Gene expression profiles modulated by the human carcinogen aristolochic acid I in human cancer cells and their dependence on TP53

• Published in: Toxicology and applied pharmacology Vol. 232; no. 1; pp. 86 - 98
• Main Authors: Simões, Maria L., Hockley, Sarah L., Schwerdtle, Tanja, Gamboa da Costa, Gonçalo, Schmeiser, Heinz H., Phillips, David H., Arlt, Volker M.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.10.2008; Elsevier
• Subjects: 60 APPLIED LIFE SCIENCES; APOPTOSIS; Apoptosis - drug effects; Apoptosis - genetics; Aristolochic acid; Aristolochic Acids - toxicity; Biological and medical sciences; Blotting, Western; Carcinogenesis, carcinogens and anticarcinogens; CARCINOGENS; Carcinogens - toxicity; CELL CYCLE; Cell Cycle - drug effects; Cell Survival - drug effects; Chemical agents; Cluster Analysis; Colonic Neoplasms - genetics; Colonic Neoplasms - metabolism; Colonic Neoplasms - pathology; DNA; DNA ADDUCTS; DNA Breaks; DNA REPLICATION; Dose-Response Relationship, Drug; FASTENING; Flow Cytometry; Gene Deletion; Gene expression; Gene Expression Profiling - methods; Gene Expression Regulation, Neoplastic - drug effects; HCT116 Cells; Humans; INHIBITION; INJURIES; Medical sciences; Microarray; MODULATION; NEOPLASMS; Oligonucleotide Array Sequence Analysis; ONCOGENES; Oxidative Stress - drug effects; Oxidative Stress - genetics; Plant poisons toxicology; RECEPTORS; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction - drug effects; Signal Transduction - genetics; Time Factors; Toxicology; TP53; TUBULES; Tumor Suppressor Protein p53 - genetics; Tumor Suppressor Protein p53 - metabolism; Tumors; Urothelial cancer; Urothelial cancer; Aristolochic acid; Gene expression; Microarray; TP53; Apoptosis; Human; Toxicity; DNA chip; Malignant tumor; Gene expression profile; Carcinogen; TP53 Gene; Cell death; Dependence; Plant origin; Tumor cell; Cancer; Tumor suppressor gene
• ISSN: 0041-008X; 1096-0333
• DOI: 10.1016/j.taap.2008.06.006

Aristolochic acid (AA) is the causative agent of urothelial tumours associated with aristolochic acid nephropathy. These tumours contain TP53 mutations and over-express TP53. We compared transcriptional and translational responses of two isogenic HCT116 cell lines, one expressing TP53 (p53-WT) and the other with this gene knocked out (p53-null), to treatment with aristolochic acid I (AAI) (50−100 μM) for 6−48 h. Modulation of 118 genes was observed in p53-WT cells and 123 genes in p53-null cells. Some genes, including INSIG1, EGR1, CAV1, LCN2 and CCNG1, were differentially expressed in the two cell lines. CDKN1A was selectively up-regulated in p53-WT cells, leading to accumulation of TP53 and CDKN1A. Apoptotic signalling, measured by caspase-3 and -7 activity, was TP53-dependent. Both cell types accumulated in S phase, suggesting that AAI-DNA adducts interfere with DNA replication, independently of TP53 status. The oncogene MYC, frequently over-expressed in urothelial tumours, was up-regulated by AAI, whereas FOS was down-regulated. Observed modulation of genes involved in endocytosis, e.g. RAB5A, may be relevant to the known inhibition of receptor-mediated endocytosis, an early sign of AA-mediated proximal tubule injury. AAI-DNA adduct formation was significantly greater in p53-WT cells than in p53-null cells. Collectively, phenotypic anchoring of the AAI-induced expression profiles to DNA adduct formation, cell-cycle parameters, TP53 expression and apoptosis identified several genes linked to these biological outcomes, some of which are TP53-dependent. These results strengthen the importance of TP53 in AA-induced cancer, and indicate that other alterations, e.g. to MYC oncogenic pathways, may also contribute.