结直肠癌与其淋巴结转移癌及结直肠癌细胞上皮-间质转化的对比研究

Comparative study of epithelial-mesenchymal transition in human colorectal carcinoma,its lymphatic metastasis and colon cancer cells

背景与目的:对上皮-间质转化(epithelial-mesenchymal transition,EMT)的研究虽有大量文献报道,但研究数据仍有争议。本研究旨在探讨淋巴结转移的结直肠癌与结直肠癌细胞系SW480、SW620的EMT特征差异。方法:Real-time RT-PCR检测结直肠癌细胞系SW480和SW620 E-cadherin和vimentin的mRNA表达;免疫组织化学法检测30例配对结直肠癌及其转移淋巴结的石蜡组织标本中E-cadherin和vimentin的表达,HE染色观察30例配对结直肠癌及其淋巴结转移癌组织形态以及SW480和SW620的细胞形态。结果:SW480与SW620中E-cadherin和vimentin的mRNA表达差异有统计学意义(P=0.037),均以后者为高;E-cadherin和vimentin在结直肠癌与其淋巴结转移癌组织中的表达差异无统计学意义(P=0.108;P=0.660)。部分淋巴结转移癌中E-cadherin的表达高于结直肠癌(4/30),且vimentin表达比结直肠癌弱,甚至表达缺失(6/30);结直肠癌与其淋巴结转移癌组织具有相似的形态学特征;SW480和SW620两者形态类似。结论:结直肠癌对比其淋巴结转移癌、SW480对比SW620发现EMT特征无显著差异,推测是由于淋巴结转移癌和SW620发生了EMT。

Background and purpose:Although there were a lot of reports about epithelial-mesenchymal transition(EMT),but the conclusion is still not exclusive.This study investigated the difference between epithelial-mesenchymal transitions in human colorectal carcinoma as well as its lymphatic metastasis and colon cancer cell lines.Methods:The expression of E-cadherin and vimentin mRNAs in human colon cancer cell lines SW480 and SW620 were detected by real-time reverse transcription-polymerase chain reaction(RT-PCR).The expression of E-cadherin and vimentin proteins in 30 pairs of human primary colorectal carcinoma and its lymphatic metastasis were detected by immunohistochemistry.The morphology of primary carcinoma and its lymphatic metastasis,SW480 and SW620 cells were observed by HE staining.Results:The expression levels of E-cadherin and vimentin mRNAs in SW620 cells were significantly higher than that in SW480 cells(P=0.037).There were no significant difference in E-cadherin and vimentin protein expression between primary colorectal carcinoma and its lymphatic metastasis(P=0.108;P=0.660).However,E-cadherin protein expression in metastatic lymph nodes were higher than in primary carcinoma(4/30),whereas vimentin protein expression in metastatic lymph nodes was lower than in primary lesions(6/30),but there were no statistically significant difference.The histopathology for colorectal carcinoma with lymphatic metastasis was similar to primary colorectal carcinoma,there was also no difference between both cell lines in terms of morphology.Conclusion:There was no significant difference of EMT characteristics in either primary colorectal carcinoma versus its lymphatic metastasis or in SW480 versus SW620.We presume a reversed process of mesenchymal-epithelial transition(MET) that may play a role in metastatic cancer and SW620 cell line.