Van Moorsel C J A, Smid K, Voorn D A, Bergman A M, Pinedo H M, Peters G J
Department of Medical Oncology, VU University Medical Center, 1007 MB Amsterdam, The Netherlands.
Int J Oncol. 2003 Jan;22(1):201-7. doi: 10.3892/ijo.22.1.201.
Gemcitabine (dFdC) and cisplatin (CDDP) act synergistically by an increase in platinum-DNA adduct formation. Since ribonucleotide (NTP) and deoxyribonucleotide (dNTP) levels are essential for DNA-synthesis and repair of DNA damage, we investigated whether disturbances might account for differences in effects between sensitive and resistant cell lines. The human ovarian cancer cell line A2780, its CDDP-resistant variant ADDP and its dFdC-resistant variant AG6000 were exposed for 24 h to dFdC or CDDP alone, or a combination causing moderate to strong growth inhibition. In AG6000 cells UTP levels were 2-fold lower and in ADDP cells almost 2-fold higher than in A2780 cells. Levels of dTTP, dATP and dCTP were 2-5-fold lower in the resistant cell lines. Drug treatment affected NTP and dNTP levels most pronounced in A2780 cells. dFdC alone, at 1.5 nM to 1 micro M increased ATP, GTP and CTP pools 1.2 to 2.0-fold, while 10 micro M dFdC increased UTP 2.5-fold. Combination of dFdC and CDDP increased all NTP levels at low dFdC and CDDP concentrations more than 1.2-fold, but at 20 micro M CDDP only CTP increased 2.4-fold. Only 1.5 nM dFdC increased all dNTP pools more than 1.6-fold, but at 0.1 and 1 micro M dFdC, dATP and dGTP decreased down to 10-fold, while dTTP increased 3-5-fold. CDDP and the combination increased all dNTP pools over 1.4 and 1.9-fold, respectively. In AG6000 cells dFdC and CDDP hardly affected the NTP and dNTP status, except at the high concentrations, which decreased ATP, GTP and UTP levels 1.2-1.8-fold. Both CDDP alone and the combination increased dTTP, dCTP and dATP pools up to 1.6-fold. In ADDP cells NTP and most dNTP levels were hardly affected, except dGTP levels which decreased to non-detectable levels. In conclusion, both dFdC and CDDP induce concentration and combination dependent changes in NTP and dNTP pools.
吉西他滨（dFdC）和顺铂（CDDP）通过增加铂-DNA加合物的形成而产生协同作用。由于核糖核苷酸（NTP）和脱氧核糖核苷酸（dNTP）水平对于DNA合成和DNA损伤修复至关重要，我们研究了这些干扰是否可能解释敏感细胞系和耐药细胞系之间效应的差异。将人卵巢癌细胞系A2780、其顺铂耐药变体ADDP及其吉西他滨耐药变体AG6000单独暴露于dFdC或CDDP 24小时，或暴露于导致中度至强烈生长抑制的联合用药。在AG6000细胞中，UTP水平比A2780细胞低2倍，在ADDP细胞中几乎比A2780细胞高2倍。耐药细胞系中dTTP、dATP和dCTP水平低2至5倍。药物处理对A2780细胞中NTP和dNTP水平的影响最为明显。单独使用1.5 nM至1 μM的dFdC可使ATP、GTP和CTP池增加1.2至2.0倍，而10 μM的dFdC可使UTP增加2.5倍。在低dFdC和CDDP浓度下，dFdC与CDDP联合使用可使所有NTP水平增加超过1.2倍，但在20 μM CDDP时，仅CTP增加2.4倍。仅1.5 nM的dFdC可使所有dNTP池增加超过1.6倍，但在0.1和1 μM dFdC时，dATP和dGTP降至10倍，而dTTP增加3至5倍。CDDP及其联合用药分别使所有dNTP池增加超过1.4倍和1.9倍。在AG6000细胞中，dFdC和CDDP对NTP和dNTP状态几乎没有影响，除非在高浓度下，此时ATP、GTP和UTP水平降低1.2至1.8倍。单独使用CDDP及其联合用药均可使dTTP、dCTP和dATP池增加至1.6倍。在ADDP细胞中，NTP和大多数dNTP水平几乎没有受到影响，除了dGTP水平降至无法检测的水平。总之，dFdC和CDDP均可诱导NTP和dNTP池的浓度和联合用药依赖性变化。
