Fig. 4: Targeting MCL-1 restricts triple-negative breast cancer cell growth in vivo

a Inhibition of MDA-MB-468 tumour growth in orthologous transplantation assay in response to MCL-1 inhibitor UMI-77. Treatment commenced when tumours were ~5 mm diameter. Graph represents weekly average tumour volume ± SEM, n = 13 vehicle-treated (black line) and n = 14 UMI-77 treated (red line) *P ≤ 0.05 (Students t-test). b Representative photograph of vehicle (upper) or UMI-77 (lower)-treated tumours (as in a) harvested at end of experiment (after 4 weeks treatment), for weights of all tumours see Supplementary Fig. S3A. c Immunohistochemical analysis of cleaved caspase 3 expression in tumours harvested 4-weeks post-treatment. Representative images shown; n = 11–12 for each group. Scale bar is 100 μm. d Quantification of cleaved caspase 3 in orthologous tumours harvested 4-weeks post-treatment; bars indicate mean ± SEM and points represent average cleaved caspase 3 staining per tumour *P ≤ 0.05 (unpaired t-test) n = 12 vehicle-treated tumours and n = 11 UMI-77-treated tumours. Results are expressed as proportion of brown pixels (cleaved caspase 3 IHC stain) to blue pixels (nuclear stain) from 3–4 fields of view (on 10X objective) per tumour, quantified using Adobe photoshop 5.1. e Inhibition of MDA-MB-468 tumour growth in orthologous transplantation assay following siRNA knockdown of MCL1. Graph represents tumour volume from date of transplantation. Weekly average of n = 16 siControl (black line) and n = 15 siMCL1 (red line) tumours is shown ± SEM *P ≤ 0.05 (unpaired t-test). f Reduced weight of siMCL1 tumours harvested after 3 weeks growth in vivo, n = 10 tumours per condition harvested at this timepoint. Points indicate individual tumour weights and bars are mean ± SD *P ≤ 0.05 (unpaired t-test)