[Growth regulation of sex steroid hormone in endometrial carcinoma transplanted into nude mice]

By using ovariectomized nude mice, the hormone reactivity of endometrial carcinoma was evaluated. HEC-88nu cultured cells originated from human endometrial carcinoma were first transplanted to the animal in each experiment. Estrogen receptor (ER) of HEC-88nu reveals positive originally. Hormone pellets containing medroxyprogesterone acetate (MPA) and 17 beta-estradiol (E2) were used. The results were as follows: 1. The proliferation of this tumor was accelerated remarkably by administration of E2 pellet. 2. By administration of MPA pellet, the proliferation was inhibited from the beginning but progressed flatly afterwards maintaining 50% of the control. 3. When MPA was administered upon priming the tumor with E2, the proliferation began to be inhibited after 2 weeks developing 60% of suppression 5 weeks later. 4. Progesterone receptor (PR) of the tumor was induced starting at week 2 when E2 was given and revealed 189 fmol/mgP at week 5. 5. As the morphological changes due to hormone, light eosin-stainability, rarefaction and swelling of the cytoplasms were the common characteristics. 6. It was suggested that both hormonal and pharmacological actions take part in the mechanism of progestin to act on endometrial carcinoma.