双重靶标c-Mpl和STAT3/5拮抗多肽的筛选及其对白血病细胞的动态调控

The proliferation and differentiation of leukemia cells depend on the exogenous cell growth factor. However, the human leukemia megakaryocytes gain the ability of auto-proliferation, which is closely related to the pathogenicity entailed by the abnormal expression of thrombopoietin receptor(c-Mpl). We have first reported the presence of a misspliced form of c-Mpl with a 24 amino acids deletion in the extracellular domain of c-Mpl existed in leukemia Dami cells. The misspliced c-Mpl plays significant role in the proliferation and differentiation of leukemia cells. This project is to further investigate the molecular features of the mutations of c-Mpl in leukemia Dami cells. We constructed a co-transfected cell model carrying aberrant c-Mpl and STAT3/5 double-targets regulatory sequences. Then screen the Phage Peptides Display Library to harvest antagonistic peptides with high-affinity for specific aberrant c-Mpl. Meanwhile, investigate the contribution of antagonistic peptides to the proliferation, differentiation and apoptosis of leukemia cells as well as deciphering their regulatory effects on signal transduction during dynamic development tof leukemia cells. This project gives further insight into the alternative mechanism of the aberrant expressing c-Mpl. It can also aid in the exploration of new targets for drugs and offer theoretical basis for developing new pharmaceutical targets regarding the prevention and treatment of acute megakaryoblastic leukemia .

白血病细胞增殖和分化依赖外源性细胞生长因子刺激作用，但人体白血病巨核系细胞有自发增殖的活性，这和血小板生成素受体（c-Mpl）异常表达导致的致病性密切相关。我们首次报道了c-Mpl胞外区域在白血病细胞Dami存在缺失的24个氨基酸的剪切形式，其对白血病增殖和分化中有重要的作用，本项目拟通过进一步发现，白血病Dami细胞株c-Mpl序列突变的分子特征，构建带有异常表达的c-Mpl和STAT3/5调控序列双靶标的共转染细胞模型。进而筛选噬菌体多肽展示文库，以获得高亲和、特异性的c-Mpl异常表达的拮抗多肽。同时，观察拮抗多肽对白血病细胞增殖、诱导分化和凋亡的影响，阐明在白血病细胞动态生长时，其对信号传导的关键调控作用。本项目的研究不但可深化对c-Mpl受体异常表达的选择机制认识，而且为寻找防治巨核细胞白血病新的药物作用靶标和分子标记提供科学依据。

白血病细胞增殖和分化依赖外源性细胞生长因子刺激作用，但人体白血病巨核系细胞有自发增殖的活性，这和血小板生成素受体（c-Mpl）异常表达导致的致病性密切相关。本课题初步明确了异常表达c-Mpl分子特征及其对白血病细胞信号转导通路的影响，确立巨核细胞系白血病药物作用分子靶标。为探讨新的白血病巨核系细胞分子病理机制提供有力的实验依据。尤其是发现c-Mp的异常剪切体c-Mpl-del巨核细胞白血病中的高表达，其介导的TPO信号促进了AMKL细胞的恶性增殖以及对化疗药物的耐受性。本课题构建了带有异常表达的c-Mpl和STAT3/5调控序列双靶标的共转染细胞模型，成功从12肽库中筛选到18株单克隆多肽展示菌株，确定了高效和特异性强防治白血病发生和发展的c-Mpl拮抗多肽。明确其对异常表达c-Mpl所介导白血病细胞动态发育的调控作用，为今后利用c-Mpl开展有关白血病靶向性分子多肽药物的临床诊断和治疗提供理论和实验基础。本课题在发表高质量的论文3篇，其中1 篇SCI影响因子达到了 25.84分以上，1篇5.19分收录。申请国家发明专利1项。培养2名博士生和4名硕士生。编著《基础血液学》（科学出版社）专业书籍。参加二次国际会议，并在其中之一做大会报告。