A Preclinical Evaluation of Antimycin A as a Potential Antilung Cancer Stem Cell Agent
Figure 3
Antimycin A dose dependently suppresses the self-renewing ability of lung cancer stem cells. (a) Different concentrations of AMA (0, 5, and 10 μM) were used to treat A549 tumor spheroids. AMA exhibited a dose-dependent ability to inhibit tumor sphere formation. Inserts depict the morphology of AMA-treated tumor spheroids. Scale bar, 50 μm. (b) Western blot analysis of AMA-treated A549 tumor spheroids. AMA dose dependently suppressed the expression of components of the β-catenin signaling cascade. (c) TOP/FOP luciferase assay was used to examine AMA’s ability to suppress β-catenin-TCF/LEF transcriptional activity in A549 SP cells. AMA treatment significantly suppressed the transcriptional activity of the β-catenin pathway as indicated by decreased luciferase activity as the concentration of AMA increased. (d) Flow cytometric and RT-PCR analyses of AMA-mediated downregulation of CD133 expression. By flow cytometric analysis, AMA treatment suppressed the percentage of A549 SP cells that expressed CD133 by approximately 40%. Consistently, RT-PCR analysis demonstrated a significantly downregulated CD133 transcript in AMA-treated A549 SP cells. GAPDH served as internal control. *denotes while **represents as compared to their respective controls.
