Molecular Mechanisms of Renal Cancer

肾癌的分子机制

• 批准号: 8611902
• 负责人: Maria F Czyzyk-Krzeska
• 金额: $ 28.34万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8611902
• 关键词: Affect; Antithymoglobulin; Autophagocytosis; Autophagosome; Body part; Calcium; Cations; Cell Death; Cell Survival; Cell membrane; Cells; Clear Cell; Clinical; Conventional (Clear Cell) Renal Cell Carcinoma; Data; Disease; Gene Expression; Genes; Growth; Health; Human; Hypoxia; Hypoxia Inducible Factor; Introns; Kidney; Lead; Light; Lysosomes; Malignant - descriptor; Malignant Epithelial Cell; Malignant Neoplasms; Mediating; Membrane; Messenger RNA; Methods; MicroRNAs; Microtubule-Associated Proteins; Modeling; Molecular; Neoplasm Metastasis; Nutrient; Oncogenes; Oncogenic; Organelles; Orthologous Gene; Pathway interactions; Phosphotransferases; Play; Process; Proteins; Publishing; Recycling; Regulation; Renal Cell Carcinoma; Renal carcinoma; Reporter; Repression; Resources; Role; Secure; Site; Source; TRP channel; Testing; Therapeutic; Tumor Suppressor Genes; Ubiquitin; Untranslated Regions; Von Hippel-Lindau Tumor Suppressor Protein; Work; Xenograft procedure; angiogenesis; cancer cell; extracellular; genetic manipulation; interest; knock-down; novel; overexpression; paralogous gene; prevent; programs; promoter; receptor; small molecule; therapeutic target; transcription factor; tumor; tumor growth; tumorigenesis

DESCRIPTION (provided by applicant): Clear-cell renal cell carcinoma (ccRCC) is the most prevalent and malignant histological type of kidney cancer, for which there are no effective methods of treatment for metastatic disease. ccRCC is characterized by early loss of the von Hippel-Lindau tumor-suppressor gene (VHL) in a majority (60%-80%) of tumors. One major oncogenic effect of VHL loss is the induction of hypoxia-inducible factor (HIF) and HIF-regulated genes leading to angiogenesis, which supports tumor growth by providing nutrients from extracellular sources. In our previous work, we discovered that loss of VHL regulates pathways that secure nutrients from intracellular sources through autophagy: VHL, by inducing expression of miR-204, targets the autophagic regulator, LC3B, and inhibits oncogenic autophagy. By inhibiting HIF, VHL induces expression of LC3C, an LC3B ortholog, which has tumor suppressive activity. This proposal is focused on the TRPM3 channel (transient receptor potential M3 Ca2+-permeable, nonselective cation channel), which is the protein product of the host gene that encodes miR-204 in its intron 6. We discovered that TRPM3 plays a pro-oncogenic role in ccRCC. TRPM3 is overexpressed in ccRCC and regulates two autophagic pathways; it is necessary for LC3B/LC3A autophagy and inhibits LC3C-mediated autophagy. In contrast to miR-204, TRPM3 is repressed by VHL at the level of protein accumulation. Our hypothesis is that the effects of TRPM3 on autophagic programs play an essential role in its ability to promote RCC tumor growth, and that the effects of TRPM3 on autophagic programs are mediated through regulation of intracellular calcium. In Aim 1, we will investigate the molecular mechanism by which VHL represses TRPM3, with the leading hypothesis that VHL-induced miR-204 targets and represses expression of its host gene product. In Aim 2, by manipulating expression of different autophagic regulators affected by TRPM3, we will identify the autophagic pathways essential for the oncogenic activity of TRPM3. In Aim 3 we will manipulate extracellular and intracellular Ca2+ and Ca2+-regulated kinases implicated in the regulation of autophagy and determine the effects on autophagy in cells that are VHL(-) or VHL(-) with TRPM3 knocked down. In Aim 4 we will study the mechanisms of transcriptional induction of LC3C in cells with knockdown of TRPM3. With this proposal, we expect to further establish VHL as a major regulator of autophagy.

描述（由申请人提供）：透明细胞肾细胞癌（ccRCC）是最常见和最恶性的肾癌组织学类型，目前尚无有效的转移性疾病治疗方法。ccRCC的特征是大多数（60%-80%）肿瘤中von Hippel-Lindau肿瘤抑制基因（VHL）的早期丢失。VHL损失的一个主要致癌作用是诱导缺氧诱导因子（HIF）和HIF调节的基因，导致血管生成，其通过从细胞外来源提供营养来支持肿瘤生长。在我们以前的工作中，我们发现VHL的丢失调节通过自噬从细胞内来源获得营养的途径：VHL通过诱导miR-204的表达，靶向自噬调节因子LC 3B，并抑制致癌性自噬。通过抑制HIF，VHL诱导具有肿瘤抑制活性的LC 3B直系同源物LC 3C的表达。该提议集中于TRPM 3通道（瞬时受体电位M3 Ca 2+渗透性非选择性阳离子通道），其是在其内含子6中编码miR-204的宿主基因的蛋白质产物。我们发现TRPM 3在ccRCC中起促癌作用。TRPM 3在ccRCC中过表达，并调节两种自噬途径;它是LC 3B/LC 3A自噬所必需的，并抑制LC 3C介导的自噬。与miR-204相反，TRPM 3在蛋白质积累水平上被VHL抑制。我们的假设是TRPM 3对自噬程序的影响在其促进RCC肿瘤生长的能力中起着至关重要的作用，并且TRPM 3对自噬程序的影响是通过调节细胞内钙来介导的。在目标1中，我们将研究VHL抑制TRPM 3的分子机制，主要假设VHL诱导的miR-204靶向并抑制其宿主基因产物的表达。在目标2中，通过操纵受TRPM 3影响的不同自噬调节因子的表达，我们将鉴定TRPM 3致癌活性所必需的自噬途径。在目标3中，我们将操纵细胞外和细胞内Ca 2+和Ca 2+调节的激酶参与自噬的调节，并确定对VHL（-）或TRPM 3敲低的VHL（-）细胞中自噬的影响。在目的4中，我们将研究TRPM 3敲低的细胞中LC 3C的转录诱导机制。有了这个提议，我们希望进一步建立VHL作为自噬的主要调节因子。