ABSTRACT
ObjectiveTo investigate the effect of kinesin family member 15 （KIF15） on the proliferation of hepatocellular carcinoma （HCC） cells and its mechanism of action. MethodsTCGA and GEPIA datasets were analyzed to determine the expression of KIF15 in HCC and its effect on tumor stage and survival. Quantitative real-time PCR and Western blot were used to measure the expression level of KIF15 in human-derived HCC cell lines （HepG2， Hep3B， MHCC-97H， and LM3） and human normal liver cell line L02 cultured in vitro， and Hep3B and HepG2 were selected for subsequent studies. CCK-8 assay， plate colony formation assay， and EdU staining were performed for Hep3B cells transfected with shRNA-NC or shRNA-KIF15 and HepG2 cells transfected with LV-vector or LV-KIF15 to evaluate the viability and proliferative capacity of these cells. GSEA was used to analyze the potential signaling pathways associated with KIF15 in HCC， and Western blot was used for detection. The independent-samples t test was used for comparison of continuous data between two groups； a one-way analysis of variance was used for comparison between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsThe analysis of TCGA and GEPIA datasets showed that in HCC patients， the expression of KIF15 in HCC tissue was significantly higher than that in normal tissue， and the HCC patients with high KIF15 expression tended to have a poorer prognosis. Compared with sh-NC-Hep3B， sh3-Hep3B showed significant reductions in the mRNA and protein levels of KIF15 （P<0.05）， cell viability， clone formation number， and EdU positive rate （all P<0.05）. Compared with vector-HepG2， LV-KIF15-HepG2 showed significant increases in the mRNA and protein levels of KIF15 （P<0.05）， cell viability， clone formation number， and EdU positive rate （all P<0.05）. Subcutaneous tumor assay showed that compared with sh-NC-Hep3B， sh3-Hep3B showed reductions in tumor volume and tumor weight， as well as a significant reduction in the immunohistochemical score of Ki67 and a significant increase in the immunohistochemical score of TUNEL （P<0.05）. GSEA analysis showed that the PI3K/AKT/mTOR pathway was positively correlated with KIF15 in HCC （NES=1.59， P<0.001）. Western blot showed that LY294002 could inhibit the PI3K/AKT/mTOR pathway upregulated in LV-KIF15-HepG2， and compared with LV-KIF15-HepG2， LY294002+LV-KIF15-HepG2 showed significant reductions in cell viability， clone formation number， and EdU positive rate （all P<0.05）. ConclusionKIF15 enhances the viability and proliferative capacity of HCC cells by upregulating the PI3K/AKT/mTOR signaling pathway.
ABSTRACT
Since there is a lack of obvious clinical symptoms in the early stage of hepatocellular carcinoma (HCC), most patients have progressed to the advanced stage at the time of confirmed diagnosis. There are limited treatment options for HCC patients who miss the opportunity for surgery, so it is of great importance to find new therapeutic targets. Tumor-associated macrophages (TAMs) are a group of macrophages existing in the tumor immune microenvironment and affect the malignant behaviors of HCC cells and the state of immune escape within the tumor. This article introduces the origin and classification of TAM, summarizes the role and mechanism of TAMs in vascular proliferation, invasion and metastasis, formation and maintenance of stemness, and anti-tumor immunity in HCC, and briefly describes the current research advances in therapeutic targets for TAM, and it is pointed out that targeting TAM may be a promising direction for clinical treatment.