Mechanism Of Mouse Embryos Invade Human Ovarian Cancer Cells In Vitro

The similarity of early embryos and malignant cells attracts the attention of scientists. Murray and the colleagues demonstrated that early embryos and malignant cells shared significant similarity on proliferation, division, invasion, immune escape and angiogenesis, etc. But why they give rise to such different outcomes? There must be different mechanisms which control the trend of them. If put the two into the same culture condition, what will result in? Can we find out the internal mechanism?To study the interaction between embryos and cancer cells, Li Daqiang cultured mouse blastocysts with hepatocellular carcinoma cell lines of different invasive and metastatic potential. He found that mouse blastocysts could invade tumor cell in vitro and this invasive behavior had universality and low selectivity which might be related with the high adaptability of early life.Based on the previous work and the co-cultured model of mouse embryos and human ovarian cancer cells, the effects of mouse embryos on human ovarian cancer cells and its possible mechanisms were studied.Objectives: To observe the effects of mouse embryos on tumor cells in the co-culture environment and explore the possible mechanism of the interaction between embryos and human ovarian cancer cell HO8910PM in vitro.Methods: After mouse embryos were cultured with tumor cells for different time, the effects of mouse embryos on morphology and growth behavior of human ovarian cancer cell HO8910PM were observed under the light microscope real-time or after H.E staining. After mouse embryos were cultured with tumor cells for different time, apoptosis of human ovarian cancer cell HO8910PM was detected under laser confocal microscope by Annexin V-EGFP/PI staining in situ. Adhesion ability of resuspended human ovarian cancer cells which were co-cultured with mouse embryos was assayed by MTT. Migration and invasion ability of human ovarian cancer cells co-cultured with mouse embryos was studied by transwell migration and invasion assay. After the activity of MMP -9 was inhibited by MMP-9 Inhibitor I, the interaction between mouse embryos and human ovarian cancer cells HO8910PM was observed.Results: Mouse embryos were able to invade co-cultured human ovarian cancer cell layer which extended in the bottom of the culture dish, and gradually push away tumor cells to form their own growth space. Tumor cells which were pushed away accumulated around the embryo. The number of apoptosis tumor cells surrounding the embryo increased under laser confocal microscope, while the apoptosis of HO8910PM cells away from the embryo had no significant difference compared with the control group. Compared with the control group, the adhesion, migration and invasion ability of HO8910PM cells after co-cultured with mouse embryos significantly lowered (P <0.05, P <0.01). After MMP-9 activity was inhibited, the interaction between mouse embryos and HO8910PM cells had no significant difference compared with the normal MMP-9 activity group.Conclusion: Mouse embryos were able to invade tumor cells and form their own growth space, promote apoptosis of human ovarian cancer cells, and lower their adhesion, migration and invasion ability in vitro co-culture system. The mouse embryo was still able to invade human ovarian cancer cells when MMP-9 activity was inhibited.