title: Identification of 5-fluorouracil-inducible target genes using cDNA microarray profiling.
abstract: The fluoropyrimidine 5-Fluorouracil (5-FU) is widely used in the treatment of cancer. To identify novel downstream mediators of tumor cell response to 5-FU, we used DNA microarray technology to identify genes that are transcriptionally activated by 5-FU treatment in the MCF-7 breast cancer cell line. Of 2400 genes analyzed, 619 were up-regulated by >3-fold. Highly up-regulated genes (>6-fold) with signal intensities of >3000 were analyzed by Northern blot. Genes that were consistently found to be up-regulated were spermine/spermidine acetyl transferase (SSAT), annexin II, thymosin-beta-10, chaperonin-10, and MAT-8. Treatment of MCF-7 cells with the antifolate tomudex and DNA-damaging agent oxaliplatin also resulted in up-regulation of each of these targets. The 5-FU-induced activation of MAT-8, thymosin-beta-10, and chaperonin-10 was abrogated by inactivation of p53 in MCF-7 cells, whereas induction of SSAT and annexin II was significantly reduced in the absence of p53. Moreover, each of these genes contained more than one potential p53-binding site, suggesting that p53 may play an important regulatory role in 5-FU-induced expression of these genes. In addition, we found that basal expression levels of SSAT, annexin II, thymosin beta-10, and chaperonin-10 were increased (by approximately 2-3-fold), and MAT-8 expression dramatically increased (by approximately 10-fold) in a 5-FU-resistant colorectal cancer cell line (H630-R10) compared with the parental H630 cell line, suggesting these genes may be useful biomarkers of resistance. These results demonstrate the potential of DNA microarrays to identify novel genes involved in mediating the response of tumor cells to chemotherapy.
authors.affiliation: Department of Oncology, Cancer Research Centre, Queen's University Belfast, University Floor, Belfast City Hospital, Lisburn Road, Belfast BT9 7AB, Northern Ireland.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Maxwell
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Longley
authors.forename: Tariq
authors.initials: T
authors.lastname: Latif
authors.forename: John
authors.initials: J
authors.lastname: Boyer
authors.forename: Wendy
authors.initials: W
authors.lastname: Allen
authors.forename: Maria
authors.initials: M
authors.lastname: Lynch
authors.forename: Ultan
authors.initials: U
authors.lastname: McDermott
authors.forename: D Paul
authors.initials: DP
authors.lastname: Harkin
authors.forename: Carmen J
authors.initials: CJ
authors.lastname: Allegra
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Johnston
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D015139:Blotting, Southern; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics*; D019008:Drug Resistance, Neoplasm; D005472:Fluorouracil / Q000494:pharmacology*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D020868:Gene Silencing / Q000187:drug effects; D016158:Genes, p53 / Q000187:drug effects / Q000235:genetics; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D009944:Organoplatinum Compounds / Q000494:pharmacology; D000077150:Oxaliplatin; D015533:Transcriptional Activation / Q000187:drug effects; D014407:Tumor Cells, Cultured
chemical_list: D000964:Antimetabolites, Antineoplastic; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D005472:Fluorouracil