Hepatocyte growth factor induces rat ovarian surface epithelial cell mitosis or apoptosis depending on the presence or absence of an extracellular matrix.

The research article investigates how the hepatocyte growth factor influences the process of cell mitosis or apoptosis in rat ovarian surface epithelial cells, depending on the presence or absence of an extracellular matrix. The study finds that gonadotropins stimulate the expression of HGF which promotes the proliferation of ovarian surface epithelial cells, but HGF only induces mitosis when an extracellular matrix is present.

Experimental Process

• The study subjects were rat ovarian surface epithelial cells and a related cell line known as ROSE-179 cells.
• Both sets of cells were found to express c-Met, the receptor for Hepatocyte Growth Factor (HGF), but they did not express the LH (HCG) receptor.
• The ROSE-179 cells were cultured for 24 hours in serum-supplemented medium on either glass or a synthetic fibronectin-like extracellular matrix protein, pronectin (RGD).
• The cells were further cultured in serum-free medium in the presence or absence of hCG or HGF.
• The number of cells and the percentage of apoptotic cells were determined at different intervals of time.

Key Findings

• The presence or absence of the synthetic fibronectin-like extracellular matrix protein, pronectin (RGD), had significant effects on the reaction of the cells to HGF. The number of ROSE-179 cells doubled in serum-supplemented medium with or without RGD.
• In serum-free medium, HGF induced mitosis (cell division) among the cells cultured on RGD, resulting in a marked increase in cell numbers. However, on a glass substrate in serum-free medium, HGF did not induce mitosis, but instead increased the percentage of apoptotic cells (cells undergoing programmed cell death).
• Cell proliferation was reduced in the serum-free medium and the percentage of apoptotic nuclei ranged between 10-15% regardless of the substrate.

Conclusion

• The study concludes that gonadotropins in vivo stimulate the Hepatocyte Growth Factor (HGF) expression and ovarian surface epithelial cell proliferation. However, the HGF only induces mitosis (cell division) in the presence of an extracellular matrix.
• The findings suggest that HGF may have potential use in the manipulation of cell proliferation in ovarian applications, but consideration must be given to the environment in which the cells are present and whether there is an extracellular matrix.