The role of cofilin-1 in vulvar squamous cell carcinoma: A marker of carcinogenesis, progression and targeted therapy

Numerous studies have revealed that cofilin-1 (CFL1) is associated with cancer cell migration and invasion in various types of tumor tissues. We investigated the roles of CFL1 in vulvar squamous cell carcinoma (VSCC). CFL1 expression was detected in VSCC and normal vulvar tissues using immunohistochemistry and western blotting. The vulvar carcinoma SW962 cell line was transfected with CFL1 small interfering RNA (siRNA) and exposed to periplocoside. We then assessed changes in cell proliferation, apoptosis, invasion and metastasis. We detected changes in CFL1 mRNA and protein expression by RT-PCR and western blotting, and alterations in protein expression of various relevant molecules by western blotting. CFL1 expression was found to be significantly upregulated in the VSCC tissues compared with the normal vulvar tissues by immunohistochemistry and western blotting (P<0.05) and was positively correlated with International Federation of Gynecology and Obstetrics (FIGO) stage, differentiation and lymphatic metastasis (P<0.05). After CFL1 knockdown by siRNA transfection, SW962 cells exhibited a decrease in growth, G1 phase cell cycle arrest, induction of apoptotic, low invasion and metastasis, and disrupted lamellipodium formation. We found that the protein expression of Bcl-xL, cyclin A1, MMP2, MMP9 and STAT3 was decreased, while expression of Bax was increased. Periplocoside inhibited SW962 cell growth, promoted apoptosis, suppressed invasion and migration, and lamellipodium formation. Periplocoside exposure resulted in lower CFL1, Bcl-xL, cyclin A1, MMP2, MMP9 and STAT3 levels, but a higher Bax level compared with the control group. We demonstrated that abnormal CFL1 expression may affect vulvar carcinogenesis and subsequent progression. CFL1 silencing by siRNA significantly inhibited VSCC cell progression, which suggests that CFL1 is a potential therapeutic target for vulvar cancer. Periplocoside, which was utilized in the present study for the clinical treatment of vulvar cancer, showed strong antitumor effects by suppression of CFL1 expression.