RT Journal Article
SR Electronic
T1 Synergism in Concomitant Chemoradiotherapy of Cisplatin and Oxaliplatin and their Liposomal Formulation in the Human Colorectal Cancer HCT116 Model
JF Anticancer Research
JO Anticancer Res
FD International Institute of Anticancer Research
SP 4395
OP 4404
VO 32
IS 10
A1 THITITIP TIPPAYAMONTRI
A1 RAMI KOTB
A1 BENOIT PAQUETTE
A1 LÉON SANCHE
YR 2012
UL http://ar.iiarjournals.org/content/32/10/4395.abstract
AB Background: We choose to test the effect of associating chemo-radiotherapy at 8 h (the highest level of DNA-platinum) and 48 h (the lower level of DNA-platinum) to clarify if irradiation at the maximum DNA-platinum concentration could improve the synergism. Materials and Methods: Growth inhibition of the human colorectal cancer cell line HCT116 treated with cisplatin, oxaliplatin, Lipoplatin™ and Lipoxal™ plus gamma-radiation was determined by a colony formation assay. The synergism was evaluated using the combination index method. Results: For 8 h and 48 h exposure to cisplatin or Lipoplatin™, followed by irradiation, drug concentrations higher than IC50 were found to be synergistic, while a lower than IC50 concentration was antagonistic. For oxaliplatin, exposure to a concentration above IC50 for 8 h was synergistic, while the exposure to oxaliplatin (at any concentrations) for 48 h was antagonistic. Lipoxal™ significantly improved synergism compared to its parent drugs. All tested platinum drugs sensitize radiation-treated HCT116 cells by inducing G2 phase. Conclusion: The difference of drug concentrations and the time interval between drug administration and radiotherapy could give different results in chemoradiation therapy.