Therapeutic Inhibition of MDM2/Bcl-2 in Pre-clinical Models of Adenoid Cystic Car

描述(由申请人提供)：问题：据估计，美国每年约有1200例新确诊的腺样囊性癌(ACC)病例。这些肿瘤的特点是不停的生长和频繁的复发。因此，这些患者的15年存活率低得令人无法接受(40%)。由于没有药物被批准用于ACC，因此主要的治疗方法仍然是根治性手术，这通常与高发病率和低生活质量有关。缺乏细胞系和小鼠模型被认为是发现ACC新疗法的主要障碍。ACC患者存活率的改善很可能来自模拟人类肿瘤微环境的动物模型的研究，并使这种恶性肿瘤的安全和有效的基于机制的治疗方法得以发现。假设：我们最近开发了一种建立人类ACC细胞系的方法，该方法由从手术标本中提取的细胞在超低贴壁平板中培养7-10天组成。暂时暴露在非贴壁条件下可以消除失巢诱导的间质细胞，并净化致瘤ACC的培养物。在这里，我们将使用我们的新的ACC细胞系来开发一种产生具有人源化血管系统的异种移植瘤的方法，该方法最适合于发育疗法研究。在临床前试验中，ACC异种移植模型将被用来评估新型MDM2/Bcl-2信号轴小分子抑制剂的效果。值得注意的是，癌蛋白MDM2和Bcl-2保护肿瘤细胞免受凋亡，与ACC的侵袭性相关，并可能与化疗耐药有关。这项工作的基本假设是，在ACC的临床前模型中，MDM2/Bcl-2信号轴的治疗性抑制使腺样囊性癌对化疗敏感。为了解决这一假设，我们提出了以下目标：具体目标1：建立和表征一种适合临床前试验的人源化血管形成的腺样囊性癌异种移植模型。具体目的#2：明确治疗抑制MDM2/Bcl-2信号轴对腺样囊性癌生长、血管生成和复发的影响。具体目的#3：确定治疗性抑制MDM2/Bcl-2信号轴对腺样囊性癌常规化疗药物(顺铂)耐药的影响。意义：这项建议集中在机制研究和临床前试验的新型小分子抑制剂的基础上。 MDM2/Bcl2通路使用独特的人源化血管构建的ACC异种移植模型。在I期和II期试验中，MDM2和Bcl-2的小分子抑制剂一直被患者耐受性良好。因此，在这里提出的研究的成功结果之后，可以迅速地在ACC患者中测试这些药物的临床试验。我们的研究团队致力于开发一种基于机制的治疗方法，以提高腺样囊性癌患者的存活率和生活质量。

DESCRIPTION (provided by applicant): The Problem: It is estimated that about 1,200 new cases of adenoid cystic carcinoma (ACC) are diagnosed each year in the United States. These tumors are characterized by relentless growth and frequent recurrence. As a consequence, the 15-year survival rate for these patients is unacceptably low (40%). Since no drug has been approved for ACC, the primary treatment still is radical surgery, which is typically associated with high morbidity and poor quality of life. The lack of cell lines and mouse models has been identified as major roadblocks for the discovery of new therapies for ACC. Improvements in the survival of patients with ACC are likely to come from studies performed in animal models that mimic the human tumor microenvironment and enable the discovery of safe and effective mechanism-based therapies for this malignancy. Hypothesis: We recently developed a method to generate human ACC cell lines that is consisted of culturing cells retrieved from surgical specimens for 7-10 days in ultra-low attachment plates. Temporary exposure to non-adherent conditions eliminates stromal cells by anoikis and purifies cultures of tumorigenic ACC. Here, we will use our new ACC cell lines to develop a method for generation of xenograft tumors with humanized vasculature that is optimized for developmental therapeutics studies. The ACC xenograft model will be used to evaluate the effect of novel small molecule inhibitors of the MDM2/Bcl-2 signaling axis in pre-clinical trials. Notably, the oncoproteins MDM2 and Bcl-2 protect tumor cells against apoptosis, correlate with the aggressiveness of ACC, and are likely involved in resistance to chemotherapy. The underlying hypothesis of this work is that therapeutic inhibition of the MDM2/Bcl-2 signaling axis sensitizes adenoid cystic carcinomas to chemotherapy in pre-clinical models of ACC. To address this hypothesis, we propose the following aims: Specific Aim #1: To develop and characterize a xenograft model of adenoid cystic carcinoma with humanized vasculature that is suitable for pre-clinical trials. Specific Aim #2: To define the effect of therapeutic inhibition of the MDM2/Bcl-2 signaling axis on adenoid cystic carcinoma growth, angiogenesis, and recurrence. Specific Aim #3: To determine the effect of therapeutic inhibition of the MDM2/Bcl-2 signaling axis on adenoid cystic carcinoma resistance to a conventional chemotherapeutic drug (Cisplatin). Significance: This proposal is centered on mechanistic studies and pre-clinical trials with novel small molecule inhibitors of the MDM2/Bcl-2 pathway using a unique xenograft model of ACC with humanized vasculature. Small molecule inhibitors of MDM2 and Bcl-2 have been well tolerated by patients in Phase I and II trials. Therefore, successful outcome of the studies proposed here can rapidly be followed by a clinical trial testing these drugs in patients with ACC. Our research team is fully committed to the development of a mechanism- based therapy that will enhance the survival and quality of life of patients with adenoid cystic carcinoma.