Effect of storage time on gene expression data acquired from unfrozen archived newborn blood spots

Copyright © 2016 Elsevier Inc. All rights reserved..

Unfrozen archived newborn blood spots (NBS) have been shown to retain sufficient messenger RNA (mRNA) for gene expression profiling. However, the effect of storage time at ambient temperature for NBS samples in relation to the quality of gene expression data is relatively unknown. Here, we evaluated mRNA expression from quantitative real-time PCR (qRT-PCR) and microarray data obtained from NBS samples stored at ambient temperature to determine the effect of storage time on the quality of gene expression. These data were generated in a previous case-control study examining NBS in 53 children with cerebral palsy (CP) and 53 matched controls. NBS sample storage period ranged from 3 to 16years at ambient temperature. We found persistently low RNA integrity numbers (RIN=2.3±0.71) and 28S/18S rRNA ratios (~0) across NBS samples for all storage periods. In both qRT-PCR and microarray data, the expression of three common housekeeping genes-beta cytoskeletal actin (ACTB), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and peptidylprolyl isomerase A (PPIA)-decreased with increased storage time. Median values of each microarray probe intensity at log2 scale also decreased over time. After eight years of storage, probe intensity values were largely reduced to background intensity levels. Of 21,500 genes tested, 89% significantly decreased in signal intensity, with 13,551, 10,730, and 9925 genes detected within 5years, > 5 to <10years, and >10years of storage, respectively. We also examined the expression of two gender-specific genes (X inactivation-specific transcript, XIST and lysine-specific demethylase 5D, KDM5D) and seven gene sets representing the inflammatory, hypoxic, coagulative, and thyroidal pathways hypothesized to be related to CP risk to determine the effect of storage time on the detection of these biologically relevant genes. We found the gender-specific genes and CP-related gene sets detectable in all storage periods, but exhibited differential expression (between male vs. female or CP vs. control) only within the first six years of storage. We concluded that gene expression data quality deteriorates in unfrozen archived NBS over time and that differential gene expression profiling and analysis is recommended for those NBS samples collected and stored within six years at ambient temperature.

Medienart:

E-Artikel

Erscheinungsjahr:

2016

Erschienen:

2016

Enthalten in:

Zur Gesamtaufnahme - volume:119

Enthalten in:

Molecular genetics and metabolism - 119(2016), 3 vom: 23. Nov., Seite 207-213

Sprache:

Englisch

Beteiligte Personen:

Ho, Nhan T [VerfasserIn]
Busik, Julia V [VerfasserIn]
Resau, James H [VerfasserIn]
Paneth, Nigel [VerfasserIn]
Khoo, Sok Kean [VerfasserIn]

Links:

Volltext

Themen:

Ambient temperature
Journal Article
MRNA gene expression
Microarray
Newborn blood spots
Quantitative real-time PCR
RNA, Messenger
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Storage time

Anmerkungen:

Date Completed 20.11.2017

Date Revised 13.11.2018

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.ymgme.2016.08.001

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM263690652