EFFECT OF PARACRINE HEPATOCYTE GROWTH FACTOR IN PANCREATIC STELLATE CELLS ON CHEMOTHERAPY RESISTANCE IN PANCREATIC CANCER
Objective To investigate the effect of pancreatic stellate cell (PSC) on chemotherapy resistance in pancreatic cancer (PC) and related mechanisms of action.Methods PC SW1990 cells were treated with the conditioned medium of PSC (PSC-CM) and gemcitabine (Gem),and Cell Counting Kit-8 (CCK 8) and flow cytometry were used to observe the change in drugresistant phenotype of PC cells.Western Blot and cell immunofluorescence were used to measure the changes in E-cadherin and Vimentin during epithelial-mesenchymal transition (EMT) ELISA and Western Blot were used to measure the expression of hepa tocyte growth factor (HGF) in PSC and SW1990 cells.Western Blot was used to measure the change in the expression of phosphory-lated c-Met (p-c-Met) in SW1990 cells treated with PSC CM or PSC-CM with the addition of c Met inhibitor PHA665752.CCK 8 and flow cytometry were used to observe the effect of PSC-CM with or without PHA665752 on Gem-induced drug resistance in SW1990 cells.Western Blot was used to observe the effect of PHA665752 on the expression of E-cadherin and Vimentin inf SW1990 cells.Results Compared with the SW1990 cells in normal culture medium,the SW1990 cells in PSC-CM had a significant increase in the half-maximal inhibitory concentration (IC50) of Gem (t =33.442,P＜0.01) and a significant reduction in cell apoptosis rate induced by Gem (t=17.439,P＜0.01).Western Blot and immunofluorescence showed that PSC-CM downregulated the expression of E-cadherin and upregulated the expression of Vimentin in SW1990 cells.ELISA results showed that the PSC supernatant had a significantly higher level of HGF than the supernatant of SW1990 cells (t 39.528,P＜0.01).Furthermore,the results of Western Blot indicated that PSC-CM induced c Met phosphorylation in SW1990 cells,while c-Met inhibitor(PHA665752) significantly inhibited the above effect of PSC-CM.Compared with those cultured in PSC-CM,the SW1990 cellscultured in PSC-CM+PHA665752 had a significant reduction in theIC50 of Gem (t =32.005,P ＜0.01) and a significant increase in apop-Tosis rate induced by Gem (t =13.182,P＜0.01).PHA665752 also inhibited EMT induced by PSC-CM in SW1990 cells.Conclusion PSC can activate the HGF/c Met signaling pathway in PC cells via paracrine HGF,induce EMT in PC cells,and thus enhance chemotherapy resistance to Gem in PC cells.
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维普
