Expression changes of FHIT and WWOX gene in nasopharyngeaI carcinoma and the mechanism

HUANG Chunni; MO Wuning; HUANG Jian; LI Ping; LIU Lei; YANG Zheng

doi:10.3969/j.issn.1002-266X.2016.26.006

Abstract：Objective To observe the expression changes of FHIT gene and WWOX gene in nasopharyngeal carcino-ma and to explore the mechanism.Methods We chose 89 patients with nasopharyngeal carcinoma as the experimental group,and took their surgical removal of the nasopharyngeal carcinoma tissue specimens and blood specimens;and 61 pa-tients with chronic nasal mucosal inflammation as the control group,and took their nasopharyngeal mucosa tissue specimens and blood specimens.RT-PCR was used to detect the expression of FHIT mRNA,WWOX mRNA and promoter methylation in nasopharyngeal carcinoma tissue specimens of the experimental group and nasopharyngeal mucosa tissue specimens of the control group.MSP was used to detect loss of heterozygosity (LOH)of FHIT and WWOX genes from blood specimens in the two groups.Results The relative expression of FHIT mRNA and WWOX mRNA in the experimental group was signifi-cantly lower than that in the control group (all P <0.05).The relative expression of FHIT mRNA and WWOX mRNA in clinical stage Ⅲ ~Ⅳ was significantly lower than that in clinical stage Ⅰ-Ⅱ of the experimental group (all P <0.05).In the experimental group,clinical stage was negatively correlated with the relative expression of FHIT and WWOX mRNA (r=-0.731,-0.816,all P <0.05).FHIT and WWOX gene promoter methylation degree in the experimental group were 0.46 ±0.34 and 0.37 ±0.28,higher than 0.15 ±0.17 and 0.11 ±0.09 in the control group (all P <0.05).Spearman correlation analysis showed that the FHIT and WWOX mRNA was negatively correlated with the degree of the gene promoter methylation in the experimental group (r =-0.689, -0.594,all P <0.05 ).In the experimental group,39 cases (43.8%)had at least 1 LOH in the FHIT gene and 42 cases (47.2%)had at least 1 LOH in the WWOX gene,which significantly higher than 3 cases (4.9%)and 2 cases (3.3%)of the control group (all P <0.05 ).The FHIT and WWOX mRNA was negatively correlated with gene LOH in the experimental group (r =-0.239, -0.364,all P <0.05).Conclusion The down-regulation expression of FHIT gene and WWOX gene is related to the occurrence and de-velopment of nasopharyngeal carcinoma.Gene promoter methylation and LOH may be the causes of the down-regulation ex-pression in the carcinoma tissues,and gene promoter methylation may be the main reason.