载脂蛋白M在结直肠癌组织中的表达及其临床病理相关性

目的探讨载脂蛋白M（apoM）在结直肠癌组织中表达水平的变化及其临床相关性。方法采用荧光定量PCR检测20例结直肠癌组织及其癌旁组织中apoM的mRNA表达：采用免疫组织化学方法检测7例正常肠黏膜、6例肠炎组织、10例肠息肉、20例结直肠癌及其癌旁组织中apoM的蛋白表达水平。结果apoMmRNA在结直肠癌组织和癌旁组织中均有表达．前者相对表达量显著低于后者（0．05±0．01比0．19±0．05,P〈0．05）。无淋巴结转移者apoMmRNA表达水平显著低于有淋巴结转移者（P〈0．01）。结直肠癌组织中apoM蛋白表达中位分值为5．50．显著低于癌旁组织（10．5,P〈0．05）、肠炎组织（9．75,P〈0．05）、肠息肉组织（11．0,P〈0．01）及正常黏膜组织（10．5,P〈0．05）。未见结肠癌组织中apoM蛋白水平与患者临床病理特征有关（P〉0．05）。结论载脂蛋白apoM在肠癌组织中的mRNA及蛋白水平较正常组织及良性病变组织显著降低。结直肠癌组织中apoMmRNA表达水平与淋巴结转移有关。

Apolipoprotein M expression in human colorectal cancer tissues and its clinicopathological relevance

Objective To investigate the mRNA and protein expression levels of apolipoprotein M（apoM） in the human colorectal cancer tissues, and to explore its clinical relevance. Methods Real- time PCR was carried out to determine the mRNA expression levels both in cancer tissue and its adjacent normal tissue from 20 patients with colorectal cancer. Immunohistochemistry was also carried out to determine the protein levels in 23 colorectal biopsy samples （7 normal mucosa, 6 inflammatory mucosa and 10 polyp tissues） and 20 cases of colorectal cancer tissues as well as the adjacent normal tissues. Results Real-time PCR result showed that apoM mRNA level in the colorectal cancer tissues was significantly lower than that in their adjacent normal tissues （0.05 ±0.01 vs. 0.19±0.05, P〈0.05）. ApoM mRNA level in colorectal cancer tissues was statistically significant higher in the patients with lymph node metastasis as compared to the patients without lymph node metastasis（P〈0.01）. The median value of apoM protein in cancer tissues was 5.50, which was significantly lower than that in the adjacent normal tissues （10.5,P〈0.05）, inflammatory mucosa tissues （9.75,P〈0.05）, polyp tissues （11.0,P〈0.01） and normal mucosa （10.5,P〈0.05）. No significant association was observed between the apoM protein level and the clinicopathological parameters of patients. Conclusions Both apoM mRNA and protein expression levels in colorectal cancer tissues are significantly decreased in contrast to normal and benign colorectal tissues. The apoM mRNA expression in colorectal cancer tissues is closely associated with nodal metastasis.