| Pancreatic cancer and colorectal cancer are common and highly malignant gastrointestinal tumors,and chemotherapy is the main treatment for them.Pancreatic cancer develops insidiently and rapidly.Most patients have lost the opportunity of surgery when diagnosed with pancreatic cancer,which can only take chemotherapy and other means to delay the disease and prolong the survival period.Compared with pancreatic cancer,colorectal cancer can be screened early by methods such as colonoscopy.However,due to the low penetration rate of colonoscopy,most patients have metastases when diagnosed,so chemotherapy is also needed to control the disease and to cooperate with adjuvant treatment before and after surgery.Patients who receive chemotherapy are usually improved in the early stages of treatment,but their tumors may return or even metastasize during subsequent treatment because of chemotherapy resistance.Therefore,it is of great theoretical and practical significance to find out the mechanism of tumor drug resistance,reverse tumor drug resistance,and find the targeted genes or pathways of tumor drug resistance and reversal for guiding clinical treatment and improving the efficacy of chemotherapy.In order to investigate the mechanism of 5-fluorouracil(5-Fu)resistance in pancreatic cancer,human pancreatic cancer 5-Fu resistance cell lines ASPC-1/5-Fu and BXPC-3/5-Fu were constructed by continuous drug induction.Meanwhile,we purchased human colorectal cancer cell line HCT-8/VCR(Vincristine,Oncovin,VCR)and its parent cell line HCT-8 from the national experimental cell resource sharing platform.Then,application of drug repositioning strategy(new with older drugs),using five kinds of "old medicine"(aspirin,melatonin,metformin,folic acid and decitabine)to handle the HCT-8/VCR and As PC-1/5-Fu and Bx PC-3/5-Fu resistant cell lines,found that melatonin and aspirin for reverse vincristine HCT-8/VCR cell line resistance and As PC-1/5-Fu and Bx PC-3/5-Fu cell lines to 5-Fu resistance has a very good effect.The drug treatment method designed by our research group was used to explore the possible relationship between the transcriptome and the epigenetic group of acquired drug-resistant cells.Taking Aspc-1 and Aspc-1/5-Fu as an example,the two cells were first cultured in 5-Fu free medium for 48 hours to eliminate the possible effects of drug residues,and then treated with 5-Fu.The samples of Aspc-1 and Aspc-1/5-Fu cell lines at 0h,24 h and 48 h were taken for RNA-seq sequencing to detect the gene expression profile.Samples treated for 0h and 48 h were taken for methylation detection.RNA-seq sequencing and methylation were performed on aspirin and melatonin-treated cell lines,respectively.For the obtained gene expression profile data,Cell Comp,a differentially expressed gene recognition algorithm designed by our group and developed for small sample cell lines,was used in this study to identify drug-resistant genes associated with pancreatic cancer and colorectal cancer,and pathway enrichment analysis was conducted to identify genes and pathways related to drug action.For colorectal cancer,vincristine resistance-related genes of HCT-8/VCR Cell lines reversed by aspirin and melatonin are enriched in Cell cycle and Cellular senescence pathways,which are also enriched in genes that undergo changes in expression and methylation during aspirin reversal of 5-Fu resistance.Therefore,these two pathways may play a key role in the HCT-8/VCR vincristine resistance and the reversal of its resistance by aspirin and melatonin.For pancreatic cancer,5-Fu resistance related genes of ASPC-1/5-Fu and BXPC-3/5-Fu cell lines are enriched in both TNF signaling pathway and Epstein-Barr virus infection.Aspirin and melatonin reverse 5-Fu resistance genes of ASPC-1/5-Fu cell line were enriched in Epstein-Barr virus infection pathway at the same time,suggesting that this pathway may play an important role in aspirin and melatonin reverse 5-Fu resistance of pancreatic cancer.Through further studies on the Epstein-Barr virus infection pathway,it was found that HDAC2 gene was a drug-resistance gene reversed after treatment with aspirin and melatonin,and this gene was significantly associated with the survival of pancreatic cancer patients receiving 5-fu-based chemotherapy regimen,suggesting that HDAC2 gene may play an important role in the 5-fu resistance of pancreatic cancer.By integrating the protein interaction network of the STRING database and the co-expression relationship of pancreatic cancer cell lines,this paper found that aspirin can reverse the 5-Fu resistance of ASPC-1/5-Fu cells to a certain extent through the HDAC2 / TP53 / TYMS pathway.In this paper,two drug-resistant pancreatic cancer cell lines were constructed,and gene sequencing was used to identify the differentially expressed genes and differentially methylated genes between tumor(pancreatic cancer and colorectal cancer)drug-resistant cell lines and their parent cell lines,enriching the drug-resistant mechanism of tumor.Then,5 kinds of "old drugs" were used for reverse drug resistance experiments.At the same time,Cellcomp,a differentially expressed gene recognition algorithm designed by our research group and developed for small sample cell lines,was used to identify drug-resistant genes related to pancreatic cancer and colorectal cancer,and pathway enrichment analysis was conducted to identify genes and pathways related to drug action.This study provides an open clinical treatment idea for the prevention and treatment of pancreatic cancer and colorectal cancer,which has a wide range of theoretical and practical value. |
PDF Full Text Request