The impact of conditioned medium of umbilical cord-derived mesenchymal stem cells toward apoptosis and proliferation of glioblastoma multiforme cells

Glioblastoma multiforme (GBM) is the human malignant and highly invasive brain tumor. Tumor growth and invasive property are affected by mesenchymal stem cells (MSCs) as a part of tumor microenvironment. However, accumulating evidences describe that MSCs could act as pro and anti tumorigenic. The different action of MSCs in regulating tumor growth is mediated by secreted factor. This research purpose was to analyze the impact of MSCs secreted factor in conditioned medium (CM) on apoptosis and proliferation of GBM cells. Primary culture of umbilical cord-derived MSCs (UCSCs) was conducted in this research. CM-UCSCs was prepared by culturing the UCSCs in serum free aMEM for 24 hours. Those CM-UCSCs was 2-fold diluted by Dulbecco's Modified Eagle Medium (DMEM) high glucose (50% concentration) and used to treat human GBM T98G cells for 24 hours. Following this treatment, apoptosis was detected using annexin V-FITC and cells proliferation was analyzed using trypan blue exclusion test. The results showed that early apoptosis occurred in 14.4 % of control cells and 14.8 % of CM-treated T98G cells, as well as late apoptosis occurred in 7.8 % of control cells and 7.2 % of CM-treated T98G cells. Whereas, GBM cells proliferation was tend to higher in the CM treated cells (3.85×10⁵ cells) compared to the control (2.97×10⁵ cells). In conclusion, CM-UCSCs does not seems to affect apoptosis, but tend to increase cells proliferation. Further research is needed to elaborate the mechanism of UCSCs secretome in stimulating cells proliferation.