Krupple样转录因子12在结直肠癌组织表达及其与肿瘤上皮-间充质转化的关系

Krupple like lactor 12 expression in colorectal cancer tissues and its relationship with epithelial mesenchymal transition

目的探讨Krüpple样转录因子12（KLF12）参与结直肠癌上皮-间充质转化（EMT）的机制。方法应用免疫组织化学技术检测85例结直肠癌手术患者肿瘤与癌旁肠黏膜组织中KLF12及E-钙黏素（E-cadherin）、N-钙黏素（N-cadherin）、波形蛋白（Vimentin）、Snail蛋白表达，患者均有完整的临床及随访资料。合成KLF12-小干扰RNA（siRNA）转染结肠癌细胞株HT29；噻唑蓝（MTT）法检测细胞活性；划痕实验和Transwell小室实验检测细胞迁移及侵袭能力；荧光实时定量反转录-聚合酶链反应（RT-PCR）和Western blot检测各基因的mRNA和蛋白表达。结果免疫组织化学结果显示结直肠癌组织中KLF12、N-cadherin、Vimentin、Snail蛋白阳性率明显高于癌旁肠黏膜，而E-cadherin在肿瘤组织中的阳性率低于癌旁肠黏膜（χ^＝43.724、26.145、35.788、10.985、59.225，P＝0.000）。KLF12蛋白阳性表达的患者肿瘤浸润程度较深（χ^＝7.773，P＝0.005）。KLF12蛋白阳性表达的患者生存率低于阴性者（χ^＝8.724，P＝0.003）。各结肠癌细胞株中，HT29的KLF12蛋白表达最强（P＝0.000）。抑制HT29细胞KLF12表达后细胞的活性及迁移和侵袭能力明显减弱（F＝22.541、15.002、21.908，P＝0.000）；抑制HT29细胞KLF12表达后N-cadherin、Snail表达减弱，E-cadherin表达增强（P＝0.000）。结论KLF12通过参与了肿瘤的EMT过程来促进结直肠癌的侵袭转移。

Objective To explore the mechanism of krüpple like lactor 12 （KLF12） in epithelial mesenchymal transition （EMT） of colorectal cancer.Methods Immunohistochemistry technique was utilized to detect the expression of KLF12, E-cadherin, N-cadherin, Vimentin and Snail in cancer tissues and adjacent mucosa tissues of 85 colorectal cancer patients, and clinical and follow-up data were also collected. KLF12-small interfering RNA （siRNA） was synthesized and transfected into HT-29 cells. Methyl thiazol tetrazolium （MTT） assay was applied to detect cell viability. Wound assay and Transwell assay were used to test invasion and migration of cells. The mRNA and protein expression of related genes was detected by real time reverse transcriptase-polymerase chain reaction （RT-PCR） and Western blotting, respectively.Results Results of immunohistochemistry demonstrated that the positive rate of KLF12, N-cadherin, Vimentin and Snail proteins in cancer tissues was higher, and that of E-cadherin was lower than that in adjacent mucosa tissues （χ^2=43.724, 26.145, 35.788, 10.985, 59.225 respectively, P=0.000）. The expression of KLF12 was associated with depth of tumors （χ^2=7.773, P=0.005）, and patients positive for KLF12 had poor prognosis （χ^2=8.724, P=0.003）. Strongest KLF12 protein was found in HT-29 cells （P=0.000）. Cell viability, invasion and migration decreased after KLF12 was inhibited （F=22.541, 15.002 and 21.908 respectively, P=0.000）. The expression of N-cadherin and Snail decreased, and E-cadherin increased after KLF12 was inhibited （P=0.000）.Conclusion KLF12 might be involved in EMT of colorectal cancer to enhance invasion and metastasis.