Figure 3.

Combined treatment with PA and TOP inhibitors enhances PA-induced inhibition of intracellular microtubule polymerization. Control represents mock-treated control. PA, Eto, and Cpt indicate each reagent only-treated sample. PA/Eto and PA/Cpt represent samples treated with a combination of PA and Eto or PA and Cpt. NCI-H1299 and A549 cells were treated with 7.5 and 15 nM PA, respectively. Both cell lines were treated with Eto (0.5 μM) or Cpt (10 nM). (A) Immunocytochemical staining for α-tubulin in NCI-H1299 and A549 cells treated with PA, Eto, Cpt or a combination of the drugs for 24 h. Nuclei are stained blue while α-tubulin is stained green. (B) Immunoblot analyses of α-tubulin in insoluble and soluble fractions of NCI-H1299 and A549 cells treated with PA, Eto, Cpt or a combination for 24 or 48 h.