FIG. 2.

G₁/S arrest inhibits Bim expression following detachment. (A) Mimosine treatment inhibits detachment-induced Bim upregulation. MCF-10A cells were treated with vehicle (Control) or mimosine as described in Materials and Methods. Following vehicle control or mimosine treatment for 24 h, cells were plated on either tissue culture plastic or Poly-HEMA-coated plates in full growth medium for 24 h. Attached (att) and suspended (susp) lysates were harvested and immunoblotted with anti-Bim antiserum to examine Bim expression. (B) Aphidicolin treatment inhibits detachment-induced Bim upregulation. Cells were treated with vehicle (Control) or aphidicolin as described in Materials and Methods. Bim expression was determined 24 h following detachment as described for panel A. (C) CKI expression inhibits detachment-induced Bim upregulation. MCF-10A cells transduced with vectors encoding p16^INK4a, p21^Cip1, p27^Kip1, or empty control vector (BABE) were plated as described for panels A and B. Bim expression was determined following detachment as described for panel A.