Liu Yongping, Ling Yang, Qi Qiufeng, Zhu Ming, Wan Meizhen, Zhang Yaping, Zhang Changsong
Clinical Oncology Laboratory, Changzhou Tumor Hospital Affiliated to Suzhou University, Changzhou, Jiangsu 213002, P.R. China ; Department of Oncology Medicine, Changzhou Tumor Hospital Affiliated to Suzhou University, Changzhou, Jiangsu 213002, P.R. China.
Department of Oncology Medicine, Changzhou Tumor Hospital Affiliated to Suzhou University, Changzhou, Jiangsu 213002, P.R. China.
Oncol Lett. 2015 Feb;9(2):999-1005. doi: 10.3892/ol.2014.2793. Epub 2014 Dec 12.
amplification occurs in ~20% of gastric cancer (GC) cases; however, in gastric and gastroesophageal junction cancer with gene amplification, trastuzumab in combination with cisplatin (DDP)-based chemotherapy has been reported to improve the oncological outcome. The aim of the present study was to evaluate the combined antitumor efficacy of trastuzumab and various platinum agents in GC cells and to elucidate mechanisms that may be involved in the interaction between trastuzumab and the platinum agents. The chemosensitivity of the GC cells to platinum agents was evaluated using the CellTiter 96 AQueous One Solution Cell Proliferation Assay kit. Treatment with 1.0μg/ml trastuzumab for 48 h significantly increased the sensitivity of NCI-N87 cells with amplification to oxaliplatin (Oxa) and DDP. This chemosensitivity was most prominent in the NCI-N87 cells, in which the half maximal inhibitory concentration of Oxa and DDP was decreased to ~3.29 and 6.91 times, respectively. The apoptotic effect of the platinum agents was evaluated by double-staining the GC cells with Annexin V-fluorescein isothiocyanate and propodium iodide. Consistent with the chemosensitivity analysis, apoptotic analysis indicated that trastuzumab significantly increased Oxa- and DDP-induced apoptosis in the NCI-N87 cells. Furthermore, the mRNA expression levels of various telomere-associated genes was determined by performing quantitative reverse transcription-polymerase chain reactions in a number of GC cell lines, and revealed that trastuzumab (alone and in combination with DDP) may downregulate the mRNA expression levels of the , , , and genes. However, western blot analysis demonstrated that trastuzumab (alone and in combination with DDP) may significantly downregulate the protein expression levels of telomeric repeat binding factor 2, protection of telomere 1 and TPP1 (formerly known as TINT1, PTOP and PIP). The results of the present study indicate a potential role of low-dose trastuzumab administration for increasing Oxa and DDP sensitivity in -amplified GC cells, possibly via the downregulation of telomere-associated gene expression.
扩增发生在约20%的胃癌（GC）病例中；然而，在伴有基因扩增的胃癌和胃食管交界癌中，据报道曲妥珠单抗联合基于顺铂（DDP）的化疗可改善肿瘤学结局。本研究的目的是评估曲妥珠单抗与各种铂类药物在GC细胞中的联合抗肿瘤疗效，并阐明可能参与曲妥珠单抗与铂类药物相互作用的机制。使用CellTiter 96 AQueous One Solution细胞增殖检测试剂盒评估GC细胞对铂类药物的化学敏感性。用1.0μg/ml曲妥珠单抗处理48小时显著增加了具有扩增的NCI-N87细胞对奥沙利铂（Oxa）和DDP的敏感性。这种化学敏感性在NCI-N87细胞中最为显著，其中Oxa和DDP的半数最大抑制浓度分别降至约3.29倍和6.91倍。通过用膜联蛋白V-异硫氰酸荧光素和碘化丙啶对GC细胞进行双重染色来评估铂类药物的凋亡作用。与化学敏感性分析一致，凋亡分析表明曲妥珠单抗显著增加了NCI-N87细胞中Oxa和DDP诱导的凋亡。此外，通过在多个GC细胞系中进行定量逆转录-聚合酶链反应来测定各种端粒相关基因的mRNA表达水平，并揭示曲妥珠单抗（单独以及与DDP联合）可能下调、、、和基因的mRNA表达水平。然而，蛋白质印迹分析表明曲妥珠单抗（单独以及与DDP联合）可能显著下调端粒重复结合因子2、端粒保护蛋白1和TPP1（以前称为TINT1、PTOP和PIP）的蛋白质表达水平。本研究结果表明低剂量曲妥珠单抗给药可能通过下调端粒相关基因表达来增加扩增的GC细胞对Oxa和DDP的敏感性。
