scholarly journals Human DNA decays faster with time than viral dsDNA: an analysis on HPV16 using pathology archive samples spanning 85 years

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Sara Nicolás-Párraga ◽  
◽  
Montserrat Torres ◽  
Laia Alemany ◽  
Ana Félix ◽  
...  

Abstract Background Quality of the nucleic acids extracted from Formalin Fixed Paraffin Embedded (FFPE) samples largely depends on pre-analytic, fixation and storage conditions. We assessed the differential sensitivity of viral and human double stranded DNA (dsDNA) to degradation with storage time. Methods We randomly selected forty-four HPV16-positive invasive cervical cancer (ICC) FFPE samples collected between 1930 and 1935 and between 2000 and 2004. We evaluated through qPCR the amplification within the same sample of two targets of the HPV16 L1 gene (69 bp, 134 bp) compared with two targets of the human tubulin-β gene (65 bp, 149 bp). Results Both viral and human, short and long targets were amplified from all samples stored for 15 years. In samples archived for 85 years, we observed a significant decrease in the ability to amplify longer targets and this difference was larger in human than in viral DNA: longer fragments were nine times (CI 95% 2.6–35.2) less likely to be recovered from human DNA compared with 1.6 times (CI 95% 1.1–2.2) for viral DNA. Conclusions We conclude that human and viral DNA show a differential decay kinetics in FFPE samples. The faster degradation of human DNA should be considered when assessing viral DNA prevalence in long stored samples, as HPV DNA detection remains a key biomarker of viral-associated transformation.

BMC Cancer ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Michal Marczyk ◽  
Chunxiao Fu ◽  
Rosanna Lau ◽  
Lili Du ◽  
Alexander J. Trevarton ◽  
...  

Abstract Background Utilization of RNA sequencing methods to measure gene expression from archival formalin-fixed paraffin-embedded (FFPE) tumor samples in translational research and clinical trials requires reliable interpretation of the impact of pre-analytical variables on the data obtained, particularly the methods used to preserve samples and to purify RNA. Methods Matched tissue samples from 12 breast cancers were fresh frozen (FF) and preserved in RNAlater or fixed in formalin and processed as FFPE tissue. Total RNA was extracted and purified from FF samples using the Qiagen RNeasy kit, and in duplicate from FFPE tissue sections using three different kits (Norgen, Qiagen and Roche). All RNA samples underwent whole transcriptome RNA sequencing (wtRNAseq) and targeted RNA sequencing for 31 transcripts included in a signature of sensitivity to endocrine therapy. We assessed the effect of RNA extraction kit on the reliability of gene expression levels using linear mixed-effects model analysis, concordance correlation coefficient (CCC) and differential analysis. All protein-coding genes in the wtRNAseq and three gene expression signatures for breast cancer were assessed for concordance. Results Despite variable quality of the RNA extracted from FFPE samples by different kits, all had similar concordance of overall gene expression from wtRNAseq between matched FF and FFPE samples (median CCC 0.63–0.66) and between technical replicates (median expression difference 0.13–0.22). More than half of genes were differentially expressed between FF and FFPE, but with low fold change (median |LFC| 0.31–0.34). Two out of three breast cancer signatures studied were highly robust in all samples using any kit, whereas the third signature was similarly discordant irrespective of the kit used. The targeted RNAseq assay was concordant between FFPE and FF samples using any of the kits (CCC 0.91–0.96). Conclusions The selection of kit to purify RNA from FFPE did not influence the overall quality of results from wtRNAseq, thus variable reproducibility of gene signatures probably relates to the reliability of individual gene selected and possibly to the algorithm. Targeted RNAseq showed promising performance for clinical deployment of quantitative assays in breast cancer from FFPE samples, although numerical scores were not identical to those from wtRNAseq and would require calibration.


1991 ◽  
Vol 163 (2) ◽  
pp. 149-151 ◽  
Author(s):  
Sarah Gledhill ◽  
Andrew S. Krajewski ◽  
Ruth F. Jarrett ◽  
J. Howard Pringle ◽  
Anthony Warford ◽  
...  

Author(s):  
Miriam Potrony ◽  
Celia Badenas ◽  
Bénédicte Naerhuyzen ◽  
Paula Aguilera ◽  
Joan Anton Puig-Butille ◽  
...  

AbstractBackground:Methods:DNA was obtained from 144 FFPE samples (62 primary melanoma, 43 sentinel lymph nodes [SLN] and 39 metastasis).Results:Complete sequencing results were obtained from 75% (108/144) of the samples, and at least one gene was sequenced in 89% (128/144) of them.Conclusions:Preserving sufficient tumor area in FFPE blocks is important. It is necessary to keep the FFPE blocks, no matter their age, as they are necessary to decide the best treatment for the melanoma patient.


2018 ◽  
Vol 143 (3) ◽  
pp. 356-361
Author(s):  
Ming Guo ◽  
Abha Khanna ◽  
Jianping Wang ◽  
Michelle D. Williams ◽  
Neda Kalhor ◽  
...  

Context.— Human papillomavirus (HPV) DNA in situ hybridization (ISH) assay and p16 immunohistochemistry (IHC) are used to determine high-risk HPV status in formalin-fixed, paraffin-embedded (FFPE) tissues in oropharyngeal squamous cell carcinoma (SCC). Although high sensitivity and specificity for HPV can be obtained by combined p16 IHC and HPV DNA ISH, the occasional discrepancy between these assays has prompted evaluation of Cervista HPV assays in FFPE tissue from patients with oropharyngeal SCC. Objective.— To compare the efficacy of Cervista HPV 16/18 and Cervista HPV HR assay to that of HPV DNA ISH assay and p16 IHC in FFPE tissue in head and neck squamous cell carcinoma of oropharyngeal origin. Design.— Archived FFPE tissue from 84 patients with SCC of oropharyngeal origin and available HPV DNA ISH and p16 IHC test results were tested with the Cervista HPV 16/18 assay and further verified by polymerase chain reaction (PCR)–based HPV16/18 genotyping tests in cases with discrepancy. Results.— Of the 84 specimens, 75% (63 of 84) were positive and 16% (13 of 84) had discrepant or equivocal findings by p16 IHC and HPV DNA ISH testing. Use of Cervista HPV assays, either to clarify discrepant/equivocal findings or as confirmation after initial p16 IHC/HPV DNA ISH tests, identified 81% (68 of 84) of HPV-positive cases without equivocal HPV results. Five of 13 cases with discrepancy or equivocal HPV DNA ISH results tested positive for HPV16 or HPV18 by Cervista HPV 16/18 assay, which was further confirmed by PCR-based HPV 16/18 genotyping. Conclusions.— The Cervista HPV assays are a reasonable alternative to HPV DNA ISH in determining HPV status in FFPE tissue specimens from patients with oropharyngeal SCC.


Author(s):  
Rui Zhang ◽  
Yanxi Han ◽  
Jie Huang ◽  
Liang Ma ◽  
Yulong Li ◽  
...  

AbstractLaboratory testing forArtificial FFPE samples were prepared from cultured cell lines to construct a proficiency panel of 10 samples covering eightThe percentages of mutant


ISRN Oncology ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Nona Arneson ◽  
Juan Moreno ◽  
Vladimir Iakovlev ◽  
Arezou Ghazani ◽  
Keisha Warren ◽  
...  

To understand cancer progression, it is desirable to study the earliest stages of its development, which are often microscopic lesions. Array comparative genomic hybridization (aCGH) is a valuable high-throughput molecular approach for discovering DNA copy number changes; however, it requires a relatively large amount of DNA, which is difficult to obtain from microdissected lesions. Whole genome amplification (WGA) methods were developed to increase DNA quantity; however their reproducibility, fidelity, and suitability for formalin-fixed paraffin-embedded (FFPE) samples are questioned. Using aCGH analysis, we compared two widely used approaches for WGA: single cell comparative genomic hybridization protocol (SCOMP) and degenerate oligonucleotide primed PCR (DOP-PCR). Cancer cell line and microdissected FFPE breast cancer DNA samples were amplified by the two WGA methods and subjected to aCGH. The genomic profiles of amplified DNA were compared with those of non-amplified controls by four analytic methods and validated by quantitative PCR (Q-PCR). We found that SCOMP-amplified samples had close similarity to non-amplified controls with concordance rates close to those of reference tests, while DOP-amplified samples had a statistically significant amount of changes. SCOMP is able to amplify small amounts of DNA extracted from FFPE samples and provides quality of aCGH data similar to non-amplified samples.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yi Luo ◽  
Zhenzhen Zhang ◽  
Jianfan Liu ◽  
Linqing Li ◽  
Xuezheng Xu ◽  
...  

Melanoma is a human skin malignant tumor with high invasion and poor prognosis. The limited understanding of genomic alterations in melanomas in China impedes the diagnosis and therapeutic strategy selection. We conducted comprehensive genomic profiling of melanomas from 39 primary and metastatic formalin-fixed paraffin-embedded (FFPE) samples from 27 patients in China based on an NGS panel of 223 genes. No significant difference in gene alterations was found between primary and metastasis melanomas. The status of germline mutation, CNV, and somatic mutation in our cohort was quite different from that reported in Western populations. We further delineated the mutation patterns of 4 molecular subgroups (BRAF, RAS, NF1, and Triple-WT) of melanoma in our cohort. BRAF mutations were more frequently identified in melanomas without chromic sun-induced damage (non-CSD), while RAS mutations were more likely observed in acral melanomas. NF1 and Triple-WT subgroups were unbiased between melanomas arising in non-CSD and acral skin. BRAF, RAS, and NF1 mutations were significantly associated with lymph node metastasis or presence of ulceration, implying that these cancer driver genes were independent prognostic factors. In summary, our results suggest that mutational profiles of malignant melanomas in China are significantly different from Western countries, and both gene mutation and amplification play an important role in the development and progression of melanomas.


2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Emily A Saunderson ◽  
Ann-Marie Baker ◽  
Marc Williams ◽  
Kit Curtius ◽  
J Louise Jones ◽  
...  

Abstract The desire to analyse limited amounts of biological material, historic samples and rare cell populations has collectively driven the need for efficient methods for whole genome sequencing (WGS) of limited amounts of poor quality DNA. Most protocols are designed to recover double-stranded DNA (dsDNA) by ligating sequencing adaptors to dsDNA with or without subsequent polymerase chain reaction amplification of the library. While this is sufficient for many applications, limited DNA requires a method that can recover both single-stranded DNA (ssDNA) and dsDNA. Here, we present a WGS library preparation method, called ‘degraded DNA adaptor tagging’ (DDAT), adapted from a protocol designed for whole genome bisulfite sequencing. This method uses two rounds of random primer extension to recover both ssDNA and dsDNA. We show that by using DDAT we can generate WGS data from formalin-fixed paraffin-embedded (FFPE) samples using as little as 2 ng of highly degraded DNA input. Furthermore, DDAT WGS data quality was higher for all FFPE samples tested compared to data produced using a standard WGS library preparation method. Therefore, the DDAT method has potential to unlock WGS data from DNA previously considered impossible to sequence, broadening opportunities to understand the role of genetics in health and disease.


2020 ◽  
Vol 73 (9) ◽  
pp. 602-604
Author(s):  
Silvia Bessi ◽  
Francesco Pepe ◽  
Marco Ottaviantonio ◽  
Pasquale Pisapia ◽  
Umberto Malapelle ◽  
...  

In the present study, we analysed 44 formalin fixed paraffin embedded (FFPE) from different solid tumours by adopting two different next generation sequencing platforms: GeneReader (QIAGEN, Hilden, Germany) and Ion Torrent (Thermo Fisher Scientific, Waltham, Massachusetts, USA). We highlighted a 100% concordance between the platforms. In addition, focusing on variant detection, we evaluated a very good agreement between the two tests (Cohen’s kappa=0.84) and, when taking into account variant allele fraction value for each variant, a very high concordance was obtained (Pearson’s r=0.94). Our results underlined the high performance rate of GeneReader on FFPE samples and its suitability in routine molecular predictive practice.


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