Effects of progesterone on ovarian tumorigenesis in xenografted mice.

Circumstantial evidence indicates that progestins reduce the risk of epithelial ovarian cancer. We report that the tumorigenic capacity of human ovarian carcinoma (SKOV-3) cells inoculated into the peritoneal cavity of athymic mice is suppressed by pretreatment with subcutaneous progesterone-releasing pellets. Numbers of tumor implants on the intestines/mesentery and invasiveness into underlying host tissues were reduced at 6 weeks following exposure to progesterone.

Inhibitory effects of progesterone on plasma membrane fluidity and tumorigenic potential of ovarian epithelial cancer cells.

The lethality of common (surface) epithelial ovarian cancer is contingent on its metastatic capacity. Dissemination of the neoplasia throughout the abdominal cavity has been associated with secretion of proteolytic enzymes from vesicles shed by ovarian cancer cells. We report that the lipophilic steroid hormone progesterone decreases the fluid dynamics of plasma membranes of human SKOV-3 adenocarcinoma cells.

Roles of the ovarian surface epithelium in ovulation and carcinogenesis.

Although ovarian mechanisms of ovulation have been a subject of investigation for more than a century, essential regulatory pathways remain uncertain. A role for the ovarian surface epithelium in ovulation has recently been demonstrated. Ovarian surface epithelial cells in close contact with the apical wall of preovulatory ovine follicles secrete a urokinase-type plasminogen activator in response to surge concentrations of (locally delivered) gonadotrophins.