Fig. 4. PD-L1 compensates for the loss of Sororin and regulates sister chromatid cohesion.

a, b Effect of double knockdown of PD-L1 and Sororin on various cellular phenotypes in MDA-MB-231 cells. Quantification of multinucleated cells (a) and colony formation (b) in cells expressing control shRNA, PD-L1 shRNA, Sororin shRNA, or combined PD-L1 shRNA and Sororin shRNA, respectively. c–h Overexpression of Sororin reversed various cellular phenotypes caused by depletion of PD-L1 in MDA-MB-231 cells. Quantification of multinucleated cells (c), colony formation (d), cell proliferation (e), representative images of myb gene distance between paired FISH signals (f), and quantification of myb gene distance between paired FISH signals (g), tumor growth in NSG mice xenografted with cells expressing control shRNA, PD-L1 shRNA, PD-L1 shRNA plus WT or AKE PD-L1, PD-L1 shRNA plus Sororin, or PD-L1 shRNA + Sororin + AKE PD-L1 expressing plasmid (h). For cell experiments, data are presented as means ± SEM, and were independently replicated three times with similar results. Statistical significance was calculated using 2-way ANOVA in e. Statistical significance was calculated using Student’s t-test in a–d. For experiments related to the xenograft mice models, tumor growth data are presented as means ± SD (n = 5) and 2-way ANOVA was used for the comparisons in h. *P < 0.05, **P < 0.01, ***P < 0.001.