Molecular Therapeutics of Kidney Cancer: VHL Gene and Fumarate Hydratase Gene

肾癌的分子治疗：VHL基因和富马酸水合酶基因

• 批准号: 9153752
• 负责人: William Marston Linehan
• 金额: $ 143.7万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9153752
• 关键词: Affect; American; Binding; Cancer Etiology; Cancer Model; Cell Line; Citric Acid Cycle; Clear Cell; Clinical; Clinical Trials; Complex; Conventional (Clear Cell) Renal Cell Carcinoma; Cutaneous Leiomyoma; Development; Disease; Enzymes; Family; Foundations; Fumarate Hydratase; Fumarates; Geldanamycin Analogue; Genes; Genetic Transcription; Goals; Growth; Heat-Shock Proteins 90; Hereditary Leiomyomatosis and Renal Cell Cancer; Hereditary Neoplastic Syndromes; Histology; Human; Hypoxia; Hypoxia Inducible Factor; In Vitro; Inherited; Kidney Neoplasms; Lead; Loss of Heterozygosity; Malignant Neoplasms; Mediating; Molecular; Mutate; Mutation; New Agents; Oncogenes; Papillary; Pathway interactions; Patients; Platelet-Derived Growth Factor; Process; Procollagen-Proline Dioxygenase; Proteins; Renal Cell Carcinoma; Renal carcinoma; Risk; Role; Scientist; Staining method; Stains; System; Therapeutic; Transforming Growth Factor alpha; Tumor Tissue; Ubiquitin; Urologic Oncology; Uterine Fibroids; VHL gene; VHL protein; Vascular Endothelial Growth Factors; Von Hippel-Lindau Syndrome; Work; beta catenin; cancer type; elongin B; elongin C; in vitro Model; in vivo; meetings; novel; prevent; protein complex; receptor; therapeutic target; transcription factor; tumor

Molecular Therapeutics of Kidney Cancer-VHL Gene and Fumarate Hydratase Gene Understanding the genes that cause kidney cancer provides the opportunity to develop approaches for molecular therapeutics for this disease. We have identified 3 genes that cause cancer of the kidney: the VHL gene (clear cell renal cell carcinoma); the c-Met gene (papillary type 1 renal carcinoma); and the BHD gene (chromophobe renal carcinoma). Targeting the VHL Clear Cell Kidney Cancer Gene Pathway Urologic Oncology Branch scientists are studying intensively how damage (mutation) to the VHL gene leads to the manifestations in VHL and sporadic renal carcinoma patients. Recently, it is has been shown that the VHL protein forms a complex with other proteins, including elongin C and B and the CUL-2 protein, and this complex targets the alpha subunit of hypoxia inducible factors (HIF1-alpha and HIF2-alpha) for ubiquitin-mediated degradation. This is a hypoxia-mediated process normally, i.e., under hypoxic conditions HIF is not degraded by the VHL complex. HIF is a transcription factor that regulates the transcription of a number of downstream genes important for cancer, such as VEGF, Glut 1, TGF-alpha and PDGF. When the VHL gene is mutated, in the germline of VHL patients or in tumor tissue from patients with clear cell renal carcinoma, the HIFs cannot be degraded and the result is the over-transcription of VEGF, Glut1, TGF-alpha and PDGF. One approach to evaluating the role of agents targeting the VHL pathway in VHL and clear cell renal carcinoma is to determine the activity of agents which block the VEGF and TGF-alpha/EGFr pathways in-vitro and in-vivo. Another approach for molecular therapeutics of clear cell RCC is by use of agents such as geldanamycin analogues, which disrupt the binding of HIF to HSP-90. In-vitro studies have shown that the 17AAG geldanamycin analogues can degrade HIF even in VHL -/- cell lines. In-vitro and in-vivo studies are underway in kidney cancer models that we have developed from human material to evaluate the role of agents which block this cancer gene pathway as a potential approach for the treatment of clear cell kidney cancer. Clinical trials evaluating the role of geldanamycin analogues as well as agents which target the VEGF/EGFr receptors and other parts of the VHL pathway are currently in progress. Targeting the Fumarate Hydratase Gene: Type 2 Papillary Kidney Cancer The Krebs cycle enzyme, fumarate hydratase (FH), is the gene for Hereditary Leiomyomatosis Renal Cell Carcinoma (HLRCC). HLRCC patients are at risk for the development of cutaneous and uterine leiomyomas as well as a very aggressive form of type 2 papillary kidney cancer. We have found mutations of the FH gene in the germline of 95% of our HLRCC families and loss of heterozygosity of the FH gene in HLRCC-associated kidney cancer. In order to understand how mutation of a Krebs cycle enzyme could cause kidney cancer we stained HLRCC-associated kidney tumors for the presence of hypoxia induced factor 1-alpha (HIF1-alpha) and hypoxia induced factor 2-alpha (HIF2-alpha). We found both HIF1-alpha and HIF2-alpha to be elevated in the HLRCC kidney tumors. We are developing novel in-vitro models from human tumors and evaluating growth in in-vitro and in-vivo systems. In in-vitro models we found that when fumarate hydratase was inactivated (with SiRNA), fumarate increased and the increase in fumarate inhibited prolyl hydroxylase. The inhibition of prolyl hydroxylase prevented normoxic VHL-mediated HIF degradation, providing a VHL-independent mechanism for dysregulation of HIF degradation in HLRCC kidney cancer. These studies provided the rationale for the development of a targeted therapeutic approach for the treatment of HLRCC-associated kidney cancer. In-vitro and in-vivo studies are underway to evaluate the role of agents which block this cancer gene pathway as a potential approach for the treatment of HLRCC-associated as well as sporadic type 2 papillary kidney cancer.

肾癌的分子治疗-VHL基因和富马酸水合酶基因了解导致肾癌的基因提供了发展这种疾病的分子治疗方法的机会。我们已经确定了3种导致肾癌的基因：VHL基因（透明细胞肾细胞癌）; c-Met基因（乳头状1型肾癌）;和BHD基因（嫌色细胞肾癌）。针对VHL透明细胞肾癌基因通路泌尿肿瘤分支科学家正在深入研究VHL基因的损伤（突变）如何导致VHL和散发性肾癌患者的表现。最近，已经显示VHL蛋白与其他蛋白质（包括延伸蛋白C和B以及CUL-2蛋白）形成复合物，并且该复合物靶向缺氧诱导因子（HIF 1-α和HIF 2-α）的α亚基，用于泛素介导的降解。这是一个缺氧介导的过程，通常，即，在低氧条件下，HIF不被VHL复合物降解。HIF是一种转录因子，调节许多对癌症重要的下游基因的转录，如VEGF、Glut 1、TGF-α和PDGF。当VHL基因突变时，在VHL患者的生殖系中或在来自透明细胞肾癌患者的肿瘤组织中，HIF不能被降解，结果是VEGF、Glut 1、TGF-α和PDGF的过度转录。评价靶向VHL途径的药剂在VHL和透明细胞肾癌中的作用的一种方法是测定体外和体内阻断VEGF和TGF-α/EGFr途径的药剂的活性。透明细胞RCC的分子治疗的另一种方法是通过使用诸如格尔德霉素类似物的试剂，其破坏HIF与HSP-90的结合。体外研究表明，17 AAG格尔德霉素类似物甚至可以在VHL -/-细胞系中降解HIF。我们正在从人体材料开发的肾癌模型中进行体外和体内研究，以评估阻断这种癌症基因通路的药物作为治疗透明细胞肾癌的潜在方法的作用。评价格尔德霉素类似物以及靶向VEGF/EGFr受体和VHL途径其他部分的药物作用的临床试验目前正在进行中。针对富马酸水合酶基因：2型乳头状肾癌克雷布斯循环酶，富马酸水合酶（FH），是遗传性平滑肌瘤病肾细胞癌（HLRCC）的基因。HLRCC患者有发生皮肤和子宫平滑肌瘤以及非常侵袭性的2型乳头状肾癌的风险。我们发现95%的HLRCC家系的种系中存在FH基因突变，HLRCC相关肾癌中FH基因杂合性缺失。为了了解克雷布斯循环酶突变如何导致肾癌，我们对HLRCC相关的肾肿瘤进行了缺氧诱导因子1-α（HIF 1-α）和缺氧诱导因子2-α（HIF 2-α）染色。我们发现HIF 1-α和HIF 2-α在HLRCC肾肿瘤中升高。我们正在开发新的人类肿瘤体外模型，并评估体外和体内系统的生长。在体外模型中，我们发现当富马酸水合酶被灭活（用SiRNA）时，富马酸增加，富马酸的增加抑制脯氨酰羟化酶。脯氨酰羟化酶的抑制阻止了常氧VHL介导的HIF降解，为HLRCC肾癌中HIF降解的失调提供了VHL非依赖性机制。这些研究为开发治疗HLRCC相关肾癌的靶向治疗方法提供了依据。体外和体内研究正在进行中，以评估阻断这种癌症基因通路的药物作为治疗HLRCC相关以及散发性2型乳头状肾癌的潜在方法的作用。