Effects of umbilical cord mesenchymal stem cells on apoptosis of MCF-7 cells

Objective To study the effects of umbilical cord mesenchymal stem cells (UCMSCs) on the apoptosis of human breast cancer cell line MCF-7. Methods MCF-7 cells were co-cultured with different concentrations of UCMSCs. The apoptosis of MCF-7 cells was detected by in situ apoptosis and flow cytometry. Nude mouse subcutaneous tumor model was established by inoculating MCF-7 and MSCs cells subcutaneously on the right side of the back of a mouse. The MCF-7 cells were inoculated on the left side of the mouse as control. The tumor volume was measured every week to compare the difference between the two groups. On the 17th day after inoculation, the tumor tissue was harvested and the apoptosis of tumor cells was observed by a transmission electron microscopy. Results In situ apoptosis and flow cytometry showed that the early and late apoptosis rates of MCF-7 cells increased first and then decreased with the increase of UCMSCs concentration. The differences between the control and the MCF-7+UCMSCs group were statistically significant for early (F=39.80, P<0.001) and late apoptosis rates (F=5.68, P<0.01). The tumor volume of MCF-7+UCMSCs group was significantly lower than that of control group in 17 days after inoculation (F=9.81, P<0.01). The representative apoptotic cells were observed by the transmission electron microscopyin the MCF-7+UCMSCs group. Conclusion The UCMSCs with a certain concentration can effectively promote the apoptosis of MCF-7 cells. This study provides a certain experimental basis for the clinical treatment of breast cancer. Key words: Umbilical cord mesenchymal stem cells; Breast cancer cells; Cell apoptosis; Flow cytometry