7 ethyl 10 hydroxycamptothecin sn 38

The human HCT116 colon carcinoma cell line was purchased from DS Pharma Biomedical Co., Ltd (Osaka, Japan). McCoy's 5A medium, Leibovitz L-15 medium (L-15), penicillin-streptomycin and fetal bovine serum (FBS) were purchased from Life Technologies (Carlsbad, CA, USA). Oxaliplatin (L-OHP), gemcitabine (Gem), DAC, AC, zebularine (Zeb), TSA and SAHA were purchased from Wako Pure Chemical Industries, Ltd (Osaka, Japan). 5-fluorouracil (5-FU) was purchased from Nacalai Tesque, Inc. (Kyoto, Japan). Irinotecan (CPT-11), 7-ethyl-10-hydroxycamptothecin (SN-38) and VPA sodium salt were purchased from Sigma-Aldrich (St. Louis, MO, USA). Monoclonal mouse anti-β-actin (dilution, 1:1,000; catalog no. sc-4778), monoclonal mouse anti-CDA (dilution, 1:1,000; catalog no. sc-365292), goat anti-mouse immunoglobulin (Ig)G-horseradish peroxidase (HRP; dilution, 1:2,000–5,000; catalog no. sc-2005) and goat anti-rabbit IgG-HRP antibodies (dilution, 1:2,000; catalog no. sc-2004) were purchased from Santa Cruz Biotechnology, Inc. (Dallas, TX, USA). Monoclonal mouse anti-DNMT1 (dilution, 1:1,000; catalog no. ab-13537), polyclonal rabbit anti-ENT1 (dilution, 1:1,000; catalog no. ab-48607) and polyclonal rabbit anti-dCK (dilution, 1:500; catalog no. ab-91599) antibodies were purchased from Abcam (Cambridge, UK). All other chemicals were of the highest grade commercially available.

The chemotherapeutics 5-fluorouracil (5-FU, Sigma-Aldrich), 7-ethyl-10-hydroxycamptothecin (SN-38, Sigma-Aldrich), oxaliplatin (Selleck Chemicals), MG-132 (Calbiochem) as well as the PHD inhibitor dimethyloxaloylglycine (DMOG, Frontier Scientific) were prepared in DMSO stock solutions and diluted to their final concentration in DMEM (10% FBS, 2 mM l-glutamine, and 1% PenStrep). Treatment times and doses were used as indicated in the results.

Mock and Slug-encoding plasmids were constructed using Vectorbuilder (Chicago, IL, USA) and contained human Stuffer_300bp (Mock) or SNAI2 (NM_003068.5, Slug), respectively, and enhanced green fluorescent protein sequences. 5(6)-Carboxy-2′,7′-dichlorofluorescein (CDCF, substrate of MRP2) was purchased from Promokine (Heidelberg, Germany). 7-Ethyl-10-hydroxycamptothecin (SN-38) was purchased from Sigma-Aldrich (St. Louis, MO, USA). Mouse anti-human GAPDH (sc-365062), Slug (sc-166476), Msn (sc-58806), goat anti-mouse IgG-HRP (sc-2005), and goat anti-rabbit IgG-HRP (sc-2004) antibodies were purchased from Santa Cruz Biotechnology (Dallas, TX, USA). MRP2 (ab-3373), Ezr (T567), and Rdx (PAS-21660) were purchased from Abcam (Cambridge, UK), Cell Signaling Technology (Danvers, MA, USA), and Invitrogen (Waltham, MA, USA), respectively. All other reagents were commercial reagent-grade products.