Targeting Glioblastoma with a Nuclear-penetrating Anti-DNA Autoantibody

摘要多形性胶质母细胞瘤是最常见的脑部原发恶性肿瘤，复发率高。 和死亡率，尽管采取了积极的手术、放射和化疗治疗。改进的方法以 靶向和治疗GBM是必要的，但血脑屏障(BBB)和遗传异质性与 GBM是药物开发的障碍。自身免疫性疾病系统性红斑狼疮提供了一种 意想不到的新方法。 我们发现狼疮抗DNA自身抗体3E10穿透活细胞核并抑制DNA修复。 这种方式不会杀死正常细胞，但对DNA双重修复中存在遗传缺陷的癌细胞具有毒性。 链断裂(DSB)，包括PTEN缺陷的癌细胞和肿瘤。3E10通过机制穿透细胞 这需要胞外dna和ent2核苷转运体同时存在，这有助于 3E10对肿瘤的选择性穿透是由于其表达ent2和增加肿瘤细胞中的DNA 环境。约40%的原代GBM是PTEN缺乏的，我们假设3E10将靶向GBM，有 单一药物对PTEN缺乏的GBM有作用，可作为放射治疗的增敏剂和 无论PTEN状态如何，均可作为GBM的药物传递配体。 我们已经重新设计了3E10片段，以下称为脱氧单抗-1(DX1)，以最大限度地发挥作用 癌细胞，并将风险降至最低。在初步研究中，DX1跨越血脑屏障定位并抑制生长 PTEN缺陷的GBM在原位患者来源的异种移植(PDX)小鼠模型中的表达，并传递共轭 原位基底膜肿瘤的纳米载体。我们现在建议进行研究，以帮助将DX1转化为一种新的治疗方法 GBM。在目标1中，我们继续进行研究，以阐明和加强DX1通过血脑屏障的机制。 GBM。在目标2中，DX1单独或联合放射治疗对存活率和DNA损伤的影响 在基底膜和正常细胞中的蓄积将被确定。DX1+/-放射治疗随后将在PDX中进行测试 和同基因小鼠建立GBM模型，评价其疗效和毒性。在目标3种方法输送药物载药 通过与DX1表面共轭的纳米载体被开发出来，并在原位GBM模型中进行了测试。 我们相信，使用一种改良的穿核狼疮抗DNA自身抗体来对抗GBM是一种创新 和有可能产生重大临床影响的引人注目的新策略，拟议的研究将 为将DX1技术推向临床试验奠定基础。

Glioblastoma multiforme (GBM), the most common primary malignancy of the brain, has high rates of relapse and mortality despite aggressive treatment with surgery, radiation, and chemotherapy. Improved methods to target and treat GBM are needed, but the blood-brain barrier (BBB) and genetic heterogeneity associated with GBM are obstacles to drug development. The autoimmune disease systemic lupus erythematosus offers an unexpected new approach. We discovered that the lupus anti-DNA autoantibody 3E10 penetrates live cell nuclei and inhibits DNA repair in a manner that does not kill normal cells but is toxic to cancer cells with genetic defects in repair of DNA double- strand breaks (DSBs), including PTEN-deficient cancer cells and tumors. 3E10 penetrates cells via a mechanism that requires both extracellular DNA and the ENT2 nucleoside transporter to be present, which facilitates preferential penetration of 3E10 into tumors due to their expression of ENT2 and increased DNA in their environment. ~40% of primary GBM is PTEN-deficient, and we hypothesize that 3E10 will target GBM, have single agent effects against PTEN-deficient GBM, and can serve as a sensitizing agent for radiation therapy and as a drug delivery ligand for GBM regardless of PTEN status. We have re-engineered a 3E10 fragment, hereafter referred to as Deoxymab-1 (DX1), to maximize effect on cancer cells and minimize risks. In preliminary studies DX1 crosses the BBB to localize into and suppress growth of PTEN-deficient GBM in an orthotopic patient-derived xenograft (PDX) mouse model, and delivers conjugated nanocarriers to orthotopic GBM tumors. We now propose studies to help translate DX1 into a novel therapy for GBM. In Aim 1 we pursue studies to elucidate and enhance the mechanism by which DX1 crosses the BBB in GBM. In Aim 2 the effects of DX1, alone or in combination with radiation therapy, on viability and DNA damage accumulation in GBM and normal cells will be determined. DX1 +/- radiation therapy will then be tested in PDX and syngeneic mouse models of GBM to evaluate efficacy and toxicity. In Aim 3 methods to deliver drug-loaded nanocarriers by surface conjugation with DX1 are developed and tested in orthotopic GBM models. We believe use of a modified nuclear-penetrating lupus anti-DNA autoantibody against GBM is an innovative and compelling new strategy that has potential for significant clinical impact, and the proposed studies will establish a foundation for advancing the DX1 technology to clinical trials.