The Rolr Of GLI1 For 5-Fu Resistance In Colorectall Cancer

Background:Colorectal cancer is a leading cause of cancer-related mortality worldwide.,Chemotherapy is one of the major treatment for advanced disease.Fluorouracil(5-FU)-based chemotherapy is frequently used as therapeutic options.But it is often fail on account of chemoresistance.Thus,identifying molecular mechanisms responsible for chemotherapy resistance will help design novel strategies to treat colorectal cancer.Purpose: To characherize the difference in expression of GLI1 gene was detected in5-Fu resistant cells and sensitive cells of colrectal cancer,and to explore GLI1 as a new therapeutic target for the clinical reversal of 5-Fu resistance in colorectal cancer.Method: The differential expression genes were detected by the second generation sequencing technique,and all the differential genes of P <0.01 were screened out to find out the GLI1 gene,which was overexpressed in drug-resistant cells.The GLI1 gene was knocked out by GLI1 in GLI1 cells,and the GLI1 gene was up-regulated by GLI1 overexpression in sensitive cell lines.Western blotting and real-time quantitative PCR were used to detect the transfection efficiency and other genes in Hedgehog Pathway and the expression of multidrug resistance genes and dry related genes.CCK8 technique was used to detect IC50 values of the cells and calculate the drug resistance index of the resistant cells.Transwell detected cell metastasis and invasive abilityResults: In this study,we established an acquired 5-FU resistant cell line,LoVo-R,from LoVo cells.Through next generation sequencing analysis,we discovered that elevated GLI1 signaling axis is a major genetic alteration in the 5-FU resistant cells,suggestive of activated hedgehog(Hh)signaling.Hh signaling,a pathway essential for embryonic development,is an important regulator for residual cancer cells.We demonstrated that knockdown of GLI1 or GLI2 sensitized LoVo-R cells to 5-FU treatment,reduced cell invasiveness and overexpression of GLI1 can reduce the sensitivity of LoVo cells to 5-Fu.The relevance of our studies to colorectal cancer patients is reflected by our discovery that high expression of GLI1 signaling molecules was associated with a high incidence of cancer relapse and a shorter survival in a larger cohort of colorectal cancer patients who underwent chemotherapy(containing 5-Fu).Conclusions: Inhibition of GLI1 expression can effectively reverse the 5-Fu resistance of drug-resistant cells and inhibit the migration of drug-resistant cells,but also can reduce the ability of drug-resistant cells form the sphere,effectively inhibit the expression of multidrug resistance and stem-related genes and to provide a theoretical basis for the invention of new colorectal cancer targeted medicine and the development of new clinical strategies for the treatment of colorectal cancer.