Fig. 1.

Brk levels are reduced in differentiation. a Normal human primary keratinocytes were induced to differentiate by either culturing in methylcellulose for 48 h (MC) (left hand panel) or in medium containing 1.2 mM Calcium ions for 5 days (Calcium) (right hand panel). Control cells were cultured under normal adherent culture conditions (Control). Cells were lysed in hot SDS-PAGE lysis buffer and relative protein levels determined by western blotting. Brk levels were then suppressed in normal human primary keratinocytes by RNAi. b 48 h following the second transfection with control (Control) or Brk-targeting siRNA (Brk siRNA), cells were lysed in hot SDS-PAGE lysis buffer and relative protein levels determined by western blotting. c 24 and 48 h following the second transfection with control (filled bars) or Brk-targeting siRNA (open bars) cells were harvested, resuspended in 0.1% trypan blue and the percentage of nonviable cells determined