Role of Cell Mediators in Asbestos-SV40 Carcinogenesis

细胞介质在石棉-SV40 致癌作用中的作用

• 批准号: 7367222
• 负责人: MICHELE CARBONE
• 金额: $ 26.3万
• 依托单位: UNIVERSITY OF HAWAII AT MANOA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-08 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7367222
• 关键词: Antigens; Applications Grants; Asbestos; Biological; Biopsy; Candidate Disease Gene; Carcinogens; Cells; Collection; Crocidolite Asbestos; Cytokine Gene; Cytokine Receptors; Data; Exposure to; Freezing; Future; Hamsters; Human; In Vitro; Individual; Infection; Inflammatory; Knockout Mice; Knowledge; Lung; Malignant - descriptor; Malignant Mesothelial Cell; Malignant Neoplasms; Malignant mesothelioma; Mediator of activation protein; Mesothelial Cell; Mesothelioma; Mineral Fibers; Modeling; Mus; Numbers; Pathogenesis; Pathway interactions; Patients; Platelet-Derived Growth Factor; Play; Preventive; Reagent; Risk; Role; Sampling; Signal Pathway; Simian virus 40; Specimen; Structure of parenchyma of lung; Testing; Therapeutic; Transcription Factor AP-1; Transforming Growth Factor beta; Transgenic Organisms; Tumor Necrosis Factor-alpha; Virus; base; carcinogenesis; cytokine; design; human TNF protein; in vivo; mouse model; mutant; novel; receptor expression; research study; tissue culture; tumor; tumorigenesis

DESCRIPTION (provided by applicant): Our hypothesis is that asbestos and SV40 are co-carcinogens in causing malignant mesothelioma (MM). This hypothesis is based on in vitro experiments using human mesothelial cells (HM) and in vivo experiments in hamsters. We found that neither asbestos nor SV40 small t antigen mutants could cause HM malignant transformation. However, when HM were exposed to both asbestos and SV40 small t mutants, malignant transformation and focus formation occurred. Moreover, preliminary results demonstrated a potent co-carcinogenic effect in hamsters coinjected with SV40 small t mutant intracardially and with asbestos intrapleurally and intraperitoneally. Our findings suggest that individuals exposed to both asbestos and SV40 are at increased risk of developing mesothelioma. Here we want to study the mechanisms of co-carcinogenesis. We propose to conduct these studies in human and in hamster mesothelial cells in tissue culture, and in hamster and human mesothelioma biopsies. In Aim 1 we will determine the biological effect of TNF-alpha, PDGF and TGF- beta in SV40-asbestos co-carcinogenesis in HM in tissue culture. In preliminary results we found that our mesothelial cells express receptors for these cytokines. We also found that TNF-alpha expression and receptor are induced in HM following asbestos exposure or SV40 infection. HM exposure to TNF-alpha induced NF-kbeta activation which plays an important role in oncogenesis. In parallel we are studying the effect of SV40 and asbestos on the Ras-ERK pathways and AP-1 induction, because we found that both, SV40 and asbestos induce ERK1/2 and downstream effectors in HM in tissue culture. Our hypothesis is that all these mechanisms are inter-related and we will study the biological significance of these mechanisms in SV40-asbestos co-carcinogenesis. In Aim 2A, the same cytokines and gene pathways studied in Aim 1, will be investigated in frozen specimens from MM we induced in hamster with asbestos, SV40, and SV40 small t mutant plus asbestos, and the results compared. By comparing the in vitro data (aim I), with those produced in an experimental MM model (Aim 2A) in which exposure, was under our control, we will identify among many possible candidate gene pathways, those that are most relevant to MM pathogenesis and to SV40-asbestos pathogenesis and co-carcinogenesis. The results will be validated by studying the same cytokines and gene pathways identified in vitro (Aim 1) and in hamster MM (aim 2A) in a unique collection of 38 frozen MM biopsies and matching lung tissue (Aim 2B). In these 38 samples we have determined SV40 status and type and amount of asbestos exposure. Finally, in Aim 3 we will attempt to establish an SV40-asbestos mouse tumor model, similar to the one we established in hasmters. The availability of a mouse model would be ideal for future mechanistic and experimental therapeutic approaches because of the large number of mouse reagents (monoclonals, transgenic mice, knock-out mice, etc.). It is anticipated that the results of the experimens proposed in this application will provide information to design novel preventive and therapeutic approaches for MM.

描述(由申请人提供)：我们的假设是石棉和SV40是导致恶性间皮瘤(MM)的共同致癌物。这一假设是基于使用人间皮细胞(HM)的体外实验和在仓鼠体内的实验。我们发现石棉和SV40小T抗原突变体都不能引起HM恶性转化。然而，当HM同时接触石棉和SV40小t突变体时，HM发生了恶性转化和病灶形成。此外，初步结果表明，在仓鼠体内注射SV40小T突变株，以及在胸腔和腹膜腔内注射石棉，都有很强的共同致癌作用。我们的发现表明，同时接触石棉和SV40的人患间皮瘤的风险增加。在这里，我们想要研究共同致癌的机制。我们建议在组织培养中的人和仓鼠间皮细胞，以及在仓鼠和人间皮瘤活检组织中进行这些研究。在目的1中，我们将在组织培养中检测肿瘤坏死因子-α、血小板衍生生长因子和转化生长因子-β在SV40-石棉共同致癌中的生物学作用。在初步结果中，我们发现我们的间皮细胞表达这些细胞因子的受体。我们还发现，石棉暴露或SV40感染后，HM中可诱导肿瘤坏死因子-α及其受体的表达。HM暴露于肿瘤坏死因子-α可诱导核因子-kβ活化，在肿瘤发生中起重要作用。同时，我们正在研究SV40和石棉对RAS-ERK通路和AP-1诱导的影响，因为我们在组织培养中发现SV40和石棉都能诱导HM中ERK1/2及其下游效应分子。我们的假设是，所有这些机制都是相互关联的，我们将研究这些机制在SV40-石棉共同致癌中的生物学意义。在目标2A中，我们将在我们用石棉、SV40和SV40小t突变加石棉诱导的地鼠多发性骨髓瘤冰冻标本中研究与目标1相同的细胞因子和基因通路，并对结果进行比较。通过将体外实验数据(Aim I)与我们控制暴露的实验性MM模型(Aim 2A)中产生的数据进行比较，我们将在许多可能的候选基因途径中识别与MM发病机制、SV40-石棉发病机制和共同致癌最相关的基因途径。这一结果将通过研究在体外(AIM 1)和仓鼠MM(AIM 2A)中确定的相同的细胞因子和基因路径来验证，该研究收集了38例冷冻MM活组织和匹配的肺组织(AIM 2B)。在这38个样本中，我们已经确定了SV40的状态以及石棉暴露的类型和数量。最后，在目标3中，我们将尝试建立一个SV40-石棉小鼠肿瘤模型，类似于我们在hasmters中建立的模型。由于大量的小鼠试剂(单克隆体、转基因小鼠、基因敲除小鼠等)，小鼠模型的可获得性将是未来机械和实验性治疗方法的理想选择。预计本申请中提出的实验结果将为设计MM的新预防和治疗方法提供信息。