ACIDIFICATION OF HUMAN MELANOMA XENOGRAFTS

高血压使可移植啮齿动物肿瘤的pH降低0.1 - 0.4 pH单位。人类肿瘤平均被酸化0.17个pH单位。 0.2单位的细胞外酸化不太可能致敏人类 因为平均pHe为7.15。这个目标 研究是显着酸化肿瘤的目的， 体温过高待检验的假设是高血糖诱导的 人黑素瘤异种移植物的酸化可以通过抑制 或通过抑制膜质子泵， 提高治疗增益。抑制呼吸将使葡萄糖 代谢向糖酵解和乳酸的产生，和 抑制膜质子泵。抑制呼吸将 使葡萄糖代谢转向糖酵解和乳酸的产生 艺术，并抑制膜蛋白泵送机制将允许 细胞外氢离子的流入。在这些研究中， 将在高血糖期间被间碘苄基胍（MIBG）抑制， 并且膜质子泵在高血糖期间将被抑制， Cariporide甲磺酸盐（Hoechst HOE 642抑制Na+/H+交换剂，NHE 1） 和DIDS（抑制Cl-HCO 3交换剂）。假设将被检验 在F2人类黑素瘤异种移植物中。通过使用侵入性和非侵入性 我们将确定MRS技术：1。肿瘤生长的治疗增益 与骨髓增殖潜能（CFU-GM）相比延迟; 2.肿瘤 与正常组织（脑肌肉）细胞内和细胞外相比 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.肿瘤血管关系 分布和葡萄糖分布; 6.肿瘤pO 2分布和7. 肿瘤Glut-1、己糖激酶活性和呼吸速率。高血糖 将通过对SCID小鼠口服或静脉注射葡萄糖诱导 直径为8-10 mm的黑素瘤，选自我们的黑素瘤冷冻肿瘤 以代谢参数为基础建立银行。MIBG或HOE 642和/或DIDS将 在血糖浓度达到峰值时腹膜内给药 随后进行热疗（通过腿部浸泡在42摄氏度下1小时）。 MRS将由宾夕法尼亚大学的Jerry Glickson博士执行。 将向项目1、2和3提供移植的肿瘤细胞。动力学 黑色素瘤细胞在低pH值下生长的适应性以及 将在培养物中测定高热反应。体外 人类黑色素瘤的特征将提供关键信息， 为项目1、2和3提供一个蜂窝基础， 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 阶段设计和实施所需的临床前数据 I/II临床试验，以急性酸化人类肿瘤与 疗法

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.