OncoTargets and Therapy (Jun 2016)
Normalization of gene expression measurement of tissue samples obtained by transurethral resection of bladder tumors
Abstract
Laura A Pop,1,* Valentina Pileczki,1,2,* Roxana M Cojocneanu-Petric,1 Bogdan Petrut,3,4 Cornelia Braicu,1 Ancuta M Jurj,1 Rares Buiga,5 Patriciu Achimas-Cadariu,6,7 Ioana Berindan-Neagoe1,8 1The Research Center for Functional Genomics, Biomedicine and Translational Medicine, Iuliu Haţieganu University of Medicine and Pharmacy, Cluj-Napoca, Cluj, Romania; 2Department of Analytical Chemistry, Iuliu Haţieganu University of Medicine and Pharmacy, Cluj-Napoca, Cluj, Romania; 3Department of Surgery II – Urology, The Oncology Institute “Prof Dr Ion Chiricuţă”, Cluj-Napoca, Cluj, Romania; 4Department of Urology, Iuliu Haţieganu University of Medicine and Pharmacy, Cluj-Napoca, Cluj, Romania; 5Department of Pathology, The Oncology Institute “Prof. Dr Ion Chiricuţă”, Cluj-Napoca, Cluj, Romania; 6Department of Surgery, The Oncology Institute “Prof Dr Ion Chiricuţă”, Cluj-Napoca, Cluj, Romania; 7Department of Surgical Oncology and Gynecological Oncology, Iuliu Haţieganu University of Medicine and Pharmacy, 8Department of Functional Genomics and Experimental Pathology, The Oncology Institute “Prof Dr Ion Chiricuţă”, Cluj-Napoca, Cluj, Romania *These authors contributed equally to this work Background: Sample processing is a crucial step for all types of genomic studies. A major challenge for researchers is to understand and predict how RNA quality affects the identification of transcriptional differences (by introducing either false-positive or false-negative errors). Nanotechnologies help improve the quality and quantity control for gene expression studies. Patients and methods: The study was performed on 14 tumor and matched normal pairs of tissue from patients with bladder urothelial carcinomas. We assessed the RNA quantity by using the NanoDrop spectrophotometer and the quality by nano-microfluidic capillary electrophoresis technology provided by Agilent 2100 Bioanalyzer. We evaluated the amplification status of three housekeeping genes and one small nuclear RNA gene using the ViiA 7 platform, with specific primers. Results: Every step of the sample handling protocol, which begins with sample harvest and ends with the data analysis, is of utmost importance due to the fact that it is time consuming, labor intensive, and highly expensive. High temperature of the surgical procedure does not affect the small nucleic acid sequences in comparison with the mRNA. Conclusion: Gene expression is clearly affected by the RNA quality, but less affected in the case of small nuclear RNAs. We proved that the high-temperature, highly invasive transurethral resection of bladder tumor procedure damages the tissue and affects the integrity of the RNA from biological specimens. Keywords: bladder cancer, transurethral resection, RNA quality, real-time PCR
