MMP－2和TIMP－2基因多态性与胃癌发生风险的关联性分析

摘要

Objective To explore the associations between matrix metalloproteinase -2 (MMP-2) and tissue inhibitor of metalloproteinase -2 (TIMP-2) polymorphisms and gastric cancer. Methods A case-control study was conducted. A total of 252 gastric cancer patients were enrolled as the case group , and 254 healthy subjects were enrolled as the control group. Denaturing high performance liquid chromatography method was utilized for detecting all genotypes under partial denaturing conditions. Shesis software was used for haplotype analysis. The immunohistochemically semi-quantitative analysis was adopted for the determination of MMP-2 and TIMP-2 expressionlevels. Results The frequencies of CC, CT and TT genotypes of MMP-2 -1306C/T in the case group were 80.2%(202/252), 19.0%(48/252) and 0.8%(2/252) respectively, and those in the control group were68.1%(173/254)、28.2%(71/254) and 3.9%(10/254), which showedsignificant difference between two groups (χ2=11.46, P=0.003). As compared with TT genotype, the patients with C allele (CC+GC) had a higher risk of gastric cancer (OR=1.845, 95%CI: 1.231~2.767). The frequencies of GG,AG and AAgenotypes of TIMP-2-303G/A in the case group were 57.1%(144/252), 38.9%(98/252) and 4.0%(10/252) respectively,and those in the control group were52.0%(132/254), 35.0%(89/254) and 13.0%(33/254). There was significant difference between two groups (χ2=13.25, P=0.001). The risk of gastric cancer in the patients with G allele (GG+GA) was 1.232 times than that of TT genotype (OR=1.232, 95%CI: 0.868~1.750). The frequencies of GG, GC and CCgenes of TIMP-2-418G/C in the case group were 56.7%(143/252),34.1%(86/252)and 9.1%(23/252) respectively,and those in the control group were68.1% (173/254),28.3% (72/254)and 3.5% (9/254).There was significant difference between two groups (χ2=6.587, P=0.037). The risk of gastric cancer in the patients with G allele (GG+GC) was 0.666 times than that of CC genotype (OR=0.666, 95%CI:0.463~0.959). There were significant difference in the frequencies of GG , AG and AAgenotypes of TIMP-2-303G/A between the serous invasion group and non-serous invasion group (P=0.005). There were also significant difference in the frequencies of (AA+AG) and GGgenotypes of TIMP-2-303G/A between the serous invasion group and non-serous invasion group (P=0.001). There was a statistical association between the gene polymorphism of MMP-2-1306C/Tand the expression of MMP-2 protein (P=0.035). The gene polymorphism of TIMP-2-303G/Awas also related tothe expression of TIMP-2 protein (P=0.021). The haplotype analysis results indicated that the CGC frequency of the case group was apparently higher than that of the control group (χ2=4.506,P=0.034), and the positive survival rate of CGC was apparently lower than the negative group (P=0.015). Conclusions MMP-2-1306C/T, TIMP-2-303G/A and -418G/C variants might be associated with gastric cancer susceptibility. Additionally , MMP-2 and TIMP-2 protein expression might have closely association with gastric cancer susceptibility.%目的：探讨基质金属蛋白酶－2（matrix metalloproteinase －2，MMP－2）和金属蛋白酶组织抑制剂－2（tissue inhibitor of metalloproteinase －2，TIMP－2）基因多态性与胃癌发生风险的关系。方法本研究为病例对照研究，纳入252例连续性的胃癌患者作为病例组，254例健康者作为对照组。采用变性高效液相色谱法，在部分变性条件下检测所有基因型，用Shesis 软件对各基因进行单倍型分析。免疫组化半定量分析方法测定胃癌组织中MMP－2和TIMP－2的表达水平。结果病例组MMP－2－1306C／T 基因 CC、CT、TT 分布的频率分别为80．2％（202／252）、19．0％（48／252）、0．8％（2／252），对照组分别为68．1％（173／254）、28．2％（71／254）、3．9％（10／254），两者差异有统计学意义（χ2＝11．46，P＝0．003）；携带C 等位基因（CC＋CT）的患者发生胃癌的风险是携带 TT 基因型的1．845倍（OR＝1．845，95％CI：1．231～2．767）。病例组 TIMP－2－303G／A 基因 GG、AG、AA 分布的频率分别为57．1％（144／252）、38．9％（98／252）、4．0％（10／252），对照组分别为52．0％（132／254）、35．0％（89／254）、13．0％（33／254），两者差异有统计学意义（χ2＝13．25，P＝0．001）；携带 G 等位基因（GG＋GA）的患者发生胃癌的风险是携带 AA 基因型的1．232倍（OR＝1．232，95％CI：0．868～1．750）。病例组 TIMP－2－418G／C 基因GG、GC、CC 分布的频率分别为56．7％（143／252）、34．1％（86／252）、9．1％（23／252），对照组分别为68．1％（173／254）、28．3％（72／254）、3．5％（9／254），两者差异有统计学意义（χ2＝6．587，P＝0．037）；携带 G 等位基因（GG＋GC）的患者发生胃癌的风险是携带 CC 基因型的0．666倍（OR＝0．666，95％CI：0．463～0．959）。TIMP－2－303G／A 在未突破浆膜层组GG、AG、AA 基因型分布与突破浆膜层组中基因型分布差异有统计学意义（P＝0．005）。 TIMP－2－303G／A 在（AA＋AG），GG 基因型分布与突破浆膜层组中基因型分布差异有统计学意义（P＝0．001）。 MMP－2－1306C／T 基因多态性与MMP－2蛋白表达存在统计学关联（P＝0．035）；TIMP－2－303G／A 基因多态性与 TIMP－2蛋白表达亦存在统计学关联（P＝0．021）。病例组单倍体型CGC 的频率明显高于对照组（χ2＝4．506，P＝0．034），且CGC 阳性患者的生存率比 CGC 阴性的生存率明显降低（P＝0．015）。结论 MMP－2基因－1306C／T 位点及TIMP－2基因－303G／A 位点以及－418G／C 位点可能与胃癌易感性相关。 MMP－2和 TIMP－2蛋白表达水平可能与胃癌易感性相关。