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

项目总结 由于肿瘤细胞存活，用细胞毒性药物治疗往往不能完全根除乳腺癌(BRCA) 这些残留的肿瘤(“残留肿瘤”)代表着最终复发的蓄水池。在三阴性乳腺癌中 (TNBC)是一种高度致命的BRCA亚型，治疗后残留癌细胞的存在与此密切相关 随着侵袭性疾病的复发。根除药物持久性的TNBC病灶可能会导致治愈，但他们的 治疗的脆弱性仍然难以捉摸，主要是因为这种癌细胞状态的真正临床前模型 一直缺乏对基因组和药理学的审问。在我们最近的研究中，我们 证实治疗后残留肿瘤细胞采用明显的可逆转录。 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有关。重要的是，我们开发了三维 (3D)基于有机化合物的体外模型(治疗-持久性有机化合物，TP-有机化合物)，如实概括 PDX和BRCA患者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的潜伏性癌症病变的体外模型。我们的分子和功能 分析强烈表明，持续化疗的休眠肿瘤细胞具有独特的基因组和 历史癌症模型未反映的药理学脆弱性(例如2D培养或 常规3D/有机培养)。我们的模型的新颖性和相关性值得对推定的 药物持久性癌细胞状态的介体，这可能揭示以前未被认识的新的治疗方法 这一临床危重环境的目标。在这个探索性项目中，我们将结合我们的TNBC TP-有机物模型 利用基因组学和药理学方法对药物持续休眠进行研究，以i)确定关键的介体 控制TNBC细胞从休眠状态退出；以及ii)开发特异性杀伤 休眠药物--持久性的TNBC肿瘤。我们将应用可控的功能损失(LOF)和功能增益 (GoF)技术，以确定Myc和/或其他基因的重新激活对于 BRCA细胞进入休眠状态。同样，我们将使用LOF方法来定位通常上调的基因 我们的临床前残留病模型评估它们对滞育型持续性TNBC生存能力的作用 细胞。同时，我们将利用我们的TP-有机系统的高通量能力来绘制景观图 持续化疗的TNBC细胞的药理脆弱性。候选靶点的治疗价值 使持续的TNBC细胞的生存能力或其退出休眠状态的能力将在 合适的体内残留病模型。这个探索性项目将勾勒出第一个临床前框架 以滞育类药物为靶点的治疗方法--持久性TNBC肿瘤。特别针对 在治疗诱导的保护性休眠中或从治疗诱导的保护性休眠中退出的候选介体 持续残留的癌细胞可能会导致持久的反应，甚至是肿瘤根除。

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.