Cancer Diagnosis Program | Biorepositories and Biospecimen Research Branch

Search BRD Papers

Impact of Cold Ischemia on the Stability of (1)H-MRS-Detected Metabolic Profiles of Ovarian Cancer Specimens.

Author(s): Ricci A, Dugo M, Pisanu ME, De Cecco L, Raspagliesi F, Valeri B, Veneroni S, Chirico M, Palombelli G, Daidone MG, Podo F, Canese R, Mezzanzanica D, Bagnoli M, Iorio E

Publication: J Proteome Res, 2024, Vol. 23, Page 483-493

PubMed ID: 38109371 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to investigate the effects of cold ischemia (defined in this study as a room temperature delay to snap-freezing; ≤10 – 120 min) duration on the metabolic profile, and the total choline peak specifically, of surgically resected epithelial ovarian cancer (EOC) specimens using high resolution proton magnetic resonance spectroscopy (HR 1H-MRS). Tumor specimens from ten patients undergoing surgical resection of epithelial ovarian tumors (3 patients with endometroid carcinoma, 1 patient with low grade serous carcinoma, 6 patients with high grade serous carcinoma) were each sectioned into four tissue fragments that were snap frozen in liquid nitrogen within 10 min of collection (≤10 min) or kept at room temperature (25°C) for 30, 60, or 120 min prior to snap-freezing. The study also investigated the potential effects of cold ischemia time (0, 2, 4, 6 h at room temperature) on the metabolomic profile of a xenograft mouse model developed using an EOC cell line (SKOV3.ip). Xenograft tumor specimens were collected and snap-frozen after 6-8 min or 2, 4, or 6 h (xenografts from three mice) or after <8 min, 15, 30, or 60 min (xenografts from five mice) at room temperature before snap-freezing.  Aqueous tissue extracts (prepared from 230-600 mg of clinical tissue or 50-100 mg of xenograft tumor) and intact tissue (from xenograft tumor specimens only) were used for metabolic analysis by HR 1H-MRS (cold ischemia time course of clinical specimens and the 0-6 h time course of xenograft specimens) or HR magic angle spinning (MAS) HR 1H-MRS (0-60 min xenograft time course).  1H-MRS spectra were analyzed with XWIN NMR 3.5 software, and the quantities of individual metabolites were reported as a percentage relative to the total metabolites evaluated in a sample.  Collection, processing, and analysis protocols were standardized and performed at a single facility by one operator to minimize potentially confounding preanalytical factors.

   Summary of Findings:

   Of the 29 metabolites quantified in aqueous tissue extracts from the surgically resected EOC specimens by HR 1H-MRS, the relative quantifications of 27, including total choline, did not differ significantly when case-matched specimens with a cold ischemia time (at room temperature) of ≤10 min and 120 min were compared. When a mixed-effects linear model was applied, significant differences in relative metabolite levels between the 120 h cold ischemia timepoint and the control (≤10 min) were limited to an increase in lysine and a decrease in glutathione (p=0.005 for both). When relative levels of individual components within the total choline peak of interest were examined (the tCho peak is comprised of PCHo, GPC, and free Cho), changes included a progressive but nonsignificant decline in GPC and a nonsignificant increase in Cho with cold ischemia, although the authors noted that between-patient variability was high. Analysis of aqueous tissue extracts from three cell line-based EOC xenografts displayed a significant 2-fold increase in relative Cho content after 2 h of cold ischemia relative to levels in the control (6-8 min of cold ischemia), which plateaued during longer cold ischemia times.  Further, Cho levels normalized to tCho (which did not display significant changes during the cold ischemia time course) displayed a 2-fold increase after 2 and 4 h of cold ischemia (p<0.01) and a 2.4-fold increase after 6 h of cold ischemia (p<0.003) relative to the control (6-8 min of cold ischemia) in xenograft EOC tumors.  The ratio of GPC to total Cho also increased 1.4-fold in EOC xenograft tissue extracts after 6 h of cold ischemia (p= 0.01) relative to the control. When EOC xenografts were used to evaluate a shorter cold ischemia time course by HS-MAS analysis, significant changes in lactate (increased), glutamate (decreased), and the glutamate and glutamine pool (decrease) were observed; choline metabolites were not affected by ≤60 min of cold ischemia in EOC xenograft specimens. The authors recommended freezing EOC specimens within 60 min of surgical excision.

   Biospecimens

   • Tissue - Ovary
   • Patient Derived Model - Ovary

   Preservative Types

   • Frozen

   Diagnoses:

   • Neoplastic - Carcinoma

   Platform:

   Analyte	Technology Platform
   Small molecule	Magnetic resonance spectroscopy (MRS)

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Acquisition	Cold ischemia time	<10 min 30 min 60 min 120 min

   View more