SEX STEROIDS REGULATE THE EXPRESSION OF PLASMINOGEN-ACTIVATOR INHIBITOR-1 (PAI-1) AND ITS MESSENGER-RNA IN UTERINE ENDOMETRIAL CANCER CELL-LINE ISHIKAWA

To know the effects of sex steroids on the potentials of growth, invas ion, and metastasis with neovascularization of endometrial cancer, the expression of plasminogen activator inhibitor (PAI)-1 [an inhibitor o f tissue-type plasminogen activator (tPA) and urokinase-type plasminog en activator (uPA)] and its mRNA in well-differentiated uterine endome trial cancer cell line Ishikawa was determined by an enzyme-linked imm unosorbent assay and reverse transcription-polymerase chain reaction-S outhern blotting (RT-PCR-SB), respectively, under the influence of sex steroids. In Ishikawa cells, either estradiol or progestins (progeste rone, medroxyprogesterone acetate, or 17 alpha-hydroxyprogesterone alo ne) induced the expression of PAI-1 and its mRNA, and those expression s were increased approximately two-fold by both estradiol and progesti n administered together. Therefore, sex steroidal induction of PAI-1 m ight contribute to the inhibition of invasion and metastasis, concomit antly with the inhibition of neovascularization associated with tPA an d uPA activities, in well differentiated endometrial cancer. Copyright (C) 1996 Elsevier Science Ltd.