Mechanisms of BAP1 activity in human cancer development

项目摘要 本申请研究了致癌作用中基因和环境相互作用的机制。 恶性间皮瘤（MM）是经常在个人不断暴露于致癌矿物 纤维，如石棉和毛沸石，但它是非常罕见的，在那些有限或没有接触。遗传学 影响对MM的易感性。我们最近证明，生殖系BAP 1突变的携带者 多种癌症类型的发病率增加，包括MM（我们将这种情况命名为“BAP 1 癌症综合征”）。在一些携带BAP 1突变的家庭中，MM占50%以上。 死亡，我们发现这可能是由于暴露于适度的 在一般人群中通常不会引起MM的石棉量。我们还发现 除了石棉外，杂合BAP 1种系突变也增加了对恶性肿瘤易感性， 暴露于电离辐射和紫外线（UV）光后的转化-这可能是 BAP 1突变携带者中黑色素瘤和皮肤癌的高患病率。BAP 1是第一个， 到目前为止，唯一的基因被证明是调节环境致癌作用的。机制， 突变的BAP 1导致MM发病机制正在阐明。肌醇1，4，5-三磷酸（IP 3）结合， 激活IP 3受体（IP 3R）。我们证明BAP 1存在于内质网中， (ER)其中它调节IP 3-受体-3（IP 3R 3）的活性，IP 3R 3是控制Ca 2+的主要ER通道 从ER释放到细胞质到线粒体，调节细胞凋亡。我们发现， 杂合BAP 1突变携带者的BAP 1水平损害细胞凋亡并有利于细胞转化 在暴露于石棉、红外线和紫外线后，细胞积累了DNA损伤。我们还发现 杂合子生殖系BAP 1突变携带者的“正常”原代细胞从有氧代谢中获得能量， 糖酵解，称为瓦尔堡效应，迄今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，我确定了与瓦尔堡效应相关的特定代谢特征 在杂合子生殖系BAP 1突变携带者的血浆中。我们的中心假设是， Ca 2+浓度导致含有BAP 1突变的细胞对细胞凋亡的抗性增加， 代谢途径的变化，这反过来又是导致在癌症中观察到的非常高的癌症转移率的原因。 BAP 1突变携带者。为了解决这一假设，我们将研究以下具体目标： 目的1：研究BAP 1基因突变引起“瓦尔堡效应”的机制。 目的2：探讨BAP 1 +/-细胞中瓦尔堡效应不依赖于HIF-1α的假说。 目的3：研究胚系BAP 1在钙信号转导和代谢改变中的作用 突变导致MM发展。 为了阐明BAP 1对I P 3 R 3的活性及其对癌症转移的相关作用，我们 我们收集了一组携带生殖系BAP 1突变的独特家族， 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 来源于遗传生殖系BAP 1突变的家庭成员以及性别和年龄， 来自相同家族的匹配对照，来自生殖系BAP 1突变携带者的血清和血浆， 匹配的对照，以及杂合BAP 1小鼠模型和衍生的细胞培养物。另外我们 组装了一组独特的杂合BAP 1和IP 3R 3小鼠，重现了人类的状况 这使我们能够研究BAP 1突变在体内暴露于致癌物后的影响。 与该领域的一些领先专家合作，Pinton博士和Giorgi博士，Ca 2+专家 信号和线粒体代谢;和Mikoshiba博士，IP 3R 3活动专家，补充和 与两个MPI的专业知识协同增效。这些研究将与多种恶性肿瘤相关 与BAP 1癌症综合征相关，在BAP 1突变携带者和那些 肿瘤发生过程中BAP 1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.