Figure 5. miR-155 Alters MAPK Signaling.

MCF-7-vector and –miR-155 cell lines were harvested for qPCR to determine basal expression levels for (A) MAPKs 1-6, (B) p38 isoforms (C) JNK1-3 and (D) MAPK associated genes. Normalization was to actin and vector cells designated as one. Error bars represent SEM, n > 3. (E) Human Phospho-Kinase Protein Array for miR-155 Targets. Representative membranes from 2 independent experiments evaluating a broad range of phosphorylation targets for MCF-7 Vector and miR-155 cell lines. Selected targets are ERK1/2 T202 Y204 (1), p70 S6 Kinase T389 (2), Src Y419 (3), mTOR S2448 (4), CREB S133 (5), and RSK1/2/3 S380/ S386/S377 (6). NC= negative control, C= reference spot. (F) Crystal violet assay for cell survival following treatment with MAPK pathway specific inhibitors PD184352 (MEK1/2 inhibitor), SP600125 (broad spectrum JNK inhibitor), RWJ67657 (p38α and p38β inhibitor, does not inhibit p38γ or δ), BIRB (broad spectrum p38 inhibitor). n = 3. * significantly different p < 0.05.