Mechanisms of radiosensitization by 2-methoxyestradiol in prostate cancer models

2-甲氧基雌二醇在前列腺癌模型中的放射增敏机制

• 批准号: 7767680
• 负责人: James M Larner
• 金额: $ 31.44万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7767680
• 关键词: 2-methoxyestradiol; Address; Adjuvant; Androgens; Animal Model; Antibodies; Binding; Biological Assay; Bioluminescence; Blood Vessels; Bromodeoxyuridine; CREB1 gene; Cancer Model; Cancer Patient; Cell Count; Cell Death; Cell Line; Cell Proliferation; Cells; Clinical Trials; DNA biosynthesis; Data; Development; Disease; Dominant-Negative Mutation; Dose; EMSA; Endothelial Cells; Estrogens; Event; Exhibits; Genetic; Histologic; Human; Image; Image Analysis; Immunofluorescence Microscopy; Immunohistochemistry; In Vitro; LNCaP; MAP Kinase Gene; MEKs; Malignant Neoplasms; Malignant neoplasm of prostate; Measurement; Measures; Mediating; Microtubule Polymerization; Microtubules; Modality; Modeling; Molecular; Monitor; Mus; Normal tissue morphology; Nude Mice; PC3 cell line; PECAM1 gene; Pathway interactions; Pelvis; Phase II Clinical Trials; Phosphorylation; Pimonidazole; Property; Prostate; Prostatic Neoplasms; Radiation; Radiation Tolerance; Radiation therapy; Radiation-Sensitizing Agents; Radiosensitization; Reporter Genes; Reporting; Role; Slice; Small Interfering RNA; Staining method; Stains; Techniques; Testing; Tissues; Toxic effect; Tubulin; Tumor Oxygenation; Vascular Endothelial Growth Factors; Western Blotting; Xenograft procedure; androgen independent prostate cancer; antiangiogenesis therapy; base; cancer cell; cancer therapy; density; in vivo; neoplastic cell; novel strategies; overexpression; preclinical study; public health relevance; research study; response; subcutaneous; synergism; transcription factor; tumor; tumor growth; tumor xenograft; uptake

DESCRIPTION (provided by applicant): Adjuvant agents that radiosensitize tumor cells without unacceptable normal tissue toxicity are potentially useful in the radiation therapy of prostate cancer. A promising candidate for enhancement of prostate tumor radiotherapy is the naturally occurring estrogen metabolite, 2-methoxyestradiol (2-ME). 2-ME interferes with microtubule function and has both anti-tumor and anti-angiogenic properties. The broad objectives of this proposal are to evaluate the radiosensitizing properties of 2-ME using both in vitro and in vivo prostate cancer models, and to study the molecular mechanisms of interaction between 2-ME and radiation. The specific aims are: 1) to investigate whether 2-ME can radiosensitize androgen-sensitive and androgen-insensitive prostate cancer models in vitro and in vivo; 2) to study the involvement of anti-angiogenesis in the mechanism of radiosensitization by 2-ME in human endothelial cells and prostate cancer xenografts; and 3) to determine the roles of MAPK, CREB, and other downstream effectors in the interaction between radiation and 2-ME in prostate cancer cells and tumors. Since current therapy for advanced prostate cancer is limited by the tendency of the disease to progress from an androgen-dependent state to an androgen-independent state, results from both androgen-dependent (LNCaP) and androgen-independent (PC3, C4-2) cell lines will be compared. Clonogenic, cell death, DNA synthesis, and other assays will be performed along with tumor xenograft (subcutaneous and orthotopic) studies in nude mice. In addition, mouse normal pelvic tissue will be histologically evaluated to assess normal tissue effects. To address the initial events of 2-ME action, the interaction between microtubules and MAPK will be examined by immunofluorescence microscopy and other quantitative techniques to test whether 2-ME disrupts the known binding between MAPK and 2-tubulin. Involvement of anti-angiogenic effects will be measured by evaluating endothelial cell proliferation (in vitro) and microvessel density (in vivo). Vascular normalization and tumor oxygenation will be addressed as potential mechanisms of radiosensitization in vivo. The roles of MAPK, CREB, HIF-11, and VEGF will be studied using traditional techniques (reporter gene assays, EMSA, and Western blotting), along with genetic modulation of these effectors. Since 2-ME as a single agent has shown anti-cancer efficacy and was well-tolerated in Phase II clinical trials against prostate cancer, these pre-clinical studies will provide important information regarding the feasibility of 2-ME as an adjuvant agent in the radiotherapy of prostate cancer. Promising results from these studies may support further clinical trials of radiation plus 2-ME in human prostate cancer patients. PUBLIC HEALTH RELEVANCE: 2-methoxyestradiol (2-ME), a naturally occurring derivative of estrogen, is a promising candidate for enhancement of prostate tumor radiotherapy, based upon our recent preliminary data in animal models. Since 2-ME as a single agent has shown limited anti-cancer activity and was well-tolerated in Phase II clinical trials against prostate cancer in humans, these pre-clinical studies will provide important information regarding the feasibility of 2-ME in combination with the radiotherapy of prostate cancer. Promising results from these studies may support further clinical trials of radiation plus 2-ME in human prostate cancer patients.

描述（由申请人提供）：放射敏化肿瘤细胞而没有不可接受的正常组织毒性的辅助药物可能在前列腺癌的放射治疗中有用。增强前列腺肿瘤放射疗法的有前途的候选者是天然存在的雌激素代谢物，2-甲氧基雌二醇（2-ME）。 2-ME会干扰微管功能，并具有抗肿瘤和抗血管生成特性。该提案的广泛目标是使用体外和体内前列腺癌模型评估2-ME的放射敏化性能，并研究2-ME和辐射之间相互作用的分子机制。具体目的是：1）研究2-ME是否可以在体外和体内放射增感雄激素敏感和对雄激素不敏感的前列腺癌模型； 2）研究抗血管生成参与2-ME在人内皮细胞和前列腺癌异种移植物中的放射敏化机理中； 3）确定MAPK，CREB和其他下游效应子在前列腺癌细胞和肿瘤中辐射与2-ME之间的相互作用中的作用。由于目前对晚期前列腺癌的治疗受到疾病趋势从依赖雄激素依赖性状态到雄激素独立状态的趋势，因此将比较雄激素依赖性（LNCAP）和与雄激素无关（PC3，C4，C4，C4，C4）细胞系产生。在裸鼠中，将与肿瘤异种移植（皮下和原位）研究一起进行克隆生成，细胞死亡，DNA合成和其他测定法。此外，将在组织学上评估小鼠正常骨盆组织以评估正常的组织效应。为了解决2-ME作用的初始事件，将通过免疫荧光显微镜和其他定量技术来检查微管与MAPK之间的相互作用，以测试2-ME是否会破坏MAPK和2-微管蛋白之间已知的结合。抗血管生成作用的参与将通过评估内皮细胞增殖（体外）和微扰动密度（体内）来衡量。血管归一化和肿瘤的氧合将作为体内放射敏的潜在机制。 MAPK，CREB，HIF-11和VEGF的作用将使用传统技术（记者基因测定，EMSA和Western blotting）以及这些效应子的基因调节进行研究。由于2-ME作为单个药物已经显示出抗癌能力，并且在针对前列腺癌的II期临床试验中占有良好的耐受性，因此这些临床前研究将提供有关2-ME作为前列腺癌放射疗法辅助药物的可行性的重要信息。这些研究的有希望的结果可能支持人类前列腺癌患者的进一步的辐射和2-ME的临床试验。公共卫生相关性：根据我们最近在动物模型中的初步数据，2-甲氧基雌二醇（2-Me）是一种天然存在的雌激素衍生物，是增强前列腺肿瘤放射疗法的有前途的候选者。由于2-ME作为单个药物已经显示出有限的抗癌活性，并且在人类针对前列腺癌的II期临床试验中耐受​​良好的耐受性，因此这些临床前研究将提供有关2-ME与前列腺癌放射疗法相结合的可行性的重要信息。这些研究的有希望的结果可能支持人类前列腺癌患者的进一步的辐射和2-ME的临床试验。