FIGURE 9:

Regulatory role of β1 integrin in androgen- or NGF-stimulated neuritogenesis of PC12 cells. PC12 cells were used. (A, B) Growing cells on polylysine-coated coverslips were transfected with β1 integrin or nt siRNA. Purified pEGFP plasmid (Amaxa) was included to help identification of transfected cells. Cells were made quiescent and then left unchallenged or challenged for 48 h with R1881 (10 nM) or NGF (100 ng/ml). In GFP-expressing cells, neurite outgrowth was analyzed by contrast phase microscopy and is expressed as percentage of transfected cells. Several coverslips were analyzed, and data from at least 200 scored cells for each coverslip were collected and graphically shown in B. The blot in A shows β1 integrin protein levels detected by Western blot of lysate proteins from PC12 cells transfected with nt siRNA or β1 integrin siRNA. (C) Growing plastic-plated cells were transfected with β1 integrin or nt siRNA. Quiescent cells were then left untreated or treated for 5 min with the indicated compounds: R1881 at 10 nM, bicalutamide (Bic) at 10 μM, and NGF at 100 ng/ml. Lysate proteins (2 mg/ml protein) were immune-precipitated with C-19 anti-AR antibodies. Proteins lysates or immune complexes were analyzed using antibodies against the indicated proteins. The C-19 anti AR Ab was used to detect AR.