Figure 1.

miRNAs with an AAGUGC motif increase proliferation and EGFR-TKI sensitivity. (a) Overview of the functional genomics screen for potentially oncogenic miRNAs with an impact on EGFR-TKI sensitivity. A library of different miRNA expression vectors (miR-Lib) was used for individual transduction into U1810 NSCLC cells. After culturing with or without EGFR-TKI (gefitinib, 10uM), miRNA inserts from all samples were recovered by PCR and enrichment or depletion of specific miRNA-expressing clones was determined by deep sequencing. (b) Analysis of the relative abundance of recovered miRNA inserts comparing baseline control cells and cells grown in normal medium for 30 days. Volcano plot indicates miRNAs with a positive impact on proliferation. Red lines indicate arbitrarily chosen cutoffs for miRNA clones enriched after 30 days in culture (Ctrl30/Ctrl0, 1.5 log2, P<0.05). (c) Analysis of the relative abundance of recovered miRNA inserts comparing cells grown in normal medium or gefitinib for 30 days. Volcano plot indicates miRNAs conferring EGFR-TKI sensitivity (miRNA clones depleted after treatment with gefitinib, Gef30/Ctrl30, −1.5 log2, P<0.05). (d) Four miRNAs enriched after long-term culturing and depleted after treatment with gefitinib share the same AAGUGC motif in the miRNA seed sequence (also indicated in b and c).