ERK PATHWAYS IN PATHOGENESIS OF MESOTHELIOMA

石棉纤维激活间皮细胞外信号调节激酶ERK 1/2和ERK 5 和气道上皮细胞，并在细胞存活中起关键作用。ERK 1/2依赖的Fra-1表达也是 与大鼠间皮细胞的形态转化和基因（c-met，cd 44）表达有因果关系 刺激细胞增殖和迁移。我们假设ERK 1/2和ERK 5信号的激活 途径发生的致癌纤维（石棉，毛沸石）在人类恶性肿瘤的发病机制 在一些实施方案中，Sv 40可抑制间皮瘤（MM）的生长，并且通过SV 40以共致癌的方式增强。最近令人兴奋的数据也 表明这些存活途径在暴露于化疗药物后的结肠中被激活， 可以被操纵以实现增加的细胞杀伤。因此，我们还假设ERK 1/2和ERK 5 这些通路单独或协同地促进化疗后MM细胞的存活。在目标1中，我们将测试 青石棉和温石棉石棉、特征良好的土耳其毛沸石（见项目1）及其非纤维性 类似物，单独和与SV 40共暴露，以确定ERK 1/2和ERK 5活性、fos/jun家族 成员，AP-1反式激活与转化模式和致癌性相关， 在Carbone博士开发的体外/体内模型中测定（核心C）。在目标2中，我们将使用面板 来自核心B的SV 40+和-SV 40-的表达，以确定显性阴性构建体和小发夹结构的作用。 (sh)靶向ERK 1/2和ERK 5的RNA干扰（RNAi）载体对体外细胞参数的影响 卡莫司汀（Carmustine，BCNU）治疗后的转化和存活率。与Testa博士合作（项目 3)我们还将确定在这些研究中AKT存活途径是否被改变。在目标3中， 原位模型将用于确定是否用shMEKI、shERKS或 在胸膜内注射和施用卡莫司汀之前，两种构建体都具有改变的生长， 转移确定细胞存活的途径在乳腺癌的发病机制是非常重要的， 预防和治疗这些毁灭性的肿瘤。该项目允许我们以前的 在啮齿动物间皮瘤模型中的机制研究将在人类间皮瘤中得到验证，并提供 我们在病毒学和MM病理学（Carbone博士），AKT生存途径（Testa博士）和使用 正常人间皮细胞和MM细胞（Pass博士）。

Extracellular signal regulated kinases, ERK1/2 and ERK5, are activated by asbestos fibers in mesothelial and airway epithelial cells and play critical roles in cell survival. ERK1/2-dependent Fra-1 expression is also linked causally to morphologic transformation of rat mesothelial cells and expression of genes (c-met, cd44) stimulating cell proliferation and migration. We hypothesize that activation of ERK1/2 and ERK5 signaling pathways occur by carcinogenic fibers (asbestos, erionite) in the pathogenesis of human malignant mesothelioma (MM) and are potentiated by SV40 in a co-carcinogenic manner. Recent exciting data also suggest that these survival pathways are activated in MMs after exposure to chemotherapeutic drugs and can be manipulated to achieve increased cell killing. Thus, we also hypothesize that ERK1/2 and ERK5 pathways contribute, alone or cooperatively, to MM cell survival after chemotherapy. In Aim 1, we will test crocidolite and chrysotile asbestos, well-characterized Turkish erionite (see Project 1), and their nonfibrous analogs, alone and with co-exposures to SV40 to determine if ERK1/2, and ERK5 activity, fos/jun family members, and AP-1 transactivation correlate with patterns of transformation and carcinogenicity as determined in the in vitro/in vivo models developed by Dr. Carbone (Core C). In Aim 2, we will use a panel of SV40+ and - MMs from Core B to determine the effects of dominant negative constructs and small hairpin (sh) RNA interference (RNAi) vectors targeting ERK1/2 and ERK5 on parameters of in vitro cell transformation and survival after treatment with Carmustine (BCNU). In collaboration with Dr. Testa (Project 3) we will also determine if the AKT survival pathway is modified in these studies. In Aim 3, a mouse orthotopic model will be used to determine if SV40+ and - MMs stably transfected with shMEKI, shERKS or both constructs before intrapleural injection and administration of Carmustine, have altered growth and metastases. Identifying the pathways of cell survival in the pathogenesis of MMs is highly significant for prevention and treatment of these devastating tumors. This Program Project allows our previous mechanistic studies in rodent mesothelioma models to be validated in human mesotheliomas and provides us with expertise on virology and MM pathology (Dr. Carbone), AKT survival pathways (Dr. Testa) and use of normal human mesothelial and MM cells (Dr. Pass).