MEK PATHWAY INHIBITION COMBINED WITH 5-AMINOLEVULINIC ACID-PHOTODYNAMIC THERAPY FOR THE TREATMENT OF DIFFUSE MIDLINE GLIOMA

项目摘要 弥漫性中线胶质瘤（DMG），包括弥漫性桥脑内胶质瘤（DIPG）， 小儿脑干肿瘤DMG是儿童脑肿瘤死亡的主要原因， 是困扰儿童的第二大常见恶性脑癌DMG的预后很差， 在诊断后一年内存活，即使使用最积极的治疗。约400名儿童 将于2022年在美国被诊断出患有DIPG，所有这些患者的中位生存期将在8年至10年之间。 11个月。由于缺乏有效的治疗，DMG疾病的结局在过去十年中趋于稳定。 治疗和有限的诊断工具。DMG中许多失败的临床试验和治疗策略可能是 这归因于两个关键问题：1）可选择性穿透的血脑屏障（BBB）限制药物递送 2）尽管DMG和成年高血压之间存在明显的遗传变异， 对于高级别胶质瘤（aHGG），考虑用于DMG临床试验的药物已通过外推法从 aHGG数据，没有治疗翻译的依据。研究表明，细胞外信号调节 蛋白激酶（ERK）是丝裂原活化蛋白激酶（MEK）的下游受体酪氨酸激酶， 在DMG中上调，提出了关于靶向MAPK/ERK通路是否可以具有抗肿瘤作用的问题。 DMG的影响。靶向MEK与氨基乙酰丙酸-光动力疗法（5-ALA-PDT）的组合是 因为已经发现抑制MEK显著增强原卟啉IX（PpIX）， 在体外和体内以肿瘤特异性方式积累。该提案采用了创新的多式联运 治疗方法，解决了成功的DMG临床试验的障碍，并利用分子 DMG细胞的组合物，以降低发病率和死亡率。通过靶向MEK和采用5-ALA-PDT，我们 预期MEK抑制将与5-ALA-PDT功效协同作用，通过引发直接的肿瘤细胞杀伤、血管生成、 关闭和免疫反应，最终提高患者的总体生存率。如果治疗成功， 适用于其他不能手术的CNS肿瘤。

PROJECT SUMMARY Diffuse midline gliomas (DMG), including diffuse intrinsic pontine gliomas (DIPG), are deleterious malignant pediatric tumors of the brainstem. DMG is the leading cause of death among pediatric brain tumors and the second most common malignant brain cancer afflicting children. DMG has a dismal prognosis of less than 1% survival within a year of diagnosis, even when using the most aggressive treatments. Approximately 400 children will be diagnosed with DIPG in the United States in 2022, all of whom will have a median survival of between 8 and 11 months. DMG disease outcomes have plateaued over the past decade due to the lack of effective treatments and limited diagnostic tools. Many failed clinical trials and therapeutic strategies in DMG can be attributed to two critical concerns: 1) the selectively penetrable blood brain barrier (BBB) restricts drug delivery to central nervous system, and 2) despite there being distinct genetic alterations between DMG and adult high- grade gliomas (aHGG), the agents considered for DMG clinical trials have been derived by extrapolation from aHGG data, without grounds for the therapeutic translation. Studies have revealed extracellular signal-regulated protein kinases (ERK), a downstream receptor tyrosine kinase of mitogen-activated protein kinase (MEK), is upregulated in DMG, raising questions about whether targeting the MAPK/ERK pathway can have anti-tumor effects in DMG. Targeting MEK in combination with aminolevulinic acid-photodynamic therapy (5-ALA-PDT) is of interest because inhibition of MEK has been found to significantly enhance protoporphyrin IX (PpIX) accumulation in vitro and in vivo in a tumor-specific manner. This proposal uses an innovative multimodal treatment approach that addresses the barriers to successful DMG clinical trials and exploits the molecular composition of DMG cells to reduce morbidity and mortality. By targeting MEK and employing 5-ALA-PDT, we anticipate MEK inhibition will synergize with 5-ALA-PDT efficacy by eliciting direct tumor cell killing, vascular shutdown and immune response, ultimately increasing overall patient survival. If successful, this treatment can be applied to other inoperable CNS tumors.