结肠良、恶性病变中细胞凋亡及其与bcl-2、bax、PCNA蛋白表达的关系

Relationship Between Apoptosis and the Expression of bcl-2,bax and PCNA Protein in Benign and Malignant Pathologic Changes of Colon

目的 了解结肠良、恶性病变中细胞凋亡与增殖 ,及其与相关基因蛋白表达的关系及其生物学意义。方法 应用免疫组织化学S P法检测 14 8例结肠良、恶性病变标本中bcl 2、bax和PCNA蛋白的表达 ;并对其中 75例标本进行凋亡指数 (AI)和有丝分裂指数 (MI)测定。结果 PCNA与AI和MI密切相关 (P <0 .0 1) ;而bcl 2和bax仅与AI有关 (P <0 .0 1) ;bcl 2和PCNA蛋白在结肠腺癌和腺瘤中表达率显著高于正常组织 (P <0 .0 1) ;而bax蛋白则相反 ,在正常及良性病变中表达率较癌组织为高 (P<0 .0 1)。其次发现 ,以结肠腺瘤为分界点 ,前半阶段凋亡指数逐渐上升 ,后半阶段则下降 ,而细胞增殖指数在整个演进过程中呈上升趋势。结论 凋亡与增殖间平衡的破坏与结肠粘膜的恶变密切相关 ,在这一过程中有多种基因参与调控 ,其中bcl 2和bax即参与了此调控过程 ,且其蛋白产物的异常表达是结肠腺癌发生过程中的早期事件。

Objective To investigate the relationship between apoptosis and the expression of related genes in human colon carcinoma.Methods The expressions of bcl-2,bax and PCNA protein were detected by immunohistochemical method in paraffin sections of 148 benign or malignant pathologic changes of colon;The TUNEL-positive cells were counted in 75 cases as apoptosis index(AI) and mitotic cells as mitotic index(MI).Results The expression of PCNA was related with both AI and MI( P <0.01),but bcl-2 and bax were only related with AI.bcl-2 and PCNA positive expression ratio were higher in carcinoma and adenoma of colon than in normal tissues( P <0.01);but bax positive expression ratio were lower in carcinoma and adenoma of colon than in normal tissues( P <0.01).AI increased in anterior partial phase and descended in posterior partial phase(adenoma as interpoint),and PI increased in whole procession.Conclusion The malignant change of colic mucosa was related with apoptosis and proliferation,many genes participate this regulation process,bcl-2 and bax was this kind of gene,and the abnormal expression of bcl-2 and bax proteins ocurred in the early stage of colon carcinoma.