Protein Quantification and Western Blotting Protocol

Bicinchoninic acid (BCA) protein assay (Pierce Biotechnology, Rockford, IL, USA) was used to determine the protein content in each sample. Quantified each sample concentration to 60-80 µg and proteins were fractionated on SDS-PAGE, transferred onto Hybond enhanced chemiluminescence nitrocellulose membranes (Amersham, Little Chalfont, UK) and detected with antibodies against P-gp (GeneTex, Inc. Irvine, CA, USA), the mammalian target of rapamycin (mTOR) (Cell Signaling, Danvers, MA, USA), phosph-mTOR (Cell Signaling), protein kinase B (AKT) (Santa Cruz Biotechnology, Inc. Santa Cruz, CA, USA), phosph-AKT (Santa Cruz Biotechnology, Inc.), p70s6K (Cell Signaling), phosph-p70s6K (Cell Signaling), caspase 3 (Cell Signaling), β-actin (Sigma Aldrich). Rabbit anti-mouse IgG-peroxidase antibody (Sigma Aldrich) and goat anti-rabbit IgG-peroxidase antibody (Sigma Aldrich) were used as the secondary antibody and protein-antibody complexes were visualized by enhanced chemiluminescence system. The Western blotting signals were quantified with ImageJ software (rsbweb.nih.gov/ij/) 14 (link), 15 (link).