Abstract: Objective To observe the effect of Sam68 gene silencing on proliferation of nasopharyngeal carcinoma (NPC) cell line
5-8F and explore its possible molecular mechanism. Methods The NPC cell line 5-8F was transfected with a small interfering
RNA (siRNA) targeting Sam68 and the cell proliferation changes were observed. Quantitative RT-PCR and Western blotting
were used to examine the changes in the expressions of Sam68, cell cycle-related proteins, and some up-stream proteins in the
transfected cells. Results Transfection of 5-8F cells with Sam68-specific siRNA significantly lowered the mRNA and proteins
levels of Sam68, suppressed cell proliferation, decreased the expression of Cyclin D1, and increased the expression of p27. The
transfected cells showed obviously decreased expressions of p-FOXO3a, p-Akt and p-GSK-3β, but the expressions of FOXO3a,
Akt and GSK-3β were not obviously affected. Conclusion Sam68 modulates the proliferation of NPC cells probably by
activating Akt/FOXO3a pathway and regulating the cell proliferation-related molecules.