Cisplatin and oxaliplatin toxicity: importance of cochlear kinetics as a determinant for ototoxicity
2009 (English)In: Journal of the National Cancer Institute, ISSN 0027-8874, E-ISSN 1460-2105, Vol. 101, no 1, 37-47 p.Article in journal (Refereed) Published
BACKGROUND: Cisplatin is a cornerstone anticancer drug with pronounced ototoxicity, whereas oxaliplatin, a platinum derivative with a different clinical profile, is rarely ototoxic. This difference has not been explained.
METHODS: In HCT-116 cells, cisplatin (20 microM)-induced apoptosis was reduced by a calcium chelator from 9.9-fold induction (95% confidence interval [CI] = 8.1- to 11.7-fold), to 3.1-fold induction (95% CI = 2.0- to 4.2-fold) and by superoxide scavenging from 9.3-fold (95% CI = 8.8- to 9.8-fold), to 5.1-fold (95% CI = 4.4- to 5.8-fold). A guinea pig model (n = 23) was used to examine pharmacokinetics. Drug concentrations were determined by liquid chromatography with post-column derivatization. The total platinum concentration in cochlear tissue was determined by inductively coupled plasma mass spectrometry. Drug pharmacokinetics was assessed by determining the area under the concentration-time curve (AUC). Statistical tests were two-sided.
RESULTS: In HCT-116 cells, cisplatin (20 microM)-induced apoptosis was reduced by a calcium chelator from 9.9-fold induction (95% confidence interval [CI] = 8.1- to 11.7-fold to 3.1-fold induction) (95% CI = 2.0- to 4.2-fold) and by superoxide scavenging (from 9.3-fold, 95% CI = 8.8- to 9.8-fold, to 5.1-fold, 95% CI = 4.4- to 5.8-fold). Oxaliplatin (20 microM)-induced apoptosis was unaffected by calcium chelation (from 7.1- to 6.2-fold induction) and by superoxide scavenging (from 5.9- to 5.6-fold induction). In guinea pig cochlea, total platinum concentration (0.12 vs 0.63 microg/kg, respectively, P = .008) and perilymphatic drug concentrations (238 vs 515 microM x minute, respectively, P < .001) were lower after intravenous oxaliplatin treatment (16.6 mg/kg) than after equimolar cisplatin treatment (12.5 mg/kg). However, after a non-ototoxic cisplatin dose (5 mg/kg) or the same oxaliplatin dose (16.6 mg/kg), the AUC for perilymphatic concentrations was similar, indicating that the two drugs have different cochlear pharmacokinetics.
CONCLUSION: Cisplatin- but not oxaliplatin-induced apoptosis involved superoxide-related pathways. Lower cochlear uptake of oxaliplatin than cisplatin appears to be a major explanation for its lower ototoxicity.
Place, publisher, year, edition, pages
Cary: Oxford University Press, 2009. Vol. 101, no 1, 37-47 p.
mammalian thioredoxin reductase, sulfur-containing compounds, guinea pig, molecular mechanisms, monohydrated complex, cerebrospinal fluid, active site, cell-death, pharmacokinetics, apoptosis
Cancer and Oncology
IdentifiersURN: urn:nbn:se:umu:diva-18621DOI: 10.1093/jnci/djn418ISI: 000262333500010PubMedID: 19116379OAI: oai:DiVA.org:umu-18621DiVA: diva2:174185