Figure 4. Pharmacological inhibition of ILK in HT29 cells reduces acquired resistance to 5-FU and oxaliplatin and lowers levels of p-Akt. (A) Results from MTT assays. Logarithmic dose-response (growth) curves, with IC50 values indicated, showing the effect of QLT0267 on parental HT29 and resistant 5-FUR (i) or OxalR cells (ii), as well as the effect of 5-FU (iii) or oxaliplatin (iv) on resistant cells (5FUR and OxalR respectively) pretreated with QLT (5FURQLT and OxalRQLT respectively). QLT0267 results in 3- to 4-fold greater inhibition of cell proliferation of 5FUR (IC50=26 μΜ) (i) and OxalR cells (IC50=34 μΜ) (ii) compared to parental HT29 cells (IC50>100μΜ. Pre-treatment with QLT0267 increases sensitivity to growth inhibition by 5-FU and oxaliplatin. (B) Protein expression by immunoblotting of ILK and p-Akt in HT29 colon cancer cells resistant to 5-FU (5-FUR) and oxaliplatin (OxalR), as well as, in resistant cells treated with ILK inhibitor QLT0267 (5-FUR+QLT and OxalR+QLT). Representative results of three independent experiments are shown.