The role of Vitamin D metabolism in Non-Small Cell Lung Cancer

描述（由申请人提供）： 维生素D代谢在非小细胞肺癌中的作用该提案旨在研究肺癌中维生素D的活性形式1，25（OH）2 D3的局部组织调节。我们的初步数据表明，肺癌与正常肺中CYP 24 A1（1，25（OH）2 D3的主要分解代谢酶）的表达存在差异，高水平的CYP 24 A1会导致早期肺癌的不良预后。我们假设肺癌中高水平的CYP 24 A1将消除1，25（OH）2D 3的抗增殖和分化作用。 在第一个目标中，我们将使用体外研究来研究高CYP 24 A1在肺癌细胞系中的功能意义。在第二个目标中，我们将比较小鼠肺癌细胞系LLC的生物侵袭性和转移潜力，该细胞系已被遗传操作以在小鼠肺癌模型中表达高或低CYP 24 A1。在第三个目标中，我们将前瞻性地研究CYP 24 A1高表达在晚期非小细胞肺癌患者中的意义。 对于第一个目标，我们将使用增殖试验，凋亡标记物，质谱和CYP 24 A1阻断剂在细胞系中，无论是高或低CYP 24 A1。将测量细胞增殖、细胞凋亡和1，24，25-二羟基D3（1，25（OH）2D 3的代谢物），作为CYP 24 A1功能活性的读数。对于第二个目标，我们将在肺癌转移的鼠模型中使用表达高或低CYP 24 A1的稳定LLC转染子。在确定肿瘤特异性CYP 24 A1表达的作用后，我们将用外源性1，25（OH）2 D3处理小鼠，以确定其在具有高或低CYP 24 A1表达的肿瘤中的治疗作用。对于第三个目标，我们将前瞻性地研究CYP 24 A1在接受支气管镜检查以诊断晚期肺癌的患者的肺肿瘤和未受影响的呼吸道上皮中的表达。我们将确定维生素D受体（VDR）/CYP 24 A1基因表达与中位生存期（主要结局）之间的关系。其次，我们将确定维生素D受体（VDR）/CYP 24 A1基因表达与癌症分期，吸烟状况和血清1，25（OH）2D 3水平的关系。 公共卫生相关性： 维生素D代谢在非小细胞肺癌中的作用：与退伍军人健康的相关性。癌症每年影响17.5万名美国退伍军人。肺癌是退伍军人癌症死亡的主要原因。超过70%的肺癌是晚期，中位生存期不到1年。该项目的目标是通过研究使维生素D失活的酶CYP 24 A1，为退伍军人和整个社会提供一种预测维生素D抗癌特性的新方法。与正常肺相比，这种酶在人类肺癌中的表达高出数倍。可能有必要确定肿瘤特异性CYP 24 A1基因表达，以调整个体患者的维生素D治疗，无论是单独治疗还是与CYP 24 A1抑制剂联合治疗。这将对使用维生素D作为晚期肺癌或早期肺癌切除术后的辅助治疗以减少复发产生重大影响。

DESCRIPTION (provided by applicant): The role of Vitamin D metabolism in Non- Small Cell Lung Cancer This proposal aims to study local tissue regulation of 1, 25 (OH)2 D3, the active form of Vitamin D in lung cancer. Our preliminary data have shown a differential expression of CYP24A1 (the major catabolizing enzyme for 1, 25 (OH)2 D3 in lung cancer versus normal lung and that high levels of CYP24A1 confer adverse prognosis in early lung cancer. It is our hypothesis that high levels of CYP24A1 in lung cancers will abrogate the antiproliferative and differentiative effects of 1, 25 (OH)2 D3. In the first aim, we will use in vitro studies to study the functional significance of high CYP24A1 in lung cancer cell lines. In the second aim, we will compare the biological aggressiveness and metastatic potential of a murine lung cancer cell line LLC that has been genetically manipulated to express high or low CYP24A1 in a mouse lung cancer model. In the third aim, we will prospectively study the significance of high CYP24A1 expression in patients with advanced non- small cell lung cancer. For the first aim, we will use proliferation assays, apoptotic markers, mass spectrophotometry and CYP24A1 blocking agents in cell lines that have either high or low CYP24A1. Cellular proliferation, apoptosis and 1, 24, 25-dihydroxy D3 (a metabolite of 1, 25 (OH)2D3) will be measured as readouts of CYP24A1 functional activity. For the second aim, we will use stable LLC transfectants that express either high or low CYP24A1 in a murine model of lung cancer metastasis. After establishing the role of tumor-specific CYP24A1 expression, we will treat mice with exogenous 1, 25 (OH)2 D3 to determine its therapeutic role in tumors with either high or low CYP24A1 expression. For the third aim, we will prospectively study the expression of CYP24A1 in both lung tumor and unaffected respiratory epithelium in patients undergoing bronchoscopy for diagnosis of late stage lung cancer. We will determine the relationship between Vitamin D receptor (VDR)/CYP24A1 gene expression and median survival (primary outcome). Secondarily, we will determine the relationship between Vitamin D receptor (VDR)/CYP24A1 gene expression and cancer stage, smoking status and serum 1,25 (OH)2 D3 levels. PUBLIC HEALTH RELEVANCE: The role of vitamin D metabolism in non- small cell lung cancer: relevance to Veterans health. Cancer affects 175,000 American war veterans annually. Lung cancer is the leading cause of cancer death in Veterans. Over 70% of lung cancers are advanced stage at presentation and have a median survival less than 1 year. The goal of this project is to provide the veterans, and society at large a novel way of predicting the anti-cancer properties of Vitamin D, by studying the enzyme CYP24A1 that inactivates it. This enzyme is expressed several fold higher in human lung cancer compared with normal lung. It may be necessary to determine tumor-specific CYP24A1 gene expression to tailor vitamin D therapy in individual patients, either by itself or in combination with a CYP24A1 inhibitor. This will have a significant impact on the use of Vitamin D as an adjunct in advanced lung cancer or following resection of early lung cancer to decrease recurrence.