Protein A/G beads, anti-mouse and anti-rabbit immunoglobulin G (IgG) conjugated horseradish peroxidase, rabbit polyclonal antibodies specific for PI3K, Akt, IKKα/β, IκB, p65, and β-actin were purchased from Santa Cruz Biotechnology (Santa Cruz, CA, USA). Rabbit polyclonal antibody specific for PI3K phosphorylated at Tyr
458/199, Akt phosphorylated at ser
473, IKKα/β phosphorylated at ser
176/180, IκBα phosphorylated at ser
32/36 and p65 phosphorylated at ser
536 were purchased from Cell Signaling and Neuroscience (Danvers, MA, USA). Mouse monoclonal antibody specific for αvβ3, αvβ5, and α5β1 integrin were purchased from Chemicon (Temecula, CA, USA). Pyrrolidine-dithiocarbamate (PDTC), L-1-tosylamido-2-phenylenylethyl chloromethyl ketone (TPCK), LY294002, Wortmannin, and pan-Akt inhibitor (1L-6-hydroxymethyl-chiro-inositol-2-((
R)-2-
O-methyl-3-
O-octadecylcarbonate) were purchased from Calbiochem (San Diego, CA, USA). IL-6 enzyme immunoassay kit was purchased from Cayman Chemical (Ann Arbor, MI, USA). The recombinant human CCN4 was purchased from PeproTech (Rocky Hill, NJ, USA). ON-TARGETplus siRNA of αv integrin, β5 integrin, p110 and control were purchased from Dharmacon Research (Lafayette, CO, USA). The NF-κB luciferase plasmid was purchased from Stratagene (La Jolla, CA, USA). The p85 and Akt1 (Akt1 K179A) dominant-negative mutants were gifts from Dr. W.M. Fu (National Taiwan University, Taipei, Taiwan). The human IL-6 promoter construct pIL6-luc651 (-651/+1), AP-1 site mutation (pIL6-luc651ΔAP1), NF-κB site mutation (pIL6-luc651ΔNF-κB), and C/EBP-β site mutation (pIL6-luc651ΔC/EBP-β) [
22] were gifts from Dr. Oliver Eickelberg (Ludwig Maximilians University Munich, Munich, Germany). The pSV-β-galactosidase vector and the luciferase assay kit were purchased from Promega (Madison, MA, USA). All other chemicals were purchased from Sigma-Aldrich (St. Louis, MO, USA).