长链非编码RNA RP11-226L15.5作为miR-93的ceRNA在Ph阳性急性淋巴细胞白血病发生中的功能和机制

The long non-coding RNA plays an important role in the development and progression of cancer. The role of lncRNA in the development of Ph+ B-cell acute lymphoblastic leukemia (Ph+ALL) is still unclear. Recent studies confirmed that the lncRNA could regulate the expression of miRNA-targeted-gene and executed related functions by acts as the competing endogenous (ceRNA) of miRNA. Our previous study found that lncRNA RP11-226L15.5 was significantly increased in samples of Ph+ALL by microarray and qRT-PCR while miR-93 was significantly decreased. Bioinformatics analysis showed that there are common binding sites with miR-93 between lncRNA RP11-226L15.5 and cyclin D2 which involve in the initiation of leukemogenesis. Thus, we hypothesize that lncRNA RP11-226L15.5 acts as a ceRNA of miR-93 regulating the expression of cyclin D2 and involving in the development of Ph+ALL. We are intended to explore the function and mechanism of lncRNA RP11-226L15.5 in the development of adult Ph+ALL through the perspective of molecules, cells and animals.

长链非编码RNA(lncRNA)在肿瘤发生发展中具有重要作用，但在Ph阳性急性淋巴细胞白血病(Ph+ALL)发生中的功能及调控尚不清楚。近年研究证实，lncRNA通过竞争性内源RNA(ceRNA)机制调节miRNA及靶基因的表达并执行相关功能。芯片筛选、qRT-PCR验证等前期研究发现，Ph+ALL中lncRNA RP11-226L15.5显著上调，miR-93表达下调，且生物信息学分析发现RP11-226L15.5和参与Ph+ALL发生的重要分子cyclin D2存在共同的miR-93结合位点。据此我们推测RP11-226L15.5作为miR-93的ceRNA调控cyclin D2表达进而参与Ph+ALL发生。本课题拟应用荧光素酶报告基因、RIP、RNA pull-down等技术，从细胞、动物、分子水平研究lncRNA RP11-2在Ph+ALL发生中的功能和机制，为临床诊治提供新思路。

前体B细胞细胞增殖与凋亡之间的失衡是前体B细胞急性淋巴细胞白血病（BCP-ALL）发病的重要原因，而其具体的调控机制尚不清楚。本研究旨在从非编码RNA的角度阐明BCP-ALL细胞增殖和凋亡的潜在机制。本研究发现在BCP-ALL患者和BCP-ALL细胞系（NALM-6和RS4; 11）的骨髓中，长链非编码RNA CRNDE（LncRNA CRNDE）显著上调。功能研究显示，在NALM-6和RS4; 11细胞中敲减LncRNA CRNDE可抑制细胞增殖并促进细胞凋亡。随后研究证实，LncRNA CRNDE与miR-345-5p结合并且对miR-345-5p表达负调控。 miR-345-5p的过表达抑制了NALM-6和RS4; 11细胞的细胞增殖并促进了细胞凋亡。进一步的实验表明，miR-345-5p通过直接靶向其mRNA来下调环状AMP反应元件结合蛋白（CREB）的表达。 CREB过表达逆转了miR-345-5p模拟物对NALM-6和RS4; 11细胞增殖和凋亡的作用。最后，体内实验显示LncRNA CRNDE敲低可延长异种移植NALM-6细胞小鼠的存活时间。总之，LncRNA CRNDE通过抑制miR-345-5p上调CREB表达，从而促进BCP-ALL中的细胞增殖并减少细胞凋亡。