A LONG-TERM 10G-HYPERGRAVITY EXPOSURE PROMOTES CELL-CELL CONTACTS AND REDUCES ADHESIVENESS TO A SUBSTRATE, MIGRATION, AND INVASIVENESS OF MCF-7HUMAN BREAST CANCER CELLS.

Abstract

G-force is a fundamental force controlling human cells. Cancer is one of the 4major health challenges in the Space missions. Cancer in Space project evaluates the reaction of human cancer cells to the conditions of the space flights, including an exposure to high g-forces. Explore an impact of 10g force on the oncogenic properties of human breast adenocarcinoma cells MCF-7. Cells were exposed to 10g force for 10days, as part of a 6-week simulation of conditions of a space flight. Then the cells were cultured for one week under normal culture conditions, before performing tests. Cell proliferation, cell viability, cell-cell contact inhibition, migration, and invasiveness were measured. Immunoblotting was used to evaluate expression of proteins. Proliferation, cell-cell interaction and formation of 3D structures, migration, and invasiveness of cells exposed to 10g were compared to parental cells cultured at 1g condition. 10g exposed cells showed a higher propensity for cell-cell contact inhibitions and lower for 3-dimensional growth in dense culture. This correlated with the decrease of proliferation in a dense culture as compared to the parental cells. The decrease of migration, adherence to a surface, and invasiveness was observed for cells subjected to the hypergravity, as compared to the parental MCF-7cells. Enhanced expression of E-cadherin and phosphorylated pY576-FAK were observed in 10g exposed cells but no impact on the expression of Erk, pErk, FAK and p53was detected. The prolonged exposure of MCF-7cells to 10g force targets cell-cell and cell-substrate interactions.