Comparison of the Effect of Adipose Mesenchymal Stem Cells-derived Secretome with and without Reovirus in CT26 Cells

Colorectal cancer is the fourth leading cause-related death of cancer which has significantly increased over the past three decades. New therapeutic approaches such as oncolytic viruses become very imperative recently to destruction of cancer cells. Use of mesenchymal stem cells secretome which are produced in response to variant conditions involves different paracrine molecules secretion that they have therapeutic potential in several chronic diseases. Mesenchymal stem cells and their derivative are used as a regenerative medicine, but there is ambiguity in the function of these cells in control of malignancy. In this study, we aim to examine the apoptotic effect of secretome derived from mesenchymal stem cells affected by encompassing oncolytic reoviruses. Mesenchymal stem cells were cultured after separation from abdominal adipose tissue of BALB/c mice. After three passages, the cells infected by reovirus at Multiplicity of Infection (MOI) of 1 Plaque-Forming Unit (PFU) per cell. Uninfected and infected secretome with reovirus were collected separately. The colorectal cancer CT26 cells were confronted with uninfected secretome, infected secretions, reovirus as positive control, and Dulbecco's Modified Eagle Medium/ High Glucose (DMEM/HG) as negative control separately. Finally, apoptosis and necrosis were evaluated by flow cytometry. The infected secretome with reovirus is capable to induce apoptosis more than uninfected secretome in CT26. However, supernatant of reovirus infected cells is more capable than others to induce cell death in comparison with infected secretome. Infected mesenchymal stem cells with oncolytic reovirus produce a type of condition media that enhance apoptosis induction and could have therapeutic effect on cancer cells. However, tumoral cells which confronted with the oncolytic reovirus showed more capability in inducing apoptosis in CT26 cells. As a result, the use of oncolytic virus and infected secretome are more effective than uninfected secretome in inducing apoptosis.