MDCK Tet-off cells secreted exogenous mLIF-D and mLIF-M predominantly in the apical direction across a range of expression levels. MDCK cells grown on permeable filters were incubated without doxycycline (No Dox) or varying concentrations of doxycycline (Dox) to regulate the expression level of mLIF-D (a, b) or mLIF-M (c-f). After 24 hours, conditioned media was collected from the apical and basal chambers and analyzed for mLIF by ELISA. a, c, e) Total amount of mLIF secreted. b, d, f) Percentage of mLIF secreted into the apical chamber. Values are expressed as mean +/-SEM (n = 3). ND (not detected at 1 μg/ml Dox). *P < 0.05; vs 1 μg/ml Dox. #P < 0.05; vs. 0.5 ng/ml Dox; ~P < 0.05; vs. 1 ng/ml Dox.
Hill and Vernallis BMC Cell Biology 2008 9:53 doi:10.1186/1471-2121-9-53