Article Title: Restoring PUMA induction overcomes KRAS-mediated resistance to anti-EGFR antibodies in colorectal cancer
Figure Lengend Snippet: KRAS -mediated resistance to anti-EGFR antibodies abrogates PUMA induction (A) MTS analysis of parental (red) and cetuximab-resistant (Cmab-R, black) DiFi cells treated with cetuximab (Cmab) or panitumumab (Pmab) at the indicated doses for 72 hr. (B) Western blotting of cleaved (C) caspase-3 in the parental and Cmab-R DiFi cells treated with 10 nM of Cmab or Pmab for 24 hr. (C) Western blotting of indicated proteins in the parental and Cmab-R DiFi cells. Lysates of Cmab-R DiFi cells were prepared from cells cultured in medium with 10 nM cetuximab (Cmab+), or without cetuximab (Cmab-) for 6 days. p-EGFR (Y1068); p-AKT (S473); p-ERK1/2 (T202/Y204). (D) Western blotting of indicated Bcl-2 family proteins in the parental and Cmab-R DiFi cells treated with 10 nM of Cmab for 24 hr. (E) Western blotting of phosphorylated (p-p73, Y99) and total p73 in the parental and Cmab-R DiFi cells treated with 10 nM Cmab for 8 hr. (F) Parental and Cmab-R DiFi cells transfected with control empty or HA-p73α-expressing vector were treated with 10 nM cetuximab for 8 hr. Binding of transfected p73α to the PUMA promoter was analyzed by chromatin immunoprecipitation (ChIP) using anti-HA antibody, followed by PCR amplification and analysis of PCR products by agarose gel electrophoresis. (G) Parental and Cmab-R DiFi cells were infected with EGFP-PUMA-expressing adenovirus (Ad-PUMA) at the indicated MOI for 24 hr. Upper, analysis of apoptosis by nuclear fragmentation; lower , western blotting of PUMA. Results were expressed as means ± s.e.m. of triplicates in two independent experiments. *** P
Article Snippet: Western blotting Western blotting was performed as previously described [ ] using antibodies against: β-Actin (A5441, Sigma), cleaved caspase-3 (#9661, Cell Signaling, Danvers, MA, USA), cleaved caspase-9 (#9502, Cell Signaling), Mcl-1 (#559027, BD Biosciences, San Jose, CA, USA), Bax (#610983, BD Biosciences), Bid (#2002, Cell Signaling), Bcl-xL (#610212, BD Biosciences), Bim (#2819, Cell Signaling), Bcl-2 (#M0887, Agilent DAKO, Santa Clara, CA, USA), cytochrome c (sc-7159, Santa Cruz Biotechnology, Santa Cruz, CA, USA), COX IV (A21348, Invitrogen), PUMA [ ], Bak (#06–536, EMD Millipore), Noxa (#OP180, EMD Millipore), p73 (A300–126A, Bethyl Laboratories, Montgomery, TX, USA), p-p73 (#4665, Cell Signaling), p-AKT (#4058, Cell Signaling), total AKT (#9272, Cell Signaling), p-ERK1/2 (#4376, Cell Signaling), total ERK1/2 (#9102, Cell Signaling), p-FoxO3A (#9464, Cell Signaling), total FoxO3A (07–702, EMD Millipore), p53 (sc-126, Santa Cruz), p-EGFR (#2234, Cell Signaling), total EGFR (#610016, BD Biosciences), KRAS (sc-30, Santa Cruz), p-Aurora A/B/C (#2914, Cell Signaling), total Aurora A (#4718, Cell Signaling), total Aurora B (#3094, Cell Signaling), and HA (#12CA5, Roche, Indianapolis, IN, USA).
Techniques: Western Blot, Cell Culture, Transfection, Expressing, Plasmid Preparation, Binding Assay, Chromatin Immunoprecipitation, Polymerase Chain Reaction, Amplification, Agarose Gel Electrophoresis, Infection