摘要目的 探讨在结肠癌肝转移的肿瘤微环境中肝再生磷酸酶-3(PRL-3)对缝隙连接蛋白26(Cx26)的影响及促进结肠癌细胞间质上皮化(MET)的机制.方法 将稳定转染PRL-3的LoVo细胞(LoVo-P)、对照组(LoVo-C)分别和肝细胞(L02)模拟肿瘤微环境进行体外共培养0～3d后,Western blot检测Cx26、上皮标志物E-钙黏蛋白(E-cadherin)和间质标志物N-钙黏蛋白(N-cadherin)的蛋白表达.Transwell侵袭小室法检测LoVo细胞侵袭能力变化.采用链霉菌抗生物素蛋白-过氧化物酶(SP)法检测20例Ⅳ期结肠癌及肝转移灶中Cx26和E-cadherin的表达.结果Western blot检测结果显示,LoVo-P细胞经共培养后Cx26的蛋白表达分别上升31.03％、58.39％、93.95％(P＜0.05),E-cadherin蛋白表达明显上升,N-cadherin蛋白表达受到抑制(P＜0.05),对照组中蛋白表达变化不明显.经过共培养后LoVo-P细胞侵袭能力明显降低(P＜0.05).免疫组织化学结果显示,Cx26和E-cadherin在肝转移灶中的阳性表达率(65％和75％)高于原发灶(40％和45％),差异有统计学意义(P＜0.05).在结肠癌肝转移灶中Cx26和E-cadherin呈正相关(r=0.545,P＜0.05).结论 在共培养环境中PRL-3能通过上调Cx26诱导LoVo细胞MET并降低其侵袭能力.

abstractsObjective To investigate the effects of connexin26(Cx26)on liver metastasis of colon cancer microenvironment and mesenchymal-epithelial transition(MET)induced by phosphatase of regenerating liver-3(PRL-3)in LoVo cell line.Methods LoVo cells which were transfected with PRL-3 and human hepatic cells(L02)simulating tumor microenvironment were co-cultured by 0-3 day.Western blotting was used to examine Cx26,E-cadherin and N-cadherin expression in LoVo cells.The invasion of LoVo cells was also detected.Immunohistochemical streptavid-in-peroxidase(SP)method was used to detect the expression of Cx26 and E-cadherin in 20 cases of colon cancer and metastatic lesions.Results The Cx26 expression was increased in LoVo-P cells after co-culture with hepatic cells,and the increasing rate was 31.03％,58.39％and 93.95％(P＜0.05)respectively,with the increased expression of E-cadherin and the decreased expression of N-cadherin(P＜0.05).In LoVo-C cells,the expression levels of Cx26,E-cadherin and N-cadherin had no significant change.The invasion ability of LoVo-P cells was significantly depressed after co-culture(P＜0.05).SP results showed that the positive rate of Cx26 and E-cadherin in metastatic lesions(65％,and 75％)was higher than in primary lesions(40％,and 45％,P＜0.05).There was a strong association between the positive expression of Cx26 and E-cadherin in metastatic lesions(r=0.545,P＜0.05).Conclusion In co-cultured microenvironment,PRL-3 up-regulates Cx26 and depresses invasion of LoVo cells through MET.