Diapause-like adaptation of triple-negative breast cancer cells during chemotherapy treatment

项目摘要 由于活的肿瘤细胞，细胞毒性药物治疗通常不能完全根除乳腺癌（BrCa） 这些肿瘤持续存在（“残留肿瘤”）并代表最终复发的储库。三阴性乳腺癌 在高致死性BrCa亚型TNBC中，治疗后残留癌细胞的存在与高致死性BrCa亚型TNBC（一种高致死性BrCa亚型）的发生密切相关。 有侵袭性疾病复发。根除药物持续性TNBC病灶可能导致治愈，但其 治疗的弱点仍然难以捉摸，主要是因为这种癌细胞状态的真正的临床前模型 基因组和药理学的研究。在我们最近的研究中， 表明治疗持续残留的肿瘤细胞采用独特的和可逆的转录， 类似于胚胎滞育的程序，由压力引发的暂停发育的休眠阶段 并与抑制Myc活性和整体生物合成相关。重要的是，我们开发了三维 (3D)基于类器官的体外模型（治疗持续性类器官，TP-类器官）， PDX和BrCa患者中残留肿瘤的表型和分子特征。据我们所知，这 是第一个化疗后残留休眠癌病变的体外模型。我们的分子和功能 分析强烈提示化学持续性休眠肿瘤细胞具有不同的基因组和 药理学脆弱性没有被历史癌症模型反映出来（例如2D培养或 常规3D/类器官培养物）。我们的模型的新奇和相关性保证了对假定的 药物持续性癌细胞状态的介质，这可能揭示新的，以前不受重视的，治疗 这一临床关键设置的目标。在这个探索性的项目中，我们将联合收割机结合我们的TNBC TP-类器官模型 用基因组学和药理学方法研究药物持续休眠，i）确定关键介质 控制TNBC细胞从休眠状态退出;和ii）开发特异性杀死TNBC细胞的治疗方法， 休眠的药物持续性TNBC肿瘤。我们将应用可控的功能损失（LOF）和功能增益 (GOF)技术来确定Myc和/或其他基因的再活化是否是必要的或足够的， BrCa细胞退出休眠。类似地，我们将使用LOF方法靶向通常在哺乳动物中上调的基因， 我们的残留病临床前模型，以评估其对滞育样持续性TNBC生存能力的作用 细胞同时，我们将利用TP-类器官系统的高通量能力来绘制景观图 化疗持续性TNBC细胞的药理学脆弱性。候选靶点的治疗价值 使持久性TNBC细胞的活力或它们从休眠状态退出的方法将在 合适的体内残留疾病模型。该探索性项目将概述第一个临床前框架， 特异性靶向滞育样药物持续性TNBC肿瘤的治疗方法。专门针对 候选介质，使生活力期间，或退出，处理诱导的保护性休眠 持续残留的癌细胞可能导致持久的反应，甚至肿瘤根除。

PROJECT SUMMARY Treatment with cytotoxic drugs often fail to completely eradicate breast cancers (BrCa) due to viable tumor cells that persist (“residual tumors”) and represent a reservoir for eventual relapse. In triple-negative breast cancer (TNBC), a highly lethal BrCa subtype, the presence of post-treatment residual cancer cells is strongly associated with aggressive disease relapse. Eradicating the drug-persistent TNBC foci could lead to cures, but their therapeutic vulnerabilities remain elusive, mainly because bona fide preclinical models of this cancer cell state amenable to genomic and pharmacological interrogation had been lacking. In our recent studies we demonstrated that treatment-persistent residual tumor cells adopt a distinct and reversible transcriptional program resembling that of embryonic diapause, a dormant stage of suspended development triggered by stress and associated with suppressed Myc activity and overall biosynthesis. Importantly, we developed 3-dimensional (3D) organoid based in vitro models (treatment-persistent organoids, TP-organoids) that faithfully recapitulate the phenotype and molecular profile of the residual tumors in PDX and in BrCa patients. To our knowledge, this is a first in vitro model of post-chemotherapy residual dormant cancer lesions. Our molecular and functional analyses strongly suggest that chemo-persistent dormant tumor cells possess distinct genomic and pharmacological vulnerabilities that are not reflected by historical cancer models (e.g. 2D cultures or conventional 3D/organoid cultures). The novelty and relevance of our models warrant the evaluation of putative mediators of the drug-persistent cancer cell state, which could reveal new, previously unappreciated, therapeutic targets for this clinically critical setting. In this exploratory project, we will combine our TNBC TP-organoid models of drug-persistent dormancy with genomic and pharmacological methods to i) identify the key mediators controlling TNBC cell exit from the dormancy state; and ii) develop therapeutic approaches that specifically kill dormant drug-persistent TNBC tumors. We will apply controllable loss-of-function (LOF) and gain-of-function (GOF) techniques to determine whether reactivation of Myc and/or other genes is necessary or sufficient for BrCa cells to exit dormancy. Similarly, we will use LOF approaches targeting genes commonly upregulated in our preclinical models of residual disease to assess their role on the viability of diapause-like persistent TNBC cells. In parallel, we will leverage the high-throughput capacity of our TP-organoid systems to map the landscape of pharmacological vulnerabilities of the chemo-persistent TNBC cells. The therapeutic value of candidate targets that enable the viability of persistent TNBC cells, or their exit from the dormant state, will be validated in appropriate in vivo residual disease models. This exploratory project will outline a first preclinical framework of therapeutic approaches to specifically target diapause-like drug-persistent TNBC tumors. Specifically targeting the candidate mediators that enable the viability during, or the exit from, treatment-induced protective dormancy of persistent residual cancer cells could lead to durable responses or even tumor eradication.