title: Molecular mechanisms underlying the interaction between ZD1839 ('Iressa') and cisplatin/5-fluorouracil.
abstract: ZD1839 ('Iressa'), an orally active, selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is currently being investigated in clinical trials as a treatment for cancer. 'Iressa' is a trademark of the AstraZeneca group of companies. We have previously demonstrated a synergistic interaction between ZD1839 and cisplatin/5-fluorouracil (5FU) in CAL33, a human head and neck cancer cell line that markedly expresses EGFR. This study examined the effects of this drug combination on the cell cycle, cell cycle regulators, apoptosis-related factors, EGFR-related signalling and DNA repair in CAL33 cells. The cells were incubated with ZD1839 alone for 48 h, then cisplatin and 5FU were added. Exposure to the drug combination continued for a further 48 h. ZD1839 alone induced accumulation of cells in the G0/G1 phase of the cell cycle at 24 h accompanied by a concomitant increase in p21, p27 and Bax, a significant decrease in Bcl2 and a decrease in Akt phosphorylation. A decrease in DNA-PK was observed at 48 h. ZD1839 alone had no effect on caspase-3 activity, but addition of ZD1839 to cisplatin-5FU led to a significant increase in caspase-3 activity at 96 h. Thus, ZD1839 affects key cellular pathways controlling cell proliferation, apoptosis and DNA repair. These data provide a rationale to support clinical trials combining ZD1839 and cisplatin-5FU and other protocols that combine EGFR-targeting agents with chemotherapy or radiotherapy.
authors.affiliation: Centre Antoine Lacassagne, Oncopharmacology Unit, 33, Avenue de Valombrose, 06189, Nice cedex 2, France.
authors.forename: N
authors.initials: N
authors.lastname: Magné
authors.forename: J-L
authors.initials: JL
authors.lastname: Fischel
authors.forename: C
authors.initials: C
authors.lastname: Tiffon
authors.forename: P
authors.initials: P
authors.lastname: Formento
authors.forename: A
authors.initials: A
authors.lastname: Dubreuil
authors.forename: N
authors.initials: N
authors.lastname: Renée
authors.forename: J-L
authors.initials: JL
authors.lastname: Formento
authors.forename: M
authors.initials: M
authors.lastname: Francoual
authors.forename: J
authors.initials: J
authors.lastname: Ciccolini
authors.forename: M-C
authors.initials: MC
authors.lastname: Etienne
authors.forename: G
authors.initials: G
authors.lastname: Milano
mesh_terms: D000970:Antineoplastic Agents / Q000493:pharmacokinetics* / Q000494:pharmacology*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000493:pharmacokinetics* / Q000494:pharmacology*; D017209:Apoptosis; D002453:Cell Cycle / Q000187:drug effects*; D002945:Cisplatin / Q000493:pharmacokinetics* / Q000494:pharmacology*; D004260:DNA Repair / Q000187:drug effects*; D004347:Drug Interactions; D004815:Epidermal Growth Factor / Q000037:antagonists & inhibitors; D066246:ErbB Receptors / Q000096:biosynthesis; D005472:Fluorouracil / Q000493:pharmacokinetics* / Q000494:pharmacology*; D000077156:Gefitinib; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011799:Quinazolines / Q000493:pharmacokinetics* / Q000494:pharmacology*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D011799:Quinazolines; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; D002945:Cisplatin; D000077156:Gefitinib; D005472:Fluorouracil