The natural product lapiferin inhibits cell proliferation and promotes cell apoptosis in gingival squamous cell carcinoma via P21 regulation

Gingival squamous cell carcinoma (GSCC) is responsible fora large proportion of oral cavity malignancies. GSCC is characterized by rapid cell growth, and progressive invasion and migration. P21 is a widely recognized tumor suppressor, which is induced by P53 activation; however, drugs that aim to promote P21-mediated tumor suppression remain to be identified. A natural compound library was used to perform broad-spectrum screening of drugs that could promote P21 expression. Subsequently, the effects of the screened drug on GSCC cell proliferation and apoptosis were evaluated. The results of the present study suggested that lapiferin was the most effective natural compound that promoted the expression of P21 at both mRNA and protein levels. Lapiferin inhibited proliferation and enhanced apoptosis of YD-38 GSCC cells in a dose-dependent manner. Furthermore, following treatment with lapiferin, the critical cell cycle regulators cell division cycle 25C and cyclin B1 and tumor cell proliferation markers proliferating cell nuclear antigen and Ki67 were markedly decreased. In addition, pro-apoptotic proteins were promoted following treatment of YD-38 cells with lapiferin. Following the depletion of P21 expression, lapiferin-mediated inhibition of cell proliferation and enhancement of cell apoptosis were significantly reduced. These results indicated that lapiferin may exert potent antitumor effects on GSCC via regulation of P21; therefore, lapiferin may be considered a potential, natural therapeutic agent for the treatment of GSCC.