Preclinical models and therapeutic strategies for treatment of giant congenital melanocytic nevi

先天性巨大黑素细胞痣的临床前模型及治疗策略

• 批准号: 10245261
• 负责人: DAVID E FISHER
• 金额: $ 35.34万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10245261
• 关键词: 1-Phosphatidylinositol 3-Kinase; Agonist; Alleles; Automobile Driving; BCG Live; Behavior; Biological Markers; Birth; Body Surface Area; Categories; Cells; Cessation of life; Chemicals; Child; Dangerousness; Data; Dermatopathology; Development; Diagnosis; Disadvantaged; Drug Delivery Systems; Epitope spreading; Excision; Exhibits; FRAP1 gene; Face; Frequencies; Genetic; Genetic Engineering; Genetically Engineered Mouse; Growth; Hair; Hair Removal; Hair follicle structure; Haptens; Histologic; Histone Deacetylase; Histone Deacetylase Inhibitor; Human; Imatinib; Imiquimod; Immune; Immunodeficient Mouse; Individual; Infant; Inflammation; Injections; Lesion; MEKs; Measures; Medical; Melanocortin 1 Receptor; Modeling; Mole the mammal; Monitor; Monobenzone; Monophenol Monooxygenase; Morbidity - disease rate; Mus; Mutation; Neonatal; Nevus; Nevus Cell; Oncogenes; Oncogenic; Operative Surgical Procedures; PI3K/AKT; Pathway interactions; Patients; Pharmacology; Pharmacotherapy; Phase; Pigments; Population; Pre-Clinical Model; Prevention; Proliferating; Property; Proto-Oncogene Proteins c-akt; Publishing; Regimen; Reporting; Resected; Risk; Signal Transduction; Skin; Stimulator of Interferon Genes; System; Tamoxifen; Testing; Therapeutic; Time; Tissue Grafts; Tissues; Topical application; Transgenic Organisms; Variant; Vitiligo; Xenograft procedure; anti-PD-1; base; drug candidate; giant congenital nevus; healing; high risk; immune checkpoint blockade; in utero; inhibitor/antagonist; lifetime risk; lipophilicity; melanocyte; melanoma; model building; mouse model; mutant; novel therapeutic intervention; pre-clinical; preclinical evaluation; prevent; promoter; psychosocial; senescence; small molecule; social; success; therapeutic evaluation; treatment strategy; tumorigenic; virtual

Project Summary Giant congenital melanocytic nevi are virtually always NRAS-driven clonal proliferations of melanocytes that develop in utero independently of UV and may cover up to 80% of the body. The most dangerous consequence of giant nevi is the risk of progression to melanoma. This prompts complete surgical excision of the lesions, producing profound and permanent morbidity. Drug treatments capable of regressing these lesions and minimizing lifetime risk of melanoma could be extremely beneficial to these children. We have generated several murine giant nevus models using either constitutive Cre or topical tamoxifen-inducible Cre expression (both melanocyte restricted) to activate oncogenic NRASQ61R expression from its endogenous promoter. In addition to clear histologic and biomarker features resembling human giant nevi, these models exhibit a proliferative phase followed by a senescent phase, and transform to invasive melanoma at similar frequencies as in humans. Aim 1 will characterize these features, identifying transition time to senescence, since therapies may produce distinct efficacies in early/proliferative vs. later/senescent lesions. We will also examine altered hair growth in our model (also similar to human giant nevi), as well as apparently increased aggressiveness of these lesions in the Mc1re/e red-haired genetic background, as recently suggested for humans. We have begun to apply surgery-sparing, primarily locally administered drug therapies to these models (Aim 2), including: 1) small molecule antagonists of NRAS downstream signaling (MEK, ERK, PI3 kinase, and AKT inhibitors); 2) melanocyte lineage-specific toxic agents (antagonists targeting cKIT, MITF, and tyrosinase); and 3) immune approaches triggering localized inflammation and epitope spreading with vitiligo-like results (imiquimod, chemical haptens [contact sensitizers], a lipophilic STING (Stimulator of Interferon Genes) agonist, and BCG, alone and in combinations with anti-PD1). Our preliminary results demonstrate significant clearance of nevus populations using multiple single and combination approaches, albeit requiring further optimization. We hypothesize that effective, safe therapies for giant congenital melanocytic nevi can be derived from application of the above approaches exploiting key benefits of localized drug delivery. Treatments will focus on eradicating both actively proliferating cells (as in neonatal lesions) and senescent cells (as in older children), both modeled here. We have validated a set of rigorous biomarkers of signaling activities as well as key cell populations, for use in sensitive monitoring of lesions and treatments. Prevention of melanoma formation can also be tested using our models. To further validate promising approaches in actual living human giant nevi, we now routinely and stably engraft surgically resected giant nevus tissue from children onto immunodeficient mice (Aim 3). These lesions will be subjected to the best single or combination (non-immunologic) regimens discovered in Aim 2, thereby permitting rigorous preclinical therapeutic assessments in living human giant nevi.

项目概要 巨大的先天性黑素细胞痣实际上总是由 NRAS 驱动的黑素细胞克隆增殖， 在子宫内发育，不受紫外线影响，可覆盖高达 80% 的身体。最危险的 巨大痣的后果是进展为黑色素瘤的风险。这促使手术完全切除 病变，产生严重且永久的发病率。能够消退这些病变的药物治疗 最大限度地降低终生患黑色素瘤的风险可能对这些儿童极为有益。我们已经生成了 使用本构型 Cre 或局部他莫昔芬诱导型 Cre 表达的几种小鼠巨痣模型 （均限制黑素细胞）从其内源启动子激活致癌性 NRASQ61R 表达。在 除了类似于人类巨型痣的清晰组织学和生物标志物特征外，这些模型还表现出 增殖期随后是衰老期，并以相似的频率转变为侵袭性黑色素瘤 就像人类一样。目标 1 将描述这些特征，确定衰老的过渡时间，因为治疗 可能对早期/增殖性病变与晚期/衰老性病变产生不同的功效。我们还将检查修改后的 我们模型中的毛发生长（也类似于人类巨型痣），以及明显增加的攻击性 正如最近对人类提出的建议，这些病变存在于 Mc1re/e 红发遗传背景中。我们已经开始了 对这些模型应用无需手术、主要是局部给药的药物疗法（目标 2），包括： 1）NRAS下游信号传导的小分子拮抗剂（MEK、ERK、PI3激酶和AKT抑制剂）； 2) 黑素细胞谱系特异性毒剂（针对 cKIT、MITF 和酪氨酸酶的拮抗剂）； 3）免疫 引发局部炎症和表位扩散并产生白癜风样结果的方法（咪喹莫特、 化学半抗原 [接触敏化剂]、亲脂性 STING（干扰素基因刺激剂）激动剂和 BCG， 单独使用或与抗 PD1 组合使用）。我们的初步结果表明痣明显清除 使用多种单一和组合方法的人群，尽管需要进一步优化。我们 假设可以从应用中获得针对巨大先天性黑素细胞痣的有效、安全的疗法 上述方法利用了局部药物输送的关键优势。治疗的重点是根除 活跃增殖的细胞（如新生儿病变）和衰老细胞（如年龄较大的儿童），均建模 这里。我们已经验证了一组严格的信号活动生物标志物以及关键细胞群，用于 用于敏感监测病变和治疗。还可以测试预防黑色素瘤形成 使用我们的模型。为了进一步验证在实际活体人类巨型痣中的有前途的方法，我们现在定期 并将通过手术切除的儿童巨痣组织稳定移植到免疫缺陷小鼠身上（目标 3）。 这些病变将接受在以下领域发现的最佳单一或组合（非免疫）治疗方案： 目标 2，从而允许对活体人类巨型痣进行严格的临床前治疗评估。