title: Trace metals and over-expression of metallothioneins in bladder tumoral lesions: a case-control study.
abstract: BACKGROUND
  Previous studies have provided some evidence of a possible association between cancer and metallothioneins. Whether this relates to an exposure to carcinogenic metals remains unclear.
  
  
  METHODS
  In order to examine the association between the expression of metallothioneins and bladder tumors, and to compare the levels of arsenic, cadmium, chromium, lead and nickel in animals with bladder tumors and animals without bladder tumors, 37 cases of bovine bladder tumors and 17 controls were collected. The detection and quantification of metallothioneins in bladder tissue of both cases and controls was performed by immunohistochemistry. And the quantification of metals in tissue and hair was assessed by inductively coupled plasma - mass spectrometry.
  
  
  RESULTS
  Increased expression of metallothioneins was associated with bladder tumors when compared with non-tumoral bladder tissue (OR = 9.3, 95% CI: 1.0 - 480). The concentrations of cadmium, chromium, lead and nickel in hair of cases were significantly higher than those of controls. However, as for the concentration of metals in bladder tissue, the differences were not significant.
  
  
  CONCLUSIONS
  Though the sample size was small, the present study shows an association between bladder tumors and metallothioneins. Moreover, it shows that concentrations of metals such as cadmium, chromium, lead and nickel in hair may be used as a biomarker of exposure.
authors.affiliation: Spanish National Cancer Research Centre (CNIO), Genetic and Molecular Epidemiology Group, Madrid, Spain. aamaral@cnio.es
authors.forename: André F S
authors.initials: AF
authors.lastname: Amaral
authors.forename: Teresa
authors.initials: T
authors.lastname: Cymbron
authors.forename: Fátima
authors.initials: F
authors.lastname: Gärtner
authors.forename: Manuela
authors.initials: M
authors.lastname: Lima
authors.forename: Armindo S
authors.initials: AS
authors.lastname: Rodrigues
mesh_terms: D000236:Adenoma / Q000737:chemistry / Q000378:metabolism / Q000662:veterinary; D000818:Animals; D002277:Carcinoma / Q000737:chemistry / Q000378:metabolism / Q000662:veterinary; D002417:Cattle; D002418:Cattle Diseases / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D006197:Hair / Q000737:chemistry; D006391:Hemangioma / Q000737:chemistry / Q000378:metabolism / Q000662:veterinary; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D008670:Metals / Q000378:metabolism*; D010212:Papilloma / Q000737:chemistry / Q000378:metabolism / Q000662:veterinary; D012307:Risk Factors; D014131:Trace Elements / Q000378:metabolism*; D001749:Urinary Bladder Neoplasms / Q000737:chemistry / Q000378:metabolism / Q000662:veterinary*
chemical_list: D008670:Metals; D014131:Trace Elements; D008668:Metallothionein