目的:探讨磷脂酰肌醇3激酶(PI3K/Akt)信号通路抑制剂LY294002在裸鼠体内对5氟尿嘧啶(5-Fu)抑制大肠癌移植瘤生长及肝转移的影响。方法:采用细胞接种法建立裸鼠异位及原位移植瘤模型,观察LY294002、5-Fu及LY294002联合5-Fu对异位裸鼠移植瘤生长的抑制作用,用流式细胞仪检测异位裸鼠移植瘤细胞凋亡,用免疫共沉淀法检测Akt和Akt-ser473蛋白表达;观察LY294002、5-Fu及LY294002联合5-Fu对原位裸鼠移植瘤肝脏转移的影响情况,用免疫共沉淀法检测原位裸鼠移植瘤Akt、Akt-ser473的表达,用免疫组化法检测β-catenin及MMP-7蛋白表达。结果:与对照组比较,5-Fu、LY294002抑制异位移植瘤的生长,促进肿瘤细胞凋亡,LY294002显著促进5-Fu诱导的肿瘤生长抑制、细胞凋亡;与对照组比较肿瘤细胞的Akt表达无改变,Akt-ser473蛋白表达下降。与对照组比较,5-Fu、LY294002抑制原位移植瘤的肝脏转移,LY294002显著增强5-Fu抑制原位移植瘤的肝脏转移;与对照组比较原位移植肿瘤细胞的Akt表达无改变,Akt-ser473、β-catenin及MMP-7蛋白表达下降。结论:LY294002可增强5-Fu抑制裸鼠移植大肠癌生长及肝脏转移的作用。 AIM: To investigate the effects of 5-Fu on the growth and hepatic metastasis of human colon carcinoma xenografts in nude mice induced by phosphatidylinositol 3-kinase (PI3K / Akt) signaling pathway inhibitor LY294002. Methods: The ectopic and orthotopic xenograft models of nude mice were established by cell inoculation. The inhibitory effects of LY294002, 5-Fu and LY294002 combined with 5-Fu on the growth of xenografts in nude mice were observed. Flow cytometry was used to detect the ectopic To study the effect of LY294002, 5-Fu and LY294002 combined with 5-Fu on the liver metastasis of orthotopic transplantation tumor in nude mice, the expression of Akt and Akt-ser473 protein were detected by co-immunoprecipitation method. The expression of Akt and Akt-ser473 in nude mice xenografts were detected by precipitation assay. The expressions of β-catenin and MMP-7 protein were detected by immunohistochemistry. Results: Compared with the control group, 5-Fu and LY294002 inhibited the growth of xenografts and promoted the apoptosis of tumor cells. LY294002 significantly enhanced 5-Fu-induced tumor growth inhibition and apoptosis. Compared with the control group, Akt No change in expression, Akt-ser473 protein expression decreased. Compared with the control group, 5-Fu and LY294002 could inhibit hepatic metastasis of orthotopic xenograft tumor. LY294002 significantly enhanced hepatic metastasis of 5-Fu in situ xenograft tumor. Compared with the control group, there was no change of Akt expression in orthotopic transplanted tumor cells. Akt -ser473, β-catenin and MMP-7 protein expression decreased. Conclusion: LY294002 can enhance the role of 5-Fu in inhibiting the growth of colon cancer and liver metastasis in nude mice.