Bmi-1及Mel-18反向调节结直肠癌的形成和发展

Bmi-1 and Mel-18 oppositely regulate carcinogenesis and progression of coiorectal cancer

目的探讨Bmi-1和Mel-18在结直肠癌组织中的表达和临床意义。方法采用免疫组织化学染色法和RT—PER检测Bmi一1和Mel一18基因与蛋白在50例结直肠癌组织、20例结直肠腺瘤组织及20例正常结直肠组织中的表达。分析两者在结直肠癌组织中的表达情况和相关性，以及两者表达与临床病理因素的关系。结果Bmi-1mRNA和蛋白的表达在正常结直肠组织、结直肠腺瘤组织、结直肠癌组织均呈明显依次递增（均P〈0．05），而Mel-18则呈反向趋势；结直肠癌组织中Bmi．1与Mel-18mRNA及蛋白表达之间均明显呈负相关（r=-0．551，P=0．000；r=-0．579，P：0．000）；Bmi-1基因表达和蛋白阳性率水平与远处转移及临床分期呈正相关（P〈0．05）。Mel-18基因表达水平与远处转移及临床分期呈负相关（P〈0．05）。结论Bmi-1高表达与Mel-18低表达可能是结直肠组织恶性转变以及结直肠癌发生浸润转移的重要生物学诊断指标。

Objective -To invesiigate theexpression JBmi：l＇ and- M＇el-18 in colorectal cancer tis- sue and their clinical significance. Methods The gene and protein expression in malignant （50 cases ） , benign（20 cases）and normal（20 cases）colorectal tissues were determined by immunohistochemical meth- od and RT-PCR, respectively. The Bmi-1 and Mel-18 expression status and their correlationship in colorec- tal cancer tissue, and the relation of their expression and clinicopathologic factors was analyzed. Results Both mRNA and protein expression of Bmi-1 increased significantly and ordinally in normal, benign and malignant colorectal tissues（P 〈 0. 05 ） , while those of the Mel-18 showed an opposite trend. There was a significant negative correlation between Bmi-1 and Mel-18 expression at either mRNA or protein level in colorectal cancer tissue （ r = - 0.551, P = 0.000 ; r = - 0. 579, P = 0. 000）. The mRNA and protein levels of Bmi-1 had a significantly positive correlation with the distant metastasis and clinical stages（ P 〈 0.05 ）. The mRNA level of Mel-18 had a significantly negative correlation with the distant metastasis and clinical stages（P 〈 0.05）. Conclusion The increased Bmi-1 expression along with decreased Mel-18 expression may probably be the important biological diagnostic markers for malignant transformation of colorectal tis- sue or invasion and metastasis of colorectal cancer.