| In human colorectal tissue samples , the gene expressions of 4 coactivators , p 300 , pCAF , TIF 2 and TRAP 220 , and 7 corepressors , N CoR , REA , MTA 1 , MTA1L1 , HDAC 1 , HDAC 2 and HDAC 3 , linked to estrogen receptors ( ER ) , were revealed by traditional RT PCR . ^^^ The decline of mRNA levels of all coactivators and the increase of NCoR , HDAC 1 , HDAC 2 and MTA 1 were observed from normal to tumor tissue , whereas REA , HDAC 3 and MTA1L1 expressions were similar in both tissue compartments . ^^^ |