Trichostatin A Suppresses EGFR Expression through Induction of MicroRNA-7 in an HDAC-Independent Manner in Lapatinib-Treated Cells
TSA but not SAHA suppressed lapatinib-induced EGFR expression. (a) Nuclear extract of HeLa cells was added with 1 mM TSA or SAHA for 30 min and then subjected to HDAC activity assays. (b) and (c) MDA-MB-231 and 231/Lap#6 cells were treated with indicated concentration of TSA (b) or SAHA (c) for 24 hours. Total lysates were prepared and subjected to Western blot analysis with indicated antibodies. (d) 231/Lap#6 cells were treated with 1 μM TSA or 5 μM SAHA for 8, 16, or 24 hours. Total lysates extracted from these cells were subjected to Western blot analysis with anti-EGFR and anti-actin antibodies. (e) 231/Lap#6 cells were treated with 1 μM TSA or 5 μM SAHA for 24 hours. Total RNA extracted from these cells was subjected to RT-qPCR with EGFR-specific primers. The induction of EGFR mRNA was normalized to GAPDH expression.