结直肠腺瘤及癌变组织PTEN和COX-2的表达及意义

目的探讨结直肠腺瘤及癌变组织抑癌基因人第10号染色体缺失的磷酸酶及张力蛋白同源基因(PTEN)和环氧化酶-2(COX-2)的表达差异。方法采用免疫组织化学SP法分别检测30例正常肠黏膜组织、30例非腺瘤性息肉、60例腺瘤性息肉及30例肠癌组织中PTEN、COX-2蛋白的表达,分析其与临床病理特征的关系及二者表达相关性。结果 PTEN在正常肠黏膜、非腺瘤性息肉、腺瘤性息肉及肠癌组织中的阳性表达率逐渐降低,腺瘤性息肉和肠癌组织阳性率显著低于正常肠黏膜和非腺瘤性息肉组织,差异有统计学意义(P0.05);COX-2在正常肠黏膜、非腺瘤性息肉、腺瘤性息肉及肠癌组织中的阳性表达率逐渐升高,腺瘤性息肉和肠癌组织COX-2阳性表达率显著高于正常肠黏膜组织,肠癌组织COX-2阳性表达率显著高于非腺瘤性息肉组织,差异均有统计学意义(P0.05);腺瘤性息肉中直径≥1 cm者PTEN阳性率低于直径1 cm者,绒毛状腺瘤PTEN阳性率低于管状腺瘤,腺瘤伴高级别上皮内瘤变及癌变的组织PTEN阳性率低于早期腺瘤,差异均有统计学意义(P0.05);腺瘤性息肉中直径≥1 cm者COX-2阳性率高于直径1 cm者,绒毛状腺瘤COX-2阳性率高于管状腺瘤,腺瘤伴高级别上皮内瘤变及癌变的组织COX-2阳性率高于早期腺瘤,差异均有统计学意义(P0.05);腺瘤性息肉和肠癌组织PTEN和COX-2表达呈负相关(P0.05)。结论 PTEN和COX-2可能共同参与结直肠腺瘤癌变,并起重要负协同作用;联合检测或可预测腺瘤癌变,对腺瘤癌变早期诊断、治疗及预后评估有一定参考价值。

PTEN and COX - 2 expression and significance in colorectal adenomas and cancerous tissues

Objective To study the differential expression of PTEN and COX-2 in colorectal adenomas and cancerous tissues. Methods Immunohistochemistry（ streptavidin-perosidase method）was used to detect PTEN and COX-2 expression,respectively,in 30 cases of normal colonic mucosae,30 cases of non-adenomatous polyps,60 cases of colorectal adenomas and 30 cases of colorectal adenocarcinomas;statistical methods were used to analyze their relationships with clinical pathological characteristics,as well as the correlation between them. Results The PTEN-positive rates gradually decreased in normal colonic mucosae,non-adenomatous polyps,colorectal adenomas and colorectal adenocarcino-mas;and PTEN-positive rates in colorectal adenomas and colorectal adenocarcinomas were significantly lower than those in normal colonic muco-sae and non-adenomatous polyps（ P 〈0. 05）. The COX-2-positive rates gradually increased in normal colonic mucosae,non-adenomatous polyps,colorectal adenomas and colorectal adenocarcinomas;and COX-2-positive rates in colorectal adenomas and colorectal adenocarcinomas were significantly higher than those in normal colonic mucosae and non-adenomatous polyps（ P 〈0. 05）. The PTEN-positive rate in adenomas with ≥1 cm in diameter was significantly lower than that in adenomas with 〈1 cm in diameter,as well as the positive rate in villous adenoma sig-nificantly lower than that in tubular adenoma,the positive rate in adenomas with high-grade intraepithelial neoplasia and cancerous tissues signifi-cantly lower than that in colorectal adenomas at the early stages（all P 〈0. 05）. The COX-2- positive rate in adenomas with≥1 cm in diameter was significantly higher than that in adenomas with 〈1 cm in diameter,as well as the positive rate in villous adenoma significantly higher than that in tubular adenoma,the positive rate in adenomas with high-grade intraepithelial neoplasia and cancerous tissues significantly higher than that in colorectal adenomas at the early stages（all P 〈0. 05）. There was a negative correlation between the expression of PTEN and COX-2 in colorectal adenomas and cancerous tissues（ P 〈0. 05）. Conclusion PTEN might participate in the carcinogenesis of colorectal adenomas with COX-2, and plays an important negative synergistic effect with the latter. Combined detection,which might predict adenoma canceration,has certain refer-ence value to the early diagnosis,treatment and prognostic evaluation of colorectal adenoma.