Fig. 5: Birinapant induces STING-mediated apoptosis of LKB1-mut cancer cells and chemotaxis of immune cells in vitro.

A Time-dependent curve of apoptotic cell counts of A549 cells treated with birinapant (500 nM), IFNγ (1 ng/mL) or in combination. (n = 3 independent biological replicates using different passages of A549 cells). B Representative images showing apoptotic A549 cells treated with birinapant (500 nM), IFNγ (1 ng/mL), or in combination. Scale bar: 100 μm. C Bar graph showing birinapant-induced STING-mediated cancer cell apoptosis. A549 cells were treated with birinapant (500 nM), IFNγ (1 ng/mL), H151 (5 μM,) or in combination as indicated for 72 h. (n = 4 independent experiments). D Representative images showing apoptotic A549 cells treated with birinapant (500 nM), IFNγ (1 ng/mL), H151 (5 μM), or in combination as indicated for 72 h. Scale bar: 100 μm. E Schematic illustration of transwell assays for measuring immune cell infiltration in vitro. F Representative images showing birinapant-induced Jurkat T cells migration. A549 cells (red) and Jurkat T cells (green) were co-cultured in transwell as shown in (E) and were treated with birinapant (100 nM), poly(dA:dT) (1 μg/mL), or in combination with H151 (5 μM), or JAK inhibitor (JAKi), tofacitinib (10 μM), for 48 h, labeled as the letters a-h. A549 was labeled with Nuclight Red fluorescence protein, and Jurkats were pre-labeled with CellTracker™ Green CMFDA Dye. IL2 and anti-CD3 antibody were used to activate Jurkat T cells. Scale bar: 200 μm. G Bar graph showing the quantification of infiltrated Jurkat T cells in transwell-based migration assays. The letters a-h in lowcase were corresponding to the conditions of F (n = 3 independent experiments). Source data are provided as a Source Data file. For (A, C, and G), data are presented as mean ± SD. P-values were calculated by unpaired Student’s t test with two-tailed analysis without adjustments.