Figure 5
From: PP2A inhibition overcomes acquired resistance to HER2 targeted therapy
PP2A regulates eEF2 phosphorylation in an additional cell line model of acquired lapatinib resistance. (A) Effect of lapatinib on growth of HCC1954-par and HCC1954-L cells. (B) Immunoblot analysis of total and phosphorylated eEF2(Thr56) in HCC1954-par and HCC1954-L cells following 24 hr lapatinib treatment. (C) Activity of PP2A in HCC1954-par and HCC1954-L cells, untreated and treated with 5 nM OA for 24 hr. (D) Immunoblot examining the effect of okadaic acid (OA) alone and in combination with lapatinib on levels of total and phosphorylated eEF2(Thr56) and AKT(Ser473). (E) Effect of 5 nM OA on growth of SKBR3-par and SKBR3-L cells. (F) Effect of OA alone and in combination with lapatinib on the growth of HCC1954-par cells and (G) HCC1954-L cells. *denotes p ≤ 0.05, **denotes p ≤ 0.01. Error bars represent the mean ± SD (n = 3).