The overexpression of Pax6 affects mesenchymal to epithelial transition (MET) pathway during iPS induction in NPC

We performed a microarray analysis to compare N31EGFP and N31Pax6 transcriptional profiles 24 h after iPS induction. Among 603 genes whose levels changed greater than two-fold (295 lower, 308 higher), we noticed a 10-fold decrease in the Cdh1 signal in N31Pax6, which was confirmed by reverse transcription-mediated quantitative polymerase chain reaction (RT-QPCR). iPS induction is known to require activation of the mesenchymal to epithelial transition (MET) pathway, which involves Cdh1 upregulation. In fact, Twist1 expression, repression of which is required for MET pathway activation was higher in N31Pax6. Dox-inducible iPS-NPC, N31, was established from the primary iPSC induced from NSEB5-2C by introducing dox-inducible Oct3/4, Sox2, Klf4 and c-Myc. EGFP or Pax6 were overexpressed in N31 by transfecting CAG-EGFP-IP or CAG-Pax6-IP by Tol2 transposon. Gene expression was measured at 24 hours after exposure to doxycycline, when apparent morphological change was observed only in N31EGFP.