title: Choline metabolism, proliferation, and angiogenesis in nonenhancing grades 2 and 3 astrocytoma.
abstract: OBJECTIVE
  To study choline metabolism in biopsies from nonenhancing Grade 2 (AS2) and Grade 3 (AS3) astrocytomas to determine whether (1) phosphocholine (PC) dominates in AS3, and (2) PC is associated with proliferation or angiogenesis. PC and glycerophosphocholine (GPC) are involved in phospholipid metabolism that accompanies mitosis. PC is the predominant peak in Grade 4 astrocytoma (GBM) while GPC dominates in AS2.
  
  
  METHODS
  We used high resolution magic angle spinning magnetic resonance spectroscopy to compare the concentrations of 10 metabolites in 41 biopsies (16 AS2 and 25 AS3) from 24 tumors. Immunohistochemistry was performed on paired biopsies to determine the cell density, Ki-67 proliferation index, and vascular endothelial growth factor (VEGF) angiogenic marker expression.
  
  
  RESULTS
  AS3 had higher PC than AS2; however, the PC:GPC was less than 1 in all cases irrespective of tumor grade. Within tumors, GPC increased with Ki-67 and PC and tCho increased with cell density. There was no association between any choline compound and VEGF.
  
  
  CONCLUSIONS
  These data suggest that PC:GPC less than 1 is not unique to low grade glioma. Furthermore, the PC concentration that is a marker of aggressive glial tumors is not tightly linked to cell proliferation or angiogenesis in nonenhancing astrocytomas.
authors: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA. tracy.mcknight@ucsf.edu
authors: Tracy R
authors: TR
authors: McKnight
authors: Kenneth J
authors: KJ
authors: Smith
authors: Philip W
authors: PW
authors: Chu
authors: King S
authors: KS
authors: Chiu
authors: Colleen P
authors: CP
authors: Cloyd
authors: Susan M
authors: SM
authors: Chang
authors: Joanna J
authors: JJ
authors: Phillips
authors: Mitchel S
authors: MS
authors: Berger
mesh_terms: D000328:Adult; D001254:Astrocytoma / Q000378:metabolism / Q000473:pathology*; D001706:Biopsy; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation; D002794:Choline / Q000378:metabolism*; D005260:Female; D005910:Glioma / Q000378:metabolism; D005997:Glycerylphosphorylcholine / Q000494:pharmacology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D019394:Ki-67 Antigen / Q000096:biosynthesis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D009389:Neovascularization, Pathologic; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D019394:Ki-67 Antigen; D042461:Vascular Endothelial Growth Factor A; D005997:Glycerylphosphorylcholine; D002794:Choline