Influence of evolution in tumor biobanking on the interpretation of translational research.
Author(s): Barnes RO, Parisien M, Murphy LC, Watson PH
Publication: Cancer Epidemiol Biomarkers Prev, 2008, Vol. 17, Page 3344-50
PubMed ID: 19064549 PubMed Review Paper? No
Suggested by: ISBER
Purpose of Paper
The purpose of this paper was to determine if the differences in cold ischemia time between pre and post-2000 biobanks affect determination of expression of c-myc and estrogen receptor (ER) in breast tumor specimens.
Conclusion of Paper
Analysis of ER expression by ligand binding assay showed a decrease in functional ER from 50.2 fmol/mg to 28.9 fmol/mg when cold ischemia time increased from less than 30 minutes to 61 -120 minutes. However, PCR analysis showed ER detection decreased by less than 10% when cold ischemia times were less than 25 hours and tissue was stored on ice. In contrast, only 75% of the initial amount of c-myc RNA was present in specimens stored on ice for 25 h prior to snap-freezing at -70 degrees C.
Studies
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Study Purpose
The purpose of this study was to determine effect of increased cold ischemia time on the expression of c-myc and ER in breast tumor specimens. Cold ischemia time commenced with surgical excision and ended with cryopreservation at either -70 degrees C or -150 degrees C.
Summary of Findings:
While prior to 2000 only 32% of specimens were cryopreserved within 30 minutes of excision, post-2000 76% of specimens were cryopreserved within 30 minutes. An analysis of ER expression by ligand binding assay showed a decrease in functional ER from 50.2 fmol/mg to 28.9 fmol/mg when cold ischemia time increased from less than 30 minutes to 61-120 minutes.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Neoplastic - Carcinoma
Platform:
Analyte Technology Platform Protein Receptor binding Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Acquisition Cold ischemia time < 30 minutes
31-60 minutes
61-120 minutes
> 120 minutes
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Study Purpose
The purpose of this study was to determine effect of storage of breast tumor specimens on ice prior to snap-freezing on the expression of c-myc and ER.
Summary of Findings:
Only 75% of the initial amount of c-myc RNA was present in specimens stored on ice for 25 h prior to snap-freezing at -70 degrees C. In contrast, in the 3 specimens which were ER positive by PCR a less than 10% decrease was observed in ER expression with cold ischemia times up to 25 h. The authors report that northern blot analysis showed no visible degradation of 18S or 28S ribosomal RNA bands with cold ischemia times up to 25 h when tissue was kept on ice.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Neoplastic - Carcinoma
Platform:
Analyte Technology Platform RNA RT-PCR RNA Northern blot Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) RT-PCR Specific Targeted nucleic acid c-myc
Estrogen receptor
Biospecimen Acquisition Cold ischemia time 1 h
4 h
7 h
25 h
Storage Storage temperature On ice