Mechanisms of BAP1 activity in human cancer development

项目总结 这项应用研究了基因和环境相互作用在癌症发生中的机制。 恶性间皮瘤(MM)在持续接触致癌矿物的个体中很常见 纤维，如石棉和埃里昂石，但在那些接触有限或没有接触的人中非常罕见。遗传学 影响对MM的易感性。我们最近证明，生殖系BAP1突变的携带者 增加了多种癌症类型的发病率，包括多发性骨髓瘤(我们将这种情况命名为BAP1 癌症综合症“)。在一些携带BAP1突变的家庭中，MM占50%以上 死亡，我们发现这可能是由于接触适量的MM增加了对MM的易感性 通常不会在一般人群中引起多发性硬化症的石棉量。我们还发现， 除石棉外，BAP1杂合胚系突变也增加了癌症的易感性 暴露在电离辐射和紫外线(UV)光下后的转变--这可能是 BAP1突变携带者中黑色素瘤和皮肤癌的高患病率。BAP1是第一个和 到目前为止，唯一被证明调控环境致癌的基因。机制(S) BAP1基因突变导致多发性骨髓瘤的发病机制正在被阐明。肌醇1，4，5-三磷酸(IP3)结合和 激活IP3受体(IP3Rs)。我们证明BAP1存在于内质网中。 (ER)调节IP3受体-3(IP3R3)的活性，IP3R3是控制钙离子的主要内质网通道 从内质网释放到细胞质，再释放到线粒体，调节细胞凋亡。我们发现减少了 BAP1杂合突变携带者中BAP1水平损害细胞凋亡并促进细胞转化 在暴露于石棉、红外线和紫外线后积累DNA损伤的细胞。我们还发现 杂合种系BAP1突变携带者的“正常”原代细胞从有氧中获得能量 糖酵解，被称为Warburg效应，到目前为止一直被认为是癌细胞的标志。我们 通过研究存在的代谢物，确定了与华宝效应相关的特定代谢特征 在杂合胚系BAP1突变携带者的血浆中。我们的中心假设是 钙离子浓度导致含有BAP1突变的细胞对凋亡的抵抗力增强 代谢途径的变化反过来又是癌症高发的原因。 BAP1突变携带者。为了解决这一假设，我们将检查以下具体目标： 目的1：研究BAP1基因突变引起“Warburg效应”的机制。 目的：研究在BAP1+/-细胞中，Warburg效应不依赖于HIF1α的假说。 目的3：研究BAP1在钙信号转导和代谢改变中的作用 突变导致多发性骨髓瘤的发生。 为了阐明BAP1在IP3R3上的活性以及对癌症外显性的相关影响，我们有 组建了一个携带生殖系BAP1突变的独特家族队列，并获得了独特的 来自这些家庭的志愿者的试剂。这些独特的试剂包括：原代细胞培养 来自遗传BAP1基因突变的家庭成员，以及性别和年龄- 来自相同家族的配对对照，来自生殖系BAP1突变携带者的血清和血浆 配对对照，杂合子BAP1小鼠模型和衍生细胞培养。此外，我们 组装了一组独特的杂合子BAP1和IP3R3小鼠，它们概括了人类的情况 这使我们能够研究体内BAP1突变对致癌物暴露的影响。 与该领域的一些顶尖专家Pinton博士和Giorgi博士合作，他们是钙离子方面的专家 信号和线粒体新陈代谢；以及IP3R3活性专家Mikoshiba博士，补体和 与两个MPI的专业知识协同工作。这些研究将与多种恶性肿瘤相关。 与BAP1癌症综合征相关，在BAP1突变携带者和发展为BAP1的人中 肿瘤发生过程中BAP1基因的体细胞突变。

PROJECT SUMMARY This application investigates mechanisms of gene and environment interaction in carcinogenesis. Malignant mesothelioma (MM) is frequent in individuals continuously exposed to carcinogenic mineral fibers such as asbestos and erionite, but it is very rare in those with limited or no exposure. Genetics influences susceptibility to MM. We have recently demonstrated that carriers of germline BAP1 mutations have increased incidence of multiple cancer types, including MM (we named this condition the “BAP1 cancer syndrome”). In some BAP1-mutation carrying families, MM accounts for more than 50% of deaths, and we found that this may be due to increased susceptibility to MM from exposure to modest amounts of asbestos that would normally not cause MM in the general population. We also found that heterozygous BAP1 germline mutations in addition to asbestos, also increase susceptibility to malignant transformation following exposure to Ionizing Irradiation and ultraviolet (UV) light –which may account for the high prevalence of melanomas and skin carcinomas in carriers of BAP1 mutations. BAP1 is the first and so far the only gene shown to regulate environmental carcinogenesis. The mechanism(s) by which mutated BAP1 causes MM pathogenesis are being elucidated. Inositol 1,4,5-trisphosphate (IP3) binds and activates the IP3 receptors (IP3Rs). We demonstrated that BAP1 is present in the endoplasmic reticulum (ER) where it regulates the activity of the IP3-Receptor-3 (IP3R3), the main ER channel that controls Ca2+ release from the ER to the cytoplasm to the mitochondria, regulating apoptosis. We discovered that reduced levels of BAP1 in carriers of heterozygous BAP1 mutations impair apoptosis and favor cellular transformation of cells that accumulated DNA damage following exposure to asbestos, IR and UV-light. We also discovered that “normal” primary cells of carriers of heterozygous germline BAP1 mutations derive energy from aerobic glycolysis, known as Warburg effect, which so far had been considered a hallmark of cancer cells. We identified a specific metabolic signature associated with the Warburg effect by studying the metabolites present in the plasma of carriers of heterozygous germline BAP1 mutations. Our central hypothesis is that changes in Ca2+ concentration lead to increased resistance of cells containing BAP1 mutations to apoptosis and to changes in metabolic pathways that in turn are responsible for the very high cancer penetrance observed in BAP1 mutation carriers. To address this hypothesis we will examine the following specific Aims: AIM 1: To study the mechanisms by which BAP1 mutations induce a “Warburg effect”. AIM 2: To study the hypothesis that the Warburg effect is HIF-1α-independent in BAP1+/- cells. AIM 3: To study the contributions of calcium signaling and metabolic alterations due to germline BAP1 mutations to MM development. To elucidate the activity of BAP1 on the I P 3 R 3 and the related effects on cancer penetrance, we have assembled a unique cohort of families carrying germline BAP1 mutations and have access to unique reagents derived from volunteers from these families. These unique reagents include: primary cell cultures derived from family members that inherited germline BAP1 mutations as well as from sex- and age- matched controls from the same families, sera and plasma from germline BAP1 mutation carriers and matched controls, and a heterozygous BAP1 mouse model and derived cell cultures. In addition, we assembled a unique sets of heterozygous BAP1 and IP3R3 mice that recapitulate the human condition and that allow us to study the effects of BAP1 mutations in vivo upon exposure to carcinogens. Collaborations with some of the leading experts in the field, Drs. Pinton and Giorgi, experts in Ca2+ signaling and mitochondrial metabolism; and Dr. Mikoshiba, expert in IP3R3 activities, complement and synergize with the expertise of the two MPIs. These studies will be relevant to the multiple malignancies associated with the BAP1 cancer syndrome, in both carriers of BAP1 mutations and those who develop somatic mutations of BAP1 during tumor development.