喉癌组织中CHFR基因mRNA表达水平及启动子区甲基化的研究

Study of mRNA expression level and hypermethylation of CHFR promoter in the laryngreal squamous cell carcinoma tissue

目的:探讨CHFR基因表达水平及启动子区CpG岛过甲基化与喉癌发生发展的关系。方法:采用荧光定量PCR技术和甲基化特异性PCR技术检测50例喉癌组织(喉癌组)和15例正常喉组织(对照组)CHFR基因mRNA表达情况及启动子区CpG岛过甲基化情况。结果:①CHFR基因在对照组mRNA全部表达,在喉癌组mRNA有2例(4%)表达缺失,48例表达量明显下调(相对表达量为0.50±0.12),其中Ⅰ期和Ⅱ期相对表达量(0.30±0.04),Ⅲ期和Ⅳ期相对表达量(0.70±0.21),与对照组比较,差异有统计学意义(P<0.01)。②在对照组中未发现CHFR基因启动子区甲基化,在喉癌组中CHFR基因启动子区甲基化率为22%(11/50),其中Ⅰ期和Ⅱ期患者共10例,Ⅲ期1例,Ⅳ期未发现甲基化,与对照组比较,差异均有统计学意义(P<0.01)。③甲基化的喉癌标本mRNA相对表达量为0.11±0.05,2例mRNA表达缺失,未甲基化的喉癌标本mRNA相对表达量为0.75±0.13,甲基化和mRNA表达相关,γ=0.387(P<0.05)。结论:喉癌组织中CHFR基因mRNA表达缺失或下调,CHFR基因启动子区CpG岛过甲基化在喉癌组织中是频发事件,二者密切相关,可能与喉癌的发生发展有关,有望能成为喉癌的早期诊断及治疗靶点基因之一。

Objective：To explore the relationship between the level of expression and hypermethylation of the CHFR gene and the occurrence and development of laryngeal squamous cell carcinoma （LSCC）.Method：The mRNA expression and promoter hypermethylation were detected by Realtime fluro-genetic quantitative PCR and methylation specific PCR in 50 LSCCs（LSCC group ） and 15 normal laryngeal tissure（control group）.Result：①CHFR mRNA was shown in the control group,while the mRNA was loss expression in the 2 LSCC （4%）,and the level of mRNA expression was significantly lower in the LSCC group. The relative ratio was 0.50±0.12,which is 0.30±0.04 at the early stage of the LSCC and 0.70±0.21 at the advanced stage,respectively.The discrepancy had statistical significance（P0.01）.②The methylation rate of CHFR was 22%（11/50） in the LSCC tissues,which was not found in the normal tissues.The aberrant methylation of CHFR was observed in 10 of the patients at the stage Ⅰ and stage Ⅱ of LSCC ,in 1 of the patients at the stage Ⅲ,and was absent at the stage Ⅳ.There was significant difference between the aberrant methylation of CHFR and the stage of carcinoma（P0.01）.③The mRNA expression level of the aberrant methylation patients was 0.11±0.05,which was significantly lower than that of the unmethylation patients 0.75±0.13.Gene inactivation was observed in 2 of the 11 patients with the aberrant promoter methylation.The methylation was associated with the expression of mRNA,with the correlation coefficient 0.387（P0.05）.Conclusion：Hypermethylation of CHFR gene promoter is associated with loss or lower expression of CHFR mRNA in the LSCCs ,and it may contribute to the occurrence and development of LSCC.The promoter aberrant methylation of CHFR may be one of the early diagnostic and therapeutic marker genes.