title: Monitoring mammary tumor progression and effect of tamoxifen treatment in MMTV-PymT using MRI and magnetic resonance spectroscopy with hyperpolarized [1-13C]pyruvate.
abstract: OBJECTIVE
  To use dynamic magnetic resonance spectroscopy (MRS) of hyperpolarized (13)C-pyruvate to follow the progress over time in vivo of breast cancer metabolism in the MMTV-PymT model, and to follow the response to the anti-estrogen drug tamoxifen.
  
  
  METHODS
  Tumor growth was monitored by anatomical MRI by measuring tumor volumes. Dynamic MRS of hyperpolarized (13)C was used to measure an "apparent" pyruvate-to-lactate rate constant (kp) of lactate dehydrogenase (LDH) in vivo. Further, ex vivo pathology and in vitro LDH initial reaction velocity were evaluated.
  
  
  RESULTS
  Tamoxifen significantly halted the tumor growth measured as tumor volume by MRI. In the untreated animals, kp correlated with tumor growth. The kP was somewhat but not significantly lower in the treated group. Studies in vitro confirmed the effects of tamoxifen on tumor growth, and here the LDH reaction velocity was reduced significantly in the treated group.
  
  
  CONCLUSIONS
  These hyperpolarized (13)C MRS findings indicate that tumor metabolic changes affects kP. The measured kp did not relate to treatment response to the same extent as did tumor growth, histological evaluation, and in vitro determination of LDH activity.
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.|Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Sadia
authors.initials: S
authors.lastname: Asghar Butt
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.
authors.forename: Lise V
authors.initials: LV
authors.lastname: Søgaard
authors.affiliation: GE Healthcare, Brøndby, Denmark.|Department of Electrical Engineering, Technical University of Denmark, Kongens Lyngby, Denmark.
authors.forename: Jan H
authors.initials: JH
authors.lastname: Ardenkjaer-Larsen
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.
authors.forename: Mette H
authors.initials: MH
authors.lastname: Lauritzen
authors.affiliation: The Finsen Laboratory/BRIC, Rigshospitalet/Copenhagen University, Copenhagen, Denmark.
authors.forename: Lars H
authors.initials: LH
authors.lastname: Engelholm
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.|Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.|Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Olaf B
authors.initials: OB
authors.lastname: Paulson
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Osman
authors.initials: O
authors.lastname: Mirza
authors.affiliation: Department of Pathology, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.
authors.forename: Susanne
authors.initials: S
authors.lastname: Holck
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Magnusson
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Åkeson
mesh_terms: D000818:Animals; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage; D066241:Carbon-13 Magnetic Resonance Spectroscopy / Q000379:methods*; D018450:Disease Progression; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008325:Mammary Neoplasms, Experimental / Q000175:diagnosis* / Q000188:drug therapy* / Q000378:metabolism; D051379:Mice; D019289:Pyruvic Acid / Q000378:metabolism / Q000493:pharmacokinetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013629:Tamoxifen / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen; D019289:Pyruvic Acid
keywords: MMTV-PymT; cancer metabolism; hyperpolarized 13C-MRS; tamoxifen