Figure 3. AXL inhibition increases sensitivity of lung cancer cells to ATR inhibitors.

A. Comparison of AXL protein expression between lung cancer cell lines sensitive (IC₅₀<3μM) and resistant (IC₅₀>3μM) to the ATR inhibitors, VX-970 and AZD6738. Fold change, F.C. and p value by Welch’s t-test are indicated. B. Relative proliferation of Calu-1, H2250 and H1299 cell lines following 4–5 day treatment with BGB324, VX-970 or their combination at indicated concentrations, as measured by CellTiter-Glo viability assay. Data are mean±s.e.m. ΔAUC value denoting shift in dose response curve of the drug combination beyond the predicted additive effect of the single agents was calculated using the BLISS independence model. ΔAUC<−0.1 indicate a greater than additive effect of the combination. C. Clonogenic survival of Calu-1 and H1299 cells following treatment with DMSO, BGB324, VX-970 or their combination. Colonies stained with 025% crystal violet after 14 days. Representative image from two independent experiments shown. D. Heatmap depicts the effect of combination (calculated as ΔAUC by BLISS model) of BGB324 with various DDR inhibitors – ATM inhibitor (AZD0156), CHK1 inhibitor (LY2606368), WEE1 inhibitor (AZD1775) and DNAPKC inhibitor (NU7441) in Calu-1 and H1299 cells. E. Heatmap shows proteins in the AXL/PI3K/AKT/mTOR signaling pathway, determined by RPPA, following 24 h treatment of Calu-1 cells with DMSO, BGB324, VX-970 or their combination (1μM), significantly altered by ANOVA comparison at FDR=0.01 cutoff.