Biobanking of Fresh-Frozen Human Adenocarcinomatous and Normal Colon Tissues: Which Parameters Influence RNA Quality?

PLoS One. 2016 Apr 28;11(4):e0154326. doi: 10.1371/journal.pone.0154326. eCollection 2016.

Abstract

Medical research projects become increasingly dependent on biobanked tissue of high quality because the reliability of gene expression is affected by the quality of extracted RNA. Hence, the present study aimed to determine if clinical, surgical, histological, and molecular parameters influence RNA quality of normal and tumoral frozen colonic tissues. RNA Quality Index (RQI) was evaluated on 241 adenocarcinomas and 115 matched normal frozen colon tissues collected between October 2006 and December 2012. RQI results were compared to patients' age and sex, tumor site, kind of surgery, anastomosis failure, adenocarcinoma type and grade, tumor cell percentage, necrosis extent, HIF-1α and cleaved caspase-3 immunohistochemistry, and BRAF, KRAS and microsatellites status. The RQI was significantly higher in colon cancer tissue than in matched normal tissue. RQI from left-sided colonic cancers was significantly higher than RQI from right-sided cancers. The RNA quality was not affected by ischemia and storage duration. According to histological control, 7.9% of the samples were unsatisfactory because of inadequate sampling. Biobanked tumoral tissues with RQI ≥5 had lower malignant cells to stromal cells ratio than samples with RQI <5 (p <0.05). Cellularity, necrosis extent and mucinous component did not influence RQI results. Cleaved caspase-3 and HIF-1α immunolabelling were not correlated to RQI. BRAF, KRAS and microsatellites molecular status did not influence RNA quality. Multivariate analysis revealed that the tumor location, the surgical approach (laparoscopy versus open colectomy) and the occurrence of anastomotic leakage were the only parameters influencing significantly RQI results of tumor samples. We failed to identify parameter influencing RQI of normal colon samples. These data suggest that RNA quality of colonic adenocarcinoma biospecimens is determined by clinical and surgical parameters. More attention should be paid during the biobanking procedure of right-sided colon cancer or laparoscopic colectomy specimen. Histological quality control remains essential to control sampling accuracy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / pathology*
  • Adult
  • Aged
  • Aged, 80 and over
  • Anastomosis, Surgical
  • Caspase 3 / metabolism
  • Cold Ischemia
  • Colectomy / methods
  • Colon*
  • Colonic Neoplasms / pathology*
  • Female
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Immunohistochemistry
  • Male
  • Microsatellite Repeats
  • Middle Aged
  • Multivariate Analysis
  • Proto-Oncogene Proteins B-raf / metabolism
  • Proto-Oncogene Proteins p21(ras) / metabolism
  • RNA / analysis*
  • RNA, Neoplasm / analysis*
  • Reproducibility of Results
  • Specimen Handling / methods*
  • Tissue Banks*

Substances

  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • KRAS protein, human
  • RNA, Neoplasm
  • RNA
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf
  • CASP3 protein, human
  • Caspase 3
  • Proto-Oncogene Proteins p21(ras)

Grants and funding

This work was supported by: 1. Ligue Nationale Contre le Cancer Conférence de Coordination Interrégionale du Grand Est, Appel d’Offre 2014. Grant Number 001N.2015 (SD), Website: http://www.liguecancer-cd68.fr/CCIR_GE.html; 2. Centre Hospitalier Universitaire de Reims, Appel d'Offre Local 2014. Grant Number AU14-03 (CB-R), Website: https://www.chu-reims.fr/la_recherche.html. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.