miRNA Expression Profiling of Murine Neuroblastoma Figure 4. Analysis of human and mouse samples based on miRNAs (n = 63) deregulated in mice tumors. A. Hierarchical clustering. Cluster ‘‘Adrenals’’ contains all the mouse adrenals. Cluster ‘‘Tumors’’ collects all the ‘‘Mouse’’ and ‘‘Human’’ tumors, highlighting a branch enriched (p,0.01) for human non-MNA samples (90.7%). B. Principal component analysis. Line ‘‘a’’ splits the samples based on the species: mouse (under) and human (above). Line ‘‘b’’ separates the samples according to the presence of the pathology: controls (left) and tumors (right). Mouse tumors (green), mouse adrenals (black), human MNA (red) and human non-MNA (purple). doi:10.1371/journal.pone.0028356.g004 were investigated in a p53- homozygous mouse knockout model [44,46]. Thus, we hypothesize that the modulation of miRNAs induced by p53 is not dose dependent in our model and that the vast majority of miRNAs are not significantly involved in the more aggressive phenotype driven by p53 haploinsufficiency. However, confirmation of this supposition would require the analysis of miRNA expression derived from mice homozygous for mutant p53. PLoS ONE | www.plosone.org 7 December 2011 | Volume 6 | Issue 12 | e28356