Fig. 3

Targeting PI3K-FOXO pathway sensitizes EAC cells to CRT. A Western blot analysis of the PI3K-FOXO pathway in eight untreated EAC cell lines, assessed by phospho-AKT, phospho-ERK and phospho-S6K. α-tubulin was used as loading control. The membrane was sliced to exclude an ESC sample, indicated by the break. B Poor CRT responder cell line 031 M and good CRT responder cell line 289B were treated for 7 days with CRT, surviving fraction was measured on day 8. Graph shows Spearman correlation of surviving fraction after CRT versus quantified p-S6K corrected to α-tubulin as in (A). C Cells were treated for 7 days with the CRT regimen, including a concentration range of 0, 62.5, 125, 250, 500 and 1000 nM Alpelisib, Idelalisib, Pictilisib or LY3023414 [26,27,28,29,30,31]. Percentage viable cells were measured on day 8 and plotted normalized to CRT. Data represents two biological replicates with SEM. D Morphological analyses of poor responder 031 M and good responder 289B cells in untreated conditions, 7 days nCRT and 7 days nCRT + LY3023414 with 500 nM. E Poor CRT responder cell line 031 M and good responder cell line 289B were treated for 7 days with the CRT regimen in addition to 500 nM of PI3K inhibitors (based on average IC50 of four compounds). Apoptosis measured by percentage of green fluorescent Annexin V-FITC. Datapoints represent biological replicates with SD