A Descriptive Study of the Physical Direct Interaction between Adipose Tissue-Mesenchymal Stem Cells and Colo 205 Cells: Impact on Cancer Cells Stemness, and Intracellular Reactive Oxygen Species Levels

BACKGROUND: Mesenchymal stem cells (MSCs) are widely used in clinical research to treat a wild spectrum of diseases due to their homing ability to damaged tissues, self-renewal capacity, and differentiation ability into various types of cells. In this research, we are describing the physical direct interaction between AT-MSCs and colon cancer cells, its impact on the stemness of colon cancer cells, along with the levels of intracellular Reactive Oxygen Species (ROS) levels in both types of cells. METHODS: Adipose-tissue mesenchymal stem cells (AT-MSCs) were characterized by the means of MSCs classical markers expression using flow cytometry, and multilineage differentiation through osteogenic and adipogenic differentiation. MSCs and colo205 cells were cocultured in monolayer and 3D techniques in a ratio of 1:3 for 72 hours without media exchange and compared to monocultured cells. The physical direct interaction of cells in adhered culture and spheroids formation in ULA plates was observed using a light-inverted microscope. MSCs classical markers and cancer stem cells (CSCs) associated surface proteins were quantified in MSCs and colo205 cells. Intracellular ROS level was measured in both cell types. Surface protein and intracellular ROS quantification were carried out using flow cytometry. RESULTS: CRC cells (colo205 cells) utilized MSCs as a feeder layer to grow and generate spheroids. The interaction increased the percentage of CSCs in colo205 population which was attributed to the increased expression of CD133, and reduced the levels of intracellular ROS in MSCs. Results indicated that MSCs support the growth, spheriod formation, and the stemness of colon cancer cells, while reducing the levels of intracellular ROS in MSCs.