Figure 4.

5-LP is regulated by GSNO and mithramycin A, an Sp1/Sp3 transcription binding site inhibitor. (A) Western blot analysis was performed on whole cell extracts made from A549 cells treated with 0.5 μM and 1 μM GSNO. In addition, the cells were treated with 1 μM GSNO in the presence of 25 nM mithramycin A for a 6-h incubation period. The membrane was stripped and re-probed with α-tubulin to verify that an equal amount of protein was loaded. (B) Blots were scanned and densitometry was performed for quantification. Twenty-five micrograms protein was loaded in each lane (n = 3; P < 0.003).