TY - JOUR
T1 - Mismatch repair proficiency is not required for radioenhancement by gemcitabine
AU - van Bree, Chris
AU - Rodermond, Hans M.
AU - de Vos, Judith
AU - Haveman, Jaap
AU - Franken, Nicolaas A. P.
PY - 2005
Y1 - 2005
N2 - Purpose: Mismatch repair (MMR) proficiency has been reported to either increase or decrease radioenhancement by 24-h incubations with gemcitabine. This study aimed to establish the importance of MMR for radioenhancement by gemcitabine after short-exposure, high-dose treatment and long-exposure, low-dose treatment. Methods and Materials: Survival of MMR-deficient HCT116 and MMR-proficient HCT116 + 3 cells was analyzed by clonogenic assays. Mild, equitoxic gemcitabine treatments (4 h, 0.1 mu M vs. 24 h, 6 nM) were combined with gamma-irradiation to determine the radioenhancement with or without recovery. Gemcitabine metabolism and cell-cycle effects were evaluated by high-performance liquid chromatography analysis and bivariate flow cytometry. Results: Radioenhancement after 4 h of 0.1 mu M of gemcitabine was similar in both cell lines, but the radioenhancement after 24 h of 6 nM of gemcitabine was reduced in MMR-proficient cells. No significant differences between both cell lines were observed in the gemcitabine metabolism or cell-cycle effects after these treatments. Gemcitabine radioenhancement after recovery was also lower in MMR-proficient cells than in MMR-deficient cells. Conclusion: Mismatch repair proficiency decreases radioenhancement by long incubations of gemcitabine but does not affect radioenhancement by short exposures to a clinically relevant gemcitabine dose. Our data suggest that MMR contributes to the recovery from gemcitabine treatment. (c) 2005 Elsevier Inc
AB - Purpose: Mismatch repair (MMR) proficiency has been reported to either increase or decrease radioenhancement by 24-h incubations with gemcitabine. This study aimed to establish the importance of MMR for radioenhancement by gemcitabine after short-exposure, high-dose treatment and long-exposure, low-dose treatment. Methods and Materials: Survival of MMR-deficient HCT116 and MMR-proficient HCT116 + 3 cells was analyzed by clonogenic assays. Mild, equitoxic gemcitabine treatments (4 h, 0.1 mu M vs. 24 h, 6 nM) were combined with gamma-irradiation to determine the radioenhancement with or without recovery. Gemcitabine metabolism and cell-cycle effects were evaluated by high-performance liquid chromatography analysis and bivariate flow cytometry. Results: Radioenhancement after 4 h of 0.1 mu M of gemcitabine was similar in both cell lines, but the radioenhancement after 24 h of 6 nM of gemcitabine was reduced in MMR-proficient cells. No significant differences between both cell lines were observed in the gemcitabine metabolism or cell-cycle effects after these treatments. Gemcitabine radioenhancement after recovery was also lower in MMR-proficient cells than in MMR-deficient cells. Conclusion: Mismatch repair proficiency decreases radioenhancement by long incubations of gemcitabine but does not affect radioenhancement by short exposures to a clinically relevant gemcitabine dose. Our data suggest that MMR contributes to the recovery from gemcitabine treatment. (c) 2005 Elsevier Inc
U2 - https://doi.org/10.1016/j.ijrobp.2005.04.012
DO - https://doi.org/10.1016/j.ijrobp.2005.04.012
M3 - Article
C2 - 15925456
SN - 0360-3016
VL - 62
SP - 1504
EP - 1509
JO - International journal of radiation oncology, biology, physics
JF - International journal of radiation oncology, biology, physics
IS - 5
ER -