Figure 6. miR-181a is upregulated in recurrent ovarian tumours and TGF-β activation correlates with poor patient outcome.

(a) IHC assessment of nuclear P-Smad2 expression in advanced EOC patients. Immune scores were established using the Allred scoring system (range 0–7). Original magnification, × 200, scale bars, 20 μM (black). (b) Kaplan–Meier curves derived from dichotomizing P-Smad2 expression at the median based on the immune scores show significant differences in PFS and OS. Differences in the PFS (top; P=0.03, OR: 7.9, 95% CI: 7.4–8.5) and median OS (bottom; P=0.05, OR: 2.9, 95% CI: 2.3–3.4; log-rank Mantel–Cox test) are shown. (c) Progression-free interval and OS outcomes in concomitant miR-181a and P-Smad2 expressions. Statistical significance was assessed for differences in PFI (P=0.0007) and PFS (P=0.0006; log-rank Mantel–Cox test) in patient samples with concomitant decrease versus increase in miR-181a and P-Smad2 expression (compared with the expression of each biomarker alone). (d) Box-plot diagrams showing the expression analysis of miR-181a in a clinical cohort of patient matched-tumour specimens from PS-O, primary surgery, ovary (naive to chemotherapy) and SCR, secondary surgery (after tumour has recurred and after two lines of chemotherapy). Left panel shows miR-181a expression in overall cohort collectively (P=0.0024, Wilcoxon signed-rank test); middle panel includes group A tumours, which have a TGF-β-mediated EMT-enriched gene signature (P=0.0006, Wilcoxon signed-rank test), and the right panel includes group B, which do not have an EMT gene signature. Within each box, the horizontal line indicates the median. The top edge of the boxes represents the 75th percentile and the bottom edge represents the 25th percentile (note the log scale on the ordinate). The range is shown as a vertical line ending above and below the 75th and 25th percentile values, respectively. Individual dots represent the outliers. **P<0.01 and ***P<0.001. Wilcoxon signed-rank test.