The Role And Mechanism Of GDF15 In Pancreatic Cancer Chemotherapy Resistance Based On PDTX Model Screening

IntroductionPancreatic cancer is one of the highly malignant tumors with poor prognosis,whose five-year survival rate is only 9%.The resistance of pancreatic cancer patients to gemcitabine is one of the main reasons for its poor prognosis.Therefore,it is significant to explore the mechanism of chemotherapy resistance in pancreatic cancer.GDF15 is a member of TGF? superfamily.Previous studies have focused on gastric cancer,colorectal cancer and other fields.However,the role of GDF15 in pancreatic cancer remains unclear.Our previous work found that GDF15expression was increased in gemcitabine-induced pancreatic cancer PDTX model,suggesting that GDF15may play an important role in pancreatic cancer chemotherapy resistance.Therefore,our study intends to study the effects of GDF15 on the proliferation,migration,EMT and chemosensitivity of pancreatic cancer cells,and preliminarily explore the specific mechanism of GDF15 mediated gemcitabine chemoresistance in pancreatic cancer.It will provide a theoretical basis for GDF15 as a new target for reversing gemcitabine resistance in pancreatic cancer.MethodsThrough the analysis of the bioinformatics database,the bioinformatics data such as the expression level and prognosis of GDF15 in human pancreatic cancer tissues were explored.RT-PCR was used to detect the expression level of GDF15 in pancreatic cancer cell lines,and appropriate pancreatic cancer cell lines were selected for the following study.RT-PCR was used to detect whether there was a gradient dependence of GDF 15 expression level in gemcitabine treatment on the treatment time and drug concentration.Stable transgenic cells with GDF 15 knock-down/overexpression were obtained by lentivirus transfection.CCK8,scratch test,Transwell and other methods were used to observe the effects of interference with the expression level of GDF 15 on the proliferation,migration and chemotherapeutic sensitivity of pancreatic cancer cells.Western Blot was used to observe whether the expression of GDF 15 has a regulatory effect on EMT of pancreatic cancer cells,and to explore the possible signaling pathway of GDF 15-mediated EMT change,in order to prove whether GDF 15 has a correlation with chemotherapy resistance of pancreatic cancer cell lines.ResultsBioinformatics analysis showed that GDF15 was expressed in kinds of tumors and was mostly associated with poor prognosis.In pancreatic cancer,GEO database analysis showed that high expression of GDF15 was correlated with poor overall survival rate.At the cell level,knocking down GDF15 significantly weakened the proliferation and migration of pancreatic cancer cells,while overexpression of GDF15 significantly enhanced the proliferation and migration.After interference with gemcitabine,the expression level of GDF15 in pancreatic cancer cells was increased in a time and drug concentration gradient-dependent manner.Knockdown of GDF15 could improve the sensitivity of cells to gemcitabine,and overexpression of GDF 15 could reduce the sensitivity.After we interfered with the expression level of GDF 15 in pancreatic cancer cells,the expression levels of Smad2/3,p-NF-?B,?-catenin and N-cadherin also changed in the same direction.ConclusionBioinformatics found that GDF 15 had potential research value in pancreatic cancer.The expression of GDF 15 can promote the proliferation,migration and drug resistance of pancreatic cancer cells.In terms of signaling pathway,GDF 15 may enhance EMT through Smad pathway or NF-?B pathway,leading to the generation of chemotherapy resistance.