Targeting Glioblastoma with a Nuclear-penetrating Anti-DNA Autoantibody

多形性胶质母细胞瘤（GBM）是最常见的原发性脑恶性肿瘤，复发率高 和死亡率，尽管积极的治疗与手术，放疗和化疗。的改进方法 需要靶向和治疗GBM，但血脑屏障（BBB）和与GBM相关的遗传异质性， GBM是药物开发的障碍。自身免疫性疾病系统性红斑狼疮 意想不到的新方法。 我们发现狼疮抗DNA自身抗体3E 10穿透活细胞核并抑制DNA修复。 一种不杀死正常细胞但对DNA双链修复有遗传缺陷的癌细胞有毒的方式， 链断裂（DSB），包括PTEN缺陷的癌细胞和肿瘤。3E 10通过一种机制穿透细胞 这需要细胞外DNA和ENT 2核苷转运蛋白都存在，这有助于 由于3E 10表达ENT 2和其细胞中DNA增加，3E 10优先渗透到肿瘤中。 环境约40%的原发性GBM是PTEN缺陷的，我们假设3E 10将靶向GBM， 单一药剂对PTEN缺陷型GBM有效，并可用作放射治疗的增敏剂， 作为GBM的药物递送配体，而不管PTEN状态如何。 我们重新设计了3E 10片段，下文称为脱氧单抗-1（DX 1），以最大化对 癌细胞，降低风险。在初步研究中，DX 1穿过BBB定位并抑制生长 在原位患者来源的异种移植物（PDX）小鼠模型中， 将纳米载体用于原位GBM肿瘤。我们现在提出的研究，以帮助翻译DX 1成为一种新的治疗， GBM。在目的1中，我们进行研究以阐明和增强DX 1在细胞内穿过BBB的机制。 GBM。在目标2中，DX 1单独或与放射疗法组合对存活力和DNA损伤的影响 将测定GBM和正常细胞中的累积。然后将在PDX中测试DX 1 +/-放射治疗 和GBM的同基因小鼠模型以评估功效和毒性。在Aim 3中， 开发了通过与DX 1表面缀合的纳米载体，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是一种创新的方法。 和引人注目的新策略，有可能产生重大的临床影响，拟议的研究将 为推进DX 1技术进入临床试验奠定基础。

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.