Development of an anti-cancer agent sensitivity gene diagnosis kit of colorectal cancer with Large-scale quantitative RT-PCR

目得：本研究的目的是鉴定与结直肠癌5-FU敏感性相关的基因，并应用这些基因预测肝转移的5-FU敏感性。方法：应用基因芯片技术，对81个与胃癌和结肠癌细胞5-FU耐药相关的候选基因进行了研究。本研究采用实时荧光定量RT-PCR方法检测了22例原发性结直肠肿瘤手术切除标本中这81个基因及5-FU相关酶基因（胸苷酸合成酶（TS）、二氢嘧啶脱氢酶（DPD）和乳清酸磷酸核糖转移酶（OPRT））的mRNA表达。临床反应通过以5-FU为基础的肝动脉注射（HAI）化疗对同步性肝转移瘤的影响来评估。研究结果：4个基因（TNFRSF 1B、SLC 35 F5、NAG-1和OPRT）在5-FU治疗无效和有效的肿瘤中的表达有显著差异（p<0.05）。在此基础上，通过判别分析，建立了与个体化疗敏感性相关性较好的TNFRSF 1B、SLC 35 F5和OPRT三基因反应指数系统。在我们的反应指数阳性评分的11例病例中，9例在5-FU基础化疗后肝转移减少，而11例阴性评分的病例中只有1例对化疗反应良好，表明准确率为86.3%（p=0.0019）。结论：我们的“反应指数”系统，包括TNFRSF 1B，SLC 35 F5和OPRT，有很大的潜力预测5-FU为基础的化疗对结直肠癌肝转移的疗效。

PURPOSE : The aim of this study is to identify genes related to 5-FU sensitivity for colorectal cancer and to apply these genes in prediction of 5-FU sensitivity for liver metastases. METHODS : 81 candidate genes concerning to 5-FU resistance in gastric and colon cancer cell lines had been already reported using a cDNA microarray. In this study, mRNA expression of this 81 selected genes and 5-FU-related enzymes' genes, including thymidylate synthase (TS), dihydropyrimidine dyhydrogenase (DPD) and orotate phosphoribosyltransferase (OPRT) are measured by real-time quantitative RT-PCR assays in surgically resected materials of primary colorectal tumors from 22 patients. Clinical responces were estimated by the effects of 5-FU based hepatic artery injection (HAI) chemotherapy for synchronous liver metastases. RESULTS : Four genes (TNFRSF1B, SLC35F5,NAG-1,and OPRT) showed significantly different expression between 5-FU-nonresponding and responding tumors (p<0.05). On that basis, "Response Index" system using three-genes (TNFRSF1B, SLC35F5, and OPRT) was developed by the discriminate analysis that was correlated well with individual chemosensitivity. Among the 11 cases with positive scores by our response-index, 9 achieved reduction of liver metastasis after 5-FU based chemotherapy, whereas the only 1 of the 11 cases with negative scores responded well to chemotherapy, suggesting accuracy rate of 86.3% (p=0.0019). CONCLUSIONS : Our "Response Index" system, consists of TNFRSF1B, SLC35F5, and OPRT, have great potential for predicting the efficacy of 5-FU based chemotherapy for fiver metastasis from colorectal cancer.