CPT11 activation by carboxylesterases in colon cancer

结肠癌中羧酸酯酶激活 CPT11

• 批准号: 6420482
• 负责人: WILLIAM F BOSRON
• 金额: $ 14.41万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-15 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6420482
• 关键词: carboxylic ester hydrolases; clinical research; colon; colon neoplasms; drug metabolism; enzyme activity; gastrointestinal epithelium; gastrointestinal pharmacology; human subject; irinotecan; neoplasm /cancer pharmacology; northern blottings; polymerase chain reaction; western blottings

This is a R21 developmental grant application in response to NCI PA- 01-010, "Exploratory studies in cancer detection, prognosis and prediction." The overall goal is to produce a CPT-11 (Irinotecan) carboxylesterase assay that could be used to predict treatment outcome and/or toxicity for patients on CPT-11 therapy for colorectal cancer. CPT-11 is a semi-synthetic pro-drug that is activated by hydrolysis in vivo to SN-38. SN-38 is a potent inhibitor of topoisomerase I and therapy inhibits cell growth. Another important metabolite called APC is also hydrolyzed to SN-38. The specific carboxylesterases responsible for the hydrolytic activation of CPT-11 and APC to SN-38 are not known. Two human carboxylesterases, hCE-1 and hCE-2 is highly expressed in intestine, which may be related to the major toxic complication of CPT- 11 therapy, diarrhea. Our hypothesis is that the tissue and cell-specific expression of CPT-1 and APC carboxylesterases may be an important determinant of the therapeutic outcome and toxicity associated with the APC carboxylesterases. Analysis of carboxylesterase-like genes in GenBank and preliminary observations in tumor cell lines suggest that there may be other carboxylesterases that could catalyze the hydrolysis of CPT-11 and APC. Proteomics and PCR methodologies will be used to screen for carboxylesterases and kinetic analysis with CPT-11 and APC as substrates will be performed with isolated or expressed enzymes. The second scientific aim of the grant is to develop and validate assays employing activity assays, gel electrophoresis or PCR methodologies for analysis of CPT-11 carboxylesterase expression in tumor and normal colon tissue from patients treated with CPT-11. A pilot study will be performed with tumor and normal tissue collected from patients at the Indiana University Cancer Center who presented with metastatic disease at diagnosis. After surgery the patients will be treated with 5- fluorouracil, Leucovorin and CPT-11. The response to CPT-11 therapy and associated toxicity will be compared to carboxylesterase expression in tumor and normal colon tissue. If there is a positive correlation, a future multi-institutional study will be proposed.

这是对NCI PA-01010的R21发育授予应用，“癌症检测，预后和预测的探索性研究”。总体目标是生产CPT-11（Irinotecan）羧酸酯酶测定法，可用于预测CPT-11治疗的结直肠癌治疗患者的治疗结果和/或毒性。 CPT-11是一种半合成促毒物，在体内水解至SN-38中被激活。 SN-38是拓扑异构酶I和治疗的有效抑制剂，可抑制细胞生长。另一个称为APC的重要代谢物也被水解为SN-38。尚不清楚负责CPT-11和APC对CPT-11和APC水解激活的特定羧酸酯酶。 HCE-1和HCE-2的两个人类羧酸酯酶在肠中高度表达，这可能与CPT-11治疗，腹泻的主要有毒并发症有关。我们的假设是，CPT-1和APC羧酸酯酶的组织和细胞特异性表达可能是与APC羧酸酯酶相关的治疗结果和毒性的重要决定因素。分析GenBank中的羧酸酯酶样基因和肿瘤细胞系中的初步观察结果表明，可能还有其他羧酸酯酶可以催化CPT-11和APC的水解。蛋白质组学和PCR方法将用于筛查羧酸酯酶的羧基酯酶，并用CPT-11和APC作为底物进行动力学分析，将使用分离或表达的酶进行。该赠款的第二个科学目的是开发和验证采用活动测定，凝胶电泳或PCR方法的测定法，以分析接受CPT-11患者的肿瘤和正常结肠组织中CPT-11的羧酸酯酶表达。将对印第安纳大学癌症中心的患者收集的肿瘤和正常组织进行试点研究，该中心出现了诊断时发生转移性疾病的情况。手术后，将用5-氟尿嘧啶，白细胞和CPT-11治疗患者。将CPT-11治疗和相关毒性的反应与肿瘤和正常结肠组织中的羧酸酯酶表达进行比较。如果存在正相关，将提出未来的多机构研究。