湖南地区鼻咽癌MHC-Ⅰ类链相关基因A第5外显子微卫星多态性研究

目的研究MHC-Ⅰ类链相关基因A(MHC class-Ⅰ chain related gene A, MICA)第5外显子微卫星多态性与湖南地区鼻咽癌之间的相关性.方法应用荧光聚合酶链反应-基因扫描技术和聚合酶链反应-序列特异性引物技术分析127例湖南地区鼻咽癌患者和112名正常人群MICA基因第5外显子微卫星等位基因及MICA基因缺失(MICA*Del)频率.结果 MICA*A9表型频率在患者组(45/127)高于对照组(20/112),相对风险值(relative risk)为2.524(P=0.001,Pc=0.006);MICA*A5.1表型频率在患者组(51/127)低于对照组(69 /112),相对风险值为0.418(P=0.0004, Pc=0.0026).进一步分析发现,MICA*A9在男性患者组的表型频率(35/101)高于男性对照组(11/78),相对风险值为3.23(P=0.00095,Pc=0.006);MICA*A5.1在男性患者组的表型频率(39 /101)低于男性对照组(49/78),相对风险值为0.372 (P=0.0007,Pc=0.004);各MICA-STR 等位基因频率在女性患者组与女性对照组之间的差异无统计学意义(Pc＞0.05).结论湖南地区MICA-STR等位基因多态性与鼻咽癌相关,MICA*A9是该人群男性个体的一个鼻咽癌遗传易感标记.

Polymorphism of short tandem repeat of exon 5 of MHC class-I chain related gene A and association with nasopharyngeal carcinoma in a southern Chinese population

OBJECTIVE: To explore the association between the short tandem repeat polymorphism of exon 5 of MICA gene (MICA-STR) and nasopharyngeal carcinoma (NPC) in a southern Chinese population. METHODS: One hundred and twenty-seven consecutive NPC patients and 112 randomly selected normal controls residing in southern China mainland were analyzed for MICA-STR allelic variation and MICA gene deletion by fluorescent polymerase chain reaction-gene scanning and polymerase chain reaction-sequence specific priming. RESULTS: MICA*A9 was observed at significantly higher frequency in the NPC patient group than in the control group (relative risk = 2.524, P = 0.001,Pc = 0.006); whereas MICA*A5.1 was present at significantly lower frequency in the NPC patient group than in the control group (RR = 0.418, P = 0.0004, Pc = 0.0026). Further analysis revealed that MICA*A9 was over-represented in male NPC patients, compared with male controls (RR = 3.23, P = 0.00095, Pc = 0.006); whereas MICA*A5.1 was present at significantly lower frequency in male NPC patients, compared with male controls (RR = 0.372, P = 0.0007, Pc = 0.004). None of the MICA-STR variants showed statistically significant frequency difference between female NPC patients and female controls (Pc > 0.05). CONCLUSION: MICA-STR polymorphism is associated with NPC, and MICA*A9 is a genetic susceptibility marker of male individuals for NPC in a southern Chinese population.