Expression of cyclin B1 after induction of senescence and cell death in non-small cell lung carcinoma A549 cells.

The purpose of this study was to evaluate the level of mitotic cyclin B1 in the context of senescence and cell death in A549 non-small cell lung carcinoma cells. This was performed through analysis of the cell cycle, the percentage of SA-β-galactosidase-positive, as well as TUNEL-positive cells. Morphological alterations were studied using a transmission electron microscope. Changes in the intracellular level and the presence of cyclin B1 in the nucleus and cytoplasm areas were detected by flow cytometry and confocal fluorescence microscopy, respectively. In the cells exposed to various concentrations of doxorubicin, different kinds of cell death and senescent phenotype were observed. Alterations in the cell cycle and increased polyploidy may be indicative of mitotic catastrophe execution. Changes in cyclin B1 may also be strictly related to its different regulation at mitotic catastrophe and senescence programs.