Molecular Therapeutics of Kidney Cancer: MET Gene and BHD Gene

肾癌的分子治疗：MET基因和BHD基因

• 批准号: 7965987
• 负责人: William Marston Linehan
• 金额: $ 139.43万
• 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/7965987
• 关键词: Affect; American; Animal Model; Animals; Area; Binding; Cancer Etiology; Cancer cell line; Cell Surface Receptors; Cells; Clear Cell; Clinical; Code; Cutaneous; Cyst; Cystic kidney; Cytoplasm; Development; Disease; Evaluation; Family; Folliculin; Foundations; Genes; Germ-Line Mutation; Growth Factor; Hepatocyte Growth Factor; Hereditary Neoplastic Syndromes; Hereditary Papillary Renal Carcinoma; Histology; Human; Hybrids; Hyperplasia; In Vitro; Inherited; Kidney; Kidney Neoplasms; Knockout Mice; Lead; Loss of Heterozygosity; Lung; MET Gene Mutation; MET gene; Modeling; Molecular; Mus; Mutation; New Agents; Nonsense Mutation; Oncogenes; Papillary; Pathway interactions; Patients; Phenotype; Phosphorylation; Protein Binding; Proteins; Renal Cell Carcinoma; Renal carcinoma; Risk; Role; Sampling; Sirolimus; Somatic Mutation; Specimen; Syndrome; Testing; Therapeutic; Tissues; Tumor Suppressor Genes; Tumor Suppressor Proteins; Tyrosine Kinase Domain; VHL gene; Work; base; cancer type; in vitro Model; in vivo; kindred; loss of function; meetings; novel; receptor; therapeutic target; tumor

Molecular Therapeutics of Kidney Cancer-MET Gene and BHD 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 MET Gene: Type 1 Papillary Kidney Cancer We have found activating mutations of the MET gene in the germline of patients with Hereditary Papillary Renal Cell Carcinoma (HPRC) as well as in a subset of tumors from patients with sporadic, type 1 papillary kidney cnacer Studies are underway to target the c-Met type 1 papillary kidney cancer gene pathway in papillary kidney cancer. The Met gene codes for a cell surface receptor for a systemically circulating growth factor, hepatocyte growth factor (HGF). The germline mutations identified in the HPRC kindreds and somatic mutations of the c-Met oncogene in sporadic type 1 papillary renal carcinoma are located in the tyrosine kinase domain of the MET gene and are predicted to activate this receptor. 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 type 1 papillary renal carcinoma. Targeting the BHD Gene: Chromophobe Kidney Cancer The BHD gene is the gene for the inherited form of chromophobe kidney cancer associated with Birt-Hogg-Dub syndrome. When we found the BHD gene it was a novel gene with no known function. Studies are currently underway to determine what type cancer gene the BHD gene, how it functions normally and how damage to this gene leads to chromophobe renal carcinoma. We have identified mutations of the BHD gene in 94% of the BHD families tested. In order to determine what type of gene the BHD gene is we searched for mutation of the second copy of the gene in kidney tumor specimens from BHD patients. We found mutation (or loss of heterozygosity) of the second copy (the wild type copy) of the BHD gene in 70% of the tumor samples evaluated. These findings provided the evidence that the BHD gene is a loss of function, tumor suppressor gene. When we found the BHD gene it was a novel gene with unknown function. In order to determine what the function of the BHD gene is we performed studies to determine which proteins bind to the BHD protein (called folliculin). We found that folliculin binds to a novel protein, called FNIP1 (folliculin interacting protein) that FNIP1 binds to AMPK, which is the cells main energy sensing protein. AMPK phosphorylates both FNIP1 and AMPK and FNIP phosphorylate folliculin. AMPK inhibits the function of MTOR through the TS pathway. We found that MTOR phosphorylates folliculin and that this phosphorylation is inhibited in-vitro by treatment with rapamycin. We have subsequently found that folliculin binds to a second protein, FNIP2, which also binds AMPK and which is also phosphorylated by AMPK and that AMPK/FNIP2 phosphorylate folliculin. Folliculin and FNIP1 and FNIP2 co-localize in the cytoplasm and the binding of folliculin to FNIP1 and FNIP2 is in the carboxy terminus of the protein. The finding that the germline BHD mutations are predominantly mutations that are predicted to truncate the protein (frameshift or nonsense mutations) suggests that folliculin binding to FNIP1/FNIP2 is critical to folliculins tumor suppressor function. In order to develop a BHD animal model to further understand the effect of mutation of the BHD gene and to provide a model for evaluation of targeted therapeutics we developed a kidney specific BHD knockout mouse. In this model BHD -/- mice developed large cystic kidneys with areas of hyperplastic tissues. These animals develop renal insufficience and survive for only 30 days. In order to evaluate the effect of a targeted therapeutic approach for the BHD gene pathway the BHD -/- animals were treated with rapamycin. The rapamycin treated animals had a significant diminution in the kidney phenotype and their survival was doubled. We have developed a unique in-vitro model of a human kidney cancer cell line from a BHD patient and are evaluating multiple agents with target the BHD pathway in our in-vivo and in-vitro models. These studies provide the basis for the development of a targeted therapeutic approach for BHD-associated kidney cancer and for a subset of patients with sporadic, non-inherited chromophobe kidney cancer.

肾癌的分子治疗-MET 基因和 BHD 基因 了解导致肾癌的基因为开发该疾病的分子治疗方法提供了机会。我们已经鉴定出 3 种导致肾癌的基因：VHL 基因（透明细胞肾细胞癌）； c-Met 基因（1 型乳头状肾癌）； 和 BHD 基因（嫌色肾癌）。靶向 MET 基因：1 型乳头状肾癌 我们在遗传性乳头状肾细胞癌 (HPRC) 患者的种系以及散发性 1 型乳头状肾患者的肿瘤子集中发现了 MET 基因的激活突变cnacer 正在进行针对乳头状肾癌中的 c-Met 1 型乳头状肾癌基因通路的研究。 Met 基因编码系统循环生长因子、肝细胞生长因子 (HGF) 的细胞表面受体。在 HPRC 家族中发现的种系突变和散发性 1 型乳头状肾癌中 c-Met 癌基因的体细胞突变位于 MET 基因的酪氨酸激酶结构域中，预计会激活该受体。 体外和体内研究正在进行中，以评估阻断该癌症基因通路的药物的作用，作为治疗 1 型乳头状肾癌的潜在方法。靶向 BHD 基因：嫌色肾癌 BHD 基因是与 Birt-Hogg-Dub 综合征相关的遗传性嫌色肾癌的基因。当我们发现 BHD 基因时，它是一个未知功能的新基因。目前正在进行研究以确定 BHD 基因是什么类型的癌症基因、它如何正常发挥作用以及该基因的损伤如何导致嫌色肾癌。我们已经在 94% 的测试 BHD 家族中发现了 BHD 基因突变。为了确定 BHD 基因是什么类型的基因，我们在 BHD 患者的肾肿瘤标本中寻找该基因第二个拷贝的突变。我们在 70% 的评估肿瘤样本中发现 BHD 基因的第二个拷贝（野生型拷贝）发生突变（或杂合性缺失）。这些发现提供了BHD基因是一种功能丧失的抑癌基因的证据。当我们发现BHD基因时，它是一个功能未知的新基因。为了确定 BHD 基因的功能是什么，我们进行了研究以确定哪些蛋白质与 BHD 蛋白质（称为卵泡素）结合。我们发现卵泡素与一种称为 FNIP1（卵泡素相互作用蛋白）的新型蛋白质结合，FNIP1 与 AMPK 结合，AMPK 是细胞主要的能量感应蛋白。 AMPK 磷酸化 FNIP1 和 AMPK，FNIP 磷酸化卵泡素。 AMPK 通过 TS 途径抑制 MTOR 的功能。我们发现 MTOR 磷酸化卵泡素，并且这种磷酸化在体外通过雷帕霉素处理被抑制。我们随后发现，卵泡素与第二种蛋白质 FNIP2 结合，FNIP2 也与 AMPK 结合，并且也被 AMPK 磷酸化，并且 AMPK/FNIP2 磷酸化卵泡素。滤泡素与 FNIP1 和 FNIP2 共定位于细胞质中，并且滤泡素与 FNIP1 和 FNIP2 的结合位于蛋白质的羧基末端。种系 BHD 突变主要是预计会截短蛋白质的突变（移码或无义突变）这一发现表明，卵泡素与 FNIP1/FNIP2 的结合对于卵泡素肿瘤抑制功能至关重要。为了开发BHD动物模型以进一步了解BHD基因突变的影响并为评估靶向治疗提供模型，我们开发了肾脏特异性BHD敲除小鼠。在该模型中，BHD -/- 小鼠发育出带有增生组织区域的大囊性肾脏。这些动物出现肾功能不全，只能存活 30 天。为了评估针对 BHD 基因途径的靶向治疗方法的效果，用雷帕霉素治疗 BHD -/- 动物。雷帕霉素治疗的动物的肾脏表型显着减少，并且它们的存活率增加了一倍。我们开发了一种独特的来自 BHD 患者的人肾癌细胞系体外模型，并正在我们的体内和体外模型中评估多种针对 BHD 途径的药物。这些研究为 BHD 相关肾癌和部分散发性非遗传性嫌色肾癌患者的靶向治疗方法的开发奠定了基础。