Human neuroblastoma cell viability and growth are affected by altered culture conditions

The effects of differing culture parameters are seldomly investigated, even though they influence the way immortalized cells grow and die. In this study, the changes in total cell number, confluency, membrane permeability, and DNA content were evaluated in SH-SY5Y and IMR-32 human neuroblastoma cells following culture at different seeding densities and media consistencies. These four endpoints were determined using a hemacytometer, phase-contrast microscope, trypan blue (0.4% v/v), and propidium iodide (50 microg/mL), respectively. Both cell lines (SH-SY5Y and IMR-32) responded in a similar manner to changing culture conditions, even though baseline values for all four endpoints were different. Higher seeding densities (19,200 and 38,400 cells/cm2) significantly increased the percent confluency and total cell number over time, but decreased the initial percentage of cells with fragmented (subG1) DNA in both cell lines when compared with lower seeding densities (4800 and 9600 cells/cm2, p < 0.05). Daily media changes significantly increased the percentage of cells in S and G2/M, but decreased the percentage of cells in G0/G1 phase of the cell cycle over time in both cell lines when compared with cultures without media changes (p < 0.05). Results suggest that environmental culture conditions greatly affect cellular mitosis and death. This information may be of particular relevance in the investigation of compounds that act on specific cell-cycle stages, such as antineoplastic agents.