Development of the method to select the most effective anti-cancer chemotherapy using in-house cDNA microarray

本研究旨在分析口腔鳞状细胞癌(OSCC)的抗癌耐药机制，寻找新的耐药分子标志物。和歌山医科大学口腔外科H-1细胞在顺铂(CDDP)浓度升高的条件下建立H-1R细胞。为了确定可能与耐药性相关的基因，我们使用了代表2,241个口腔疾病起源基因的内部cDNA微阵列。四甲基偶氮唑盐比色法显示，H-1R细胞对顺铂的耐药性是H-1细胞的10倍。H-1R细胞多药耐药基因表达上调。基因芯片分析结果表明，与亲本细胞相比，抗性细胞中有34个基因表达上调2倍以上，19个基因表达下调2倍以上。基因芯片检测结果经实时定量聚合酶链式反应证实。在上调的基因中，CD55基因在口腔鳞癌细胞系和临床组织标本中普遍高表达。我们的结果表明，在顺铂耐药细胞中差异表达的基因，特别是CD55，可能成为新的耐药分子标记。

The aim of the study is to analyze the mechanism involved in anticancer-drug resistance in oral squamous cell carcinoma (OSCC) and to find new molecular markers for drug resistance. H-1R cells were established in the presence of increasing concentrations of Cisplatin (CDDP) from H-1 cells in Department of Oral Surgery, Wakayama Medical University. To identify genes that might be associated with drug resistance, we used an in-house cDNA microarray representing 2,241 oral disease origin genes. H-1R exhibited 10-fold increased resistance to CDDP, compared with H-1 cells by MTT assay. The expressions of MDR genes were up-regulated in H-1R cells. The results of microarray analysis showed that 34 genes were identified to be up-regulated 2-fold or higher and 19 genes were down-regulated 2-fold or more in resistant cell, compared with parent cell. The results which were detected by the cDNA microarray were confirmed by real time PCR. Out of the up-regulated genes, the high expression of CD55 gene was commonly detected among cell lines and clinical tissue samples of OSCC. Our result suggested that the genes, especially CD55, identified to be differentially expressed in CDDP resistant cells could be new molecular markers for drug resistance.