CTS-treated MCF10A cell viability is time-dependent and serum-sensitive.
A) MCF10A (dashed line) cells incubated with 500 nM ouabain showed a time-dependent decrease in viability during CTS treatment. MDA-MB-231 (solid line) viability was unaffected during the 48 hour duration of ouabain treatment. B) MCF10A cells grown with serum deprivation or with serum concentrations less than 5% had reduced viability when treated with 500 nM ouabain for 24 hours (dashed line). MDA-MB-231 cell viability was not affected by ouabain treatment when grown in 0-10% serum concentrations (solid line). C) MCF10A isolated membranes were incubated with 0-10% serum with or without 500 nM ouabain prior to ATPase assay. The difference in ATPase activity between untreated and ouabain treated was measured and displayed according to serum level. No significant difference in ATPase inhibition by ouabain exists from altering serum levels (p > 0.05).