Department of Obstetrics & Gynecology & Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, PR China.
Indian J Med Res. 2013 Mar;137(3):527-32.
BACKGROUND & OBJECTIVES: Drug resistance is the primary cause of failure in the treatment of cancers. It has been suggested that the enhancement of DNA repair capability may be responsible for the drug resistance of the tumour cells, and poly(ADP-ribosyl)ation plays an important role in DNA repair. This study investigated the effect of PARP inhibitor 3-aminobenzamide (3-AB) on the cisplatin resistance and proliferation of the cisplatin-resistant ovarian cancer C13 FNx01 cells in vitro.
C13 FNx01 cells were treated with various concentrations of 3-AB in vitro. MTT assay was used to determine the effect of 3-AB on the cisplatin sensitivity and proliferation of cells. The expression levels of PARP-1 mRNA and protein in the C13 FNx01 cells were examined using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, and changes caused by 3-AB treatment were investigated. Immunofluorescence microscopy was used to detect the localization and expression of the PARP-1 proteins before and after treatment with 5 mmol/l 3-AB.
The inhibitory ratio and the cisplatin sensitivity of C13 FNx01 cells significantly increased with the increase of the concentration of 3-AB (P<0.05). The RT-PCR analysis revealed that the expression of PARP-1 mRNA was decreased when platinum (Pt) and 3-AB were combined. The expression levels of PARP-1 protein were decreased by 23.15 ± 2.53, 59.11 ± 2.23 and 73.24 ± 3.88 per cent, respectively, in C13 FNx01 cells with the increase of the concentration of 3-AB (P<0.05). The immunofluorescence microscopy results indicated that the expression level of PARP-1 protein was significantly decreased after treatment with 3-AB (P,<0.05).
INTERPRETATION & CONCLUSIONS: 3-AB inhibited the proliferation activity of C13 FNx01 cells, and increased the cellular sensitivity to cisplatin. Our findings show that the PARP inhibitor 3-AB can downregulate the expression of PARP-1 at transcriptional and translational levels in C13 FNx01 cells.
耐药性是癌症治疗失败的主要原因。有人提出，肿瘤细胞的 DNA 修复能力增强可能是导致其耐药的原因，而聚（ADP-核糖）化在 DNA 修复中发挥着重要作用。本研究探讨了 PARP 抑制剂 3-氨基苯甲酰胺（3-AB）对体外顺铂耐药卵巢癌细胞 C13 FNx01 耐药性和增殖的影响。
在体外用不同浓度的 3-AB 处理 C13 FNx01 细胞。采用 MTT 法检测 3-AB 对细胞顺铂敏感性和增殖的影响。采用逆转录-聚合酶链反应（RT-PCR）和 Western blot 检测 C13 FNx01 细胞中 PARP-1 mRNA 和蛋白的表达水平，并观察 3-AB 处理引起的变化。用免疫荧光显微镜检测 5mmol/L 3-AB 处理前后 PARP-1 蛋白的定位和表达。
随着 3-AB 浓度的增加，C13 FNx01 细胞的抑制率和顺铂敏感性均显著增加（P<0.05）。RT-PCR 分析显示，铂与 3-AB 联合应用时 PARP-1 mRNA 的表达降低。随着 3-AB 浓度的增加，C13 FNx01 细胞中 PARP-1 蛋白的表达水平分别降低了 23.15±2.53%、59.11±2.23%和 73.24±3.88%（P<0.05）。免疫荧光显微镜结果表明，3-AB 处理后 PARP-1 蛋白的表达水平显著降低（P<0.05）。
3-AB 抑制了 C13 FNx01 细胞的增殖活性，并增加了细胞对顺铂的敏感性。我们的研究结果表明，PARP 抑制剂 3-AB 可以下调 C13 FNx01 细胞中 PARP-1 的表达，在转录和翻译水平上。
