Fig. 6

Co-variations between stromal score and MCL-1 expression characterize luminal breast cancers resistant to BCL-2 inhibition. a 169 ER⁺ primary human tumor samples were cultured 48 h with 1 μM ABT-737 or left untreated and then analyzed for active caspase-3 by immunohistochemistry. Left: data are represented as percentage of tumoral cells positive for active caspase-3 immunostaining in each treated and corresponding untreated specimen. Middle: percentage of tumoral cells positive for active caspase-3 immunostaining induced by ABT-737 above control (ABT-737 treated- untreated slice) is represented for all samples. Right: percentage of tumoral cells positive for active caspase-3 immunostaining induced by ABT-737 above control (ABT-737 treated- untreated slice) depending on the percentage of KI67 labelling as indicated. P-value were calculated using Wilcoxon test. b Left and Right: Data from the 71 samples used for molecular analysis are shown as in Fig. 5a Left and Right respectively. c Stromal score (z-score, Left) and MCL1 expression (z-score, Right) in “resistant” and “sensitive” groups (see Text for further details). P-value was calculated using Wilcoxon test. d Left: Plot of the 71 affymetrix samples with respect to their MCL1 mRNA expression and Stromal score (z-score) to which was added the TCGA regression line inferred from data used in Table 1. “Resistant” and “sensitive” groups are colored in gray and blue respectively. Right: Differences between MCL1 expression expected from the TCGA regression line and MCL1 expression samples from each group are presented as boxplots