TSA dual regulation of ABCB1 promoters. A. Western blot analysis of Pgp expression in K-562 (lane 1), K-562/Adr (lane 2), negative and positive control respectively and the colon carcinoma cell lines Colo 320 (lane 3), DLD-1 (lane 4) and LS 174 T (lane 5). β-Actin is included as internal control. B. RT-PCR amplification with F1 and R1 primers of the long 5′ UTR of the MDR1 cDNA. Lane 1. Molecular markers. Lanes 2 and 3.K562/Adr and HTC-15 (positive controls). Lane 4, 6 and 8, Ls174T, Colo320 and DLD1 untreated cell lines. Lane 5, 7 and 9, Ls174T, Colo320 and DLD1 cell lines treated with 1 μM TSA for 24 h. C. Pgp activity in the erythroleukaemia cell lines K-562 (negative control), K-562 (d20) and K-562/Adr (positive control) treated or no treated with 1 μM TSA for 24 h and in the presence or absence of 2.5 μM verapamil (Pgp inhibitor). Pgp activity was estimated as daunomycin accumulation determined by flow cytometry. D. MDR1 mRNA levels determined by real time RT-PCR. K-562, K-562 (d450) and K-562/Adr cell lines were treated or not with 1 μM TSA for 24 h. GAPDH mRNA was also determined as internal control. Results are shown as the mean ± SD of at least three independent experiments with three replicates in each experiment.
Balaguer et al. BMC Molecular Biology 2012 13:25 doi:10.1186/1471-2199-13-25