诱导型一氧化氮合酶在结肠癌组织中表达及其与p53增殖细胞核抗原的相关关系

目的 :探讨诱导型一氧化氮合酶 (iNOS)的产物一氧化氮 (NO)在结肠癌癌变过程中可能作用机制 ,进一步研究结肠癌中iNOS、p5 3及增殖细胞核抗原 (PCNA)表达的相关关系。方法 :应用免疫组织化学检测 60例结肠癌、3 0例癌旁组织及 3 0例正常结肠粘膜中iNOS蛋白表达 ,同时检测 60例结肠癌中p5 3、PCNA蛋白表达。应用原位分子杂交方法检测 60例结肠癌中iNOSmRNA表达。结果 :60例结肠癌组织中iNOS表达阳性率为 75 % (4 5 60 ) ,3 0例癌旁组织中iNOS阳性表达率为 2 0 % (6 3 0 ) ,3 0例正常结肠粘膜组织中iNOS呈阴性表达。结肠癌组织中iNOS表达明显高于癌旁组织 ,统计学分析有显著性差异 (P <0 .0 1)。DukesA、B期iNOS蛋白及iNOSmRNA的表达明显高于DukesC、D期 ,差异有显著性 (P <0 .0 1)。iNOS表达与p5 3表达呈正相关 (r =0 .743 2 ,P <0 .0 0 1) ,iNOS表达与PCNA表达呈正相关 (r =0 .612 2 ,P <0 .0 5 )。结论 :iNOS在结肠癌组织中表达上调 ,提示iNOS可能在结肠粘膜细胞癌变过程中起重要作用。iNOS表达可促进结肠癌细胞增殖。iNOS的异常表达及抑癌基因p5 3的失活在结肠癌的癌变过程中起协同作用。

Expression of iNOS Protein and Its Relationship with Expression of p53 PCNA Proteins in Human Colorectal Carcinoma

Objective:To study the expressions of iNOS and its relationship with expression of p53?PCNA in human colorectal carcinoma.Methods:Immunohistochemical assay was used to detect the expressions of iNOS?PCNA and p53 proteins in 85 human colorectal carcinoma samples,30 adjacent non tumor colorectal mucous and 25 normal colorectal mucous tissues.The exprssion of iNOS mRNA in colorectal carcinoma was detected by hybridization in situ.Results:The expression of iNOS protein was detected in a significantly greater proportion of human colorectal carcinoma (75%) than in adjacent non tumor colorectal mucous tissue(20%) ( P <0.01), howerver, the expression of iNOS was negative in normal colorectal mucous tissues. The expressions of iNOS protein and iNOS mRNA in Dukes A?B stages were significantly higher than in Dukes C?D stages ( P <0.01). The expression of iNOS protein was significantly correlated with that of p53 or PCNA.Conclusion: The up regulation expression of iNOS in human colorectal carcinoma suggested that iNOS played a role in the pathway of carcinogenesis in colorectal carcinoma. The expression of iNOS might promote the proliferation of tumor cells.Inactivation of antioncogene p53 and up regulation of iNOS might play synergetic roles in the process of carcinogenesis of colorectal carcinoma.