Genome-wide profiling of miRNA associated with BCR-FGFR1 fusion kinase driven stem cell leukemia and lymphoma I

The BBC1 and BBC2 cell lines were isolated from pre-B-cell lymphoma models of a murine BCR-FGFR1 driven SCLL. miRNA profiles for BBC2 cells, were established using miRNA arrays. First, BBC2 cells were compared with FACS sorted, normal, murine splenic CD19+ B cells isolated from BALB/c mice, where upregulated and downregulated miRNAs in BBC2 cells were identified. We next investigated which of these miRNAs were affected by loss of FGFR1 function. Previously we showed that the FGFR inhibitor BGJ398 suppresses suppressed phosphoactivation of chimeric FGFR1 kinases. When BBC2 cells were treated with 50nM BGJ398 for 24 hours, up- and down-regulated miRNAs by FGFR1 signaling were identified. By comparasion of the two subsets of differentially expressed miRNAs, we were able to define core candidate miRNAs which appear to be regulated by BCR-FGFR1 in SCLL. The miRNA profiles of BBC2 cell sample and FACS sorted normal mouse CD19+ B cell sample were detected with miRNA microarray.

本研究中的BBC1与BBC2细胞系分离自小鼠BCR-FGFR1驱动的SCLL前B细胞淋巴瘤模型。我们通过miRNA阵列(miRNA arrays)构建了BBC2细胞的微小RNA(miRNA)表达谱：首先将BBC2细胞与从BALB/c小鼠体内分离的、经荧光激活细胞分选(FACS)的正常小鼠脾脏CD19⁺ B细胞进行比对，以此鉴定BBC2细胞中表达上调与下调的miRNA。后续我们进一步探究了上述miRNA中哪些会因FGFR1功能缺失而发生表达改变。此前我们已证实，成纤维细胞生长因子受体(FGFR)抑制剂BGJ398可抑制嵌合FGFR1激酶的磷酸化激活；当以50nM浓度的BGJ398处理BBC2细胞24小时后，我们鉴定出了受FGFR1信号通路调控的差异表达miRNA。通过对这两组差异表达miRNA的比对分析，我们得以确定在SCLL中受BCR-FGFR1调控的核心候选miRNA。本研究通过miRNA微阵列(miRNA microarray)检测了BBC2细胞样本与经FACS分选的正常小鼠CD19⁺ B细胞样本的miRNA表达谱。