MCM7和CDX2蛋白在Ⅱ期结直肠癌组织中的表达及意义

Prognostic significance of expression of MCM7 and CDX2 in stage Ⅱ colorectal cancer

目的:探讨微型染色体维持蛋白7(minichromosome maintenance proteins 7,MCM7)和尾型同源盒基因-2蛋白(caudal-related homeobox gene 2,CDX2)在Ⅱ期结直肠癌组织中的表达水平及其与预后相关的临床意义.方法:采用免疫组织化学法检测220例Ⅱ期结直肠癌患者癌组织与癌旁组织中MCM7和CDX2蛋白的表达水平;分析MCM7和CDX2蛋白的表达与Ⅱ期结直肠癌患者临床病理特征及预后的关系.结果:MCM7蛋白在结直肠癌组织中的阳性表达率为62%,显著高于癌旁正常组织(12%,P<0.001).CDX2蛋白在结直肠癌组织中的阳性表达率76%,显著低于癌旁正常组织(98%,P<0.01).M C M7和C D X2蛋白的表达与Ⅱ期结直肠癌患者的性别、年龄和浸润深度均无关(P>0.05),MCM7的表达仅与肿瘤的分化程度呈正相关(P<0.01),CDX2蛋白的表达仅与肿瘤的分化程度呈负相关(P<0.01).在结直肠癌组织中,MCM7和CDX2蛋白的表达呈负相关(r=-0.773,P<0.05).生存分析的结果显示,220例Ⅱ期结直肠癌患者的中位无病生存时间为51 mo.MCM7阳性/CDX2阴性患者的预后最差,而MCM7阴性/CDX2阳性患者的预后最好.结论:MCM7和CDX2蛋白表达水平的联合检测对预测Ⅱ期结直肠癌患者的预后具有重要的临床意义,但是否可作为判断结直肠癌患者预后的标志物仍需进一步研究.

AIM： To investigate the expression of minichromosome maintenance protein 7（MCM7） and caudal-related homeobox gene 2（CDX2） in stage Ⅱ colorectal cancer（CRC） and to analyze their correlation with pathological characteristics and prognosis.METHODS： Immunohistochemistry was used to detect the expression of MCM7 and CDX2 in 220 pairs of stage Ⅱ CRC and adjacent normal tissues. Differential MCM7 and CDX2 expression was analyzed according to the donors＇ pathological features and prognosis.RESULTS： MCM7 expression in CRC tissues was significantly higher than that in corresponding adjacent normal tissues（P〈0.001）, whereas CDX2 abundance in malignant tissues was dramatically lower compared with corresponding normal counterparts（P〈0.01）. Moreover, MCM7 was correlated inversely with tumor differentiation, whereas CDX2 was positively related to tumor differentiation. Kaplan-Meier survival analysis revealed that MCM7-/CDX2＋patients had a better outcome. CONCLUSION： The elevated expression of MCM7 and decreased expression of CDX2 could be combined to act as a prognostic factor for stage Ⅱ CRC.