[Effects of arsenic trioxide combined with cisplatin on the growth of human nasopharyngeal carcinoma cells and reversion of RASSF1A hympermethylation].

OBJECTIVE: To investigate the effect of arsenic trioxide (As2O3) combined with cisplatin on expression of RASSF1A in nude mice with human nasopharyngeal carcinoma xenograft. METHOD: The models of human poorly differentiated nasopharyngeal carcinoma in nude mice were established and randomly divided into four groups, control group (NaCl group), As2O3 group, DDP group and As2O3 + DDP group. The expression of RASSF1A mRNA and protein were detected by Real-time RT-PCR and immunohistochemistry respectively. The methylation rate of RASSF1A promoter CpG islands was analyzed by HRM. RESULTS: Experimental groups could obviously inhibit the growth of tumor and up-regulate the expression of RASSF1A. The methylation rate of RASSF1A in transplanted tumors in experimental groups was lower than the control group. Especially As2O3 combined with DDP were superior to the single drug use. CONCLUSION: As2O3 inhibits the growth of human nasopharyngeal carcinoma cell strain CNE2 xenograft in nude mice and increases mRNA expression of RASSF1A. As2O3 inhibits the malignant phenotypes of human nasopharyngeal carcinoma cells and reverses hypermethylation of RASSF1A.