Potential of Exendin-4 in HT29 and HCT116 colorectal cancer cell lines in activation of SIRT1 and the concomitant suppression of GS3Kβ/β-catenin/NF-κB axis 盎真科研造假 Exendin-4在HT29和HCT116大肠癌细胞系中激活SIRT1和同时抑制