State Key Laboratory of Oncology in South China and Department of Neurosurgery/Neuro-oncology, Cancer Center Sun Yat-sen University, Guangzhou, China.
Cancer Biol Ther. 2012 May;13(7):496-503. doi: 10.4161/cbt.19592. Epub 2012 May 1.
Cisplatin is one of the most commonly used chemotherapeutic agents for glioma patients. In this study, array comparative genomic hybridization (aCGH) was used to identify genes associated with cisplatin resistance in a human glioma cell line. The cisplatin-resistant U251/CP2 cell line was derived by stepwise selection using cisplatin. The genetic aberrations of the U251 parental cell line and the U251/CP2 cells were analyzed using aCGH. RT-PCR was used to detect the expression of the altered genes revealed by aCGH. The sensitivity of glioma cells to cisplatin was determined by using the MTT assay. Apoptosis was detected using flow cytometry and western blot analysis. The IC 50 value of cisplatin in U251/CP2 cells was five times higher than its IC 50 in U251 cells. The U251 cells lost at least one copy each of the CFHR1 and CFHR3 genes, and both CFHR1 and CFHR3 were homozygously deleted in U251/CP2 cells. The U251/CP2 cells gained two to three copies of C8orf70 and IL-7 genes. IL-7 mRNA expression was studied in 12 glioma cell lines, and expression was positively correlated with the IC 50 of cisplatin. Furthermore, IL-7 mRNA expression was also positively correlated with the IC 50 of cisplatin in 91 clinical glioma specimens. Additionally, treatment with recombinant human IL-7 (rhIL-7) enhanced cisplatin resistance and increased the relative growth rate of the glioma cells. Moreover, the apoptosis induced by cisplatin could be inhibited by IL-7. In conclusion, our results suggest that IL-7 may play an important role in cisplatin resistance in glioma.
顺铂是胶质母细胞瘤患者最常用的化疗药物之一。在这项研究中，采用阵列比较基因组杂交（aCGH）技术鉴定与人类胶质母细胞瘤细胞系顺铂耐药相关的基因。顺铂耐药 U251/CP2 细胞系是通过逐步选择顺铂诱导而来。采用 aCGH 技术分析 U251 亲本细胞系和 U251/CP2 细胞的遗传异常。采用 RT-PCR 检测 aCGH 揭示的改变基因的表达。采用 MTT 检测法测定胶质母细胞瘤细胞对顺铂的敏感性。采用流式细胞术和 Western blot 分析检测细胞凋亡。U251/CP2 细胞中顺铂的 IC50 值是 U251 细胞的 5 倍。U251 细胞至少丢失了 CFHR1 和 CFHR3 基因的一个拷贝，U251/CP2 细胞中 CFHR1 和 CFHR3 均为纯合缺失。U251/CP2 细胞获得了 2 到 3 个拷贝的 C8orf70 和 IL-7 基因。在 12 种胶质母细胞瘤细胞系中研究了 IL-7mRNA 的表达，其表达与顺铂的 IC50 值呈正相关。此外，91 例临床胶质母细胞瘤标本中 IL-7mRNA 的表达与顺铂的 IC50 值也呈正相关。此外，重组人白细胞介素-7（rhIL-7）治疗可增强顺铂耐药性，并增加胶质瘤细胞的相对增长率。此外，IL-7 可抑制顺铂诱导的细胞凋亡。总之，我们的研究结果表明，IL-7 可能在胶质母细胞瘤的顺铂耐药中发挥重要作用。
