Newly synthesized pyrrolidine analog SS13 induces extrinsic and intrinsic apoptotic pathways in colorectal cancer cells

Abstract

Abstract Background A series of experiments on colorectal cancer cells (Caco-2 and HCT116) were conducted to provide new information about the antiproliferative and pro-apoptotic effect of newly synthesized (2S,3S,4R)-2-Tridecylpyrrolidine-3,4-diol hydrochloride (SS13). Methods BrdU proliferation and MTT assays were performed to verify the antiproliferative activity and determine the IC50 value. Flow cytometry was used for cell cycle analysis, phosphatidylserine externalization, mitochondrial membrane potential, and casp-3/7 activation. Cleavage of PARP and casp-8, as well as protein levels of Bad, pBad, Bcl-2, pBcl-2, and Bcl-xL were detected by western blot. Gene expression was determined by qRT–PCR. The impact of SS13 on cell migration was monitored by scratch assay. Results SS13 showed the concentration-dependent cytotoxic and antiproliferative effect on both cell lines with IC50: 3.2 ± 0.1 μmol/L - MTT / vs. 6.46 ± 2.84 μmol/L - BrdU for HCT116 and 2.17 ± 1.5 μmol/L – MTT vs. 1.59 ± 0.72 μmol/L BrdU for Caco-2. SS13-induced apoptosis was associated with externalization of phosphatidylserine, reduced MMP, activation of casp-3/7, cleavage of PARP and casp-8, overexpression of TNF-α, FasL, and dysregulation of Bcl-2 family proteins. SS13 induced intrinsic and extrinsic apoptotic pathways in colorectal cancer cells and inhibited their migration potential. Conclusions Newly synthesized pyrrolidine SS13 induced intrinsic and extrinsic apoptotic pathways in colorectal cancer cells and suppressed their migration. Our results suggest that pyrrolidine SS13 may have potential in prevention and treatment of colorectal cancer.