Properties of miRNA expression across cell lines. (A) Overlaps between miRNA expression across the aggregated cell line and tissue data sets, at different thresholds of miRNA expression in at least one tissue or cell line, respectively. (B) Summary of overlap of miRNAs (≥1 read) between cell lines and tissues. (C) Percentage distribution of the top 20 expressed miRNAs in individual cell line and tissue data sets (normalized by total miRNA reads). (D) Examples of cell-specific singletons, i.e., expressed in a few cell lines and miRNAs. (E) Example of a highly cell-specific miRNA cluster. All the members of the mir-972→979 cluster are specifically coexpressed in S1 and G2 cells. (F) Examples of genomic miRNA clusters, whose members exhibit disparate expression patterns across different cell lines. (G) A cluster of genomically separate miRNAs that exhibits largely correlated expression patterns across different cell lines. (H) Global anti-correlation of miRNAs and their targets. Target expression (RPKM) for targets of the highly expressed miRs (miR-184/bantam/K box miRNAs), 40th–60th percentile moderately expressed miRNAs, and the lowest 20th percentile miRNAs.
