【作者】 王楠；

【导师】 胡以国；

【作者基本信息】 四川大学 ， 药学， 2022， 硕士

【摘要】 白血病是一种血液细胞异常增生性肿瘤。血液系统恶性肿瘤发生、发展与原癌基因异常激活密切相关,其中染色体重排导致的原癌基因过表达和活化在白血病种最为常见。成人中约20%的急性B细胞白血病(B-ALL)与t(9;22)(q34;q11)易位形成的费城(Ph)染色体相关。该易位形成BCR/ABL融合基因,其产物BCR/ABL蛋白有持续的激酶活性,是导致B-ALL发生发展核心原因之一。目前B-ALL仍是不可治愈的恶性肿瘤之一,其发病机制还需继续深入研究。Rora基因在调节昼夜节律、炎症、代谢和细胞发育等方面发挥重要作用,但Rora在B细胞发育与功能及B-ALL发生发展中的作用还没有相关的研究。本课题主要基因修饰小鼠,BCR/ABL诱导的B-ALL疾病模型及硫酸胆固醇(cholesterol sulfate,CS)诱导Rora高表达等工具与技术手段,对于Rora在B细胞发育及B-ALL疾病中的作用和机制进行了深入探究。研究发现通过Pipc诱导在血液细胞中敲除Rora基因后导致小鼠外周血、骨髓和脾脏中B细胞明显增加;CS诱导Rora蛋白水平升高后导致B细胞数量减少。临床数据显示Ph~+B-ALL肿瘤B细胞中RORA的表达较正常人B细胞中RORA的表达显著降低。BCR/ABL1转化的Ba F3细胞较BCR/ABL1-Rora转化Ba F3细胞增殖速率显著增加,BCR/ABL1-Rora转化Ba F3细胞生长受阻并伴随细胞凋亡率增加。我们进一步利用BCR-ABL1诱导的B-ALL动物模型,对Rora在Ph~+B-ALL发生发展中的作用研究,发现在BCR/ABL1诱导的B-ALL小鼠模型中,过表达Rora可显著抑制BCR/ABL1转化的肿瘤细胞生长,延长病鼠存活时间。本研究探讨了Rora在B细胞增殖和分化中的作用,以及在Ph~+B-ALL中的作用。实验结果提示Rora在B细胞发育和Ph~+白血病发生中的新作用。我们期望深入研究Rora在B细胞增殖和分化和肿瘤发生中的生物学调控网络,并探究其作为血液系统相关疾病潜在治疗靶点的可能性。更多还原

【Abstract】 Leukemia is a tumor with dysplasia of blood cells.The occurrence and development of hematological malignant tumors are closely related to the abnormal activation of proto-oncogenes,in which the overexpression and activation of proto-oncogenes caused by chromosome rearrangement are the most common in leukemia.About 20%of acute B-cell leukemia(B-ALL)in adults is associated with the Philadelphia(Ph)chromosome formed by t(9)(Q34)(Q11)translocation.This translocation forms the BCR/ABL fusion gene,and its product BCR/ABL protein has persistent kinase activity,which is one of the core reasons for the occurrence and development of B-ALL.At present,B-ALL is still one of the incurable malignant tumors,and its pathogenesis needs to be further studied.Rora gene plays an important role in regulating circadian rhythm,inflammation,metabolism and cell development,but the role of Rora in B cell development and function and the occurrence and development of B-ALL has not been studied.In this study,tools and techniques such as genetically modified mice,B-ALL disease model induced by BCR/ABL and high expression of Rora induced by cholesterol sulfate(cholesterolsulfate,CS)were used to explore the role and mechanism of Rora in B cell development and B-ALL disease.It was found that knockout of Rora gene in blood cells induced by Pipc led to a significant increase of B cells in peripheral blood,bone marrow and spleen,while the increase of Rora protein level induced by CS led to a decrease in the number of B cells.Clinical data showed that the expression of RORA in Ph~+B-ALL tumor B cells was significantly lower than that in normal B cells.The proliferation rate of Ba F3 cells transformed by BCR/ABL1 was significantly higher than that of Ba F3 cells transformed by BCR/ABL1-Rora,while the growth of Ba F3cells transformed by BCR/ABL1-Rora was blocked and the rate of apoptosis increased.We further used BCR-ABL1-induced B-ALL animal model to study the role of Rora in the occurrence and development of Ph~+B-ALL.It was found that overexpression of Rora could significantly inhibit the growth of tumor cells transformed by BCR/ABL1and prolong the survival time of diseased mice in BCR/ABL1-induced B-ALL mouse model.This study explored the role of Rora in B cell proliferation and differentiation,as well as in Ph~+B-ALL.The results suggest that Rora plays a new role in B cell development and Ph+leukemia.We expect to further study the biological regulatory network of Rora in B cell proliferation and differentiation and tumorigenesis,and explore its potential as a potential therapeutic target for hematological diseases.更多还原