DNA解旋酶 BRIP1在慢性粒单核细胞白血病及急性髓系白血病发生发展和预后中的作用研究

Although the prognostic grading systems have been proposed for chronic myelomonocytic leukemia (CMML) and acute myelogenous leukemia (AML), new molecular prognostic markers are needed to be included into to enrich them. Moreover, the exact pathogenesis of CMML and AML is still unclear and to be elucidated. In this project, a severe congenital neutropenia patient who had progressed to CMML, an ideal model for revealing mutistep pathogenesis of hematological malignant disease, was adopted to explore the new molecular prognostic markers of hematological neoplasm and to elucidate the molecular pathogenesis of hematological neoplasm. The matched tumor and normal genomes of this patient had been analyzed and compared with the aid of next-generation sequencing technology, and 28 somatic gene mutations occurring in exon coding regions of tumor cells were found, including one BRIP1 mutation. Moreover, BRIP1 mutation was confirmed to have reoccurrence in 1 patients among other 30 CMML patients and in 4 patients among a group of 50 AML patients. In the following research, the prognostic value of BRIP1 gene mutation would be judged by investigating its incidence in much larger groups of CMML and AML patients and analyzing its correlationship with the CMML and AML patients' clinical data. The prognostic grading system of CMML and AML would be enriched by this research findings. Additionally, the recurrent BRIP1 gene mutation would be cloned into expressing vectors, and its function would be further investigated by in vitro experiments using cell transfection, gene chip analysis, co-immunoprecipitation along with in vivo experiment by using model animal experiment. The roles played by mutated BRIP1, which would be revealed by in vivo and in vitro experiment, would give import hints for exploring the pathogenesis of CMML and AML.

慢性粒单核细胞白血病(CMML)及急性髓系白血病(AML)虽有预后分级系统，但仍需分子指标的纳入使其完善，且其发病机理尚未完全阐明。本项目中，我们借助于研究恶性血液病多步骤病理生理发病机制的理想模型，即一从重型先天性中性粒细胞减少症恶变为CMML的患者，采用二代测序技术对患者肿瘤基因组和匹配的正常基因组测序、对比分析，最终确定出肿瘤细胞外显子区域28种体细胞基因突变，BRIP1突变为其中之一。在随后检测的40例CMML和53例AML中分别出现1例和4例完全相同的BRIP1突变。我们将进一步研究BRIP1突变在CMML和AML中复现性及与疾病临床关联性，确定其预后价值，丰富CMML和AML的预后分级系统；同时利用细胞转染、免疫共沉淀、基因芯片、模式动物等方法，从体内外揭示BRIP1在CMML和AML发病中作用，为探索CMML和AML新的分子发病机理提供重要线索。

BRIP1基因突变常见于乳腺癌、范可尼贫血及卵巢癌疾病中，在急性白血病中的基因突变情况尚未有报道。本项目原计划研究的内容已经基本完成，并在原有的基础之上进行了适当拓展。具体研究进展表现为：（1） BRIP1基因编码区错义突变在急性髓系白血病（AML）中发生率约为12.4%。（2） BRIP1在AML中发现的错义突变影响了蛋白结构稳定性、DNA解旋酶活性、细胞对交联药物的敏感性等。（3） BRIP1错义突变是一个独立的AML预后变差的标志物，这为下一步研究AML预后分级、开发靶向治疗药物奠定理论基础。（4） 本项目共发表5篇SCI文章，4篇中文核心期刊文章；通过本项目主持人获得了多项省市人才称号；另外培养了5名硕士研究生。除此之外，研究团队在项目支持下多次参加学术交流活动并受邀在国内学术会议大会发言。