FOXM1 Contributes to Chemotherapy Sensitivity in Cervical Cancer by Regulating TTK.

ABSTRACT

BACKGROUND: The emergence of chemotherapy resistance usually causes therapeutic failure in advanced cervical cancer. Forkhead box protein M1 (FOXM1) and threonine tyrosine kinase (TTK) are closely associated with cancer drug sensitivity, but the mechanism of FOXM1 on TTK involvement in chemo-treated cervical cancer remains unclear. Here, we aimed to observe the effects of FOXM1 on TTK and on chemotherapy sensitivity in cervical cancer. METHODS: The expressions of FOXM1 and TTK in cervical cancer tissues and para-cancerous tissues were analyzed by immunohistochemistry. SiHa and Hela cells were transfected with human lentivirus-FOXM1, small interfering RNA (siRNA) or pcDNA3.1/FOXM1 to analyze the changes in TTK protein expression. Furthermore, the cells were treated with paclitaxel (8 µM) or cisplatin (10 µM) to analyze the effects of FOXM1 on chemotherapy sensitivity. SiHa cells were used to construct a xenograft model to study the effects of FOXM1 expression in response to paclitaxel treatment. The tumor size and weight were observed. The expressions of Ki-67, FOXM1, and TTK protein in tumor tissues were measured by immunohistochemistry. RESULTS: High expression of FOXM1 and TTK were found in the cervical cancer tissues (p < 0.05). The TTK protein expressions were decreased by FOMX1-siRNA transfection in SiHa and Hela cells (p < 0.01). The cell viability and cell cycle were also suppressed by FOMX1-siRNA transfection (p < 0.01) but enhanced by pcDNA3.1/FOXM1 transfection (p < 0.01). For paclitaxel or cisplatin treatment, the cell viability and cell DNA damage were improved due to the FOXM1 overexpression (p < 0.01). TTK inhibitor significantly suppressed the effects of FOXM1 overexpression (p < 0.01). CONCLUSIONS: FOXM1 regulated TTK and affected the therapeutic efficacy of cisplatin and paclitaxel in cervical cancer.