Fig. 7
TAK1 inhibition abrogates the SASP development and deprives cancer cells of stroma-conferred malignancy. a Heatmap profiling of stromal cell transcriptomics after treatment by bleomycin alone, or together with each of 5Z-7, SB203580 (SB), and RAD001. Cells were collected 7d after drug treatment. The SASP-associated soluble factors are selectively displayed on the top list per expression fold change. b Transcript expression assay of several SASP canonical factors. Cells were treated by bleomycin alone or co-treated by bleomycin/SASP inhibitors. Signals were normalized to untreated samples per factor. Data analyzed by Student’s t-test. c GSEA profiling with significant enrichment scores showing a SASP-specific expression signature composed of canonical soluble factors. Head-to-head comparison of differentially expressed SASP factors was performed between cells treated by bleomycin only and cells co-treated by bleomycin/SASP inhibitors. P values determined by GSEA software. d The prostate cancer (PCa) cell line PC3 was subject to treatment by mitoxantrone (MIT) while being incubated with several types of conditioned media (CM). Upper, representative images of PC3 cells upon different treatments. Arrows, apoptotic cells; arrowheads, damaged cells. Scale bars, 50 μm. Lower, viability assessment of several cell lines incubated with various types of CM and exposed to MIT at the IC50 concentration pre-determined per line. Data analyzed by Student’s t-test. e Measurement of apoptosis in culture conditions. Results were depicted in relative luminescence units (RLUs) representing signal readings proportional to caspase-3/7 activity of PC3 cells. Data analyzed by Student’s t-test. f Dose response curves (non-linear regression fit) of PC3 cells treated by PSC27-derived CM. The concentration of MIT was plotted in an exponential scale, with cell viability assessed in relative to the untreated group and calculated in percentage. Data in all bar plots are shown as mean ± SD and representative of 3 biological replicates.* P < 0.05, ** P < 0.01, *** P < 0.001. BLEO bleomycin, SB SB203580, 5Z-7 5Z-7-oxozeaenol
