Mouse trophoblastic cells exhibit a dominant invasiveness phenotype over cancer cells.

Invasion process occurs both in mammalian embryo implantation during development and malignant cancer cell metastasis. We investigated the interactions between trophoblasts and metastatic cancer cells and found the phenomenon that mouse trophoblastic cells invaded the monolayer of malignant cancer cells in vitro and appeared the general trait of invasiveness to more than 30 types of malignant cancer cell lines which were derived from different histological origins and with different invasive or metastatic potential. We further investigated the cellular and molecular changes in the process of mouse trophoblastic cells invading human ovarian cancer HO-8910 cells. The results show that the invasion of trophoblastic cells lead HO-8910 cells near mouse embryo to apoptosis, and expression of cell-cycle-related protein cyclinD1 and Ki-67 mRNA were steadily remained both in mouse blastocysts and human ovarian cancer HO-8910 cells, which in part explain the proliferation activities of these cells. Our study also shows that expression of some proteins including MMP-9, FAK and Integrinαvβ3 was changeable in trophoblastic cells and HO-8910 cells in the process of blastocyst invasion, which suggested temporal expression of these molecules may involved in the invasive behavior of trophoblasts cells to cancer cells.