摘要:
Objective To investigate the expression of FHIT,WWOX and MDR1 gene in nasopharyngeal carcinoma and FHIT and WWOX mechanism of inactivation.Methods Real-time PCR was used to test FHIT,WWOX and MDR1 gene′s mRNA expression in 89 nasopharyngeal carcinoma patients (experimental group) and 61 inflammatory patients (control group).Q-MSP was used to test the FHIT and WWOX promoter methylation status.Denatured polyacrylamide gel electrophoresis was used to test the LOH of FHIT and WWOX gene.Results (1)The three genes′ mRNA expression were different between experimental group and control group (P<0.05).After grouped according to the histological type and clinical stages,the expression of FHIT and WWOX mRNA between the patients with serious illness or poorly differentiated squamous cell carcinoma and mild cases or highly differentiated squamous cell carcinoma were significantly different in the experimental group,the difference is statistically significant (P<0.05)Meanwhile,the FHIT and WWOX mRNA expression had statistical association with the clinical stage and histological type(r=-0.731,P=0.000;r=-0.816,P=0.000;r=-0.626,P=0.000;r=-0.536,P=0.001).The MDR1 mRNA expression was different between poorly and highly differentiated squamous cell carcinoma (P=0.021),which was statistical associated with the histological type (r=-0.697,P<0.001).(2)The degrees of FHIT and WWOX promoter methylation in the experimental group was higher than those in the control group,the difference was statistically significant (P<0.05);Also,the expression of FHIT and WWOX mRNA were closely related to the degree of promoter methylation(r=-0.689,P=0.000;r=-0.594,P=0.000).(3) In the experimental group,there were 39 cases (43.8%) of LOH in the FHIT gene,and 42 cases (47.2%)of the WWOX genes were significantly higher than those in the control group (4.9% and 3.3%),the difference was statistically significant (P<0.05).The FHIT and WWOX gene mRNA were negatively correlated with the loss of heterozygosity(r=-0.239,P=0.049;r=-0.364,P=0.013).Conclusion Promoter methylation is the main reason for the down-regulation of FHIT gene and WWOX gene expression in nasopharyngeal carcinoma patients,which may be the main reason for the occurrence and development of nasopharyngeal carcinoma.The higher expression of MDR 1 mRNA is statistical association with the histological type.%目的 探讨FHIT、WWOX基因组在鼻咽癌患者中的表达、失活机制及MDR1基因在鼻咽癌中的表达.方法 采用荧光相对定量RT-PCR法检测89例鼻咽癌患者(试验组)和61例慢性鼻黏膜炎患者(对照组)鼻咽部组织WWOX、FHIT和MDR1基因mRNA表达水平,甲基化特异性(MSP)方法及变性聚丙烯酰胺凝胶电泳分析FHIT和WWOX基因mRNA表达下调原因.结果 (1)实验组鼻咽组织中FHIT、WWOX和MDR1基因的mRNA表达量与对照组间的差异有统计学意义(P<0.05);按临床分期和分化程度分层后,试验组中病情较严重者较病情轻者,分化程度低的较分化程度高者间的FHIT和WWOX基因表达量差异有统计学意义(P<0.05),且FHIT和WWOX基因表达量与临床分期、分化程度呈负相关(r=-0.731,P=0.000;r=-0.816,P=0.000;r=-0.626,P=0.000;r=-0.536,P=0.001);试验组低分化者MDR1基因mRNA与高分化者间差异有统计学意义(P=0.021),且组织学类型与MDR1基因mRNA相对表达量呈负相关(r=-0.697,P=0.000);试验组的FHIT与WWOX基因的mRNA相对表达量呈正相关(r=0.540,P=0.000).(2) 试验组的FHIT和WWOX基因启动子甲基化程度明显高于对照组,差异有统计学意义(P<0.05);且FHIT 和WWOX 的mRNA与该基因启动子甲基化程度呈正相关(r=-0.689,P=0.000;r=-0.594,P=0.000). (3) 试验组中有39例(43.8%)在FHIT基因中至少有1个位点存在杂合性缺失(LOH),在WWOX基因中42例(47.2%)至少一个位点存在LOH,明显高于对照组的3例和2例(4.9%,3.3%),差异有统计学意义(P<0.05).且FHIT和WWOX基因mRNA与该基因基因杂合性缺失呈负相关(r=-0.239,P=0.049;r=-0.364,P=0.013).结论 启动子甲基化是鼻咽癌患者WWOX和FHIT基因表达下调的主要原因,可能也是鼻咽癌的发生、发展的主要原因.MDR1基因过度表达与鼻咽癌的分化程度密切相关.