title: Disulfiram-mediated inhibition of NF-kappaB activity enhances cytotoxicity of 5-fluorouracil in human colorectal cancer cell lines.
abstract: 5-Fluorouracil (5-FU) is the major chemotherapeutic component for colorectal cancer (CRC) and other types of solid tumours. Resistance of cancer cells to 5-FU is considered the major obstacle for successful chemotherapy. NF-kappaB is a transcription factor. Cancer cells with high NF-kappaB nuclear activity demonstrate robust chemo- and radio-resistance. We demonstrated that nuclear NF-kappaB activity in CRC cell lines, DLD-1 and RKO(WT), was significantly induced by 5-FU in a concentration- and time-dependent manner. 5-FU induced IkappaBalpha degradation and promoted both NF-kappaB nuclear translocation and its DNA binding activity. 5-FU treatment did not influence the activities of AP-1, AP-2, Oct-1, SP-1, CRE-B and TFIID. Disulfiram (DS), a clinically used anti-alcoholism drug, strongly inhibited constitutive and 5-FU-induced NF-kappaB activity in a dose-dependent manner. DS inhibited both NF-kappaB nuclear translocation and DNA binding activity but had no effect on 5-FU-induced IkappaBalpha degradation. Used in combination, DS significantly enhanced the apoptotic effect of 5-FU on DLD-1 and RKO(WT) cell lines and synergistically potentiated the cytotoxicity of 5-FU to both cell lines. DS also effectively abolished 5-FU chemoresistance in a 5-FU resistant cell line H630(5-FU) in vitro. As DS has extensive preclinical and clinical experience, translating its anticancer usage from in vitro study to clinical trials is relatively straightforward.
authors.affiliation: Department of Medicine and Therapeutics, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom. w.wang@beatson.gla.ac.uk
authors.forename: Weiguang
authors.initials: W
authors.lastname: Wang
authors.forename: Howard L
authors.initials: HL
authors.lastname: McLeod
authors.forename: James
authors.initials: J
authors.lastname: Cassidy
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D017209:Apoptosis / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004247:DNA / Q000378:metabolism; D004221:Disulfiram / Q000494:pharmacology*; D004357:Drug Synergism; D005472:Fluorouracil / Q000494:pharmacology*; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D014407:Tumor Cells, Cultured
chemical_list: D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D000072000:NF-KappaB Inhibitor alpha; D004247:DNA; D004221:Disulfiram; D005472:Fluorouracil