多巴胺受体D2基因多态性与吸烟行为及肺癌风险的相关性

Study on the association between smoking behavior and dopamine receptor D2 gene polymorphisms among lung cancer cases

目的 探讨多巴胺受体D2 (DRD2 )基因多态性在汉族人群中的分布及其与吸烟行为和肺癌风险的关系。方法 用聚合酶链反应 限制性片段长度多态性 (PCR RFLP)分析方法 ,检测 32 6名正常人群和 32 6例肺癌病人DRD2基因TaqIA和TaqIB多态频率。 结果 在对照人群中 ,DRD2A1和A2等位基因频率分别为 4 1.3%和 5 8.7% ,B1和B2基因频率分别为 4 3.6 %和 5 6 .4 %。DRD2基因多态与吸烟与否和吸烟年数无明显相关。然而 ,在日吸烟量≥ 2 5支的吸烟者中 ,A2 /A2和B2 /B2基因型频率分别为 4 2 .5 %和 4 0 .0 % ,高于日吸烟量 <2 5支的吸烟者 (2 6 .1% ;P =0 .0 4 7和 0 .0 91)。肺癌病人中吸烟者的比例显著高于正常对照 ,但两组的DRD2基因型频率差异无显著性。结论 DRD2 A2 /A2基因型可能与吸烟成瘾性有一定关系 ,但尚需更大样本量的独立研究加以证实。

Objective To investigate the possible association between dopamine D2 receptor (DRD2) TaqI A and TaqI B genotypes as well as smoking behavior and the risk of lung cancer among Chinese Han people. Methods PCR was used to perform genotyping on peripheral WBC DNA from 326 lung cancer patients and 326 age, sex and ethnicity matched healthy controls. Subjects were interviewed to obtain relevant information and lifetime history of tobacco use. Results There were no statistically significant differences in the distribution of DRD2 genotypes between lung cancer cases and controls. The DRD2 genotypes and smoking status showed no correlation among cases and among controls as well. However, among controls, the frequency of the DRD2*A2/A2 genotype in smokers who smoked ≥25 cigarettes/day appeared to be higher than that in those who smoked <25 cigarettes/day ( 42.5 % versus 26.1 %, P = 0.047 ). A similar trend was also found for the DRD2*B2/B2 genotype, which was linked to the DRD2*A2/A2 genotype, although the difference was not significant ( 40.0 % versus 26.1 %, P = 0.091 ). In contrast to controls, no association was found between the DRD2 genotypes and smoking among lung cancer cases. Conclusion Our results suggested that DRD2*A2/A2 genotype might be associated with a greater smoking intensity in Chinese.Further studies are needed to confirm this preliminary finding.