A number of kinesin proteins (KIFs) have been implicated in the development of multiple cancers. However, little is known about the expression and function of KIF15 in human breast cancer. Herein, we detected KIF15 expression in breast cancer tissues and paired adjacent normal tissues using immunohistochemistry and quantitative real-time polymerase chain reaction analysis, and the correlation of KIF15 expression with clinicopathological parameters was evaluated statistically. The role of KIF15 in cell proliferation, migration, tumor growth and metastasis of breast cancer cells was investigated in vitro and in vivo, and we explored potential molecular mechanisms underlying the effects of KIF15 in breast cancer through western blot analysis. The results revealed that increased KIF15 expression in breast cancer tissues were positively related with tumor size, lymph node metastasis and TNM stage, and higher KIF15 expression predicts a worse prognosis of patients with breast cancer. Furthermore, KIF15 knockdown markedly attenuated breast cancer cell proliferation, migration, tumor growth and metastasis in vitro and in vivo, and silenced KIF15 expression significantly inhibited the expression of phosphorylated AKT, phosphorylated JNK, and cyclin D1, while both p53 and p21 protein expressions were strongly enhanced. These results suggest that KIF15 is a potential oncogene in human breast cancer.
Keywords: Breast cancer; Cell proliferation; KIF15; Metastasis; Migration.