Fig. 5: ERK5-mediated signaling regulates IL-8 expression.
From: MEK5/ERK5 activation regulates colon cancer stem-like cell properties
a, b Gene expression profiling was performed in HCT116 tumorspheres using the Human Cancer Stem Cells RT2 Profiler PCR Array. a Heatmap representation of differentially expressed genes between vehicle- and XMD8-92-treated tumorspheres (green: downregulation; red: upregulation). b PCR array results are expressed as mean ± SD log2-transformed fold change to vehicle control-treated spheres. c The effect of ERK5 inhibition on IL-8 expression was validated by independent qRT-PCR in HCT116, HT29, SW480, and SW620 tumorspheres treated with XMD8-92 versus vehicle control, and d ERK5 small interfering RNA (siRNA) versus control siRNA HCT116 tumorspheres. e IL-8 mRNA levels were further measured in tumorspheres versus adherent cultures, and f CA-MEK5-overexpressing versus empty vector SW480 cells. Results are expressed as mean ± standard error of mean from at least three independent experiments. *p < 0.05, **p < 0.01, and ***p < 0.001 from vehicle control treatment (c), control siRNA spheres (d), parental adherent cultures (e), or empty vector cells (f). Min minimum, Avg average, Max maximum, CA constitutively active
