The tissue culture plastic plates (six-well) and 30 mm culture dishes were purchased from BD Biosciences (Lincoln Park, NJ); culture plate inserts used for fastening AM from Millipore (Bedford, MA); amphotericin B, Dulbecco’s modified Eagle’s medium (DMEM), fetal bovine serum (FBS), gentamicin, Hank’s balanced salt solutions (HBSS), HEPES buffer, phosphate buffered saline (PBS), 0.05% trypsin/0.53 mM EDTA, and RNA extraction reagent (Trizol) from Invitrogen-Gibco (Grand Island, NY); 4% to 15% gradient SDS-polyacrylamide gel and horseradish secondary anti-rabbit antibody from Bio-Rad (Hercules, CA); collagenase A from Roche Diagnostics (Indianapolis, IN); aminobenzamidine, EDTA tetrasodium salt, guanidine, hydrochloric acid, isopropanol, chloroform, endo-β-galactosidase, sodium acetate, and urea from Sigma-Aldrich (St. Louis, MO). A cell viability assay (Live/Dead Assay) was obtained from Molecular Probes (Eugene, OR).