C-miR146a targets NF-κB signaling and inhibits progression of del(5q) MDS and AML. (A) Del(5q) HL-60 or MDSL cells or Flt3 mutation MV4-11 leukemia cells were treated in vitro by using 500 nM of C-miR146a or C-scrRNA for 6 days, and the percentages of live cells were assessed by using flow cytometry. Representative results obtained from 3 independent experiments; means ± SEM. Systemic administration of C-miR146a extended survival of human HL-60 AML-bearing mice. NSG-SGM3 mice engrafted with disseminated HL-60-luc cells were injected daily intravenously by using 10 mg/kg of C-miR146a or C-scrRNA, and leukemia progression was monitored by using bioluminescent imaging (B), leukemia progression (C), and the Kaplan-Meier survival curves (D). Shown are representative results from at least 2 independent experiments; means ± SEM (n = 10). (E) NF-κB pathway gene analysis in HL-60 AML-bearing mice after 10 injections of C-miR146a, C-scrRNA, or PBS (n = 3/group). Total RNA isolated from bone marrow was analyzed by using RT2 Profiler PCR arrays. The clustergram of significantly (>1.5 fold) downregulated genes. (F) Low miR-146a expression is associated with worse overall survival of patients with AML based on The Cancer Genome Atlas data set. The optimal cut-point was identified by using log-rank statistics in a survfit model. The log-rank test P value is shown. (G) Gene Set Enrichment Analysis in AML patients with high versus low miR-146a expression based on The Cancer Genome Atlas data set with a NF-κB gene set from Gene Ontology (70 genes). Samples having both miRNA and mRNA expression data (n = 151) were applied to this analysis. Normalized enrichment score (NES) and P value are shown. (H) Standard boxplots were applied to visualize the distribution of log₂-transformed expression of IRAK1, NFKB1, and NFKB2 with the low and high miR-146a expression groups. ***P < .001 and **P < .01 compared to untreated groups or as indicated.