Fig. 6

Inhibitors of the PTEN/AKT/mTOR pathway abolished the effect of EpCAM on NPC cell invasion and stem-like properties. a The invasive abilities of S-18 and 6–10B cells expressing EpCAM or the empty vector were assessed with transwell assays after pretreatment with or without 5 μM MK2206 (AKT inhibitor) (left) or 100 nM rapamycin (right). b The sphere formation efficiency of S-18 and 6–10B cells expressing EpCAM or the empty vector was evaluated after pretreatment with or without 5 μM MK2206 (left) or 100 nM rapamycin (right). c EpCAM-induced CD44 and ABCG2 expression was diminished by MK2206 and rapamycin treatment. d Suppression of PTEN expression by siRNA restored the reduced invasion and CD44 and ABCG2 expression in EpCAM-depleted HONE1 cells. Transwell assays were performed with HONE1 cells transfected with siRNA-EpCAM, siRNA-EpCAM plus siRNA-PTEN, or NC. Suppression of PTEN expression by siRNA in EpCAM-repressed cells rescued AKT/mTOR activities