Fig. 4

MTA1 overexpression significantly inhibited the transcription of the intrinsic inhibitor of NE, elafin, in a HDAC and/or DNMT dependent manner. a Overexpression of MTA1 significantly downregulated the mRNA level of intrinsic inhibitors of NE, elafin and α1-PI, and serine protease inhibitors Serpin B5 and Serpin B7, but didn’t significantly change the transcription of NE, MNEI, Serpin B6, and SLPI. Mean ± SD, n = 3, *P < 0.05, ***P < 0.001, t test. b MTA1 overexpression decreased the protein level of elafin. c Knocking down of elafin decreased MTA2 and MTA1 at protein level. d HDAC inhibitor and e DNMT inhibitor treatments increased the mRNA level of elafin. ZR-75-30-MTA1 cells were treated with HDAC inhibitor SAHA and DNMT inhibitor, AZA, for 48 h, after which the mRNA level of elafin significantly elevated, even to a value higher than that of ZR-75-30-Vector. Mean ± SD, n = 3, **P < 0.01, ***P < 0.001, t test