Detection of Fusion Gene Transcripts in Fresh-Frozen and Formalin-Fixed Paraffin-Embedded Tissue Sections of Soft-Tissue Sarcomas After Laser Capture Microdissection and RT-PCR

2003 ◽  
Vol 12 (4) ◽  
pp. 224-230 ◽  
Author(s):  
L. Jin ◽  
J. Majerus ◽  
A. Oliveira ◽  
C. Y. Inwards ◽  
A. G. Nascimento ◽  
...  
2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 11032-11032
Author(s):  
B. M. Müller ◽  
R. Kronenwett ◽  
G. Hennig ◽  
K. Weber ◽  
K. Bohmann ◽  
...  

11032 Background: Personalized cancer therapy depends on the evaluation of tissue-based biomarkers in routine tumor samples. As many new biomarkers are measured on the mRNA level, standardized procedures for mRNA analysis in formalin-fixed, paraffin-embedded (FFPE) tissue are needed. In this study, we present a novel, standardized, and fully automated method for fast isolation of total RNA from FFPE tissue sections. Methods: Tissue samples (n = 501) from 167 breast carcinomas which had been stored between 2 months and 21 years were investigated. Total RNA was extracted from tissue sections using a new method based on silica-coated iron oxide beads in combination with a specific liquid-handling robot. Novel and unique features of the method are an automated extraction-integrated deparaffinization step and a bead-based negative selection step to eliminate any undigested tissue. Yield of RNA was assessed using the Ribogreen assay. mRNA fragment lengths were estimated by reverse transcription PCR (RT-PCR) for G6PDH. Expression of the breast cancer biomarkers ESR1, PGR and HER2 was measured by kinetic RT-PCR (kPCR) and compared with immunohistochemistry (IHC). Results: RNA was successfully isolated from all samples, with a mean yield of 1.4 μg/sample (range: 0.1–7.8 μg) and fragment lengths of at least 150 bp in 99% of samples. PCR analyses could be performed in all samples. Investigating three sections of each tumor, we observed a low section-to-section variability of kPCR results (root of mean squared errors of relative ESR1, PGR or HER2 expression in three sections: 0.2–0.5 Ct values). Comparing kPCR results with IHC, we detected a good concordance between both methods, with agreements of 98.4% (standard error [SE]: 2.7%) for ESR1, 84.4% (SE: 5.3%) for PGR and 89.9% (SE: 8.9%) for HER2. Conclusions: This novel RNA extraction method is a major technical improvement for implementation of reproducible, high-throughput and cost-efficient testing of cancer biomarkers in the clinical routine and in gene-expression research studies using archived FFPE material in molecular labs. [Table: see text]


2016 ◽  
Vol 54 (11) ◽  
pp. 2798-2803 ◽  
Author(s):  
Elham Salehi ◽  
Mohammad T. Hedayati ◽  
Jan Zoll ◽  
Haleh Rafati ◽  
Maryam Ghasemi ◽  
...  

In a retrospective multicenter study, 102 formalin-fixed paraffin-embedded (FFPE) tissue specimens with histopathology results were tested. Two 4- to 5-μm FFPE tissue sections from each specimen were digested with proteinase K, followed by automated nucleic acid extraction. Multiple real-time quantitative PCR (qPCR) assays targeting the internal transcribed spacer 2 (ITS2) region of ribosomal DNA, using fluorescently labeled primers, was performed to identify clinically important genera and species of Aspergillus , Fusarium , Scedosporium , and the Mucormycetes . The molecular identification was correlated with results from histological examination. One of the main findings of our study was the high sensitivity of the automated DNA extraction method, which was estimated to be 94%. The qPCR procedure that was evaluated identified a range of fungal genera/species, including Aspergillus fumigatus , Aspergillus flavus , Aspergillus terreus , Aspergillus niger , Fusarium oxysporum , Fusarium solani , Scedosporium apiospermum , Rhizopus oryzae , Rhizopus microsporus , Mucor spp., and Syncephalastrum . Fusarium oxysporum and F. solani DNA was amplified from five specimens from patients initially diagnosed by histopathology as having aspergillosis. Aspergillus flavus , S. apiospermum , and Syncephalastrum were detected from histopathological mucormycosis samples. In addition, examination of four samples from patients suspected of having concomitant aspergillosis and mucormycosis infections resulted in the identification of two A. flavus isolates, one Mucor isolate, and only one sample having both R. oryzae and A. flavus . Our results indicate that histopathological features of molds may be easily confused in tissue sections. The qPCR assay used in this study is a reliable tool for the rapid and accurate identification of fungal pathogens to the genus and species levels directly from FFPE tissues.


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