Identify Myeloid Differentiation-Related MiRNAs Response to ATRA Induction by RNA Sequencing and CRISPR/Cas9 Gene Editing / 中国实验血液学杂志

OBJECTIVE@#To identify differentiation related miRNA and evaluate roles of miRNA during ATRA induced myeloid differentiation.@*METHODS@#The small RNA sequencing was used to analyze differential expressed miRNAs in ATRA induced NB4 cells. Then the several up or down-regulated miRNA were selected as the research candidates. SgRNAs targeting the genome of each miRNA were designed and NB4 cells with inducible expression of Cas9 protein were generated. After transduced sgRNA into NB4/Cas9 cells, the mutation level by PCR and surveyor assay were evaluated. The cell differentiation level was investigated by surface CD11b expression via flow cytometry.@*RESULTS@#A total of 410 mature miRNAs which expressed in NB4 cells were detected out after treated by ATRA, 74 miRNAs were up-regulated and 55 were down-regulated miRNAs with DNA cleavage generated by CRISPR/Cas9 was assayed directly by PCR or surveyor assay, quantitative PCR showed that the expression of miRNA was downregulated, which evaluated that gene edition successfully inhibitied the expression of mature miRNA. MiR-223 knockout showed the myeloid differentation of NB4 significantly inhibitied, while miRNA-155 knockout showed the myeloid differentation of NB4 cells significantly increased.@*CONCLUSION@#CRISPR/Cas9 is a powerful tool for gene editing and can lead to miRNA knockout. Knockouts of miR-223 and miR-155 have shown a differentiation-related phenotype, and the potential mechanism is the integrative regulation of target genes.

Knockout of Micro-RNA-21 Gene in DLBCL OCI-Ly3 cells by TALEN Technique / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore an efficient way to knockout microRNA genes in hemapoietic cell lines with a very low transfection efficiency, so as to facilitate the study of microRNA function in hematopoietic malignancies.</p><p><b>METHODS</b>TALE-nucleases was utilized to knockout the microRNA-21 gene in human diffuse large B-cell lymphoma cells (OCI-Ly3). The OCI-Ly3 single cell clones without expression of miR-21 were established through eGFP(+) enrichment, PCR screening, and microRNA quantification. Finally, the miR-21 changes of mutant clones were identified by sequencing.</p><p><b>RESULTS</b>Four miR-21-knockouted OCI-Ly3 single-cell-derived clones were established after 2 round transfection and screening. The miR-21 knockout efficiency was around 10/10(6) original cells. Sequencing the mutant clones indicated that miR-21 expression could be drastically reduced by simply altering sequences immediately adjacent to the microRNA duplex.</p><p><b>CONCLUSION</b>This strategy may be applied to knockout any microRNA of interest even in hemapoietic cell lines with very low transfection efficiency.</p>