1
|
Ji B, Chen J, Gong H, Li X. Streamlined Full-Length Total RNA Sequencing of Paraformaldehyde-Fixed Brain Tissues. Int J Mol Sci 2024; 25:6504. [PMID: 38928210 PMCID: PMC11204141 DOI: 10.3390/ijms25126504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 06/04/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024] Open
Abstract
Paraformaldehyde (PFA) fixation is the preferred method for preserving tissue architecture for anatomical and pathological observations. Meanwhile, PFA reacts with the amine groups of biomolecules to form chemical cross-linking, which preserves RNA within the tissue. This has great prospects for RNA sequencing to characterize the molecular underpinnings after anatomical and pathological observations. However, RNA is inaccessible due to cross-linked adducts forming between RNA and other biomolecules in prolonged PFA-fixed tissue. It is also difficult to perform reverse transcription and PCR, resulting in low sequencing sensitivity and reduced reproducibility. Here, we developed a method to perform RNA sequencing in PFA-fixed tissue, which is easy to use, cost-effective, and allows efficient sample multiplexing. We employ cross-link reversal to recover RNA and library construction using random primers without artificial fragmentation. The yield and quality of recovered RNA significantly increased through our method, and sequencing quality metrics and detected genes did not show any major differences compared with matched fresh samples. Moreover, we applied our method for gene expression analysis in different regions of the mouse brain and identified unique gene expression profiles with varied functional implications. We also find significant dysregulation of genes involved in Alzheimer's disease (AD) pathogenesis within the medial septum (MS)/vertical diagonal band of Broca (VDB) of the 5×FAD mouse brain. Our method can thus increase the performance of high-throughput RNA sequencing with PFA-fixed samples and allows longitudinal studies of small tissue regions isolated by their in situ context.
Collapse
Affiliation(s)
- Bingqing Ji
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (B.J.); (J.C.); (H.G.)
- MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jiale Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (B.J.); (J.C.); (H.G.)
- MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hui Gong
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (B.J.); (J.C.); (H.G.)
- MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Research Unit of Multimodal Cross Scale Neural Signal Detection and Imaging, HUST-Suzhou Institute for Brainsmatics, JITRI, Chinese Academy of Medical Sciences, Suzhou 215125, China
| | - Xiangning Li
- Research Unit of Multimodal Cross Scale Neural Signal Detection and Imaging, HUST-Suzhou Institute for Brainsmatics, JITRI, Chinese Academy of Medical Sciences, Suzhou 215125, China
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou 570228, China
| |
Collapse
|
2
|
Steinacher C, Rieder D, Turner JE, Solanky N, Nishio SY, Usami SI, Hausott B, Schrott-Fischer A, Dudas J. Validation of RNA Extraction Methods and Suitable Reference Genes for Gene Expression Studies in Developing Fetal Human Inner Ear Tissue. Int J Mol Sci 2024; 25:2907. [PMID: 38474154 DOI: 10.3390/ijms25052907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/21/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
A comprehensive gene expression investigation requires high-quality RNA extraction, in sufficient amounts for real-time quantitative polymerase chain reaction and next-generation sequencing. In this work, we compared different RNA extraction methods and evaluated different reference genes for gene expression studies in the fetal human inner ear. We compared the RNA extracted from formalin-fixed paraffin-embedded tissue with fresh tissue stored at -80 °C in RNAlater solution and validated the expression stability of 12 reference genes (from gestational week 11 to 19). The RNA from fresh tissue in RNAlater resulted in higher amounts and a better quality of RNA than that from the paraffin-embedded tissue. The reference gene evaluation exhibited four stably expressed reference genes (B2M, HPRT1, GAPDH and GUSB). The selected reference genes were then used to examine the effect on the expression outcome of target genes (OTOF and TECTA), which are known to be regulated during inner ear development. The selected reference genes displayed no differences in the expression profile of OTOF and TECTA, which was confirmed by immunostaining. The results underline the importance of the choice of the RNA extraction method and reference genes used in gene expression studies.
Collapse
Affiliation(s)
- Claudia Steinacher
- Department of Otorhinolaryngology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Dietmar Rieder
- Institute of Bioinformatics, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Jasmin E Turner
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE1 4EP, UK
| | - Nita Solanky
- UCL Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Shin-Ya Nishio
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, Matsumoto 3-1-1 Asahi, Nagano 390-8621, Japan
| | - Shin-Ichi Usami
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, Matsumoto 3-1-1 Asahi, Nagano 390-8621, Japan
| | - Barbara Hausott
- Institute of Neuroanatomy, Medical University Innsbruck, 6020 Innsbruck, Austria
| | | | - Jozsef Dudas
- Department of Otorhinolaryngology, Medical University Innsbruck, 6020 Innsbruck, Austria
| |
Collapse
|
3
|
Channathodiyil P, Houseley J. Glyoxal fixation facilitates transcriptome analysis after antigen staining and cell sorting by flow cytometry. PLoS One 2021; 16:e0240769. [PMID: 33481798 PMCID: PMC7822327 DOI: 10.1371/journal.pone.0240769] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/04/2021] [Indexed: 01/07/2023] Open
Abstract
A simple method for extraction of high quality RNA from cells that have been fixed, stained and sorted by flow cytometry would allow routine transcriptome analysis of highly purified cell populations and single cells. However, formaldehyde fixation impairs RNA extraction and inhibits RNA amplification. Here we show that good quality RNA can be readily extracted from stained and sorted mammalian cells if formaldehyde is replaced by glyoxal—a well-characterised fixative that is widely compatible with immunofluorescent staining methods. Although both formaldehyde and glyoxal efficiently form protein-protein crosslinks, glyoxal does not crosslink RNA to proteins nor form stable RNA adducts, ensuring that RNA remains accessible and amenable to enzymatic manipulation after glyoxal fixation. We find that RNA integrity is maintained through glyoxal fixation, permeabilisation with methanol or saponin, indirect immunofluorescent staining and flow sorting. RNA can then be extracted by standard methods and processed into RNA-seq libraries using commercial kits; mRNA abundances measured by poly(A)+ RNA-seq correlate well between freshly harvested cells and fixed, stained and sorted cells. We validate the applicability of this approach to flow cytometry by staining MCF-7 cells for the intracellular G2/M-specific antigen cyclin B1 (CCNB1), and show strong enrichment for G2/M-phase cells based on transcriptomic data. Switching to glyoxal fixation with RNA-compatible staining methods requires only minor adjustments of most existing staining and sorting protocols, and should facilitate routine transcriptomic analysis of sorted cells.
Collapse
Affiliation(s)
| | - Jonathan Houseley
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
- * E-mail:
| |
Collapse
|
4
|
Kolenda T, Ryś M, Guglas K, Teresiak A, Bliźniak R, Mackiewicz J, Lamperska K. Quantification of long non-coding RNAs using qRT-PCR: comparison of different cDNA synthesis methods and RNA stability. Arch Med Sci 2021; 17:1006-1015. [PMID: 34336028 PMCID: PMC8314425 DOI: 10.5114/aoms.2019.82639] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/29/2018] [Indexed: 12/02/2022] Open
Abstract
INTRODUCTION Long non-coding RNAs (lncRNAs), a class of regulatory RNA molecules, are over 200 nucleotides long and could be used as a new potential biomarker, but their detection methods such as qRT-PCR are still not validated, and the influence of RNA degradation on lncRNA quantification is not clear. In this study, commercially available cDNA synthesis kits were tested and the influence of RNA degradation was compared. MATERIAL AND METHODS Total RNA from FaDu cells was isolated and high quality RNA and highly degraded RNA samples were used. Reverse transcription was performed using three different commercially available kits and quantifications were performed using lncRNA Primer Plate and SYBR Green I Master by LightCycler 96. qRT-PCR was performed using three different cDNA samples and results are presented as the mean Ct values. A p-value < 0.05 was considered to be significant. RESULTS Lower lncRNA Ct values (61/90; 67.78%) after qRT-PCR quantification were observed for cDNA synthesized using random hexamer primers preceded by polyA-tailing and adaptor-anchoring steps. It was observed that 9/90 (10.00%) lncRNAs were not detectable using different cDNA synthesis methods. For 75/90 (83%) lncRNAs, RNA degradation weakly influenced lncRNA Ct values and no differences were observed between high quality RNA and degraded samples. Seventy percent of examined lncRNAs showed significantly different Ct values depending on RNA degradation. CONCLUSIONS cDNA synthesis kits with random hexamer primers preceded by polyA-tailing and adaptor-anchoring steps allows enhancement of lncRNA quantification specificity and sensitivity. In most cases degradation of RNA samples does not affect lncRNA quantification because these molecules have good stability.
Collapse
Affiliation(s)
- Tomasz Kolenda
- Chair of Medical Biotechnology, Poznan University of Medical Sciences, Poznan, Poland
- Laboratory of Cancer Genetics, Greater Poland Cancer Centre, Poznan, Poland
- Postgraduate School of Molecular Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Marcel Ryś
- Chair of Medical Biotechnology, Poznan University of Medical Sciences, Poznan, Poland
- Laboratory of Cancer Genetics, Greater Poland Cancer Centre, Poznan, Poland
| | - Kacper Guglas
- Chair of Medical Biotechnology, Poznan University of Medical Sciences, Poznan, Poland
- Laboratory of Cancer Genetics, Greater Poland Cancer Centre, Poznan, Poland
- Postgraduate School of Molecular Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Anna Teresiak
- Laboratory of Cancer Genetics, Greater Poland Cancer Centre, Poznan, Poland
| | - Renata Bliźniak
- Laboratory of Cancer Genetics, Greater Poland Cancer Centre, Poznan, Poland
| | - Jacek Mackiewicz
- Department of Medical and Experimental Oncology, Heliodor Swiecicki Clinical Hospital, Poznan University of Medical Sciences, Poznan, Poland
- Department of Biology and Environmental Sciences, Poznan University of Medical Sciences, Poznan, Poland
- Department of Diagnostics and Cancer Immunology, Greater Poland Cancer Centre, Poznan, Poland
| | | |
Collapse
|
5
|
Expression of MAPK and PI3K/AKT/mTOR Proteins according to the Chronic Liver Disease Etiology in Hepatocellular Carcinoma. JOURNAL OF ONCOLOGY 2020; 2020:4609360. [PMID: 33178273 PMCID: PMC7644337 DOI: 10.1155/2020/4609360] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 10/12/2020] [Accepted: 10/15/2020] [Indexed: 02/07/2023]
Abstract
Aims Chronic liver disease (CLD) of different etiologies leads to hepatocellular carcinoma (HCC) by multiple mechanisms that may be translated into clinicopathological differences. We evaluated the tissue expression of the MAPK and PI3K/Akt/mTOR pathway proteins and their association with long-term outcome and other parameters, according to the etiology of the CLD, in HCC patients. Methods Clinicopathological data from 80 patients who underwent orthotopic liver transplantation for HCC treatment in a Brazilian referral center were compared according to CLD etiology. Event (tumor recurrence or death from any cause) occurrence and event-free survival (EFS) were analyzed. Pathway protein expression was assessed by immunohistochemistry (IHQ) in both tumor and underlying cirrhosis and by RT-PCR in tumor tissue. Results Strong expression (SE) of KRAS was more frequent in tumors arising from viral (26.8%) than the nonviral group of liver disease (7.7%, p=0.024) and also than cirrhotic parenchyma (0%, p=0.004). SE of PI3K was more frequent in tumor than in cirrhosis (p=0.048, p < 0.01), without differences in its tumor expression among etiologic groups (p=0.111). mRNA of ERK, PI3K, and BRAF was expressed in the tumor, without differences between CLD etiologies, and there was no association with IHQ findings. Older age and microvascular invasion (MIV) were the only parameters independently associated with the event. MIV was also associated with shorter EFS. Conclusions Hepatitis B and C virus can lead to HCC by different mechanisms compared with nonviral hepatopathy. KRAS and PI3K may have a role in carcinogenesis. The prognostic and therapeutic implications need to be investigated.
Collapse
|
6
|
Frönicke L, Bronner DN, Byndloss MX, McLaughlin B, Bäumler AJ, Westermann AJ. Toward Cell Type-Specific In Vivo Dual RNA-Seq. Methods Enzymol 2018; 612:505-522. [PMID: 30502956 DOI: 10.1016/bs.mie.2018.08.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Dual RNA-seq has emerged as a genome-wide expression profiling technique, simultaneously measuring RNA transcript levels in a given host and its pathogen during an infection. Recently, the method was transferred from cell culture to in vivo models of bacterial infections; however, specific host cell-type resolution has not yet been achieved. Here we present a detailed protocol that describes the application of Dual RNA-seq to murine colonocytes isolated from mice infected with the enteric pathogen Salmonella Typhimurium. At day 5 after oral infection, the mice were humanely euthanized, their colons extracted, and colonocytes isolated and fixed. Upon antibody staining of cell type-specific surface markers, the fraction of Salmonella-invaded colonocytes was collected by fluorescence-activated cell sorting based on a fluorescent signal emitted by the internalized bacteria. Total RNA was extracted from cells enriched by this method, and ribosomal transcripts from host and microbial cells were removed prior to cDNA synthesis and library generation. We compared different protocols for library preparation and discuss their respective advantages and caveats when applied to minute RNA amounts that constitute an inherent challenge for in vivo transcriptomics. Our results introduce an ultralow input protocol that holds promise for cell type-specific in vivo Dual RNA-seq for charting gene expression of a bacterial pathogen within its respective in vivo niche, along with the consequent host response.
Collapse
Affiliation(s)
- Lutz Frönicke
- University of California Davis Genome Center, Davis, CA, United States
| | - Denise N Bronner
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA, United States
| | - Mariana X Byndloss
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA, United States
| | - Bridget McLaughlin
- Comprehensive Cancer Center Flow Cytometry Shared Resource, University of California Davis, Davis, CA, United States
| | - Andreas J Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA, United States
| | - Alexander J Westermann
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, Würzburg, Germany; Helmholtz Institute for RNA-Based Infection Research (HIRI), Würzburg, Germany.
| |
Collapse
|
7
|
Greytak SR, Engel KB, Zmuda E, Casas-Silva E, Guan P, Hoadley KA, Mungall AJ, Wheeler DA, Doddapaneni HV, Moore HM. National Cancer Institute Biospecimen Evidence-Based Practices: Harmonizing Procedures for Nucleic Acid Extraction from Formalin-Fixed, Paraffin-Embedded Tissue. Biopreserv Biobank 2018; 16:247-250. [PMID: 29920119 DOI: 10.1089/bio.2018.0046] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
| | | | - Erik Zmuda
- 3 Cytogenetics/Molecular Genetics Laboratory at Nationwide Children's Hospital , Columbus, Ohio
| | - Esmeralda Casas-Silva
- 4 Biorepositories and Biospecimen Research Branch, Cancer Diagnosis Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute , Bethesda, Maryland
| | - Ping Guan
- 4 Biorepositories and Biospecimen Research Branch, Cancer Diagnosis Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute , Bethesda, Maryland
| | - Katherine A Hoadley
- 5 Department of Genetics, Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Andrew J Mungall
- 6 Canada's Michael Smith Genome Sciences Center , BC Cancer Agency, Vancouver, Canada
| | - David A Wheeler
- 7 Human Genome Sequencing Center , Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Harsha V Doddapaneni
- 7 Human Genome Sequencing Center , Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Helen M Moore
- 4 Biorepositories and Biospecimen Research Branch, Cancer Diagnosis Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute , Bethesda, Maryland
| |
Collapse
|
8
|
Westermann AJ, Förstner KU, Amman F, Barquist L, Chao Y, Schulte LN, Müller L, Reinhardt R, Stadler PF, Vogel J. Dual RNA-seq unveils noncoding RNA functions in host-pathogen interactions. Nature 2016; 529:496-501. [PMID: 26789254 DOI: 10.1038/nature16547] [Citation(s) in RCA: 335] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 12/18/2015] [Indexed: 12/12/2022]
Abstract
Bacteria express many small RNAs for which the regulatory roles in pathogenesis have remained poorly understood due to a paucity of robust phenotypes in standard virulence assays. Here we use a generic 'dual RNA-seq' approach to profile RNA expression simultaneously in pathogen and host during Salmonella enterica serovar Typhimurium infection and reveal the molecular impact of bacterial riboregulators. We identify a PhoP-activated small RNA, PinT, which upon bacterial internalization temporally controls the expression of both invasion-associated effectors and virulence genes required for intracellular survival. This riboregulatory activity causes pervasive changes in coding and noncoding transcripts of the host. Interspecies correlation analysis links PinT to host cell JAK-STAT signalling, and we identify infection-specific alterations in multiple long noncoding RNAs. Our study provides a paradigm for a sensitive RNA-based analysis of intracellular bacterial pathogens and their hosts without physical separation, as well as a new discovery route for hidden functions of pathogen genes.
Collapse
Affiliation(s)
- Alexander J Westermann
- University of Würzburg, RNA Biology Group, Institute for Molecular Infection Biology, Josef-Schneider-Straße 2/D15, D-97080 Würzburg, Germany
| | - Konrad U Förstner
- University of Würzburg, RNA Biology Group, Institute for Molecular Infection Biology, Josef-Schneider-Straße 2/D15, D-97080 Würzburg, Germany.,University of Würzburg, Core Unit Systems Medicine, Josef-Schneider-Straße 2/D15, D-97080 Würzburg, Germany
| | - Fabian Amman
- University of Leipzig, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Härtelstraße 16-18, D-04107 Leipzig, Germany.,University of Vienna, Theoretical Biochemistry Group, Institute for Theoretical Chemistry, Währinger Straße 17, A-1090 Vienna, Austria
| | - Lars Barquist
- University of Würzburg, RNA Biology Group, Institute for Molecular Infection Biology, Josef-Schneider-Straße 2/D15, D-97080 Würzburg, Germany
| | - Yanjie Chao
- University of Würzburg, RNA Biology Group, Institute for Molecular Infection Biology, Josef-Schneider-Straße 2/D15, D-97080 Würzburg, Germany
| | - Leon N Schulte
- University of Würzburg, RNA Biology Group, Institute for Molecular Infection Biology, Josef-Schneider-Straße 2/D15, D-97080 Würzburg, Germany
| | - Lydia Müller
- University of Leipzig, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Härtelstraße 16-18, D-04107 Leipzig, Germany
| | - Richard Reinhardt
- Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, D-50829 Cologne, Germany
| | - Peter F Stadler
- University of Leipzig, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Härtelstraße 16-18, D-04107 Leipzig, Germany.,University of Vienna, Theoretical Biochemistry Group, Institute for Theoretical Chemistry, Währinger Straße 17, A-1090 Vienna, Austria.,Max Planck Institute for Mathematics in the Sciences, Inselstraße 22, D-04103 Leipzig, Germany.,Santa Fe Institute, 1399 Hyde Park Rd, Santa Fe, New Mexico 87501, USA
| | - Jörg Vogel
- University of Würzburg, RNA Biology Group, Institute for Molecular Infection Biology, Josef-Schneider-Straße 2/D15, D-97080 Würzburg, Germany.,Research Centre for Infectious Diseases (ZINF), University of Würzburg, D-97070 Würzburg, Germany
| |
Collapse
|
9
|
Hara K, Watanabe A, Matsumoto S, Matsuda Y, Kuwata T, Kan H, Yamada T, Koizumi M, Shinji S, Yamagishi A, Ishiwata T, Naito Z, Shimada T, Uchida E. Surgical Specimens of Colorectal Cancer Fixed with PAXgene Tissue System Preserve High-Quality RNA. Biopreserv Biobank 2015; 13:325-34. [DOI: 10.1089/bio.2014.0101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Keisuke Hara
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan
| | - Atsushi Watanabe
- Department of Biochemistry and Molecular Biology, Nippon Medical School Graduate School, Tokyo, Japan
| | - Satoshi Matsumoto
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan
| | - Yoko Matsuda
- Department of Pathology and Integrative Oncological Pathology, Nippon Medical School Graduate School, Tokyo, Japan
| | | | - Hayato Kan
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan
| | - Takeshi Yamada
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan
| | - Michihiro Koizumi
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan
| | - Seiichi Shinji
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan
| | - Aya Yamagishi
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan
| | - Toshiyuki Ishiwata
- Department of Pathology and Integrative Oncological Pathology, Nippon Medical School Graduate School, Tokyo, Japan
| | - Zenya Naito
- Department of Pathology and Integrative Oncological Pathology, Nippon Medical School Graduate School, Tokyo, Japan
| | - Takashi Shimada
- Department of Biochemistry and Molecular Biology, Nippon Medical School Graduate School, Tokyo, Japan
| | - Eiji Uchida
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan
| |
Collapse
|
10
|
Hamatani K, Eguchi H, Koyama K, Mukai M, Nakachi K, Kusunoki Y. A novel RET rearrangement (ACBD5/RET) by pericentric inversion, inv(10)(p12.1;q11.2), in papillary thyroid cancer from an atomic bomb survivor exposed to high-dose radiation. Oncol Rep 2014; 32:1809-14. [PMID: 25175022 DOI: 10.3892/or.2014.3449] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 08/06/2014] [Indexed: 11/06/2022] Open
Abstract
During analysis of RET/PTC rearrangements in papillary thyroid cancer (PTC) among atomic bomb survivors, a cDNA fragment of a novel type of RET rearrangement was identified in a PTC patient exposed to a high radiation dose using the improved 5' RACE method. This gene resulted from the fusion of the 3' portion of RET containing tyrosine kinase domain to the 5' portion of the acyl-coenzyme A binding domain containing 5 (ACBD5) gene, by pericentric inversion inv(10)(p12.1;q11.2); expression of the fusion gene was confirmed by RT-PCR. ACBD5 gene is ubiquitously expressed in various human normal tissues including thyroid. Full-length cDNA of the ACBD5-RET gene was constructed and then examined for tumorigenicity. Enhanced phosphorylation of ERK proteins in the MAPK pathway was observed in NIH3T3 cells transfected with expression vector encoding the full-length ACBD5/RET cDNA, while this was not observed in the cells transfected with empty expression vector. Stable NIH3T3 transfectants with ACBD5-RET cDNA induced tumor formation after their injection into nude mice. These findings suggest that the ACBD5-RET rearrangement is causatively involved in the development of PTC.
Collapse
Affiliation(s)
- Kiyohiro Hamatani
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Hidetaka Eguchi
- Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Kazuaki Koyama
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Mayumi Mukai
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Kei Nakachi
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Yoichiro Kusunoki
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| |
Collapse
|
11
|
Comparison of two methods of RNA extraction from formalin-fixed paraffin-embedded tissue specimens. BIOMED RESEARCH INTERNATIONAL 2014; 2014:151724. [PMID: 25105117 PMCID: PMC4106052 DOI: 10.1155/2014/151724] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/29/2014] [Accepted: 06/16/2014] [Indexed: 11/30/2022]
Abstract
The present study aimed to compare two different methods of extracting RNA from formalin-fixed paraffin-embedded (FFPE) specimens of diffuse large B-cell lymphoma (DLBCL). We further aimed to identify possible influences of variables—such as tissue size, duration of paraffin block storage, fixative type, primers used for cDNA synthesis, and endogenous genes tested—on the success of amplification from the samples. Both tested protocols used the same commercial kit for RNA extraction (the RecoverAll Total Nucleic Acid Isolation Optimized for FFPE Samples from Ambion). However, the second protocol included an additional step of washing with saline buffer just after sample rehydration. Following each protocol, we compared the RNA amount and purity and the amplification success as evaluated by standard PCR and real-time PCR. The results revealed that the extra washing step added to the RNA extraction process resulted in significantly improved RNA quantity and quality and improved success of amplification from paraffin-embedded specimens.
Collapse
|
12
|
Trypanosoma cruzi necrotizing meningoencephalitis in a Venezuelan HIV⁺-AIDS patient: pathological diagnosis confirmed by PCR using formalin-fixed- and paraffin-embedded-tissues. Anal Cell Pathol (Amst) 2014; 2014:124795. [PMID: 25763312 PMCID: PMC4334046 DOI: 10.1155/2014/124795] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Revised: 12/11/2014] [Accepted: 12/12/2014] [Indexed: 12/19/2022] Open
Abstract
Coinfections with human immunodeficiency virus (HIV) and infectious agents have been recognized since the early 90s. In the central nervous system (CNS) of HIV+ patients, parasitic protozoans like Toxoplasma gondii have been described as responsible for the space occupying lesions (SOL) developed. However, the involvement of Trypanosoma cruzi is also described but appears to be less frequent in acquired immunodeficiency syndrome (AIDS) and transplant recipients, associated with necrotizing myocarditis and neurological symptoms related to the occurrence of necrotizing pseudotumoral encephalitis (NPE) and meningoencephalitis (NME). The present work aims to present a Venezuelan case of NME associated with the coinfection of HIV and a T. cruzi-like trypanosomatid as well as its evolution and diagnosis by histopathological techniques, electron microscopy, and PCR methods using formalin-fixed- (FF-) and paraffin-embedded- (PE-) tissues. Postmortem cytological studies of leptomeninges imprints reveal the presence of trypomastigotes of Trypanosoma sp. Histopathological and electron microscopy studies allowed us to identify an amastigote stage and to reject the involvement of other opportunistic microorganisms as the etiological agent of the SOL. The definitive confirmation of T. cruzi as the etiological agent was achieved by PCR suggesting that the NME by T. cruzi was due to a reactivation of Chagas' disease.
Collapse
|
13
|
Kimura Y, Kubo S, Koda H, Shigemoto K, Sawabe M, Kitamura K. RNA analysis of inner ear cells from formalin fixed paraffin embedded (FFPE) archival human temporal bone section using laser microdissection--a technical report. Hear Res 2013; 302:26-31. [PMID: 23660400 DOI: 10.1016/j.heares.2013.04.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Revised: 04/16/2013] [Accepted: 04/22/2013] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Molecular analysis using archival human inner ear specimens is challenging because of the anatomical complexity, long-term fixation, and decalcification. However, this method may provide great benefit for elucidation of otological diseases. Here, we extracted mRNA for RT-PCR from tissues dissected from archival FFPE human inner ears by laser microdissection. METHODS Three human temporal bones obtained at autopsy were fixed in formalin, decalcified by EDTA, and embedded in paraffin. The samples were isolated into spiral ligaments, outer hair cells, spiral ganglion cells, and stria vascularis by laser microdissection. RNA was extracted and heat-treated in 10 mM citrate buffer to remove the formalin-derived modification. To identify the sites where COCH and SLC26A5 mRNA were expressed, semi-nested RT-PCR was performed. We also examined how long COCH mRNA could be amplified by semi-nested RT-PCR in archival temporal bone. RESULTS COCH was expressed in the spiral ligament and stria vascularis. However, SLC26A5 was expressed only in outer hair cells. The maximum base length of COCH mRNA amplified by RT-PCR was 98 bp in 1 case and 123 bp in 2 cases. CONCLUSION We detected COCH and SLC26A5 mRNA in specific structures and cells of the inner ear from archival human temporal bone. Our innovative method using laser microdissection and semi-nested RT-PCR should advance future RNA study of human inner ear diseases.
Collapse
Affiliation(s)
- Yurika Kimura
- Department of Otolaryngology, Tokyo Metropolitan Geriatric Medical Hospital, 35-2, Itabashi, Tokyo 173 0015, Japan.
| | | | | | | | | | | |
Collapse
|
14
|
Mougeot JLC, Mougeot FK, Peterson DE, Padilla RJ, Brennan MT, Lockhart PB. Use of archived biopsy specimens to study gene expression in oral mucosa from chemotherapy-treated cancer patients. Oral Surg Oral Med Oral Pathol Oral Radiol 2013; 115:630-7. [DOI: 10.1016/j.oooo.2013.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 11/29/2012] [Accepted: 01/02/2013] [Indexed: 11/28/2022]
|
15
|
Hamatani K, Mukai M, Takahashi K, Hayashi Y, Nakachi K, Kusunoki Y. Rearranged anaplastic lymphoma kinase (ALK) gene in adult-onset papillary thyroid cancer amongst atomic bomb survivors. Thyroid 2012; 22:1153-9. [PMID: 23050789 PMCID: PMC3487115 DOI: 10.1089/thy.2011.0511] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND We previously noted that among atomic bomb survivors (ABS), the relative frequency of cases of adult papillary thyroid cancer (PTC) with chromosomal rearrangements (mainly RET/PTC) was significantly greater in those with relatively higher radiation exposure than those with lower radiation exposure. In contrast, the frequency of PTC cases with point mutations (mainly BRAF(V600E)) was significantly lower in patients with relatively higher radiation exposure than those with lower radiation exposure. We also found that among ABS, the frequency of PTC cases with no detectable gene alterations in RET, neurotrophic tyrosine kinase receptor 1 (NTRK1), BRAF, or RAS was significantly higher in patients with relatively higher radiation exposure than those with lower radiation exposure. However, in ABS with PTC, the relationship between the presence of the anaplastic lymphoma kinase (ALK) gene fused with other gene partners and radiation exposure has received little study. In this study, we tested the hypothesis that the relative frequency of rearranged ALK in ABS with PTC, and with no detectable gene alterations in RET, NTRK1, BRAF, or RAS, would be greater in those having relatively higher radiation exposures. METHODS The 105 subjects in the study were drawn from the Life Span Study cohort of ABS of Hiroshima and Nagasaki who were diagnosed with PTC between 1956 and 1993. Seventy-nine were exposed (>0 mGy), and 26 were not exposed to A-bomb radiation. In the 25 ABS with PTC, and with no detectable gene alterations in RET, NTRK1, BRAF, or RAS, we examined archival, formalin-fixed, paraffin-embedded PTC specimens for rearrangement of ALK using reverse transcription-polymerase chain reaction and 5' rapid amplification of cDNA ends (5' RACE). RESULTS We found rearranged ALK in 10 of 19 radiation-exposed PTC cases, but none among 6 patients with PTC with no radiation exposure. In addition, solid/trabecular-like architecture in PTC was closely associated with ALK rearrangements, being observed in 6 of 10 PTC cases with ALK rearrangements versus 2 of 15 cases with no ALK rearrangements. The six radiation-exposed cases of PTC harboring both ALK rearrangements and solid/trabecular-like architecture were associated with higher radiation doses and younger ages at the time of the A-bombing and at diagnosis compared to the other 19 PTC with no detectable gene alterations. CONCLUSION Our findings suggest that ALK rearrangements are involved in the development of radiation-induced adult-onset PTC.
Collapse
Affiliation(s)
- Kiyohiro Hamatani
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Mayumi Mukai
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Keiko Takahashi
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Yuzo Hayashi
- Geriatric Health Service Facility Hidamari, Hiroshima, Japan
| | - Kei Nakachi
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Yoichiro Kusunoki
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| |
Collapse
|
16
|
Harrington SC, Weroha SJ, Reynolds C, Suman VJ, Lingle WL, Haluska P. Quantifying insulin receptor isoform expression in FFPE breast tumors. Growth Horm IGF Res 2012; 22:108-115. [PMID: 22551578 PMCID: PMC3392524 DOI: 10.1016/j.ghir.2012.04.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 03/17/2012] [Accepted: 04/02/2012] [Indexed: 12/21/2022]
Abstract
BACKGROUND The development of predictive biomarkers for IGF targeted anti-cancer therapeutics remains a critical unmet need. The insulin receptor A isoform (InsR-A) has been identified as a possible biomarker candidate but quantification of InsR-A in widely available formalin fixed paraffin embedded (FFPE) tissues is complicated by its similarities with the metabolic signaling insulin receptor isoform B (InsR-B). In the present study, qPCR based assays specific for InsR-A, InsR-B and IGF-1R were developed for use in FFPE tissues and tested for feasible use in clinical archived FFPE estrogen receptor (ER)+and ER- breast cancer tumors. DESIGN FFPE compatible primer sets were designed with amplicon sizes of less than 60 base pairs and validated for target specificity, assay repeatability and amplification efficiency. FFPE tumors from ER+ (n=83) and ER-(n=64) primary untreated breast cancers, and ER+ hormone refractory (HR ER+) (n=61) breast cancers were identified for feasibility testing. The feasible use of InsR-A and InsR-B qPCRs were tested using all tumor groups and the feasibility of IGF-1R qPCR was determined using HR ER+ tumors. RESULTS All qPCR assays were highly reproducible with amplification efficiencies between 96-104% over a 6 log range with limits of detection of 4 or 5 copies per reaction. Greater than 90% of samples were successfully amplified using InsR-A, InsR-B or IGF-1R qPCR primer sets and greater than 88% of samples tested amplified both InsR isoforms or both isoforms and IGF-1R. InsR-A was the predominant isoform in 82% ER+, 68% ER- and 100% HR ER+ breast cancer. Exploratory analyses demonstrated significantly more InsR-A expression in ER+ and HR ER+ groups compared to InsR-B (ER+ p<0.05, HR ER+ p<0.0005) and both groups had greater InsR-A expression when compared to ER- tumors (ER+ p<0.0005, HR ER+ p<0.05). IGF-1R expression of HR ER+ tumors was lower than InsR-A (p<0.0005) but higher than InsR-B (p<0.0005). The InsR-B expression of HR ER+ tumors was significantly reduced compared other tumor subgroups (ER+ and ER-, p<0.0005) and lead to a significant elevation of HR ER+ InsR-A: InsR-B ratios (ER+ and ER-, p<0.0005). CONCLUSIONS The validated, highly sensitive InsR-A and InsR-B qPCR based assays presented here are the first to demonstrate the feasible amplification of InsR isoforms in FFPE tissues. Quantification data generated from this feasibility study indicating InsR-A is more predominant than InsR-B in breast cancer support the use of these assays for further investigation of InsR-A and InsR-B as predictive biomarkers for IGF targeted therapeutics.
Collapse
Affiliation(s)
| | - S. John Weroha
- Department of Oncology, Mayo Clinic, Rochester, MN 55905
| | - Carol Reynolds
- Division of Anatomical Pathology, Mayo Clinic, Rochester, MN 55905
| | - Vera J. Suman
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN 55905
| | - Wilma L. Lingle
- Division of Experimental Pathology and Laboratory Medicine, Mayo Clinic, Rochester, MN 55905
| | - Paul Haluska
- Department of Oncology, Mayo Clinic, Rochester, MN 55905
| |
Collapse
|
17
|
Kotorashvili A, Ramnauth A, Liu C, Lin J, Ye K, Kim R, Hazan R, Rohan T, Fineberg S, Loudig O. Effective DNA/RNA co-extraction for analysis of microRNAs, mRNAs, and genomic DNA from formalin-fixed paraffin-embedded specimens. PLoS One 2012; 7:e34683. [PMID: 22514653 PMCID: PMC3326040 DOI: 10.1371/journal.pone.0034683] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 03/08/2012] [Indexed: 01/03/2023] Open
Abstract
Background Retrospective studies of archived human specimens, with known clinical follow-up, are used to identify predictive and prognostic molecular markers of disease. Due to biochemical differences, however, formalin-fixed paraffin-embedded (FFPE) DNA and RNA have generally been extracted separately from either different tissue sections or from the same section by dividing the digested tissue. The former limits accurate correlation whilst the latter is impractical when utilizing rare or limited archived specimens. Principal Findings For effective recovery of genomic DNA and total RNA from a single FFPE specimen, without splitting the proteinase-K digested tissue solution, we optimized a co-extraction method by using TRIzol and purifying DNA from the lower aqueous and RNA from the upper organic phases. Using a series of seven different archived specimens, we evaluated the total amounts of genomic DNA and total RNA recovered by our TRIzol-based co-extraction method and compared our results with those from two commercial kits, the Qiagen AllPrep DNA/RNA FFPE kit, for co-extraction, and the Ambion RecoverAll™ Total Nucleic Acid Isolation kit, for separate extraction of FFPE-DNA and -RNA. Then, to accurately assess the quality of DNA and RNA co-extracted from a single FFPE specimen, we used qRT-PCR, gene expression profiling and methylation assays to analyze microRNAs, mRNAs, and genomic DNA recovered from matched fresh and FFPE MCF10A cells. These experiments show that the TRIzol-based co-extraction method provides larger amounts of FFPE-DNA and –RNA than the two other methods, and particularly provides higher quality microRNAs and genomic DNA for subsequent molecular analyses. Significance We determined that co-extraction of genomic DNA and total RNA from a single FFPE specimen is an effective recovery approach to obtain high-quality material for parallel molecular and high-throughput analyses. Our optimized approach provides the option of collecting DNA, which would otherwise be discarded or degraded, for additional or subsequent studies.
Collapse
Affiliation(s)
- Adam Kotorashvili
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Andrew Ramnauth
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Christina Liu
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Juan Lin
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Kenny Ye
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Ryung Kim
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Rachel Hazan
- Department of Pathology, Albert Einstein College of Medicine of Yeshiva University, Bronx , New York, United States of America
| | - Thomas Rohan
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Susan Fineberg
- Department of Pathology, Albert Einstein College of Medicine of Yeshiva University, Bronx , New York, United States of America
| | - Olivier Loudig
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
- Department of Pathology, Albert Einstein College of Medicine of Yeshiva University, Bronx , New York, United States of America
- * E-mail:
| |
Collapse
|
18
|
The effect of formaldehyde fixation on RNA: optimization of formaldehyde adduct removal. J Mol Diagn 2011; 13:282-8. [PMID: 21497290 DOI: 10.1016/j.jmoldx.2011.01.010] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 01/08/2011] [Accepted: 01/26/2011] [Indexed: 11/23/2022] Open
Abstract
Formalin-fixed, paraffin-embedded tissues generally provide low yields of extractable RNA that exhibit both covalent modification of nucleic acid bases and strand cleavage. This frustrates efforts to perform retrospective analyses of gene expression using archival tissue specimens. A variety of conditions have been reported to demodify formaldehyde-fixed RNA in different model systems. We studied the reversal of formaldehyde fixation of RNA using a 50 base RNA oligonucleotide and total cellular RNA. Formaldehyde-adducted, native, and hydrolyzed RNA species were identified by their bioanalyzer electrophoretic migration patterns and RT-quantitative PCR. Demodification conditions included temperature, time, buffer, and pH. The reversal of formaldehyde-fixed RNA to native species without apparent RNA hydrolysis was most successfully performed in dilute Tris, phosphate, or similar buffers (pH 8) at 70°C for 30 minutes. Amines were not required for efficient formaldehyde demodification. Formaldehyde-fixed RNA was more labile than native RNA to treatment with heat and buffer, suggesting that antigen retrieval methods for proteins may impede RNA hybridization or RNA extraction. Taken together, the data indicate that reliable conditions may be used to remove formaldehyde adducts from RNA to improve the quality of RNA available for molecular studies.
Collapse
|
19
|
Shi SR, Shi Y, Taylor CR. Antigen retrieval immunohistochemistry: review and future prospects in research and diagnosis over two decades. J Histochem Cytochem 2011; 59:13-32. [PMID: 21339172 DOI: 10.1369/jhc.2010.957191] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
As a review for the 20th anniversary of publishing the antigen retrieval (AR) technique in this journal, the authors intend briefly to summarize developments in AR-immunohistochemistry (IHC)-based research and diagnostics, with particular emphasis on current challenges and future research directions. Over the past 20 years, the efforts of many different investigators have coalesced in extending the AR approach to all areas of anatomic pathology diagnosis and research and further have led to AR-based protein extraction techniques and tissue-based proteomics. As a result, formalin-fixed paraffin-embedded (FFPE) archival tissue collections are now seen as a literal treasure of materials for clinical and translational research to an extent unimaginable just two decades ago. Further research in AR-IHC is likely to focus on tissue proteomics, developing a more efficient protocol for protein extraction from FFPE tissue based on the AR principle, and combining the proteomics approach with AR-IHC to establish a practical, sophisticated platform for identifying and using biomarkers in personalized medicine.
Collapse
Affiliation(s)
- Shan-Rong Shi
- Department of Pathology, University of Southern California Keck School of Medicine, Los Angeles, California 90033, USA.
| | | | | |
Collapse
|
20
|
Seo AN, Kim JH, Lee D, Jeong JY, Park JY. Comparison of the DNA Preservation in Neutral-Buffered Formalin Fixed Paraffin-Embedded Tissue and in Non-Buffered Formalin Fixed Paraffin-Embedded Tissue. KOREAN JOURNAL OF PATHOLOGY 2011. [DOI: 10.4132/koreanjpathol.2011.45.6.549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- An Na Seo
- Department of Pathology, Kyungpook National University School of Medicine, Daegu, Korea
| | - Jae-Hoon Kim
- Department of Pathology, Kyungpook National University Hospital, Kyungpook National University School of Medicine, Daegu, Korea
| | - Dakeun Lee
- Department of Pathology, Kyungpook National University School of Medicine, Daegu, Korea
| | - Ji Yun Jeong
- Department of Pathology, Kyungpook National University School of Medicine, Daegu, Korea
| | - Ji-Young Park
- Department of Pathology, Kyungpook National University School of Medicine, Daegu, Korea
| |
Collapse
|
21
|
|
22
|
Lopes RA, Cardoso TC, Luvizotto MCR, de Andrade AL. Occurrence and expression of p53 suppressor gene and c-Myc oncogene in dog eyelid tumors. Vet Ophthalmol 2010; 13:69-75. [DOI: 10.1111/j.1463-5224.2009.00753.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
23
|
Hamatani K, Eguchi H, Mukai M, Koyama K, Taga M, Ito R, Hayashi Y, Nakachi K. Improved method for analysis of RNA present in long-term preserved thyroid cancer tissue of atomic bomb survivors. Thyroid 2010; 20:43-9. [PMID: 19785523 DOI: 10.1089/thy.2009.0098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Since many thyroid cancer tissue samples from atomic bomb (A-bomb) survivors have been preserved for several decades as unbuffered formalin-fixed, paraffin-embedded specimens, molecular oncological analysis of such archival specimens is indispensable for clarifying the mechanisms of thyroid carcinogenesis in A-bomb survivors. Although RET gene rearrangements are the most important targets, it is a difficult task to examine all of the 13 known types of RET gene rearrangements with the use of the limited quantity of RNA that has been extracted from invaluable paraffin-embedded tissue specimens of A-bomb survivors. In this study, we established an improved 5' rapid amplification of cDNA ends (RACE) method using a small amount of RNA extracted from archival thyroid cancer tissue specimens. METHODS Three archival thyroid cancer tissue specimens from three different patients were used as in-house controls to determine the conditions for an improved switching mechanism at 5' end of RNA transcript (SMART) RACE method; one tissue specimen with RET/PTC1 rearrangement and one with RET/PTC3 rearrangement were used as positive samples. One other specimen, used as a negative sample, revealed no detectable expression of the RET gene tyrosine kinase domain. RESULTS We established a 5' RACE method using an amount of RNA as small as 10 ng extracted from long-term preserved, unbuffered formalin-fixed, paraffin-embedded thyroid cancer tissue by application of SMART technology. This improved SMART RACE method not only identified common RET gene rearrangements, but also isolated a clone containing a 93-bp insert of rare RTE/PTC8 in RNA extracted from formalin-fixed, paraffin-embedded thyroid cancer specimens from one A-bomb survivor who had been exposed to a high radiation dose. In addition, in the papillary thyroid cancer of another high-dose A-bomb survivor, this method detected one novel type of RET gene rearrangement whose partner gene is acyl coenzyme A binding domain 5, located on chromosome 10p. CONCLUSION We conclude that our improved SMART RACE method is expected to prove useful in molecular analyses using archival formalin-fixed, paraffin-embedded tissue samples of limited quantity.
Collapse
Affiliation(s)
- Kiyohiro Hamatani
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Fedorowicz G, Guerrero S, Wu TD, Modrusan Z. Microarray analysis of RNA extracted from formalin-fixed, paraffin-embedded and matched fresh-frozen ovarian adenocarcinomas. BMC Med Genomics 2009; 2:23. [PMID: 19426511 PMCID: PMC2694827 DOI: 10.1186/1755-8794-2-23] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Accepted: 05/08/2009] [Indexed: 11/18/2022] Open
Abstract
Background Gene expression profiling of formalin-fixed, paraffin-embedded (FFPE) samples represents a valuable approach for advancing oncology diagnostics and enhancing retrospective clinical studies; however, at present, this methodology still requires optimization and thus has not been extensively used. Here, we utilized thorough quality control methods to assess RNA extracted from FFPE samples and then compared it to RNA extracted from matched fresh-frozen (FF) counterparts. We preformed genome-wide expression profiling of FF and FFPE ovarian serous adenocarcinoma sample pairs and compared their gene signatures to normal ovary samples. Methods RNA from FFPE samples was extracted using two different methods, Ambion and Agencourt, and its quality was determined by profiling starting total RNA on Bioanalyzer and by amplifying increasing size fragments of beta actin (ACTB) and claudin 3 (CLDN3) by reverse-transcriptase polymerase chain reaction. Five matched FF and FFPE ovarian serous adenocarcinoma samples, as well as a set of normal ovary samples, were profiled using whole genome Agilent microarrays. Reproducibility of the FF and FFPE replicates was measured using Pearson correlation, whereas comparison between the FF and FFPE samples was done using a Z-score analysis. Results Data analysis showed high reproducibility of expression within each FF and FFPE method, whereas matched FF and FFPE pairs demonstrated lower similarity, emphasizing an inherent difference between the two sample types. Z-score analysis of matched FF and FFPE samples revealed good concordance of top 100 differentially expressed genes with the highest correlation of 0.84. Genes characteristic of ovarian serous adenocarcinoma, including a well known marker CLDN3, as well as potentially some novel markers, were identified by comparing gene expression profiles of ovarian adenocarcinoma to those of normal ovary. Conclusion Conclusively, we showed that systematic assessment of FFPE samples at the RNA level is essential for obtaining good quality gene expression microarray data. We also demonstrated that profiling of not only FF but also of FFPE samples can be successfully used to identify differentially expressed genes characteristic of ovarian carcinoma.
Collapse
Affiliation(s)
- Grazyna Fedorowicz
- Department of Molecular Biology, Genentech, Inc,, 1 DNA Way, South San Francisco, CA 94080, USA.
| | | | | | | |
Collapse
|
25
|
Zhang X, Chen J, Radcliffe T, Lebrun DP, Tron VA, Feilotter H. An array-based analysis of microRNA expression comparing matched frozen and formalin-fixed paraffin-embedded human tissue samples. J Mol Diagn 2008; 10:513-9. [PMID: 18832457 DOI: 10.2353/jmoldx.2008.080077] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
MicroRNAs (miRNAs) are small, noncoding RNAs that suppress gene expression at the posttranscriptional level via an antisense RNA-RNA interaction. miRNAs used for array-based profiling are generally purified from either snap-frozen or fresh samples. Because tissues found in most pathology departments are available only in formalin-fixed and paraffin-embedded (FFPE) states, we sought to evaluate miRNA derived from FFPE samples for microarray analysis. In this study, miRNAs extracted from matched snap-frozen and FFPE samples were profiled using the Agilent miRNA array platform (Agilent, Santa Clara, CA). Each miRNA sample was hybridized to arrays containing probes interrogating 470 human miRNAs. Seven cases were compared in either duplicate or triplicate. Intrachip and interchip analyses demonstrated that the processes of miRNA extraction, labeling, and hybridization from both frozen and FFPE samples are highly reproducible and add little variation to the results; technical replicates showed high correlations with one another (Kendall tau, 0.722 to 0.853; Spearman rank correlation coefficient, 0.891 to 0.954). Our results showed consistent high correlations between matched frozen and FFPE samples (Kendall tau, 0.669 to 0.815; Spearman rank correlation coefficient, 0.847 to 0.948), supporting the use of FFPE-derived miRNAs for array-based, gene expression profiling.
Collapse
Affiliation(s)
- Xiao Zhang
- Department of Pathology and Molecular Medicine, Queen's Laboratory for Molecular Pathology, Kingston, ON, Canada
| | | | | | | | | | | |
Collapse
|
26
|
Hamatani K, Eguchi H, Ito R, Mukai M, Takahashi K, Taga M, Imai K, Cologne J, Soda M, Arihiro K, Fujihara M, Abe K, Hayashi T, Nakashima M, Sekine I, Yasui W, Hayashi Y, Nakachi K. RET/PTC rearrangements preferentially occurred in papillary thyroid cancer among atomic bomb survivors exposed to high radiation dose. Cancer Res 2008; 68:7176-82. [PMID: 18757433 DOI: 10.1158/0008-5472.can-08-0293] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A major early event in papillary thyroid carcinogenesis is constitutive activation of the mitogen-activated protein kinase signaling pathway caused by alterations of a single gene, typically rearrangements of the RET and NTRK1 genes or point mutations in the BRAF and RAS genes. In childhood papillary thyroid cancer, regardless of history of radiation exposure, RET/PTC rearrangements are a major event. Conversely, in adult-onset papillary thyroid cancer among the general population, the most common molecular event is BRAF(V600E) point mutation, not RET/PTC rearrangements. To clarify which gene alteration, chromosome aberration, or point mutation preferentially occurs in radiation-associated adult-onset papillary thyroid cancer, we have performed molecular analyses on RET/PTC rearrangements and BRAF(V600E) mutation in 71 papillary thyroid cancer cases among atomic bomb survivors (including 21 cases not exposed to atomic bomb radiation), in relation to radiation dose as well as time elapsed since atomic bomb radiation exposure. RET/PTC rearrangements showed significantly increased frequency with increased radiation dose (P(trend) = 0.002). In contrast, BRAF(V600E) mutation was less frequent in cases exposed to higher radiation dose (P(trend) < 0.001). Papillary thyroid cancer subjects harboring RET/PTC rearrangements developed this cancer earlier than did cases with BRAF(V600E) mutation (P = 0.03). These findings were confirmed by multivariate logistic regression analysis. These results suggest that RET/PTC rearrangements play an important role in radiation-associated thyroid carcinogenesis.
Collapse
Affiliation(s)
- Kiyohiro Hamatani
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima-shi, Hiroshima 732-0815, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Oberli A, Popovici V, Delorenzi M, Baltzer A, Antonov J, Matthey S, Aebi S, Altermatt HJ, Jaggi R. Expression profiling with RNA from formalin-fixed, paraffin-embedded material. BMC Med Genomics 2008; 1:9. [PMID: 18423048 PMCID: PMC2359756 DOI: 10.1186/1755-8794-1-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Accepted: 04/19/2008] [Indexed: 11/25/2022] Open
Abstract
Background Molecular characterization of breast and other cancers by gene expression profiling has corroborated existing classifications and revealed novel subtypes. Most profiling studies are based on fresh frozen (FF) tumor material which is available only for a limited number of samples while thousands of tumor samples exist as formalin-fixed, paraffin-embedded (FFPE) blocks. Unfortunately, RNA derived of FFPE material is fragmented and chemically modified impairing expression measurements by standard procedures. Robust protocols for isolation of RNA from FFPE material suitable for stable and reproducible measurement of gene expression (e.g. by quantitative reverse transcriptase PCR, QPCR) remain a major challenge. Results We present a simple procedure for RNA isolation from FFPE material of diagnostic samples. The RNA is suitable for expression measurement by QPCR when used in combination with an optimized cDNA synthesis protocol and TaqMan assays specific for short amplicons. The FFPE derived RNA was compared to intact RNA isolated from the same tumors. Preliminary scores were computed from genes related to the ER response, HER2 signaling and proliferation. Correlation coefficients between intact and partially fragmented RNA from FFPE material were 0.83 to 0.97. Conclusion We developed a simple and robust method for isolating RNA from FFPE material. The RNA can be used for gene expression profiling. Expression measurements from several genes can be combined to robust scores representing the hormonal or the proliferation status of the tumor.
Collapse
Affiliation(s)
- Andrea Oberli
- Department of Clinical Research, University of Bern, Murtenstrasse 35 CH-3010 Bern, Switzerland.
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Cox ML, Eddy SM, Stewart ZS, Kennel MR, Man MZ, Paulauskis JD, Dunstan RW. Investigating fixative-induced changes in RNA quality and utility by microarray analysis. Exp Mol Pathol 2008; 84:156-72. [DOI: 10.1016/j.yexmp.2007.11.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2007] [Revised: 11/12/2007] [Accepted: 11/14/2007] [Indexed: 10/22/2022]
|
29
|
Nakachi K, Hayashi T, Hamatani K, Eguchi H, Kusunoki Y. Sixty years of follow-up of Hiroshima and Nagasaki survivors: current progress in molecular epidemiology studies. Mutat Res 2008; 659:109-17. [PMID: 18406659 DOI: 10.1016/j.mrrev.2008.02.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Revised: 01/30/2008] [Accepted: 02/04/2008] [Indexed: 11/26/2022]
Abstract
This article provides an overview of the on-going molecular epidemiology studies among atomic-bomb survivors conducted at the Radiation Effects Research Foundation in Japan. The focus is on: (a) inter-individual variations in sensitivity to radiation-induced somatic mutations (glycophorin A (GPA) mutations) and their potential relevance to differences in susceptibility to radiation-related cancers and (b) the role of specific mutations/rearrangements in radiation-induced thyroid and colorectal cancers. The glycophorin A mutant fractions showed large differences between the survivors at each of the estimated bone marrow doses. Of note is the finding at doses>or=1 Gy; that the slope of the mutant fraction was significantly higher in the 'cancer group' than in the 'non-cancer group'. This study provided the basis for validating the use of gammaH2AX and reticulocyte micronucleus assays for evaluating radiosensitivity differences and genetic instability, respectively, in our studies in the coming years. Preliminary results from our molecular oncology studies on adult-onset papillary thyroid cancer provide evidence for the induction of RET/PTC rearrangements and BRAF point mutation (both known to be early stage events in adult-onset papillary thyroid cancer) but with a difference: cases associated with the rearrangements were more frequent at high doses, and developed sooner than those with BRAF mutation. In the case of colorectal cancer, the results suggest that radiation exposure might influence microsatellite instability (MSI) status through MSI-related epigenetic and genetic alterations-processes that might occur in the early stage of colorectal carcinogenesis.
Collapse
Affiliation(s)
- Kei Nakachi
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation (RERF), 5-2 Hijiyama Park, Minami-ku, Hiroshima-shi, Hiroshima 732-0815, Japan.
| | | | | | | | | |
Collapse
|
30
|
Li J, Smyth P, Cahill S, Denning K, Flavin R, Aherne S, Pirotta M, Guenther SM, O'Leary JJ, Sheils O. Improved RNA quality and TaqMan Pre-amplification method (PreAmp) to enhance expression analysis from formalin fixed paraffin embedded (FFPE) materials. BMC Biotechnol 2008; 8:10. [PMID: 18254955 PMCID: PMC2259333 DOI: 10.1186/1472-6750-8-10] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Accepted: 02/06/2008] [Indexed: 01/02/2023] Open
Abstract
Background Archival formalin-fixed paraffin-embedded (FFPE) tissues represent an abundant source of clinical specimens; however their use is limited in applications involving analysis of gene expression due to RNA degradation and modification during fixation and processing. This study improved the quality of RNA extracted from FFPE by introducing a heating step into the selected extraction protocols. Further, it evaluated a novel pre-amplification system (PreAmp) designed to enhance expression analysis from tissue samples using assays with a range of amplicon size (62–164 bp). Results Results from the Bioanalyzer and TaqMan® data showed improvement of RNA quality extracted using the modified protocols from FFPE. Incubation at 70°C for 20 minutes was determined to be the best condition of those tested to disrupt cross-links while not compromising RNA integrity. TaqMan® detection was influenced by master mix, amplicon size and the incorporation of a pre-amplification step. TaqMan® PreAmp consistently achieved decreased CT values in both snap frozen and FFPE aliquots compared with no pre-amplification. Conclusion Modification to extraction protocols has facilitated procurement of RNA that may be successfully amplified using QRT-PCR. TaqMan® PreAmp system is a robust and practical solution to limited quantities of RNA from FFPE extracts.
Collapse
Affiliation(s)
- Jinghuan Li
- Deptment of Histopathology, University of Dublin, Trinity College, Dublin, Ireland.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Ribeiro-Silva A, Zhang H, Jeffrey SS. RNA extraction from ten year old formalin-fixed paraffin-embedded breast cancer samples: a comparison of column purification and magnetic bead-based technologies. BMC Mol Biol 2007; 8:118. [PMID: 18154675 PMCID: PMC2233637 DOI: 10.1186/1471-2199-8-118] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2007] [Accepted: 12/21/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The development of protocols for RNA extraction from paraffin-embedded samples facilitates gene expression studies on archival samples with known clinical outcome. Older samples are particularly valuable because they are associated with longer clinical follow up. RNA extracted from formalin-fixed paraffin-embedded (FFPE) tissue is problematic due to chemical modifications and continued degradation over time. We compared quantity and quality of RNA extracted by four different protocols from 14 ten year old and 14 recently archived (three to ten months old) FFPE breast cancer tissues. Using three spin column purification-based protocols and one magnetic bead-based protocol, total RNA was extracted in triplicate, generating 336 RNA extraction experiments. RNA fragment size was assayed by reverse transcription-polymerase chain reaction (RT-PCR) for the housekeeping gene glucose-6-phosphate dehydrogenase (G6PD), testing primer sets designed to target RNA fragment sizes of 67 bp, 151 bp, and 242 bp. RESULTS Biologically useful RNA (minimum RNA integrity number, RIN, 1.4) was extracted in at least one of three attempts of each protocol in 86-100% of older and 100% of recently archived ("months old") samples. Short RNA fragments up to 151 bp were assayable by RT-PCR for G6PD in all ten year old and months old tissues tested, but none of the ten year old and only 43% of months old samples showed amplification if the targeted fragment was 242 bp. CONCLUSION All protocols extracted RNA from ten year old FFPE samples with a minimum RIN of 1.4. Gene expression of G6PD could be measured in all samples, old and recent, using RT-PCR primers designed for RNA fragments up to 151 bp. RNA quality from ten year old FFPE samples was similar to that extracted from months old samples, but quantity and success rate were generally higher for the months old group. We preferred the magnetic bead-based protocol because of its speed and higher quantity of extracted RNA, although it produced similar quality RNA to other protocols. If a chosen protocol fails to extract biologically useful RNA from a given sample in a first attempt, another attempt and then another protocol should be tried before excluding the case from molecular analysis.
Collapse
Affiliation(s)
- Alfredo Ribeiro-Silva
- Department of Surgery, Stanford University School of Medicine, MSLS Bldg Room P214; 1201 Welch Road, Stanford, CA 94305-5494, USA.
| | | | | |
Collapse
|
32
|
Takizawa T, Eguchi H, Namimatsu S, Jeschke U, Fuchs R, Robinson JM. Histochemistry for Placenta Research: Theory and Application. J NIPPON MED SCH 2007; 74:268-73. [PMID: 17878696 DOI: 10.1272/jnms.74.268] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Histochemical techniques have contributed significantly to advances in placental biology and cell biology. In this mini-review, we describe recent advances in histochemical technologies and show how these technologies can profoundly improve our understanding of placenta morphological function related to health and disease. Fundamental theories and applications of five separate methods discussed here are 1) tissue-based polymerase chain reaction by laser microdissection, 2) a novel antigen retrieval method using citraconic anhydride plus heating, 3) immunohistochemical detection of Lewis-related antigen expression and galectin-1 binding in the human placenta, 4) confocal microscopy analysis of IgG transport in placental trophoblasts, and 5) high-resolution immunofluorescence and correlative microscopy using ultrathin cryosections in placental research. This review article is based on a presentation given in a workshop entitled Histochemistry: Theory and Application at the 12th International Federation of Placenta Associations Meeting held in Kobe, Japan, on September 9, 2006.
Collapse
Affiliation(s)
- Toshihiro Takizawa
- Department of Molecular Anatomy, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
| | | | | | | | | | | |
Collapse
|