KIFC1 promotes the proliferation of hepatocellular carcinoma in vitro and in vivo

Abstract

Hepatocellular carcinoma (HCC) is a common type of malignant tumor worldwide with a high mortality rate. In the past 20 years, the morbidity rate of HCC has increased. Progress has been made in the clinical diagnosis and therapy for HCC. However, due to the high heterogeneity and metastasis targeted therapy for HCC exhibits great promise, and novel therapeutic targets for HCC are urgently required. Kinesin family member C1 (KIFC1) is a member of the kinesin superfamily of proteins. Previous studies have indicated a potential association between KIFC1 and cancer progression. However, the potential role of KIFC1 in the development of HCC remains unclear. The present study aimed to explore the function of KIFC1 in HCC. Immunohistochemical (IHC) assays were performed to explore the KIF15 expression levels in 74 samples of HCC and corresponding non-tumor tissues. The potential association between KIF15 expression levels and clinical features was analyzed, and the effects of KIF15 on cell proliferation of HCC were detected by colony formation and MTT assays. In addition, the proliferation-related proteins Ki67 and PCNA were detected by western blotting. The possible effects of KIF15 on tumor growth were measured in mice. The results demonstrated that a high expression level of KIFC1 was associated with poor prognosis of HCC. Further results indicated that KIFC1 promoted cell proliferation of HCC in vitro. In addition, knockdown of KIFC1 suppressed tumor formation and growth in mice. Therefore, these results provide a potential therapeutic target for the treatment of HCC.

Keywords: hepatocellular carcinoma; kinesin family member C1; poor prognosis; proliferation; therapeutic target.

Figure 1.

KIFC1 expression levels in HCC tissues are associated with poor prognosis (A) Immunohistochemical staining demonstrated the low and high expression levels of KIFC1 in HCC tissues. Magnification, ×100 and ×200. (B) Immunohistochemical staining revealed the low expression level of KIFC1 in the normal liver tissues. Magnification, ×100 and ×200. (C) Kaplan-Meier method and log-rank analysis of overall survival and relapse-free survival rates between low and high-expression groups of KIFC1. HCC, hepatocellular carcinoma; KIFC1, kinesin family member C1.

Figure 2.

KIFC1 is significantly downregulated by its targeted shRNA in Hep3B and SNU-475 hepatocellular carcinoma cells. (A) Reverse transcription- quantitative PCR assays and (B) western blot analysis revealed the expression level of KIFC1 was significantly reduced in Hep3B and SNU-475 cells following transfection. Data are presented as mean ± standard deviation. *P<0.05. KIFC1, kinesin family member C1; shRNA, short hairpin RNA.

Figure 3.

Knockdown of KIFC1 reduces proliferation of Hep3B and SNU-475 cells. (A) Colony formation and (B) MTT assays examined Hep3B and SNU-475 cell lines transfected with control or KIFC1 shRNA plasmids. (C and D) Western blot analysis demonstrated that (C) Ki67 and (D) PCNA expression was downregulated in Hep3B and SNU-475 cells. Data are presented as mean ± standard deviation. *P<0.05. PCNA, proliferating cell nuclear antigen; KIFC1, kinesin family member C1; shRNA, short hairpin RNA; OD, optical density.

Figure 4.

KIFC1 promotes tumor formation and growth of hepatocellular carcinoma cells in nude mice. (A) Subcutaneous tumors formed by Hep3B cells transfected with control and KIF5A shRNA lentivirus in nude mice were measured after two weeks, every 4 days. n=6 per group. Representative images of tumors from each group were obtained. (B) Western blot analysis and quantification of the expression of KIFC1 and β-actin in control and KIFC1 shRNA groups. (C) Immunohistochemical analysis of KIFC1 expression levels in control and KIFC1 shRNA groups. Magnification, ×200. Data are presented as mean ± standard deviation. *P<0.05. shRNA, short hairpin RNA; KIFC1, kinesin family member C1.