ERK PATHWAYS IN PATHOGENESIS OF MESOTHELIOMA

细胞外信号调节激酶ERK1/2和ERK5被间皮细胞中的石棉纤维激活 和呼吸道上皮细胞，并在细胞生存中发挥关键作用。依赖ERK1/2的Fra-1表达也是 与大鼠间皮细胞形态转化和基因表达相关(c-met、CD44) 刺激细胞增殖和迁移。我们假设ERK1/2和ERK5信号的激活 致癌纤维(石棉、埃里昂)在人类恶性肿瘤发病机制中的作用 间皮瘤(MM)和SV40以共同致癌的方式增强。最近令人兴奋的数据也 提示这些生存通路在接触化疗药物后在MMS中被激活 可以被操纵以实现更多的细胞杀伤力。因此，我们还假设ERK1/2和ERK5 通路单独或协同作用对化疗后MM细胞的存活起作用。在目标1中，我们将测试 青石棉和温石棉，特性良好的土耳其埃里昂石(见项目1)及其非纤维 类似物，单独和联合暴露于SV40以确定ERK1/2和ERK5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，如 由Carbone博士(Core C)开发的体外/体内模型确定。在目标2中，我们将使用一个面板 来自核心B的SV40+和-MMS来确定显性负结构和小发夹的影响 靶向ERK1/2和ERK5的(Sh)RNA干扰载体对体外细胞参数的影响 卡莫司汀(BCNU)治疗后的转化和存活。与Testa博士合作(项目 3)我们还将在这些研究中确定AKT生存途径是否被修改。在《目标3》中，一只老鼠 原位模型将用于确定SV40+和-MMS是否稳定地转导shMEKI、Sherks或 在胸膜腔内注射和注射卡莫司汀之前，这两种结构都改变了生长和 转移瘤。明确MMS发病机制中的细胞存活途径对 预防和治疗这些毁灭性的肿瘤。此计划项目允许我们以前的 啮齿动物间皮瘤模型的机制研究将在人类间皮瘤中得到验证，并提供 美国拥有病毒学和MM病理学(Carbone博士)、AKT生存途径(Testa博士)和使用方面的专业知识 正常人间皮细胞和MM细胞(Dr.Pass)。

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).