Anticancer research
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Anticancer research · Jan 1996
Comparative StudyNovel trans platinum complexes: comparative in vitro and in vivo activity against platinum-sensitive and resistant murine tumours.
Two pairs of cis/trans platinum complexes, JM118 (cis-ammine(cyclohexylamine) dichloro platinum(II)) and its trans counterpart, JM334 and JM149 (cis-ammine(cyclohexylamine) dichloro-dihydroxo platinum(IV)) and its trans counterpart JM335 have been evaluated (both in vitro and in vivo) against two murine tumour models of historical importance in the discovery of novel platinum drugs; the ADJ/PC6 plasmacytoma and the L1210 leukaemia and sublines selected for resistance to platinum drugs. In vitro, results showed that the trans complexes induced comparable growth inhibitory properties to those observed for cisplatin and their respective cis isomers. Moreover, retention of activity was observed in a series of 5 acquired platinum drug (cisplatin, carboplatin, iproplatin, tetraplatin and JM149)-resistant L1210 sublines whereas at least partial cross-resistance was observed to the cis isomer JM149 in the acquired carboplatin and iproplatin-resistant lines (in addition to being 11-fold resistant in the line selected for resistance to JM149 itself). ⋯ Interestingly, the trans platinum(II) counterpart of JM335(JM334) was inactive in vivo. These data indicate that the trans platinum(IV) complex JM335 possess several in vitro growth inhibitory- and in vivo antitumour properties which are distinct from those observed for cisplatin (or its cis isomer). Thus, JM335 contravenes the original structure-activity rules determined for platinum-containing compounds and, because of its level of activity against cisplatin-resistant tumours, establishes the complex as of interest in the search for new platinum drugs active against cisplatin-resistant disease.
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Anticancer research · Jan 1996
Effect of paclitaxel and Cremophor EL on mast cell histamine secretion and their interaction with adriamycin.
The effect of paclitaxel and of its solvent Cremophor EL, a polyoxyethylated castor oil on histamine release in rat peritoneal mast cells has been tested. Paclitaxel dissolved in Cremophor EL/ethanol and Cremophor EL alone induced a moderate histamine release; this secretory activity is provoked by the solvent Cremophor EL but is so scanty that it seems most unlikely to be responsible of the severe hypersensitivity reactions frequently caused by this drug. ⋯ This is an interesting observation since it has been suggested that anthracycline-induced histamine release is involved in the pathogenesis of the cardiotoxicity caused by these drugs. Low concentrations of paclitaxel in Cremophor EL and Cremophor EL alone inhibited adriamycin uptake into the granules of mast cells, a process mediated by an active transport system, recently identified with the P-170 glycoprotein pump.