PO.TB10.03 · 肿瘤生物学
星形胶质细胞对放疗抵抗性胶质母细胞瘤进行重编程，揭示新的治疗易感性
Astrocytes reprogram radiation-resistant glioblastoma to reveal new therapeutic vulnerabilities
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
胶质母细胞瘤（GBM）是一种高度侵袭性且对治疗抵抗的脑肿瘤，治疗选择有限，患者预后差。有效治疗的一个主要障碍是肿瘤与周围脑微环境的相互作用，尤其是星形胶质细胞，它可以调节治疗反应并促成抵抗。为了研究星形胶质细胞如何影响抵抗并揭示可利用的易感性，我们使用患者来源的（HW1）GBM细胞和原代人星形胶质细胞，按多种比例（10:90、50:50和90:10）铺板，建立了直接共培养和transwell共培养体系。这一新型共培养系统使我们能够模拟接触依赖性和旁分泌性星形胶质细胞信号传导。我们在放疗后的情境下，测试了不同密度的星形胶质细胞是否能够调节肿瘤对一组临床和临床前药物的反应。GBM-星形胶质细胞共培养物暴露于临床相关的放疗方案（每日2 Gy，连续5天，共三个周期），并针对12种药物进行筛选，涵盖DNA损伤剂、多激酶抑制剂和核转运抑制剂。值得注意的是，在直接共培养中，即使低浓度的星形胶质细胞（低至10%）也能显著改变GBM对多种化合物的敏感性。此外，与星形胶质细胞共培养时，放疗在GBM细胞中诱导出一种在GBM单培养中不存在的治疗易感性，即对selinexor、afatinib、altiratinib和crenolanib敏感，在中等星形胶质细胞:GBM比例（10:90、50:50）时效果最强。Transwell实验显示了类似的敏感性变化，支持这样的假说：仅星形胶质细胞分泌的旁分泌因子就足以重编程GBM的药物反应。这些观察结果表明，星形胶质细胞在放疗后重编程了GBM细胞系中与抵抗相关的通路，可能劫持了饱和的DNA修复机制、细胞周期检查点、应激信号传导和转运体活性，所有这些都值得进一步的机制研究。基于这些发现，正在进行的研究包括对候选通路的基因验证、扩展的transwell实验以进一步区分接触依赖性和旁分泌机制，以及活细胞成像以界定抵抗的时间动态。总之，我们的研究表明，仅星形胶质细胞的存在就显著影响GBM对治疗的反应，而放疗可以进一步暴露由星形胶质细胞信号驱动的连带敏感性。对这些微环境相互作用进行建模和机制解析，对于确定可能改善这一亟需创新的癌症类型患者预后的联合治疗新途径至关重要。
查看英文原文 English abstract
Glioblastoma (GBM) is a highly aggressive and therapy-resistant brain tumor, with limited treatment options and poor patient prognosis. One major barrier to effective treatment is the tumor's interaction with the surrounding brain microenvironment, particularly astrocytes, which can modulate therapeutic responses and contribute to resistance. To investigate how astrocytes influence resistance and uncover exploitable vulnerabilities, we developed direct and transwell co-cultures using patient-derived (HW1) GBM cells and primary human astrocytes plated across multiple ratios (10:90, 50:50, and 90:10). This novel co-culture system enabled us to model both contact-dependent and paracrine astrocyte signaling. We tested whether astrocytes at different densities were able to modulate tumor response to a panel of clinical and pre-clinical drugs, in the post-radiation setting. GBM-astrocyte cocultures were exposed to a clinically relevant radiation protocol (three cycles of 2 Gy daily x 5 days) and screened against 12 drugs, encompassing DNA-damaging agents, multi-kinase inhibitors, and nuclear transport inhibitors. Notably in direct co-cultures, even low concentrations of astrocytes (as few as 10%) significantly altered GBM sensitivity to multiple compounds. Additionally, radiation induced a therapeutic vulnerability in GBM cells when co-cultured with astrocytes, not present in GBM monocultures, to selinexor, afatinib, altiratinib, and crenolanib, with strongest effects at intermediate astrocyte:GBM ratios (10:90, 50:50). Transwell experiments demonstrated similar shifts in sensitivity, supporting the hypothesis that astrocyte-secreted paracrine factors alone are sufficient to reprogram GBM drug response. These observations imply that astrocytes reprogram resistance-associated pathways in GBM cell lines post-radiation treatment, potentially hijacking saturated DNA repair mechanisms, cell cycle checkpoints, stress signaling, and transporter activity, all of which invites further mechanistic investigation. Building upon these findings, ongoing studies include genetic validation of candidate pathways, expanded transwell assays to further separate contact-dependent and paracrine mechanisms, and live-cell imaging to define the temporal resistance dynamics. In conclusion, our study demonstrates that the presence of astrocytes alone significantly influences GBM response to therapy, and radiation therapy can further expose collateral sensitivities driven by astrocyte signaling. Modeling and mechanistically dissecting these microenvironmental interactions is essential for identifying new avenues for combination therapies that may improve outcomes in a cancer type where innovation is urgently needed.
利益披露 Disclosure
R. Abdelgawad, None..
A. Dhawan, None.