Sp1促β-arrestin1转录从而调控急性T淋巴细胞白血病细胞生长机制研究

Although, we found that the lower expression of β-arrestin1（Arrb1） was in T acute lymphoblastic leukemia (T-ALL), and low-expression Arrb1 promoted proliferation of T-ALL cell, how to regulate the expression of Arrb1 is still unclear. Sp1, is a transcription factor, could promote or inhibit the transcription of oncogenes. Firstly, we found that the expression of Sp1 is positively related with the expression of Arrb1 by analyzing the GSE data and RNA Sequencing. Then, software predicted and luciferase gene reporter assay demonstrated that Sp1 bind to the promoter of Arrb1, and promoted the transcription of Arrb1. Further, we uncovered that the expression of Sp1 was lower in T-ALL, and lower Sp1 was correlated with more proliferation of T-ALL. Thus, we try to clarify that Sp1 promoting the transcription of Arrb1, and the possible new mechanism of Sp1 regulating the proliferation of T-ALL in vivo and in vitro. Which not only do provide the new possible for therapeutic drug of T-ALL. But also do enrich the mechanism for pediatric T-ALL.

项目组前期研究发现β-arrestin1（Arrb1）在儿童急性T淋巴细胞白血病（T-ALL）中低表达,且低表达Arrb1促进T-ALL细胞增殖，但Arrb1如何被调控却不甚清楚。Sp1, 是人体内广泛存在的转录因子，可调控多种基因转录。近期预实验我们利用GSE数据、RNA-Seq发现Sp1与Arrb1表达正相关，多种软件预测及双荧光素酶报告基因实验证实Sp1结合于Arrb1启动子区，且促进其转录。进一步发现，低表达Sp1促进T-ALL细胞增殖。本项目延续前期研究，利用体内外模型，重点探讨Sp1结合于Arrb1启动子区，促进其转录，进而调控T-ALL细胞生长的可能新机制。不仅为开发T-ALL治疗药物提供新的思路，且丰富儿童T-ALL发病机制学说。

研究背景.儿童急性T淋巴细胞白血病（T-ALL）因进展及浸润快，预后仍较差。T-ALL发病新机制阐释，新靶向药物研发是进一步提高其生存的关键。课题组前期研究发现β-arrestin1影响T-ALL发生、发展。支架蛋白β-arrestin1如何被调控及揭示其在T-ALL中发挥的多功能作用是该项目要研究的重点。.研究内容.探讨β-arrestin1被转录因子SP1调控的可能及机制；研究β-arrestin1通过micro RNA对T-ALL胞内活性氧含量调节的可能及机制；关注miR-652-5p对T-ALL细胞糖酵解的作用及其机制。.研究结果.1.转录因子 SP1 通过直接结合于β-arrestin1启动子区，促进ARRB1转录与表达。.2.过表达 SP1 增加T-ALL细胞株Jurkat凋亡比例（22.78%），阻滞于G1期细胞比例（63.00%）；延长白血病小鼠生存时间（33.8天 vs 26.5天）。.3.microRNA芯片，RNA-Seq数据分析并稳定细胞株验证发现β-arrestin1敲低后miR-652-5p高表达；.4.miR-652-5p在T-ALL病人及细胞株中均高表达。敲低miR-652-5p后，T-ALL细胞糖酵解水平降低，凋亡细胞增多，延缓其生长；同时，延长T-ALL白血病鼠寿命。.5.miR-652-5p结合于Tigar mRNA 3‘UTR区，抑制Tigar表达, 从而调节T-ALL细胞糖酵解水平。.科学意义.本研究阐释β-arrestin1被SP1调控的可能；miR-652-5p在T-ALL的作用及其对T-ALL糖酵解的调控机制，丰富T-ALL发病机制学说，为T-ALL靶向药物研制提供可能靶点及实验数据。