Total RNA from cells was isolated with RNeasy total RNA isolation kit (Qiagen, Valencia, CA). The isolated 1 mg of total RNA was reverse-transcribed using Superscript III first-strand synthesis system (Invitrogen) according to the manufacturer's protocol. Real-time RT-PCR was performed using SYBR Green ER qPCR super mix (Invitrogen) and an Applied Biosystems Step One Plus Real-Time PCR system (Applied Biosystems, Carlsbad, CA). All reactions were carried out in a 20 ml reaction volume in triplicate. Primers for human GAPDH, E-cadherin, occludin, vimentin, fibronectin 1, a-smooth muscle actin, snail, slug, CCL2, CCL3, CCL4, CCL5, CCL17, CCL19, CCL20, CCL21, CCL22 and CXCL12 were as previously described [46,47,48,49,50, 51,52,53, Lin, 2009 