[The effects of exogenous p16 gene on proliferation and apoptosis of human nasopharyngeal carcinoma cell line CNE-2].

OBJECTIVE: To study the effects of exogenous p16 gene on proliferation and apoptosis of human nasopharyngeal carcinoma cell line CNE-2. METHODS: Exogenous p16 gene was transfected into CNE-2 cells by lipofectin. After G418 selection, we obtained p16 stably expressed NPC cell clones (CNE-2-p16), and compared it with the mock-transfected clones(CNE-2-vect). Cell cycle was determined by flow cytometry, and cell apoptosis was examined by fluorescent (Hoechst) staining and TUNEL. P16 protein and p53 protein were stained immunohistochemically with relevant antibodies. RESULTS: Exogenous p16 gene was successfully expressed by CNE-2 2 cells. The growth of CNE-2-p16 cells was inhibited significantly. In CNE-2-p16 cells, cycle arrest in G1 phase, with decrease in percentage of S phase cells. Apoptotic index of CNE-2-p16 was significantly increased. CNE-2-p16 cells were positive for p53 protein that it was negative in CNE-2 cells. CONCLUSION: Exogenous p16 inhibits proliferation and induces apoptosis of human nasopharyngeal cancer CNE-2 cell line. It may be related to the up-regulation of wild type p53 gene.