FGFR1信号异常通过上调ADAM10活化Notch1诱发T淋巴母细胞白血病/淋巴瘤

T lymphoblastic leukemia / lymphoma (T-ALL/LBL) is a common hematopoitic malignancy and is a serious threaten to human health. However, the mechanisms of T-ALL/LBL oncogenesis is still poorly understood. 8p11 syndrome (EMS) is a hematopoietic stem cell disease with FGFR1 gene affected (ZNF198-FGFR1 is the most common), which showing myeloid hyperplasia and a high chance of T-ALL/LBL tendency. Also EMS is a rare disease, it may provide a ideal model to explore the mechanism of T-ALL/LBL oncogenesis. Notch1 signaling pathway plays an important role in T-ALL/LBL, but its relationship between FGFR1 signaling and Notch1 signal is currently rarely documented. Based on the previous study of our research group, we advanced that ZNF198-FGFR1 can promote Notch1 cleavage via upregulation of ADAM10, result in T-ALL/LBL oncogenesis. This study may elucidate ADAM10 as a critical bridge between the FGFR1 signaling and Notch1 signal using mice EMS model. And this project may elucidate the transcription regulation mechanism of ADAM10 transcription. If succed, our result should be help to further understanding of the EMS-induced T-ALL/LBL, and to provide theoretical support for treatment targeting ADAM10 in T-ALL/LBL treatment.

T淋巴母细胞白血病/淋巴瘤（T-ALL/LBL）是严重威胁人类健康的血液系统肿瘤，其发生机制未明。8p11综合征（EMS）系FGFR1基因受累（以ZNF198-FGFR1最常见）所致的造血干细胞疾病，表现为髓系增生和高度发生T-ALL/LBL的倾向，为研究T-ALL/LBL发生机制提供了良好的模型。Notch1信号通路在T-ALL/LBL的发生中起重要作用，但其与FGFR1信号模块间的关系罕有报道。根据前人和本团队研究结果，我们提出EMS时ZNF198-FGFR1通过上调ADAM10促进Notch1切割活化而导致T-ALL/LBL的发生。研究拟通过小鼠EMS模型明确ADAM10是否是FGFR1信号与Notch1信号间的关键桥梁，并明确ZNF198-FGFR1上调ADAM10转录的调控机制。如期完成后可加深对EMS诱发T-ALL/LBL的认识，为靶向ADAM10的治疗提供理论支持。

8P11综合征（EMS）是一种FGFR1与多种对手基因融合而导致的造血干细胞疾病，具有高度发生T-ALL/LBL的倾向，但其以髓系增殖为首发表现而极易继发T-ALL/LBL的机制不明。按照课题计划，本研究完成了以下工作：1. 通过逆转录病毒将ZNF198-FGFR1导入小鼠造血干细胞建立了EMS模型（1）具有髓系增殖和嗜酸粒细胞增多的首发表现；（2）具有高度发生T-ALL/LBL的倾向。2. 证实ZNF198-FGFR1能通过上调PKC活化ADAM10，继而活化NOTCH1信号（1）转染ZNF198-FGFR1后PKC活性增高；（2）转染ZNF198-FGFR1后ADAM10活性增高，且能够被PKC和FGFR1抑制剂所抑制。3. 抑制ADAM10活性抑制T-ALL细胞增殖并促其凋亡（1）给予Jurkat、CCRF-CEM和MOLT4 ADAM10抑制剂GI254023X处理后切割后NOTCH1和下游基因水平明显下降；（2）GI254023X处理后增殖受抑而凋亡增加。4. 敲除ADAM10/ADAM17影响但不能完全阻断NOTCH1切割（1）使用CRISPR敲除Jurkat、CCRF-CEM和MOLT4 ADAM10后切割后NOTCH1水平下降；（2）进一步敲除ADAM17基因后切割后NOTCH1水平进一步下降，但不会消失。5. ADAM10是抗GVHD的良好靶点（1）建立了T细胞特异性ADAM10敲基因小鼠并以此建立单倍体相合allo-HSCT模型；（2）敲除ADAM10明显减少GVHD的死亡率和严重程度。研究意义：基本阐明了EMS急变为T-ALL/LBL的分子机制，为防治EMS进展提供了ADAM10、PKC等备选靶点；同时探索了T-ALL中NOTCH1活化的S2切割调控机制，发现了有不依赖ADAM10/17的机制存在，为开发T-ALL治疗新策略提供参考。此外，证实了ADAM10是良好的抗GVHD靶点。