title: Influence of evolution in tumor biobanking on the interpretation of translational research.
abstract: OBJECTIVE
  Translational cancer research increasingly relies on human tissue biospecimens and this has coincided with a shift in tissue biobanking approach. Newer biobanks (post year 2000) deploy standard operating procedures to reduce variability around biospecimen collection. Because current translational research is based on pre-2000 and post-2000 era biospecimens, we consider whether the collection era may influence gene expression data.
  
  
  METHODS
  We compared the range of breast tumor collection times from pre-2000 and post-2000 era biobanks and compared estrogen receptor (ER) protein expression with collection time. We then collected 10 breast tumor biospecimens under a standardized protocol and examined whether the expression of c-myc and ER was influenced by storage on ice < or = 24 hours.
  
  
  RESULTS
  The range of collection times achieved at a pre-2000 versus post-2000 era biobank differed. Thirty-two percent of biospecimens were cryopreserved within 30 minutes at the pre-2000 era biobank versus 76% at the post-2000 era biobank. Collection time and ER protein level was inversely correlated (r = -0.19, P = 0.025; n = 137). We observed a wide range in initial c-myc and ER mRNA levels (50- versus 130-fold). Although mRNA levels of both genes declined with increasing collection time, the rate of change differed because c-myc was significantly reduced after 24 hours (mean reduction to 79% of initial) versus ER (94% of initial).
  
  
  CONCLUSIONS
  The overall shift in biobanking around the year 2000 is reflected in the ranges of collection times associated with pre-2000 and post-2000 era biobanks. Because collection time can differentially alter gene expression, the biospecimen collection era should be considered in gene expression studies.
authors.affiliation: Tumour Tissue Repository and Deeley Research Center, BC Cancer Agency, Victoria, British Columbia, Canada.
authors.forename: Rebecca O
authors.initials: RO
authors.lastname: Barnes
authors.forename: Michelle
authors.initials: M
authors.lastname: Parisien
authors.forename: Leigh C
authors.initials: LC
authors.lastname: Murphy
authors.forename: Peter H
authors.initials: PH
authors.lastname: Watson
mesh_terms: D018070:Biological Specimen Banks / Q000639:trends*; D035843:Biomedical Research / Q000639:trends*; D015152:Blotting, Northern; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D001955:British Columbia; D002352:Carrier Proteins / Q000378:metabolism; D016009:Chi-Square Distribution; D004268:DNA-Binding Proteins / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D008350:Manitoba; D012333:RNA, Messenger / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D012042:Registries; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C116115:MYCBP protein, human; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D014157:Transcription Factors; C010140:estrophilin