Figure 1

In co-culture system the embryonic development and its effects on tumor cells in different time stages. (a) A mouse blastocyst was put on tumor cell layer immediately. (b) At 24 h the mouse blastocyst zona pellucida was taking off; (c) At 48 h embryonic trophoblast cells adhered and began to expand; (d) At 72 h tumor cells were pushed away by the growth of embryos; (e) At 120 h the expansion area of trophoblast cells stopped enlarging. (100×) (f) A blank gap (red arrow) was seen between mouse embryos and tumor cells. (H&E staining, 200×).