Figure 1.

EGF-driven microcircuitry hijacks the wound-healing switch. (A) Schematic representation of the transcript that functions as either FSTL1 mRNA or primary miR-198 transcript. UTR, untranslated region. (B) Expression of miR-198 detected by in situ hybridization (red signal, top) and immunohistochemical localization of FSTL1 protein (brown stain, bottom) on normal tongue (n = 11) and HNSCC (n = 64) tissue sections. In both panels, nuclei are stained blue. Bars, 100 µm. (C) Quantification of FSTL1 and miR-198 expression in HNSCC sections. The plot shows an inverse correlation between FSTL1 and miR-198 expression in HNSCC sections. χ² analysis with Bonferroni postcorrection was used to calculate p-values. (D) Immunocytochemistry staining using FSTL1 and KSRP specific antibodies on A253 cells treated with EGF and EGFR inhibitor (representative images of three independent experiments). Bars, 20 µm. (E) Histogram representing relative transcript abundance of miR-198 in A253 cells treated with EGF and EGFR inhibitor as measured by qRT-PCR. Error bar denotes SEM. Representative of three independent experiments. (F) miR-181a binding site in KSRP mRNA (NM_003685). (G) Histogram representing relative transcript abundance of miR-181a in A253 cells treated with EGF and EGFR inhibitor as measured by qRT-PCR. Error bar denotes SEM. Representative of three independent experiments. (H) Immunofluorescence staining of KSRP on normal tongue (n = 11) and HNSCC (n = 64) tissue sections (top). In situ hybridization with LNA probes specific for mature miR-181a on normal tongue (n = 11) and HNSCC (n = 64) tissue sections (bottom). Bars, 100 µm. (I) Quantification of KSRP and miR-181a expression in HNSCC sections. Plot shows an inverse correlation between KSRP and miR-181a expression in HNSCC sections. χ² analysis with Bonferroni postcorrection was used to calculate p-values. (J) Western blot detection of KSRP, FSTL1, and β-actin on HNSCC cells transfected with control or anti–miR-181a (representative of three independent experiments). Band intensities were quantified by ImageJ and normalized to β-actin. (K) miR-198 relative transcript abundance in HNSCC cells treated with control oligonucleotides or anti–miR-181a. Error bars denote mean ± SEM. Student’s t test was used to calculate p-values. (L) Schematic representation of EGF-driven microcircuitry, which hijacks the molecular switch. *, P < 0.05; **, P < 0.01.