Maeda Osamu, Ando Takafumi, Ohmiya Naoki, Ishiguro Kazuhiro, Watanabe Osamu, Miyahara Ryoji, Hibi Yoko, Nagai Taku, Yamada Kiyofumi, Goto Hidemi
Department of Advanced Research of Gastroenterology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Japan.
Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Japan.
Oncol Rep. 2014 Apr;31(4):1883-90. doi: 10.3892/or.2014.3014. Epub 2014 Feb 6.
The mechanisms of drug resistance in cancer are not fully elucidated. To study the drug resistance of gastric cancer, we analyzed gene expression and DNA methylation profiles of 5-fluorouracil (5-FU)- and cisplatin (CDDP)-resistant gastric cancer cells and biopsy specimens. Drug-resistant gastric cancer cells were established with culture for >10 months in a medium containing 5-FU or CDDP. Endoscopic biopsy specimens were obtained from gastric cancer patients who underwent chemotherapy with oral fluoropyrimidine S-1 and CDDP. Gene expression and DNA methylation analyses were performed using microarray, and validated using real-time PCR and pyrosequencing, respectively. Out of 17,933 genes, 541 genes commonly increased and 569 genes decreased in both 5-FU- and CDDP-resistant AGS cells. Genes with expression changed by drugs were related to GO term 'extracellular region' and 'p53 signaling pathway' in both 5-FU- and CDDP-treated cells. Expression of 15 genes including KLK13 increased and 12 genes including ETV7 decreased, in both drug-resistant cells and biopsy specimens of two patients after chemotherapy. Out of 10,365 genes evaluated with both expression microarray and methylation microarray, 74 genes were hypermethylated and downregulated, or hypomethylated and upregulated in either 5-FU-resistant or CDDP-resistant cells. Of these genes, expression of 21 genes including FSCN1, CPT1C and NOTCH3, increased from treatment with a demethylating agent. There are alterations of gene expression and DNA methylation in drug-resistant gastric cancer; they may be related to mechanisms of drug resistance and may be useful as biomarkers of gastric cancer drug sensitivity.
癌症中的耐药机制尚未完全阐明。为了研究胃癌的耐药性，我们分析了5-氟尿嘧啶（5-FU）和顺铂（CDDP）耐药胃癌细胞及活检标本的基因表达和DNA甲基化谱。通过在含5-FU或CDDP的培养基中培养超过10个月建立耐药胃癌细胞。从接受口服氟嘧啶S-1和顺铂化疗的胃癌患者中获取内镜活检标本。使用微阵列进行基因表达和DNA甲基化分析，并分别通过实时PCR和焦磷酸测序进行验证。在17,933个基因中，5-FU和顺铂耐药的AGS细胞中共有541个基因普遍增加，569个基因减少。在5-FU和顺铂处理的细胞中，因药物而表达改变的基因与GO术语“细胞外区域”和“p53信号通路”相关。在两名患者化疗后的耐药细胞和活检标本中，包括KLK13在内的15个基因表达增加，包括ETV7在内的12个基因表达减少。在通过表达微阵列和甲基化微阵列评估的10,365个基因中，74个基因在5-FU耐药或CDDP耐药细胞中发生高甲基化并下调，或低甲基化并上调。在这些基因中，包括FSCN1、CPT1C和NOTCH3在内的21个基因的表达因去甲基化剂处理而增加。耐药胃癌中存在基因表达和DNA甲基化改变；它们可能与耐药机制有关，并且可能作为胃癌药物敏感性的生物标志物。
