ACIDIFICATION OF HUMAN MELANOMA XENOGRAFTS

人类黑色素瘤异种移植物的酸化

基本信息

批准号：
6102771
负责人：
DENNIS B. LEEPER
金额：
$ 18.41万
依托单位：
THOMAS JEFFERSON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-03-01 至 2000-01-31
项目状态：
已结题

项目摘要

Hyperglycemia reduces the pHe of transplantable rodent tumors by 0.1 - 0.4 pH unit. Human tumors are acidified by an average of 0.17 pH unit. Extracellular acidification of 0.2 unit is unlikely to sensitize human tumors to hyperthermia since the average pHe is 7.15. The goal of this research is to significantly acidify tumors for the purpose of hyperthermia. The hypothesis to be tested is that hyperglycemia-induced acidification of human melanoma xenografts can be increased by inhibition of mitochondrial respiration or by inhibition of membrane proton pumps to enhance the therapeutic gain. Inhibition of respiration will shift glucose metabolism toward glycolysis and the production of lactic acid, and inhibition of the membrane proton pumping. Inhibition of respiration will shift glucose metabolism toward glycolysis and the production of lactic art, and inhibition of the membrane protein pumping mechanism will allow the inflow of extracellular hydrogen ions. In these studies respiration will be inhibited during hyperglycemia with meta-iodobenzylguanide (MIBG), and membrane proton pumps will be inhibited during hyperglycemia by Cariporide mesilate (Hoechst HOE642 to inhibit the Na+/H+ exchanger, NHE1) and DIDS (to inhibit the Cl-HCO3-exchanger). The hypothesis will be tested in F2 human melanoma xenografts. By using both invasive and non-invasive MRS techniques we will determine: 1. Therapeutic gain by tumor growth delay compared to bone marrow proliferative potential (CFU-GM); 2. Tumor versus normal tissue (brain muscle) intracellular and extracellular acidification; 3. Tumor and normal tissue lactic acid levels; 4. Tumor and normal tissue blood flow; 5. Relationship of tumor vasculature distribution and glucose distribution; 6. Tumor pO2 distribution and 7. Tumor Glut-1, hexokinase activity and rate of respiration. Hyperglycemia will be induced by oral or i.v. glucose administration to SCID mice bearing 8-10 mm diameter melanomas selected from our melanoma frozen tumor bank on the basic of metabolic parameters. MIBG or HOE642 and/or DIDS will be administered i.p. at the time of peak blood glucose concentration followed by hyperthermia (1 hour at 42 degrees Celsius by leg immersion). MRS will be performed by Dr. Jerry Glickson, University of Pennsylvania. Explanted tumor cells will be provided to Projects 1, 2 & 3. The kinetics of adaptation of melanoma cells to growth at low pHe and the effect of hyperthermia response will be determined in culture. The in vitro characterization of the human melanomas will provide critical information for Projects 1, 2 & 3 and will provide a cellular basis for the hyperthermia response of xenografts. Furthermore, in vivo results will validate findings from Projects 1, 2, & 3. These results will provide the preclinical data required for the design and implementation of a phase I/II clinical trial to acutely acidify human tumors in association with therapy.

高血糖将可移植啮齿动物肿瘤的PHE降低0.1-0.4 pH单元。人类肿瘤平均为0.17 pH单位。 0.2单位的细胞外酸化不太可能使人类敏感由于平均PHE为7.15，因此肿瘤到热疗。目标的目标研究是为了使肿瘤显着酸化热疗。要检验的假设是高血糖诱导的人黑色素瘤异种移植的酸化可以通过抑制增加线粒体呼吸或通过抑制膜质子泵至增强治疗性增长。抑制呼吸会改变葡萄糖糖酵解和乳酸的产生的代谢，抑制膜质子泵送。抑制呼吸将葡萄糖代谢转向糖酵解和乳酸产生艺术和抑制膜蛋白泵送机制将允许细胞外氢离子的流入。在这些研究呼吸中在高血糖期间，将被抑制使用元二苯甲酰胺（MIBG），在高血糖期间，膜质子泵将被抑制 Cariporide中甲酸（Hoechst Hoe642抑制Na+/H+交换器，NHE1）并涂DIDS（抑制Cl-HCO3-exchanger）。该假设将进行检验在F2人黑色素瘤异种移植物中。通过使用侵入性和非侵入性 MRS技术我们将确定：1。肿瘤生长的治疗增益与骨髓增殖潜力（CFU-GM）相比延迟； 2。肿瘤与正常组织（脑部肌肉）细胞内和细胞外酸化; 3。肿瘤和正常组织乳酸水平； 4。肿瘤和正常组织血流； 5。肿瘤脉管系统的关系分布和葡萄糖分布； 6。肿瘤PO2分布和7。肿瘤GLUT-1，己糖激酶活性和呼吸速率。高血糖将由口服或i.v.诱导葡萄糖给予SCID小鼠从我们的黑色素瘤冷冻肿瘤中选择的轴承直径为8-10毫米基于代谢参数的基本。 MIBG或HOE642和/或DIDS 被授予i.p.在峰值血糖浓度时其次是热疗（在42摄氏度时通过腿部浸入1小时）。夫人将由宾夕法尼亚大学杰里·格里克森（Jerry Glickson）博士进行。将提供给植物的肿瘤细胞向1、2和3。动力学黑色素瘤细胞对低PHE生长的适应和高温反应将在培养中确定。体外人类黑色素瘤的特征将提供关键信息对于项目1、2和3，将为异种移植物的高温反应。此外，体内结果将验证项目1、2和3的发现。这些结果将提供设计和实施阶段所需的临床前数据 I/II临床试验，急性酸化人类肿瘤治疗。