The expression and clinical significance of hypoxia-induced factor-1 α in gallbladder carcinoma tissues and its role on metformin-suppressed metastasis in GBC-SD cells / 中华肝胆外科杂志

ABSTRACT

Objective To study the expression and the clinical significance of hypoxia-induced factor-1α (HIF-1α) in gallbladder cancer tissues,and the role and mechanism of HIF-1α in metformin-suppressed metastasis in gallbladder carcinoma GBC-SD cells.Methods 24 specimens of gallbladder cancer tissues and 5 specimens of chronic cholecystitis were collected from the First Affiliated Hospital of Zhengzhou University between June 2016 and February 2017.Immunohistochemistry and qPCR were used to detect the expression of HIF-1α in gallbladder cancer tissues,in adjacent non-cancer tissues and in chronic cholecystitis,and the clinical significance was analyzed.The model of metastasis was induced by hypoxia;the wound healing assay and the Transwell assay were used to detect the ability of cell metastasis;the expressions of HIF-1α and VEGF in gallbladder carcinoma GBC-SD cells were detected by western blotting assay and immunofiuorescence.Results The expression of HIF-1α in gallbladder cancer tissues was higher than the adjacent non-cancer tissues and in chronic cholecystitis.The expression of HIF-1α was correlated with lymph node metastasis and TNM staging in gallbladder cancer tissues (P ＜ 0.05).The wound healing rate after 48 h in the negative control group and in the treatment with hypoxia group (1％ O2) in GBC-SD cells were (46.5 ± 4.8) ％ and (67.3 ± 4.0) ％,respectively.The Transwell data showed that the numbers of metastasis after 24 h in the negative control group and in the treatment with hypoxia group GBC-SD cells were (147.4 ± 11.7) and (234.4 ± 17.7),respectively.When compared with the negative control group,treatment with hypoxia significantly increased the ability of metastasis and up-regulated the expression of HIF-1α and VEGF in GBC-SD cells (P ＜ 0.05).The wound healing rate after 48 h in the negative control group,the metformin group,the hypoxia group and the metformin and hypoxia group in GBC-SD cells were (40.6 ± 7.1) ％,(16.4 ± 9.4) ％,(69.5 ± 4.0) ％ and (22.4 ± 7.4) ％,respectively.The Transwell data showed that the numbers of metastasis after 24 h in the negative control group,the metformin group,the hypoxia group and the metformin and hypoxia group in GBC-SD cells were (148.4 ± 6.9),(90.0 ± 8.4),(185.8 ± 10.2) and (113.4± 8.6),respectively.When comparcd with the hypoxia group,treatment with metformin and hypoxia significantly decreased the ability of metastasis and down-regulated the expression of HIF-1α and VEGF in GBC-SD cells (P ＜ 0.05).The wound healing rate after 48 h in the negative control group,the 2MeoE2 group,the hypoxia group,the 2MeoE2 and hypoxia group in GBC-SD cells were (43.4 ±4.4)％,(25.9 ±9.0)％,(63.3 ±2.2)％,(46.2 ±4.5)％,respectively.The Transwell data showed that the numbers of metastasis after 24 h in the negative control group,the 2MeoE2 group,the hypoxia group,the 2MeoE2 and hypoxia group in GBC-SD cells were (144.2 ± 12.6),(80.2 ±7.7),(203.8 ±7.0),(124.0 ± 5.2),respectively.When compared with the hypoxia group,treatment with HIF-1α inhibitor 2MeoE2 and hypoxia significantly decreased the ability of metastasis and down-regulated the expression of HIF-1α and VEGF in GBC-SD cells (P ＜ 0.05).Conclusions The expression of HIF-1 α was correlated with lymph node metastasis and TNM staging in gallbladder cancer tissues.Treatment with hypoxia significantly increased the expression of HIF-1α and VEGF and promoted metastasis of GBC-SD cells,while treatment with metformin decreased the ability of metastasis induced by hypoxia via inhibiting the HIF-1o/VEGF pathway in GBC-SD cells.