Ras oncogene and Hypoxia-inducible factor-1 alpha (hif-1α) expression in the Amazon fish Colossoma macropomum (Cuvier, 1818) exposed to benzo[a]pyrene

• Published in: Genetics and molecular biology 2017-04, Vol.40 (2), p.491-501
• Main Authors: Silva, Grazyelle Sebrenski da, Fé, Luciana Mara Lopes, Silva, Maria de Nazaré Paula da, Val, Vera Maria Fonseca de Almeida E
• Format: Article
• Language: English
• Subjects: B[a]P; Benzo(a)pyrene; Bioassays; BIOCHEMISTRY & MOLECULAR BIOLOGY; Cancer; Colossoma macropomum; Comet assay; Corn oil; Damage; Damage detection; Deoxyribonucleic acid; DNA; DNA damage; Exposure; Fish; Gene expression; GENETICS & HEREDITY; genotoxic damage; Genotoxicity; hif-1α; Hypoxia; Hypoxia-inducible factor 1; Hypoxia-inducible factor 1a; Hypoxia-inducible factors; Liver; Mutagenesis; Oncogenes; Pyrene; Ras oncogene; tambaqui; Toxicity
• ISSN: 1415-4757; 1678-4685; 1678-4685
• DOI: 10.1590/1678-4685-GMB-2016-0066

Benzo[a]pyrene (B[a]P) is a petroleum derivative capable of inducing cancer in human and animals. In this work, under laboratory conditions, we analyzed the responses of Colossoma macropomum to B[a]P acute exposure through intraperitoneal injection of four different B[a]P concentrations (4, 8, 16 and 32 μmol/kg) or corn oil (control group). We analyzed expression of the ras oncogene and the Hypoxia-inducible factor-1 alpha (hif-1α) gene using quantitative real-time PCR. Additionally, liver histopathological changes and genotoxic effects were evaluated through the comet assay. Ras oncogene was overexpressed in fish exposed to 4, 8 of 16 μmol/kg B[a]P, showing 4.96, 7.10 and 6.78-fold increases, respectively. Overexpression also occurred in hif-1α in fish injected with 4 and 8 μmol/kg B[a]P, showing 8.82 and 4.64-fold increases, respectively. Histopathological damage in fish liver was classified as irreparable in fish exposed to 8, 16 and 32 μmol/kg μM B[a]P. The genotoxic damage increased in fish injected with 8 and 16 μmol/kg in comparison with the control group. Acute exposure of B[a]P was capable to interrupt the expression of ras oncogene and hif-1α, and increase DNA breaks due to tissue damage.