[Experimental study of the antitumor properties and mechanism of action of kortifen]. / Eksperimental'noe izuchenie protivoopukholevykh svoistv i mekhanizma deistviia kortifena.

Cortiphen, a newly developed hormonal cytostatic ester of 11-desoxy-17 alpha-hydroxycorticosterone and chlorophenacyl, is described. It was studied in transplantable, spontaneous and induced tumors of 7 sites: hemoblastosis (5), hepatoma (3), mammary gland (5), lung (2), gastrointestinal tract (3), sarcoma (2) and melanoma. Practically all the tumors were shown to respond to cortiphen action. Among the antitumor effects of the drug were: long-term inhibition of tumor growth or tumor regression, contribution to longer survival, antimetastatic action and sustained action during repeated courses of administration. Cortiphen was found to interact with glucocorticoid receptors in both animal and human tumors. The role of the hormonal component of the drug's molecule in the realization of its antitumor effect is discussed.

[Use of the peptide hormone melanostatin and its analogs for the synthesis of new antitumor compounds]. / Ispol'zovanie peptidnogo gormona melanostatina i ego analogov dlia sinteza novykh protivoopukholevykh soedinenii.

A hypothalamic hormone--melanostatin H-L-Pro-L-Leu-NH2- and its 9 analogs were synthesized and their antitumor properties studied. Melanostatin caused a 52-72% inhibition of tumor growth (p less than 0.05) in mice bearing adenocarcinoma of the mammary gland Ca-755, cervical carcinoma CC-5 and melanoma B-16. Non-cytotoxic analogs containing D-leucine or L-lysine showed low activity. Among analogs containing sarcolysine stereomers, chlorphenacyl or chlorambucil, derivatives with L-sarcolysin exerted a high antitumor effect on Ca-755, CC-5, Lewis lung carcinoma, lymphoid leukemia L-1210, sarcoma-37, melanoma B-16 and S-91 (80-99% inhibition of tumor growth, p less than 0.05). L-sarcolysin alone had a higher effect on S-91 only (p less than 0.05). Antitumor effect of melanostatin is due to its amino acid sequences. Melanostatin analogs modified by L-phenylalanine retain their antitumor properties.

[The antineoplastic activity of testiphenon]. / Protivoopukholevoe deistvie testifenona.

The paper describes the antitumor activity of a newly-developed hormonocytostatic drug testiphenon--a complex ether of 5 alpha-dihydrotestosterone and chlorphenacyl (17 beta-[n-di/2-chloroethyl/aminophenylacetate]-5 alpha-androstan-17 beta-ol-3-on). Its antitumor properties were studied in 15 models of transplantable solid tumors and systemic neoplasms of mice and rats such as sarcoma 298, sarcoma 37, sarcoma-180, Lewis lung epidermoid carcinoma, carcinoma of the forestomach-5, large bowel adenocarcinoma, Harding-Passey's melanoma, cervical cancer-5, mammary adenocarcinoma Ca-755, hemoblastosis La, plasmacytoma MOPC-406, Rauscher's erythroblastosis, Walker's carcinosarcoma 256, sarcoma 45, alveolar carcinoma of the mammary gland and DMBA-induced mammary tumors of mice. The spectrum of antitumor activity of testiphenon proved wider than those of its components or other estrogeno-cytostatic drugs--phenestrol and estracyt. The drug is specifically intended for selective action upon target tissues for androgens and tumors developing from the said tissues.

[Mechanism of mammary cancer regression in lactating rats]. / K mekhanizmu regressii raka molochnoi zhelezy u laktiruiushchikh krys.

Dependence of the incidence of regression of the transplantable carcinoma of the mammary gland RMK-1 in albino rats on lactation conditions was studied. The tumour was subject to regression in 47% of the animals nursing 8 +/- 1 ratlings. Following ovariectomy and cortisone and oxytocine administration which produced mediated inhibitory effect of FSH secretion of the hypophysis the frequency of the tumour regression in rats nursing the same number of ratlings rose to 71--81%. In rats with prolonged lactation nursing 8 +/- 1 ratlings for 2--2.5 months and in rats with intensive lactation nursing 13 +/- 2 ratlings the tumour regression practically failed to occur. The data obtained confirmed the suggestion that along with high LTH of the hypophysis secretion of importance for regression of mammary carcinoma in the course of lactation was reduction of the secretion of FSH of the hypophysis.