Effects of NGX6 expression on proliferation and invasion of nasopharyngeal carcinoma cells and survival of patients

摘要

OBJECTIVE: To detect the expressions of nasopharyngeal carcinoma-associated gene 6 (NGX6) in nasopharyngeal carcinoma cells and tissues, and to investigate the effects of NGX6 on the proliferation and invasion of nasopharyngeal carcinoma cells and the survival of patients. PATIENTS AND METHODS: The human nasopharyngeal carcinoma cells (HONE1) and immortalized human nasopharyngeal epithelial cells (NP69) were selected and cultured. The mRNA and protein expression levels of NGX6 were detected via quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. The expression of NGX6 in HONE1 was up-regulated using the gene transfection technique. Moreover, the effects of NGX6 on the proliferation and invasion capacities of HONE1 were observed via methyl thiazolyl tetrazolium (MTT) assay and Transwell assay. 50 biopsy tissue specimens of nasopharyngeal carcinoma and 20 non-neoplastic nasopharyngeal biopsy tissue specimens were collected, and the immunohistochemical method was used to detect the protein expression of NGX6 in tumor tissues of patients with esophageal carcinoma. Finally, the follow-up data of patients were recorded, Kaplan-Meier method was used for survival analysis, and the difference in survival rates was detected using the Log-rank test. RESULTS: The results of qRT-PCR and Western blot showed that the mRNA and protein expressions of NGX6 in HONE1 were significantly lower than those in nasopharyngeal carcinoma cells (NP69). After the overexpression of NGX6, the protein expression of NGX6 in HONE1 was significantly increased, but the proliferation and invasion capacities of HONE1 were significantly decreased. Besides, the immunohistochemical results revealed that the expression of NGX6 in tumor tissues of patients with nasopharyngeal carcinoma was significantly lower than that in normal tissues; the survival analysis showed that the level of NGX6 was positively correlated with the survival and prognosis of patients with nasopharyngeal carcinoma. CONCLUSIONS: NGX6 is lowly expressed in nasopharyngeal carcinoma, and it can inhibit the proliferation and invasion of nasopharyngeal carcinoma cells, whose expression is positively correlated with the survival and prognosis of patients with nasopharyngeal carcinoma.