Institute of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China.
PLoS One. 2012;7(10):e47579. doi: 10.1371/journal.pone.0047579. Epub 2012 Oct 15.
GSTM1 and GSTT1 are involved in the detoxification of carcinogens such as smoking by-products, and polymorphisms in these two genes with a result of loss of enzyme activity may increase risk of carcinogenesis. Although many epidemiological studies have investigated the association between GSTM1 or GSTT1 null genotype and head and neck squamous cell carcinoma (HNSCC), the results remain conflicting. To elucidate the overall association of GSTM1, GSTT1 and HNSCC, we included all available studies and performed this meta-analysis.
METHODOLOGY/PRINCIPAL FINDINGS: A dataset including 42 articles for GSTM1, 32 articles for GSTT1, and 15 articles for GSTM1 and GSTT1 in combination were identified by a search in PubMed. Associations beween HNSCC and polymorphisms of GSTM1 and GSTT1 alone and in combination were analysed by software RevMan 5.1. Stratification analysis on ethnicity and smoking status, sensitivity analysis, heterogeneity among studies and their publication bias were also tested. Association was found in overall analysis between HNSCC and GSTM1 and GSTT1 null genotype. Stratified by ethnicity, we found increased risks of HNSCC in carriers with GSTM1 null genotype in Asian, GSTT1 null genotype in South American, and dual null genotype in European and Asian. When stratified by smoking, a more significant association of GSTM1 null genotype with HNSCC risk was observed in smokers.
CONCLUSIONS/SIGNIFICANCE: This meta-analysis presented additional evidence of the association between GSTM1 and GSTT1 polymorphisms and HNSCC risk.
GSTM1 和 GSTT1 参与致癌物的解毒，如吸烟的副产物，这些基因的多态性导致酶活性丧失，可能会增加致癌风险。尽管许多流行病学研究已经调查了 GSTM1 或 GSTT1 缺失基因型与头颈部鳞状细胞癌（HNSCC）之间的关系，但结果仍存在争议。为了阐明 GSTM1、GSTT1 与 HNSCC 之间的总体相关性，我们纳入了所有可用的研究并进行了这项荟萃分析。
方法/主要发现：通过在 PubMed 中搜索，确定了一个包含 42 篇关于 GSTM1、32 篇关于 GSTT1 和 15 篇关于 GSTM1 和 GSTT1 联合的文章数据集。使用软件 RevMan 5.1 分析了 HNSCC 与 GSTM1 和 GSTT1 单独和联合的多态性之间的关联。还进行了分层分析、敏感性分析、研究间的异质性及其发表偏倚。总体分析显示，HNSCC 与 GSTM1 和 GSTT1 缺失基因型之间存在关联。按种族分层，我们发现亚洲人群中 GSTM1 缺失基因型、南美人群中 GSTT1 缺失基因型以及欧洲和亚洲人群中双重缺失基因型与 HNSCC 风险增加相关。按吸烟状况分层时，在吸烟者中，GSTM1 缺失基因型与 HNSCC 风险的相关性更为显著。
结论/意义：这项荟萃分析提供了更多证据表明 GSTM1 和 GSTT1 多态性与 HNSCC 风险之间存在关联。
