MMP-2), β-catenin, Slug, and Zinc finger E-box-binding homeobox 1, were downregulated, whereas the expression of E-cadherin was upregulated. The overexpression of KIFC1 was correlated closely with the progression of HCC and poor prognosis, and suggested that the expression levels of KIFC1 are a potential prognostic biomarker and therapeutic target in HCC.