急性髓系白血病是髓系原始细胞恶性增殖性疾病，发病机制不清楚。JAK-STAT信号通路的异常激活占有重要地位，LNK在该信号通路上通过与TPOR/JAK2的结合负性调控着下游STAT3基因的活化，从而调节细胞增殖及凋亡。我们研究发现，AML的患者同时存在LNK及STAT3的高表达，这说明LNK对STAT3失去了调控作用。我们推测可能是LNK的突变导致其不能与TPOR/JAK2结合，从而出现STAT3的异常活化。拟用AML患者骨髓，通过全外显子测序，确定LNK的突变类型；根据不同突变类型构建表达载体，用腺病毒转染至AML细胞，siRNA干扰技术做体外实验,探索LNK与AML的发病关系，为将来特异性靶向治疗提供理论依据。

Acute myeloid leukemia is a type of malignant clonal and proliferative disease of myeloid cells in hematopoietic system, and its pathogenesis is unclear. The newest research shows that, abnormal activation of JAK-STAT signaling pathway plays an important role in the pathogenesis of acute myeloid leukemia. LNK gene is an important regulator and suppressor in the JAK-STAT signaling pathway, and negative regulates the activation of the downstream gene STAT3 by binding to TPOR/JAK2. Our studys have found that LNK and STAT3 highly expressed in AML patients simultaneously, while this phenomenon shows that LNK has lost downstream regulatory functions for STAT3. We hypothesiz that LNK mutations which cause abnormal function can not combines with TPOR/JAK2, so it appears that downstream gene STAT3 is activating. The project intends to use the bone marrow samples of AML patients to sequence the whole exon of LNK,and define type of LNK mutation,construct expression vectors based on different types of mutations, and then transfect into AML cells via adenovirus, and use siRNA to knockdown LNK expression, to explore the relationship between the incidence of LNK and AML, Our study will be helpful for the exploration of target therapy.

急性髓系白血病是髓系原始细胞恶性增殖性疾病，发病机制不清楚。JAK-STAT信号通路的异常激活占有重要地位，LNK在该信号通路上通过与TPOR/JAK2的结合负性调控着下游STAT3基因的活化，从而调节细胞增殖及凋亡。本项目拟用AML患者骨髓，通过全外显子测序，确定LNK的突变类型；通过QRT-PCR及Western blot检测EPO、EPOR、LNK及相关基因的表达；体外用慢病毒转染THP-1细胞，沉默LNK基因并过表达STAT3基因，观察白血病细胞增殖情况，探索LNK与AML的发病关系，结果发现，AML患者中存在有EPO、EPOR的高表达，同时存在有LNK基因的突变，LNK基因在AML组表达明显升高，下游STAT3基因表达也明显升高，细胞增殖明显增强；LNK沉默后，STAT3蛋白表达显著下调，THP-1细胞增殖明显受阻，同时沉默LNK基因并过表达STAT3基因，THP-1细胞增殖得以恢复，过表达LNK基因，STAT3蛋白表达显著升高，THP-1细胞增殖明显增强，以上证据表明，LNK可能参与了AML的发生发展；其机制可能是影响EPO/EPOR的结合，并通过JAK-STAT信号通路，STAT3 基因活化导致AML 细胞大量增殖。针对该关键点开发进行靶向治疗的药物，将对提供AML 的治疗有着极其重要的意义，本课题所获得的结果有望将来用于发展针对特异性基因变异的靶向治疗方法提供理论依据。