title: Arginase activity in patients with breast cancer: an analysis of plasma, tumors, and its relationship with the presence of the estrogen receptor.
abstract: BACKGROUND
  Breast cancer is an important cause of cancerrelated death in women. In this pathological condition, arginase plays a role by providing ornithine as a substrate for the biosynthesis of polyamines which are important in tumor progression. The aim of this work was to determine the arginase activity in the plasma and tumors of patients with breast cancer; also, we investigated the relationship between this activity and the presence of the estrogen receptor.
  
  
  METHODS
  We evaluated the plasma arginase activity levels in 80 women with breast cancer and 42 healthy control subjects. We also measured the arginase levels in 42 breast cancer biopsies and 42 control tissues.
  
  
  RESULTS
  The mean activity of arginase in plasma was higher in breast cancer patients (0.78 nM/min/mg protein ± 0.04; p = 0.001) than in healthy volunteers (0.53 nM/ min/mg protein ± 0.04); however, this difference was indicative of patients in the advanced stages of the disease (n = 38, stage III; p < 0.0001). In addition, we did not find a relationship between the estrogen receptor and arginase activity.
  
  
  CONCLUSIONS
  Our results show a higher arginase activity in the plasma of patients in the advanced stages of the disease, suggesting that arginase activity could serve as a possible biological marker of breast cancer progression.
authors.affiliation: Department of Oncology, Hospital General Regional No. 72, Mexican Institute for Social Security, Mexico.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Perez
authors.forename: Ivonne M
authors.initials: IM
authors.lastname: Olivares
authors.forename: Magdalena G
authors.initials: MG
authors.lastname: Rodriguez
authors.forename: Guillermo M
authors.initials: GM
authors.lastname: Ceballos
authors.forename: Jose R
authors.initials: JR
authors.lastname: Garcia Sanchez
mesh_terms: D000328:Adult; D000368:Aged; D001119:Arginase / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D015995:Prevalence; D011960:Receptors, Estrogen / Q000097:blood*; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D011960:Receptors, Estrogen; D001119:Arginase