Transcription profiling by array of Mus musculus expressing Cbfb-MYH11

It is known that CBFB-MYH11, the fusion gene generated by inversion of chromosome 16 in human acute myeloid leukemia, is causative for oncogenic transformation. However, the mechanism by which CBFB-MYH11 initiates leukemogenesis is not clear. Previously published reports showed that CBFB-MYH11 dominantly inhibits RUNX1 and CBFB, and such inhibition has been suggested as the mechanism for leukemogenesis. However, knockin mice expressing Cbfb-MYH11 (Cbfb+/MYH11) showed defects in primitive hematopoiesis not seen in Cbfb null (Cbfb-/-) embryos indicating that Cbfb-MYH11 has repression independent activities as well. To identify gene expression changes associated with this novel activity, we compared the gene expression profile in the blood cells of Cbfb+/MYH11 and Cbfb-/- embryonic day 12.5 (E12.5) embryos with that of their wildtype littermates. Cbfb-MYH11 chimeras were mated to C57/Bl6 females to generate Cbfb+/MYH11 (Cbfb+/MYH11) and Cbfb+/+ (WT) embryos. Cbfb+/- x Cbfb+/- matings were used to generate Cbfb+/+ (Cbfb+/+) and Cbfb-/- (Cbfb-/-) embryos. Blood from 8-10 E12.5 embryos of the same genotype was pooled, and RNA was isolated, labeled, and hybridized to Affymetrix Genechip mouse microarray (430 2.0) chips. 4 chips were used for both the Cbfb+/MYH11 and littermate control samples. 3 chips were used for the Cbfb-/- samples and littermate control samples.已知人类急性髓系白血病中由16号染色体倒位产生的融合基因CBFB-MYH11可介导致癌转化，但其启动白血病发生的具体机制仍未阐明。既往研究显示，CBFB-MYH11可显性抑制RUNX1与CBFB，该抑制作用曾被认为是其致白血病发生的核心机制。然而，表达Cbfb-MYH11的基因敲入小鼠（Cbfb+/MYH11）在原始造血过程中出现了Cbfb基因完全敲除（Cbfb-/-）胚胎未观察到的发育缺陷，这表明Cbfb-MYH11还存在不依赖于转录抑制的独立活性。为鉴定与该新型活性相关的基因表达变化，本研究比较了Cbfb+/MYH11、Cbfb-/-胚胎及对应野生型同窝胚胎在胚胎发育第12.5天（E12.5）的血细胞基因表达谱。将Cbfb-MYH11嵌合小鼠与C57/Bl6雌性小鼠交配，以获得Cbfb+/MYH11与Cbfb+/+（野生型，WT）胚胎；通过Cbfb+/- × Cbfb+/-的交配组合，构建Cbfb+/+与Cbfb-/-胚胎。收集8~10枚相同基因型的E12.5胚胎的血液并混合，提取RNA并进行标记，随后与Affymetrix Genechip小鼠基因微阵列（430 2.0）芯片进行杂交。其中，Cbfb+/MYH11组及其同窝对照样本均使用4张芯片完成检测，Cbfb-/-组及其对应对照样本则使用3张芯片完成检测。