TCF12 is required for rHSP90α-induced E-cadherin down-regulation.
A, rHSP90α induces TCF12 expression in CRC cells. RT-PCR and immunoblot analyses were performed to demonstrate that TCF12 mRNA and protein levels were both increased in 15 μg/ml rHSP90α-treated HCT-115, LoVo, SW480, and SW620 cells. Representative images from three independent experiments are shown. B and C, TCF12 knockdown prevents rHSP90α-induced E-cadherin down-regulation. The LoVo and SW620 cell clones stably expressing control shRNA or TCF12 shRNA (sequence 1 or 2) were treated with PBS or rHSP90α. RT-PCR and immunoblot analyses were performed to investigate TCF12 and E-cadherin expression levels. Representative images from three independent experiments are shown in B. TCF12 shRNA sequences 1 and 2 were against nucleotides 986∼1006 and 1727∼1747 of TCF12 mRNA, respectively. The sequence of the control shRNA used did not match any known human gene. Real-time RT-PCR was also performed, and the means ± S.D. of three independent experiments are expressed in C to show relative mRNA levels of TCF12, Twist, E-cadherin, and fibronectin in the representative cell clones (stably expressing control shRNA or TCF12 shRNA sequence 1) after treatment with or without rHSP90α.