title: The prolyl hydroxylase enzymes are positively associated with hypoxia-inducible factor-1α and vascular endothelial growth factor in human breast cancer and alter in response to primary systemic treatment with epirubicin and tamoxifen.
abstract: BACKGROUND
  The purpose of the present study was to investigate the relationship of expression of hypoxia inducible factor (HIF)-1α-modifying enzymes prolyl hydroxylase (PHD)1, PHD2 and PHD3 to response of tumours and survival in breast cancer patients enrolled in a phase II trial of neoadjuvant anthracycline and tamoxifen therapy.
  
  
  METHODS
  The expression of PHD1, PHD2 and PHD3 together with HIF-1α and the HIF-inducible genes vascular endothelial cell growth factor (VEGF) and carbonic anhydrase IX were assessed by immunohistochemistry using a tissue microarray approach in 211 patients with T2-4 N0-1 breast cancer enrolled in a randomised trial comparing single-agent epirubicin versus epirubicin and tamoxifen as the primary systemic treatment.
  
  
  RESULTS
  PHD1, PHD2 and PHD3 were detected in 47/179 (26.7%), 85/163 (52.2%) and 69/177 (39%) of tumours at baseline. PHD2 and PHD3 expression was moderate/strong whereas PHD1 expression was generally weak. There was a significant positive correlation between HIF-1α and PHD1 (P = 0.002) and PHD3 (P < 0.05) but not PHD2 (P = 0.41). There was a significant positive relationship between VEGF and PHD1 (P < 0.008) and PHD3 (P = 0.001) but not PHD2 (P = 0.09). PHD1, PHD2 and PHD3 expression was significantly increased after epirubicin therapy (all P < 0.000) with no significant difference in PHD changes between the treatment arms. There was no significant difference in response in tumours that expressed PHDs and PHD expression was not associated with survival.
  
  
  CONCLUSIONS
  Although expression of the PHDs was not related to response or survival in patients receiving neoadjuvant epirubicin, our data provide the first evidence that these enzymes are upregulated on therapy in breast cancer and that the biological effects independent of HIF make them therapeutic targets.
authors.affiliation: Peter MacCallum Cancer Centre, St Andrews Place, East Melbourne, Victoria 3002, Australia. stephen.fox@petermac.org
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Fox
authors.forename: Daniele
authors.initials: D
authors.lastname: Generali
authors.forename: Alfredo
authors.initials: A
authors.lastname: Berruti
authors.forename: Maria P
authors.initials: MP
authors.lastname: Brizzi
authors.forename: Leticia
authors.initials: L
authors.lastname: Campo
authors.forename: Simone
authors.initials: S
authors.lastname: Bonardi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bersiga
authors.forename: Giovanni
authors.initials: G
authors.lastname: Allevi
authors.forename: Manuela
authors.initials: M
authors.lastname: Milani
authors.forename: Sergio
authors.initials: S
authors.lastname: Aguggini
authors.forename: Teresa
authors.initials: T
authors.lastname: Mele
authors.forename: Luigi
authors.initials: L
authors.lastname: Dogliotti
authors.forename: Alberto
authors.initials: A
authors.lastname: Bottini
authors.forename: Adrian L
authors.initials: AL
authors.lastname: Harris
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology* / Q000235:genetics; D015251:Epirubicin / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases / Q000378:metabolism; D011379:Prognosis; D064828:Prolyl Hydroxylases / Q000235:genetics / Q000378:metabolism*; D013629:Tamoxifen / Q000494:pharmacology / Q000627:therapeutic use*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D042461:Vascular Endothelial Growth Factor A; D013629:Tamoxifen; D015251:Epirubicin; D064828:Prolyl Hydroxylases; C490190:EGLN1 protein, human; C447780:EGLN2 protein, human; C488894:EGLN3 protein, human; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases