HORMONAL-REGULATION OF EPIDERMAL TUMOR-DEVELOPMENT

[摘要] The effects of hormones and hormone-like substances such as thyroxine, estradiol, hydrocortisone, calcitonin, prostaglandins (PGF2.alpha., PGA2) or hormone deficiency (hypophysectomy, gonadectomy) on the development of carcinomas in mice and rats induced by 3-methylcholanthrene were investigated. Thyroxine, PGF2.alpha., calcitonin and estradiol markedly enhanced the development of squamous cell carcinomas and basal cell carcinomas. Tumor inhibition occurred following hydrocortisone, hypophysectomy and gonadectomy. DNA labeling with [3H]-thymidine and radioautography revealed that DNA synthesis in neoplastic cells is markedly influenced by the same hormones. An increase of epithelial pearls, hyperchromatic basophilic cells, tonofilaments, polyribosomes and lysosomes was observed following thyroxine and PGF2.alpha.. An increase of keratinization and intramitochondrial granules occurred with estradiol, and increased sclerosis followed calcitonin administration. A marked reduction of cell organelles occurred after hydrocortisone, hypophysectomy and gonadectomy. Scanning EM shows changes in tumor cytoarchitecture and cell surfaces (blebs, ruffles). Hormones apparently can change the development of carcinomas, DNA synthesis and cellular differentiation, and may be important modulators of epidermal carcinogenesis.