Fish p53 as a possible biomarker for genotoxins in the aquatic environment

The p53 gene is a tumour suppressor gene which has a fundamental role in cell cycle control and division, and in mammals certain genotoxic agents induce specific mutations in p53, leading to tumourigenesis. Fish have been investigated as models for studying carcinogens, but as yet very little data exists that links exposure to specific chemicals with the aetiology of tumours found in wild populations. In this study, p53 was sequenced from five species of fish with a view to the possible use of mutations in the highly conserved domains of p53 to identify genotoxins in the aquatic environment. A 0.8kb fragment of the cDNA encompassing the conserved DNA‐binding domain of p53 was sequenced in three Oncorhynchus salmonid fish: coho (O. kisutch), chum (O. keta), and chinook (O. tshawytscha) and full‐length p53 cDNAs were sequenced in the puffer fish (Tetraodon miurus) and the barbel (Barbus barbus). The full‐length puffer fish and barbel p53 cDNAs were 1834 bp and 1790 bp in length, encoding a 367 aa protein and a 369 aa protein, respectively. The deduced aa sequences of the p53 cDNA in the Oncorhynchus salmon shared a 100% identity in the five conserved regions (I–V). Comparisons of the deduced aa sequences for puffer fish and barbel p53 with other fish p53s revealed a high homology within the conserved DNA binding domain (68–86% for puffer fish and between 66–88% for barbel). “Conserved” domain I was not highly conserved in fish, as it is in mammals, and, therefore, conserved domains II–V are most likely to provide the valuable sequences in fish p53 for use in mutational studies to fingerprint genotoxins in the aquatic environment. Environ. Mol. Mutagen. 33:177–184, 1999 © 1999 Wiley‐Liss, Inc.

[1]  S. Friend,et al.  Mutational analysis of the carboxy-terminal portion of p53 using both yeast and mammalian cell assays in vivo. , 1995, Oncogene.

[2]  M. Krause,et al.  Cloning of the p53 tumor suppressor gene from the Japanese medaka (Oryzias latipes) and evaluation of mutational hotspots in MNNG-exposed fish. , 1997, Gene.

[3]  D. C. Malins,et al.  The etiology of cancer: hydroxyl radical-induced DNA lesions in histologically normal livers offish from a population with liver tumors , 1991 .

[4]  C. Harris,et al.  Mutations in the p53 tumor suppressor gene: clues to cancer etiology and molecular pathogenesis. , 1994, Cancer research.

[5]  A. Yang,et al.  Monoallelically Expressed Gene Related to p53 at 1p36, a Region Frequently Deleted in Neuroblastoma and Other Human Cancers , 1997, Cell.

[6]  P. Chomczyński,et al.  Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. , 1987, Analytical biochemistry.

[7]  Harris Cc,et al.  Molecular epidemiology of human cancer: contribution of mutation spectra studies of tumor suppressor genes. , 1998 .

[8]  C. Prives,et al.  p53: puzzle and paradigm. , 1996, Genes & development.

[9]  T. Soussi,et al.  Structural aspects of the p53 protein in relation to gene evolution: a second look. , 1996, Journal of molecular biology.

[10]  D. Williams,et al.  Fish models for environmental carcinogenesis: the rainbow trout. , 1996, Environmental health perspectives.

[11]  K. Kinzler,et al.  Carcinogens leave fingerprints , 1992, Nature.

[12]  J. Thompson,et al.  CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice. , 1994, Nucleic acids research.

[13]  C. Bamberger,et al.  A novel protein with strong homology to the tumor suppressor p53 , 1997, Oncogene.

[14]  C. Tyler,et al.  Incidences of gross morphological disorders in barbel (Barbus barbus) in three rivers in southern England , 1993 .

[15]  J. Hendricks,et al.  Anticarcinogenesis in fish. , 1992, Mutation research.

[16]  T. Soussi,et al.  Rainbow trout p53: cDNA cloning and biochemical characterization. , 1992, Gene.

[17]  S. Brenner,et al.  Characterization of the pufferfish (Fugu) genome as a compact model vertebrate genome , 1993, Nature.

[18]  D. Powers.  Fish as model systems. , 1989, Science.

[19]  D. Lipman,et al.  Improved tools for biological sequence comparison. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[20]  F. Sanger,et al.  DNA sequencing with chain-terminating inhibitors. , 1977, Proceedings of the National Academy of Sciences of the United States of America.

[21]  R. Sonstegard.  ENVIRONMENTAL CARCINOGENESIS STUDIES IN FISHES OF THE GREAT LAKES OF NORTH AMERICA * , 1977, Annals of the New York Academy of Sciences.

[22]  E. Marshall.  NIH Nomination on Hold for This Year , 2000, Science.

[23]  L. Hartwell,et al.  Cell cycle control and cancer. , 1994, Science.

[24]  A. Levine,et al.  A comparison of the biological activities of wild‐type and mutant p53 , 1993, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[25]  R. E. Wolke,et al.  Epizootic Carcinoma in the Winter Flounder, Pseudopleuronectes americanus , 1985, Science.

[26]  C. Harris,et al.  p53 tumor suppressor gene: from the basic research laboratory to the clinic--an abridged historical perspective. , 1996, Carcinogenesis.

[27]  C. Weghorst,et al.  Mutations in the p53 tumor suppressor gene in rat esophageal papillomas induced by N-nitrosomethylbenzylamine , 1996 .

[28]  M. Schiewe,et al.  Field and laboratory studies of the etiology of liver neoplasms in marine fish from Puget Sound. , 1987, Environmental health perspectives.

[29]  G. Mcmahon,et al.  Identification of a c-Ki-ras oncogene in a neoplasm isolated from winter flounder , 1988 .