Enteric Glia is New Biological Target to Block Drug Resistance in Colon Cancer

项目摘要/摘要 对抗癌治疗的抵抗在很大程度上解释了晚期癌症患者糟糕的5年生存率 结肠癌。传统的化疗方案被设计成有效地阻止细胞增殖和启动 癌细胞中的凋亡，但没有意识到细胞发出的促化疗耐药信号 围绕着肿瘤。我们已经确定了肿瘤微环境的一种新的细胞成分：肠道 胶质细胞(EGC)。我们和其他人在过去的15年里已经证明，EGC是屏障的有效诱导者 在健康的结肠中的功能和愈合。最近我们已经证明了EGC网络实质上 人结肠腺癌的侵袭并通过旁分泌促进肿瘤干细胞的形成能力 PGE2-EP4途径。然而，EGC是否会影响结肠癌对化疗的耐药性仍然存在。 未知。我们的初步研究表明，EGC对肿瘤干细胞的诱导凋亡具有保护作用 化疗药物，允许在化疗的情况下促进肿瘤的形成和生长 治疗。我们也有证据表明：(1)这依赖于MRN-ATM通路的激活--一个中枢 参与DNA修复的癌细胞和(2)在化疗中激活EGC而加剧的。使用体量 光谱分析，我们已经确认FSTL3是一种新的EGC衍生因子，并产生了初步的 结果FSTL3参与EGC的化学保护作用。因此，我们建议测试假设“在 对化疗药物的反应，EGC在肿瘤微环境中释放更多的FSTL3， 它增强了癌症干细胞的抗药性，并通过促进DNA促进肿瘤的形成和生长 由MRN-ATM通路驱动的修复“。特异靶1将确定EGC是否促进肿瘤干细胞 通过释放FSTL3对化疗药物产生耐药性。《特定目标2》将测试EGC的保护作用 是由MRN-ATM通路激活导致的DNA修复增加所介导的。具体目标3将 确定阻断EGC中FSTL3的产生是否会在体内使结肠癌对化疗敏感。 研究将使用与翻译相关的人类EGC和癌细胞的原代培养，3D共培养平台， 免疫缺陷小鼠原位共移植、小鼠结肠癌发生模型、转基因小鼠 允许EGC的化学激活(GFAP-hM3Dq)和EGC的可诱导基因打靶(GFAP-hM3Dq) CreERT2)，除了使用单细胞RNA序列和质谱学的尖端分子图谱 研究确定参与的前化疗耐药因子(S)(特别是FSTL3)和途径(S)。这些 研究不仅将提高我们对导致结肠癌的细胞和分子机制的理解 化疗耐药，但也将展示联合靶向治疗策略的治疗潜力 针对EGC来源的FSTL3和传统化疗方案的治疗。

PROJECT SUMMARY/ABSTRACT Resistance to anti-cancer therapies largely explains the abysmal 5-year survival rate of patients with advanced colon cancer. Traditional chemotherapy regimens have been designed to efficiently stop proliferation and initiate apoptosis in cancer cells, but have failed to appreciate the pro-chemoresistance signals emanating from cells surrounding the tumor. We have identified a novel cellular component of the tumor microenvironment: the enteric glial cells (EGC). We and others have shown over the last 15 years that EGC are potent inducers of barrier function and healing in a healthy colon. Recently we have demonstrated that the EGC network substantially infiltrates human colon adenocarcinomas and promotes cancer stem cell tumor-forming abilities via a paracrine PGE2-EP4 pathway. Nevertheless, whether EGC impact colon cancer resistance to chemotherapy remains unknown. Our preliminary studies indicate that EGC protect cancer stem cells against apoptosis induced by chemotherapeutic drugs, allowing for enhanced tumor formation and growth despite the chemotherapy treatment. We also have evidence that this is (1) dependent on activation of the MRN-ATM pathway - a central player in DNA repair- in cancer cells and (2) exacerbated by EGC activation with chemotherapy. Using mass spectrometry analyses, we have identified FSTL3 as a novel EGC-derived factor and generated preliminary results implicating FSTL3 in EGC chemoprotective effects. Therefore, we propose to test the hypothesis that “in response to chemotherapeutic drugs, EGC release larger amounts of FSTL3 in the tumor microenvironment, which enhances cancer stem cell chemoresistance and allows for tumor formation and growth by promoting DNA repair driven by the MRN-ATM pathway”. Specific Aim 1 will determine whether EGC promote cancer stem cell resistance to chemotherapies via the release of FSTL3. Specific Aim 2 will test whether EGC protective effects are mediated by increased DNA repair as a result of activation of the MRN-ATM pathway. Specific Aim 3 will determine whether blocking FSTL3 production in EGC sensitizes colon tumors to chemotherapies in vivo. Studies will use translationally relevant primary cultures of human EGC and cancer cells, 3D co-culture platforms, orthotopic co-engraftment in immunodeficient mice, murine models of colon carcinogenesis, transgenic mice allowing for chemogenetic activation of EGC (GFAP-hM3Dq) and inducible gene targeting in EGC (GFAP- CreERT2), in addition to cutting-edge molecular profiling using single cell RNA seq and mass spectrometry studies to identify the pro-chemoresistance factor(s) (and in particular FSTL3) and pathway(s) involved. These studies will not only improve our understanding of the cellular and molecular mechanisms driving colon cancer chemoresistance but will also demonstrate the therapeutic potential of developing strategies combining targeted therapies against EGC-derived FSTL3 and traditional chemotherapy regimens.