Therapeutic strategies for treatment of giant congenital melanocytic nevi

摘要 先天性黑色素细胞痣（CMN）可以达到巨大的尺寸，转化为儿童黑色素瘤，从而引发 先发制人的手术导致严重的发病率。在上一个融资期，我们构建了四个CMN模型 来测试旨在避免手术的退化诱导疗法。三个是基因工程小鼠 通过（floxed）NRASQ 61 R癌基因，负责大多数人CMN，通过他莫昔芬靶向黑素细胞- 从Tyr或Dct启动子的诱导型或组成型表达（不同强度）。第四种模型是异种移植 在免疫缺陷小鼠上切除的人CMN。几个模型显示黑色素瘤转化后长时间 延迟。诱导型NRASQ 61 R阐明了增殖期与衰老期痣的动力学，并证实了 回归治疗在任何一个阶段都取得成功。Tyr-Cre; NRASQ 61 R表现出严重的类人CNS和皮肤 而较弱的Dct-Cre诱导更典型的皮肤限制性巨痣， PI 3 K或cKIT诱导不完全（~80%）消退，并且组合完全耗尽视神经细胞。局部 用促炎性半抗原方酸二丁酯（SADBE）处理诱导完全视觉CMN 3次给药后消退。在所有治疗组中，该方案也完全预防了鼠黑色素瘤转化。 皮肤痣。我们发现局部SADBE需要巨噬细胞（而不是B、T或NK细胞），因此可以在 异种移植到SHO小鼠（缺乏适应性免疫但保留巨噬细胞）上的人CMN。SADBE 将鼠巨噬细胞募集到人异种移植物中，并使约90%的人神经细胞消退。以来 SADBE已经在皮肤科的其他地方使用，并已报告可诱导“脱色”，我们计划 进行临床测试然而，由于NIAMS的R 01不支持具有疗效终点的临床试验， 我们正在寻求单独的资金来支持这项已经获得FDA/IND和IRB批准的临床试验。 虽然我们对在此融资期间发现的模型和战略感到兴奋，但我们认为这是至关重要的， 在这一进展的基础上，增加实现真实的治疗突破的可能性， 儿童疾病。因此，目标1-3使用我们的模型，大胆地寻求进一步提高疗效， 治疗的毒性：目标1深入和系统地开发激酶抑制剂组合。它还测试了MEK 抑制剂（MEKi）与SADBE，因为两者都表现出单独的功效，MEKi最近被证明可以促进M1- M2样巨噬细胞分化，这是一种可能增强 SADBE的功效目的2寻求局部T细胞适应性免疫募集，以补充SADBE 巨噬细胞诱导我们已经证明抗PD 1触发了黑素细胞（gp 100）靶向T细胞的募集 当与局部SADBE结合时。我们还将结合联合收割机部分激光治疗加抗PD 1，因为我们 最近发表的，也触发了黑素细胞靶向T细胞的局部募集。目标3系统地使用我们的 用于测试婴儿中常用的抗炎方法的不同剂量/时间表的模型， 优化SADBE的痣消退功效，同时最大限度地减少皮肤毒性和炎症症状。

Abstract Congenital Melanocytic Nevi (CMN) can reach giant sizes, transform to childhood melanoma, and thus trigger pre-emptive surgery inducing profound morbidity. In the prior funding period, we constructed four CMN models to test regression-inducing treatments aimed at avoiding surgery. Three are genetically engineered mice driven by the (floxed)NRASQ61R oncogene, responsible for most human CMN, with melanocyte-targeting via tamoxifen- inducible or constitutive expression from Tyr or Dct promoters (varied strengths). The fourth model is xenografted resected human CMNs on immunodeficient mice. Several models displayed melanoma transformation after long latency. Inducible NRASQ61R clarified the kinetics of proliferative vs senescent nevus phases and verified regressive treatments to succeed in either phase. Tyr-Cre;NRASQ61R exhibited severe human-like CNS and skin lesions whereas the weaker Dct-Cre induced a more typical skin-restricted giant nevi for which inhibitors of MEK, PI3K, or cKIT induced incomplete (~80%) regressions and combinations fully depleted visual nevocytes. Topical treatment with the proinflammatory hapten Squaric Acid Dibutyl Ester (SADBE) induced complete visual CMN regression after 3 doses. This regimen also fully prevented murine melanoma transformation, within all treated nevus skin. We found that topical SADBE requires macrophages (not B, T, or NK cells), so it could be tested in human CMN xenografted onto SHO mice (which lack adaptive immunity but retain macrophages). SADBE recruited murine macrophages into the human xenografts and regressed ~90% of the human nevocytes. Since SADBE is already used elsewhere in dermatology, and has been reported to induce “depigmentation,” we plan to test it clinically. However, since clinical trials with efficacy endpoints are not supported in R01s from NIAMS, we are seeking separate funding to support this clinical trial that already received FDA/IND and IRB approvals. While we are excited by the models and strategies uncovered during this funding period, we believe it is crucial to build on this progress to increase the likelihood of achieving real therapeutic breakthrough for this devastating children’s disease. Accordingly Aims 1-3 use our models to boldly seek further enhanced efficacy and minimized toxicity of treatments: Aim 1 deeply and systematically develops kinase inhibitor combinations. It also tests MEK inhibitors (MEKi) with SADBE, as both exhibit individual efficacy and MEKi was recently shown to promote M1- like (pro-inflammatory) over M2-like macrophage differentiation, a mechanistic feature that may enhance SADBE’s efficacy. Aim 2 seeks localized T cell adaptive immunity recruitment, to complement SADBE’s macrophage induction. We have shown anti-PD1 triggers recruitment of melanocyte (gp100) targeted T-cells when combined with topical SADBE. We will also combine fractional laser treatment plus anti-PD1 which, as we recently published, also triggers local recruitment of melanocyte-targeted T-cells. Aim 3 systematically uses our models to test varied dose/schedules of anti-inflammatory approaches that are commonly used in infants, to optimize SADBE’s nevus regression efficacy while minimizing cutaneous toxicity and inflammatory symptoms.