Nicotinamide nam

Human colorectal carcinoma cell lines HCT116, SW620 and SW480 were obtained from the Cell Bank of the Type Culture Collection of the Chinese Academy of Sciences (Shanghai, China), where they were authenticated. These procedures were based on cross species checks, DNA authentication and quarantine. Cells were maintained in RPMI1640 with 10% serum, penicillin (100 IU/ml), streptomycin (100 μg/ml) (Invitrogen). Cells were grown at 37°C in an atmosphere containing 5% CO₂. Nicotinamide (NAM) was purchased from Sigma.

Normal human bronchial epithelial cells (HBE) were obtained from Lonza, Basel, Switzerland and grown in bronchial epithelial cell growth medium (BEGM) medium. Normal human dermal fibroblasts (HDF) (Lonza, Walkersville, MD, USA) were grown as adherent cultures in fibroblast basal medium supplemented with FGM SingleQuots (Lonza). Human lung adenocarcinoma cells (A549) and Madin-Darby canine kidney (MDCK) cells were obtained from the American Type Culture Collection (ATCC, Manassas, VA, USA). A549 cells were cultured in Roswell Park Memorial Institute (RPMI)-1640 medium (Invitrogen, Carlsbad, CA, USA) supplemented with 10% fetal bovine serum (FBS), 100 U/mL penicillin, and 100 µg/mL streptomycin and maintained at 37℃ with 5% CO₂ in a humidified atmosphere. MDCK cells were grown in Dulbecco's Modified Eagle's Medium (DMEM) (Invitrogen) supplemented with 10% FBS, 100 U/mL penicillin, and 100 µg/mL streptomycin.
Sodium butyrate (NaB), and nicotinamide (NAM) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Recombinant human interferon (IFN)-α, λ1, λ2 was purchased from R&D (Minneapolis, MI, USA) and interferon-β (IFN-β) protein was obtained from PBL Assay Science (Piscataway, NJ, USA).

EVO (S2382, purity 99.76%; Selleck Chemicals, Houston, Texas, USA) was dissolved in dimethyl sulfoxide (Me₂SO) and PBS, respectively. The concentration of Me₂SO was maintained below 0.1% to avoid cytotoxicity [Nicotinamide (NAM, 47865-U, purity 99.9%; Sigma company); Cell Counting Kit-8 (Takara Bio Inc., Shiga, Japan)]. The following antibodies were used for western blot and immunofluorescence: Sirt1 and β-actin (Santa Cruz Biotechnology, Inc., Dallas, Texas, USA); NF-κB p65 and acetyl-NF-κB p65 (Cell Signaling Technology, Danvers, Massachusetts, USA); and MMP-9 (Boster Biological Technology, Wuhan, Hubei, China).