华北地区结直肠癌发病风险与基质金属蛋白酶-9表达及基因多态性的相关性

Association between matrix metalloproteinase - 9 expression, gene polymorphism and risk of color- ectal cancer in North China

目的探讨基质金属蛋白酶-9（MMP-9）活性水平、蛋白水平及基因多态性与华北地区结直肠癌发病风险的关系。方法应用明胶酶图分析法检测60例结直肠癌患者MMP-9在肿瘤组织和正常组织中的活性及在不同TNM分期的表达。应用免疫组织化学染色法检测60例结直肠癌患者MMP-9在不同TNM分期肿瘤组织中的表达。应用等位基因特异性聚合酶链反应（PCR）技术检测60例结直肠癌患者（结直肠癌组）和83例正常健康人（对照组）血清中MMP-9基因Q279R和－1562 C/T位点基因型及等位基因频率分布。结果明胶酶图分析显示在不同TNM分期中，肿瘤组织与正常组织比较，肿瘤组织MMP-9活性明显高于正常组织（Ⅰ期：45.3±7.2比14.3±1.8，t＝14.54，P＝0.000；Ⅱ期：42.7±7.9比13.6±1.9，t＝12.45，P＝0.000；Ⅲ期：72.9±8.5比18.2±3.2，t＝21.21，P＝0.000）；不同TNM分期的肿瘤组织中，Ⅲ期MMP-9的活性高于Ⅰ期和Ⅱ期（72.9±8.5比45.3±7.2，t＝9.24，P＝0.000；72.9±8.5比42.7±7.9，t＝9.80，P＝0.000）。免疫组织化学染色证实，Ⅲ期MMP-9蛋白表达显著高于Ⅰ期和Ⅱ期（33.70±5.25比20.43±2.73，t＝8.03，P＝0.000；33.70±5.25比22.37±3.76，t＝6.44，P＝0.000）。在143名研究对象（结直肠癌组和对照组）中，MMP-9基因Q279R位点均为AA、AG和GG基因型，两组间基因型分布差异无统计学意义（χ2＝0.645，P＝0.722），两组A、G等位基因频率差异无统计学意义（χ2＝0.017，P＝0.896）。MMP-9基因－1562 C/T位点两组间基因型分布差异无统计学意义（χ2＝ 0.872，P＝0.647），两组C、T等位基因频率差异无统计学意义（χ2＝0.380，P＝0.538）。结论MMP-9的活性及蛋白表达与结直肠癌发生及进展密切相关，但MMP-9基因Q279R、－1562 C/T位点多态性在我国华北地区汉族人群中与结直肠癌发生无明显相关。

Objective To investigate the association of the activity, protein expression and gene polymorphism in matrix metalloproteinase-9 （MMP-9） with the risk of colorectal cancer （CRC） in North China. Methods Zymography was used to examine the activity of MMP-9 in 60 cases of cancer tissues and the matched normal tissues. Immunohistochemical staining was used to detect the expressions of MMP-9 in 60 cases of colorectal carcinoma at different stages. Genotypes of MMP-9 （Q279R and -1562 C/T） were analyzed by polymerase chain reaction （PCR） method among 60 cases of CRC specimens and 83 frequency-matched controls. Results The result of zymography showed that the activity of MMP-9 in the cancer tissues was significantly higher than that in the matched normal tissues （Ⅰ： 45.3±7.2 vs. 14.3±1.8, t=14.54, P=0.000; Ⅱ： 42.7±7.9 vs. 13.6±1.9, t=12.45, P=0.000; Ⅲ： 72.9±8.5 vs. 18.2±3.2, t=21.21, P=0.000）, and the activity of MMP-9 was significantly higher in stage-Ⅲ than that in stage-Ⅰ and -Ⅱ （72.9±8.5 vs. 45.3±7.2, t=9.24, P=0.000; 72.9±8.5 vs. 42.7±7.9, t=9.80, P=0.000）. Immunohistochemistry results also showed that the expression of MMP-9 was significantly higher in stage-Ⅲ than that in stage-Ⅰ and -Ⅱ （33.70±5.25 vs. 20.43±2.73, t=8.03, P=0.000; 33.70±5.25 vs. 22.37±3.76, t=6.44, P=0.000）. We found similar MMP-9 （Q279R and -1562 C/T） genotypes, allelic and haplotypes distributions in the two study groups （CRC group and control group）.Conclusion The activity and protein expression of MMP-9 may be involved in colorectal cancer progression, but the polymorphisms of MMP-9 gene Q279R and -1562C/T in the population of North China are not associated with the risk of CRC.