Nicotinic Receptor Ligands and Tobacco-induced Lung Cancer

描述（由申请人提供）：申请资金用于支持我们正在进行的研究，以确定烟草亚硝胺对呼吸细胞的致癌作用的分子机制，并开发使用尼古丁乙酰胆碱受体（nAChR）配体的新型抗癌疗法。初步研究发现，呼吸细胞细胞膜上表达的nAChRs的规范配体和非规范配体都具有抗肿瘤潜能。这些受体在药理学剂量的烟草衍生致癌物亚硝胺4-（甲基亚硝胺）-1-（3-吡啶基）-1-丁酮（NNK）引起的BEP2D细胞恶性转化中发挥作用。nnk转化的肺癌细胞对新型胆碱能肽SLURP-1（哺乳动物分泌的Ly-6/尿激酶纤溶酶原激活物受体[uPAR]相关蛋白）诱导的凋亡高度敏感。整合SLURP-1与NNK对呼吸细胞作用的结构和功能信息，将有助于更好地理解肺部肿瘤监测的生理机制，并可能导致烟草相关肺癌预防和治疗的新方法的发展。我们将对以下工作假设进行验证：1)SLURP-1在体外和体内可以阻止呼吸细胞依赖nnk的转化；2)细胞质捕获SLURP-1导致nnk转化的BEP2D细胞和肺癌细胞质膜上nAChRs的表达改变；3) SLURP-1作为竞争性nAChR拮抗剂，17个nAChR亚型介导了SLURP-1的大部分作用；4) SLURP-1干扰正常和恶性人呼吸细胞中NNK连接的nAChR亚型下游受体介导的信号。具体目的将是确定：1)SLURP-1在呼吸细胞免受NNK致癌性的生理保护中的作用；2) SLURP-1诱导恶性呼吸道细胞凋亡敏感性增高的分子机制；3)介导SLURP-1药理活性的nAChR亚型及其对呼吸细胞表达的nAChR的作用模式；4) SLURP-1和NNK连接的nachr下游的信号通路。

DESCRIPTION (provided by applicant): Funding is requested to support our ongoing studies toward identification of molecular mechanisms mediating oncogenic effects of tobacco nitrosamines on respiratory cells and development of novel anti-cancer therapies using nicotinic acetylcholine receptor (nAChR) ligands. Preliminary studies revealed an anti-tumor potential of both canonical and non-canonical ligands of the nAChRs expressed on the cell membrane of respiratory cells. These receptors play a role in the malignant transformation of BEP2D cells caused by pharmacologic doses of the tobacco-derived carcinogenic nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The NNK-transformed and lung cancer cells are highly sensitive to apoptosis induced by the novel cholinergic peptide SLURP-1 (secreted mammalian Ly-6/urokinase plasminogen activator receptor [uPAR]-related protein). Integrating structural and functional information about SLURP-1 vs. NNK actions on respiratory cells will facilitate a better understanding of the physiologic mechanism of tumor surveillance in lungs, and may lead to the development of novel methods of prevention and treatments of tobacco-related lung cancer. We will test the following working hypotheses: 1) SLURP-1 can prevent NNK-dependent transformation of respiratory cells in vitro and in vivo; 2) cytoplasmic trapping of SLURP-1 results in altered expression of nAChRs on the plasma membrane of NNK-transformed BEP2D and lung cancer cells; 3) SLURP-1 acts as a competitive nAChR antagonist with the 17 nAChR subtype mediating most of SLURP-1 effects; and 4) SLURP-1 interferes with the receptor-mediated signaling downstream of the nAChR subtype(s) ligated by NNK in normal and malignant human respiratory cells. The Specific Aims will be to determine: 1) the role of SLURP-1 in the physiologic protection of respiratory cells from NNK carcinogenicity; 2) the molecular mechanism of increased sensitivity of malignant respiratory cells to the apoptosis induced by SLURP-1; 3) the nAChR subtype(s) mediating the pharmacologic activity of SLURP-1 and the mode of its action on the nAChRs expressed by respiratory cells; and 4) the signaling pathways downstream of the nAChRs ligated by SLURP-1 and NNK.