Knockdown of Kinesin Family 15 Inhibits Osteosarcoma through Suppressing Cell Proliferation and Promoting Cell Apoptosis

Kinesin family (KIF) members have vital roles in mitosis, meiosis, and transport of macromolecules in eukaryotic cells. In this study, we aimed to investigate the role of KIF15 in osteosarcoma. Immunohistochemical staining was performed to determine expression levels of KIF15 in osteosarcoma tissues and adjacent normal tissues. Tissue microarray analysis showed a correlation between the expression of KIF15 and pathological features of patients. Subsequently, lentivirus was used to inhibit the expression of KIF15 in osteosarcoma cells. An MTT assay was performed to examine cell proliferation. Transwell and wound healing assays were used to estimate the invasion and migration of osteosarcoma cells, respectively. Flow cytometric analysis was employed to define the apoptosis of osteosarcoma cells. Our results showed that KIF15 expression was significantly upregulated in osteosarcoma tissues compared with adjacent normal tissues. The Mann-Whitney U test and Spearman correlation analysis showed that the expression levels of KIF15 in osteosarcoma tissues were positively correlated with tumor infiltrate, a pathological characteristic of patients. The expression of KIF15 was successfully suppressed by shKIF15, and the knockdown efficiency reached 80 and 69% in MNNG/HOS and U2OS cells, respectively. Subsequently, knockdown of KIF15 significantly inhibited the capacity of cell proliferation, colony formation, invasion, and migration, but enhanced G2 phase arrest and partially enhanced cell apoptosis. This study preliminarily showed KIF15 to be a critical regulatory molecule involved in osteosarcoma cell proliferation. Consequently, KIF15 can be a potential diagnostic and therapeutic target for osteosarcoma.