Background: Resistance to anticancer agents is a major obstacle for successful chemotherapy in tongue squamous cancer. Sam68 is an oncogenic-related protein in oral tongue squamous cell carcinoma functions as a signaling molecule mediating apoptosis, whose over-expression is associated with the clinicopathologic characteristics and prognosis of patients. The present study was to examine the effect of Sam68 on chemotherapeutics-induced apoptosis in oral tongue squamous cell carcinoma, and its clinical significance in oral tongue squamous cell carcinoma progression.
Methods: The effect of Sam68 on apoptosis induced by cisplatin was examined both in vitro and in vivo, using Annexin V staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays. Real-time PCR and Western blotting analysis were used to detect mRNA and protein expression levels.
Results: Upregulation of Sam68 significantly inhibited cisplatin-induced apoptosis in oral tongue squamous cell carcinoma cells, associated with induction of anti-apoptotic proteins caspase-9, caspase-3, and PARP. In contrast, Silencing Sam68 expression significantly enhanced the sensitivity of oral tongue squamous cell carcinoma cells to apoptosis induced by cisplatin both in vitro and in vivo.
Conclusions: The current study suggests that Sam68 could enhance the anti-apoptosis activity of oral tongue squamous cell carcinoma cells. Sam68 is a potential pharmacologic target for the treatment of oral tongue squamous cell carcinoma and inhibition of Sam68 expression might represent a novel strategy to sensitize oral tongue squamous cell carcinoma to chemotherapy.
Keywords: Anti-apoptosis; Chemotherapy; Sam68; Tongue squamous cell carcinoma.