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）复合物1（mTORC 1）的机制靶标整合了来自多个途径的输入， 感知不同的信号来调节细胞生长、蛋白质翻译和增殖1，2。鉴于空间 区室化可以增强信号传导的特异性和效率3，4，mTORC 1的空间调节出现 对于这种多方面的信号复合体5是至关重要的，因为已经报道了在许多亚细胞位置6 -9。 例如，溶酶体中的mTORC 1受氨基酸和生长因子的调节，其功能是 促进翻译和抑制自噬10.该复合物还在过氧化物酶体中被鉴定， mTORC 1对活性氧有反应7.然而，mTORC 1在其他亚细胞位置的作用 在已报道其存在的地方，特别是在细胞核中，尚不清楚。的主要限制 该领域是评估空间分隔信号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监测mTORC 1活性， Zhang实验室此前已经发现了一个核mTORC 1池，其功能尚未定义。基于 根据我们的初步数据，我们假设核mTORC 1调节促炎转录。我们将 通过将mTORC 1的靶向抑制与磷酸化蛋白质组学实验相结合来验证这一假设， 生化分析最后，由于基因突变激活磷酸肌醇3-激酶（PI 3 K）/蛋白激酶 B（Akt）/mTOR信号传导是口腔鳞状细胞癌（OSCC）11、12和mTORC 1中的显著改变 抑制可以诱导肿瘤消退13，14，我们将研究亚细胞mTORC 1信号传导在生长中的作用。 体外和小鼠体内口腔鳞癌细胞耐药性的研究。我们假设，抑制mTORC 1在 细胞核或胞质溶胶将不同地影响OSCC中的细胞生长和EGFR抑制剂抗性。拟议 该项目将阐明以前未定义的核mTORC 1库的功能，并阐明 亚细胞mTORC 1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.