Studies on the mechanism of action of LS 1727, a nitrosocarbamate of 19-nortestosterone
Abstract
LS 1727, a nitrosocarbamate of 19-nortestosterone, was active against lymphoid, antimetabolite-sensitive, cell lines in vitro especially L1210 and Ehrlich ascites tumour lines. It was less effective against alkylating agent-sensitive lines such as the Walker 256 carcinosarcoma. These results suggested a possible antimetabolite mode of action but LS 1727 had no effect on deoxy-or ribonucleotide pool sizes in L1210 cells. Studies on macromolecular synthesis showed an early inhibition of DNA synthesis whilst RNA and protein synthesis continued for 24-48 hours. This was reminiscent of a classic alkylating agent-like effect. In vivo studies with specific alkylating agent-sensitive, or antimetabolite-sensitive tumours showed no antitumour activity although significant inhibition of Ehrlich ascites tumour cell growth was observed at high doses. In vitro cytotoxicity studies showed LS 1727 to be inactivated in the presence of mouse, rat and dog liver supernatants. This would explain the poor antitumour effects in vivo compared with the in vitro observations. Because LS 1727 is a nitrosocarbamate its possible mutagenic activity was investigated. LS 1727 was highly mutagenic but this property was also lost in the presence of a rat liver ...Continue Reading
References
A study of nitrosamines and S-carboxyl derivatives of cysteine as lung carcinogens in adult SWR mice
Citations
Related Concepts
Related Feeds
Carcinosarcoma
Carcinosarcoma is a malignant neoplasm that contains elements of carcinoma and sarcoma so extensively intermixed as to indicate neoplasia of epithelial and mesenchymal tissue. Discover the latest research on carcinosarcoma here.