Effects of Wharton's jelly mesenchymal stem cells-derived secretome on colon carcinoma HT-29 cells

Secreted factors (secretome) of Wharton's jelly mesenchymal stem cells (WJMSCs) have therapeutic impacts. This study was conducted to investigate the impact of WJMSCs-derived secretome (WJMSCs-Se) in apoptosis and the growth of HT-29 cells. HT-29 cells treated with 25 or 50 mu g/mL WJMSCs-Se for 24 h. Colony formation and MTT test was used to assess the proliferation and cytotoxicity of the HT-29 cells. Annexin V/PI staining was done for the assessment of apoptosis. The mRNA expression of important apoptosis-related genes was also examined. In the WJMSCs-Se-treated HT-29 cells, colony numbers and viability percentages were significantly reduced in a concentration-dependent manner. Apoptotic and necrotic indexes of WJMSCs-Se-treated HT-29 cells considerably enhanced in comparison to the control. The Caspase-9 and -3 activities were significantly increased in the WJMSCs-Se-exposed HT-29 cells. The mRNA expression of Caspase-9, Caspase-3, and Bax/ Bcl-2 ratio was considerably elevated in the WJMSCs-Se-treated HT-29 cells. Caspase-8 activity and expression of the p53 gene were not affected by the WJMSCs-Se. Taken together, we concluded that WJSCs-Se significantly prevented cell growth and enhanced colon cancer cell death in a concentration-dependent manner mainly through the intrinsic apoptotic pathway.