结直肠腺癌中PTEN和NDRG1的表达及其与预后的关系

Expression characteristics of PTEN and NDRG1 in colorectal carcinoma and their prognostic value

目的探讨PTEN和分化相关基因（NDRG1）在结直肠腺癌组织中的表达及其临床病理意义。方法收集91例结直肠腺癌、30例结直肠腺瘤和21名正常肠黏膜组织标本及其临床资料，采用免疫组织化学法检测PTEN和NDRG1蛋白的表达，并结合临床资料分析其临床意义。结果PTEN和NDRG1在结直肠腺癌中的阳性表达率分别为55．0％（50／91）和76．9％（70／91），与正常肠黏膜组和结直肠腺瘤组比较，差异有统计学意义（P〈0．05）。PTEN表达下调和NDRG1过度表达与淋巴结转移明显相关（P〈0．05）。结直肠腺癌组织中PTEN和NDRG1的表达存在负相关关系（rs＇=0．251，P=0．016）。PTEN蛋白阴性表达组的结直肠腺癌患者无病生存时间和总生存时间明显低于PTEN蛋白阳性表达组，差异有统计学意义（P〈0．05）。结论PTEN失表达有可能成为结直肠腺癌癌变早期的分子生物学标志物之一，并可作为评估结直肠腺癌患者预后的指标之一。NDRG1与结直肠腺癌的发生发展有关，但不能作为临床评估结直肠腺癌患者预后的指标。联合检测PTEN和NDRG1，可作为疑难病例的辅助诊断指标。

Objective To study the expression status and clinical significance of PTEN and NDRG1 in colorectal carcinoma. Methods Tissue samples of 91 coloreetal cancers, 30 colorectal adenomas and 21 eolorectal normal mucosa tissues were collected. Postoperative specimens were examined by immunohistochemistry for PTEN and NDRG1 expression. The expression of PTEN and NDRG1 was correlated with clinicopathological feature. Results The expression of PTEN and NDRG1 in the studied cases was detected in 55.0% （50/91） and 76. 9% （70/91）, respectively. Their expression was significantly different from that of colorectal adenomas and normal coloreetal mucosa tissues （P〈 0. 05）. Decreased expression of PTEN and over expression of NDRG1 were significantly related to the lymph node metastasis （P〈0. 05）. The expression of PTEN was negatively related to that of NDRG1 in colorectal carcinoma （rs ＇=-0. 251,P=0. 016）. The patients with negative expression of PTEN showed a lower disease free survival and overall survival（ P〈 0.05）. Conclusions Loss of expression of PTEN protein may be an important molecular marker in predicting the occurrence and PTEN may be useful as a prognostic marker of colorectal carcinoma. NDRG1 plays a role in the development of colorectal carcinoma, although not a prognostic indicator. The ancillary study with combined detection of PTEN and NDRG1 may be useful in difficult cases.