Spatial regulation of mechanistic target of rapamycin complex 1 (mTORC1) and its role in oral squamous cell carcinoma

项目摘要 雷帕霉素(MTOR)复合体的机械靶1(MTORC1)整合了来自多个途径的信息，并 感知不同的信号来调节细胞生长、蛋白质翻译和增殖1，2。 区域化可以提高信号的特异性和效率3，4，mTORC1的空间调节出现 对于这种多方面的信号复合体是至关重要的，因为它已经在许多亚细胞位置6-9被报道。 例如，溶酶体上的mTORC1受氨基酸和生长因子的调节，其功能是 促进翻译，抑制自噬。在过氧化物体中也发现了该复合体，其中 MTORC1对活性氧物种7作出反应。然而，mTORC1在其他亚细胞位置的作用 据报道，它在哪里存在，特别是在细胞核中，还不是很清楚。一个主要的限制是 该领域是评估空间划分的信令的活动和功能的工具的可用性 活细胞中的酶。使用基因编码的荧光生物传感器来监测mTORC1的活性， 张实验室此前发现了一个核mTORC1池，其功能尚未定义。基座 根据我们的初步数据，我们假设核mTORC1调控促炎转录。我们会 通过将mTORC1的靶向抑制与磷酸蛋白质组学实验相结合来验证这一假说 生化分析。最后，由于基因突变激活了磷脂酰肌醇3-激酶(PI3K)/蛋白激酶 B(Akt)/mTOR信号通路在口腔鳞状细胞癌(OSCC)11、12和mTORC1中的显著改变 抑制可以诱导肿瘤退化13，14，我们将研究亚细胞mTORC1信号在生长中的作用 以及口腔鳞状细胞癌细胞在体内外的耐药性。我们假设，抑制mTORC1基因在 胞核或胞浆对口腔鳞癌的细胞生长和EGFR抑制剂耐药有不同程度的影响。建议数 该项目将阐明以前未定义的核mTORC1池的功能，并澄清 亚细胞mTORC1在口腔鳞癌生长和耐药中的作用

Project Summary Mechanistic target of Rapamycin (mTOR) complex 1 (mTORC1) integrates inputs from multiple pathways and senses diverse signals to regulate cell growth, protein translation, and proliferation1,2. Given that spatial compartmentalization can enhance signaling specificity and efficiency3,4, spatial regulation of mTORC1 appears to be critical for this multifaceted signaling complex5 as it has been reported at many subcellular locations6–9. For example, mTORC1 at the lysosome is regulated by both amino acids and growth factors and functions to promote translation and suppress autophagy10. The complex has also been identified at peroxisomes, where mTORC1 responds to reactive oxygen species7. However, the roles of mTORC1 at other subcellular locations where its presence has been reported, in particular in the nucleus, are not well understood. A major limitation in the field is the availability of tools to assess the activity and function of spatially compartmentalized signaling enzymes in living cells. Using a genetically encoded fluorescent biosensor to monitor mTORC1 activity, the Zhang lab has previously discovered a pool of nuclear mTORC1, which has yet to be defined in function. Based on our preliminary data, we hypothesize that nuclear mTORC1 regulates pro-inflammatory transcription. We will test this hypothesis by combining targeted inhibition of mTORC1 with a phosphoproteomics experiment and biochemical assays. Lastly, since genetic mutations activating phosphoinositide 3-kinase(PI3K)/protein kinase B (Akt)/mTOR signaling are prominent alterations in oral squamous cell carcinoma (OSCC)11,12 and mTORC1 inhibition can induce tumor regression13,14, we will study the role of subcellular mTORC1 signaling in the growth and drug resistance of OSCC cells in vitro and in vivo in mice. We hypothesize that inhibiting mTORC1 in the nucleus or the cytosol will differentially effect cell growth and EGFR inhibitor resistance in OSCC. The proposed project will elucidate the function of the previously undefined pool of nuclear mTORC1 and clarify the roles of subcellular mTORC1 in the growth and drug resistance of OSCC.