title: [In vitro assay for cyclophosphamide-sensitivity of human tumours: the effect of 4-hydro-peroxy-cyclophosphamide on the incorporation of 3H-uridine into the nucleic acids of human tumour cells (author's transl)].
abstract: The utility of 4-hydro-peroxy-cyclophosphamide for testing the selectivity of human tumours cells against cyclophosphamide in vitro was studied. 4-hydro-peroxy-cyclophosphamide in aqueous solution spontaneously decomposes to 4-hydroxy-cyclophosphamide, the primary product of metabolic activation of cyclophosphamide thus representing a new form of "activated" cyclophosphamide. From 31 human tumours including 21 mammarian-, 4 ovarial-, 2 uterine-carcinomas, 2 seminomas, 1 hypernephroma and 1 rectum-carcinoma cell suspensions were made and the effect on the 3H-Uridine- and the 3H-Thymidine-incorporation into the nucleic acids after short time incubation with the effect of 4-hydro-peroxy-cyclophosphamide and 4-hydroxy-cyclophosphamide. 7 malignomas showed high sensitivity both against 4-hydro-peroxy-cyclophosphamide and against 4-hydroxy-cyclophosphamide. No additional inhibitory effect of the peroxyde function besides of that of the alkylating moiety of the molecule was found. Accordingly 4-hydro-peroxy-cyclophosphamide because of its better availibility and stability may be used as "activated" cyclophosphamide in screening tests for cyclophosphamide-sensivity of human tumours in vitro.
mesh_terms: D000328:Adult; D000368:Aged; D003520:Cyclophosphamide / Q000031:analogs & derivatives / Q000627:therapeutic use*; D004273:DNA, Neoplasm / Q000096:biosynthesis*; D004341:Drug Evaluation; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy*; D010545:Peroxides; D012334:RNA, Neoplasm / Q000096:biosynthesis*
chemical_list: D004273:DNA, Neoplasm; D010545:Peroxides; D012334:RNA, Neoplasm; D003520:Cyclophosphamide
vernacular_title: Zum Problem der in vitro-Sensibilitätstestung von Tumoren gegen Cyclophosphamid. 3H-Uridineinbau in Ribonucleinsäure menschlicher Tumorzellen nach Inkubation mit 4-Hydro-peroxy-Cyclophosphamid