Anti-cancer drug design
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Anti-cancer drug design · Jan 1998
Chemical, biochemical and pharmacological activity of the novel sterically hindered platinum co-ordination complex, cis-[amminedichloro(2-methylpyridine)] platinum(II) (AMD473).
cis-[Amminedichloro(2-methylpyridine)] platinum(II) (AMD473) is a novel sterically hindered anti-tumour compound designed to circumvent platinum drug resistance and is due to begin clinical trials in 1997. This paper reports the rationale behind the development of AMD473 with regard to its chemical and DNA binding properties. AMD473 circumvents resistance in vitro in acquired cisplatin resistant human ovarian carcinoma (HOC) cell line models (2 h SRB assay mean resistance factor = 2.8 +/- 1.2 microM for AMD473, versus 6.5 +/- 3.5 microM for cisplatin). ⋯ As steric hindrance was increased from AMD494 (unsubstituted pyridine) through AMD473 to AMD508 (2,6-dimethylpyridine), by addition of methyl groups on the pyridine ligand, cross-link formation rates became slower. By alkaline elution, at equimolar doses, AMD473 ICL formation after 24 h incubation was less than that of cisplatin after 4 h. Understanding the chemical and biochemical properties of these sterically hindered platinum complexes may aid the development of more novel platinum chemotherapeutic agents capable of further improving anti-tumour activity in resistant tumours.
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Anti-cancer drug design · Jan 1998
Antitumor activity of a PKC-alpha antisense oligonucleotide in combination with standard chemotherapeutic agents against various human tumors transplanted into nude mice.
A 20-mer phosphorothioate oligodeoxynucleotide (ODN) directed against human protein kinase C-alpha (CGP 64128A = ISIS 3521) was analyzed for its antitumor activity either alone or in combination therapy. Combination studies with CGP 64128A and standard chemotherapeutic agents (cisplatin, mitomycin-C, vinblastine, estracyt and adriamycin) were performed in nude mice that had been transplanted s.c. with a variety of human tumors (breast, prostate, large cell lung and small cell lung carcinomas, and melanomas). Additive antitumor effects with CGP 64128A and the cytotoxins were found for half of the combinations studied. ⋯ CGP 64128A in combination with adriamycin resulted in superadditive antitumor effects against BT20 human breast carcinomas with complete tumor responses, and in combination with mitomycin-C superadditive antitumor effects with cures were observed against NCI-H460 human large cell carcinomas. The antitumor activity of CGP 64128A appeared to be due to a sequence-dependent mechanism of action as two 20-mer control ODNs were completely inactive as single agents against A549 and NCI-H69 human lung carcinomas. The antitumor activity of cisplatin against NCI-H69 human small cell lung carcinomas was slightly inhibited by one of the control ODNs, indicating that the superadditive antitumor activities of CGP 64128A in combination with cisplatin are the result of a sequence-dependent mechanism of action.