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Fulltext The Role of ISL1 and LHX5 LIM Homeobox Genes in Bladder Tumourigenesis

Akhir MKAM, Choy CS, Abdullah MA, Ghani FA, Veerakumarasivam A, Hussin H

Malays J Med Sci, 2020 Feb;27(1):37-45.
PMID: 32158343 MyJurnal DOI: 10.21315/mjms2020.27.1.4

Introduction: Lin-11, Isl-1 and Mec-3 domains (LIM) homeobox genes are among the most important sub-families of homeobox genes. These genes are thought to play an important role in cancer. In this study, the protein expression of these genes was examined in urothelial carcinoma of the bladder. The expression pattern of Islet-1 (ISL1) and LIM homeobox 5 (LHX5) across different cancer stages and grades, as well as the association between the protein expression of these genes and patient demographics and clinicopathological features, were examined.
Methods: A total of 100 formalin-fixed paraffin-embedded urothelial carcinoma tissues were selected from the Department of Pathology, Hospital Kuala Lumpur and the protein expression of ISL1 and LHX5 was determined using immunohistochemistry.
Results: Positive expression of ISL1 and LHX5 was detected in 94% and 98% of the samples, respectively. There were no distinct LHX5 expression patterns associated with different cancer stages, but the proportion of high-expressing tumours was higher in high-grade tumours. In addition, there was a significant association between the expression of LHX5 and tumour grade. The proportion of tumours expressing high levels of ISL1 was found to be highest in later stage tumours.
Conclusion: The high percentage of tumours expressing both these genes suggests that ISL1 and LHX5 play an important role in bladder tumourigenesis across multiple stages.

Matched MeSH terms: Paraffin Embedding
A mouse IgM monoclonal antibody recognizes breast and colon cancer

Bakar AF, Alitheen NB, Keong YS, Hamid M, Ali SA, Ali AM

Hybridoma (Larchmt), 2009 Jun;28(3):199-203.
PMID: 19519247 DOI: 10.1089/hyb.2007.0531

Hybridoma clone C3A8, which is a fusion product between splenic lymphocytes of Balb/c mice immunized with MCF7 breast carcinoma cells and SP2/0 myelomas, was produced and characterized. A stable clone that secreted IgM monoclonal antibody (MAb) with kappa light chain was obtained through limiting dilutions. Cell-ELISA screening, flow cytometry analysis, and immunofluorescence staining revealed that the MAb C3A8 had bound specifically and strongly to MCF7 and HT29 but cross reacted weakly or not on HeLa cell line. The MAb C3A8 reacted positively with paraffin-embedded tissues of human breast and colon cancers but there were no positive reactions on normal tissues. Western blot analysis showed the MAb recognized a 55 kDa protein, which was present in the extract of MCF7 and HT29 cell lines. Our results demonstrated that MAb C3A8 could be used for basic and clinical research of breast and colon cancers.

Matched MeSH terms: Paraffin Embedding
Detection of Candida albicans ADH1 and ADH2 mRNAs in human archival oral biopsy samples

Bakri MM, Cannon RD, Holmes AR, Rich AM

J Oral Pathol Med, 2014 Oct;43(9):704-10.
PMID: 24931506 DOI: 10.1111/jop.12193

The aim of this study was to investigate the relationship between expression of Candida albicans alcohol dehydrogenases (ADH) genes in archival formalin-fixed paraffin-embedded (FFPE) samples from biopsies of leukoplakia.

Matched MeSH terms: Paraffin Embedding
Fulltext Differential expression of stem cell-like proteins in normal, hyperplastic and dysplastic oral epithelium

Barakat SM, Siar CH

J Appl Oral Sci, 2015 Jan-Feb;23(1):79-86.
PMID: 25760270 DOI: 10.1590/1678-775720140245

The identification of stem cells (SC) remains challenging. In the human oral mucosal epithelium, these cells are believed to be in the basal layer (stem cell niche), but their exact location is unclear. The aim of this study was to examine the dysplastic oral epithelium for these SC-like proteins in order to assess their diagnostic value as biomarkers complementing the histological grading of dysplasia.

Matched MeSH terms: Paraffin Embedding
Detection of the human papillomavirus in cervical carcinoma: a comparison between non-isotopic in-situ hybridisation and polymerase chain reaction as methods for detection in formalin-fixed, paraffin-embedded tissues

Cheah PL, Looi LM

Malays J Pathol, 2008 Jun;30(1):37-42.
PMID: 19108410

Cervical carcinoma, the second most common malignancy in Malaysian females, is aetiologically linked to the human papillomavirus (HPV). A study was conducted at the Department of Pathology, University of Malaya Medical Centre to compare the identification of HPV 6, 11, 16 and 18 in 40 archived formalin-fixed, paraffin-embedded cervical carcinoma by non-isotopic in-situ hybridisation (NISH) and polymerase chain reaction (PCR). HPV L1 ORF consensus PCR was also carried in cases which were negative on HPV type-specific PCR. NISH detected HPV 16 in 13 (32.5%) cases with one case demonstrating a concomitant HPV 18. beta-globin DNA PCR was carried out on the same paraffin block as for NISH in 27 cases and on a different paraffin block in 13, with amplification in 9 of the former and 3 of the latter. Thus only 12 cases were subjected to further HPV PCR. HPV was detected in 10 (83.3%) with HPV 16 in 9 cases and HPV L1 ORF in one. When using the same paraffin block for both methods of HPV detection, NISH detected HPV in 6 and PCR in 7. NISH failed to detect HPV in a case detected by PCR. 2 cases were negative for HPV using both methods. Hence, HPV detection results by NISH and PCR were concordant in 88.9%. Interestingly, NISH detected HPV in 2 cases with non-amplifiable beta-globin DNA. Using an alternative paraffin block for HPV PCR from NISH, HPV DNA was detected in 3 cases, two of which also showed type-specific positivity on NISH. The third case did not reveal type-specific positivity with NISH or PCR but demonstrated HPV DNA on L1 ORF consensus PCR. It thus appears that PCR and NISH can be successfully used to detect HPV in formalin-fixed, paraffin-embedded tissue and in the presence of intact DNA NISH may be as sensitive as PCR.

Matched MeSH terms: Paraffin Embedding
Fulltext DNA mismatch repair and CD133-marked cancer stem cells in colorectal carcinoma

Cheah PL, Li J, Looi LM, Teoh KH, Ong DB, Arends MJ

PeerJ, 2018;6:e5530.
PMID: 30221090 DOI: 10.7717/peerj.5530

Background: Except for a few studies with contradictory observations, information is lacking on the possibility of association between DNA mismatch repair (MMR) status and the presence of cancer stem cells in colorectal carcinoma (CRC), two important aspects in colorectal carcinogenesis.
Methods: Eighty (40 right-sided and 40 left-sided) formalin-fixed, paraffin-embedded primary CRC were immunohistochemically studied for CD133, a putative CRC stem cell marker, and MMR proteins MLH1, MSH2, MSH6 and PMS2. CD133 expression was semi-quantitated for proportion of tumor immunopositivity on a scale of 0-5 and staining intensity on a scale of 0-3 with a final score (units) being the product of proportion and intensity of tumor staining. The tumor was considered immunopositive only when the tumor demonstrated moderate to strong intensity of CD133 staining (a decision made after analysis of CD133 expression in normal colon). Deficient MMR (dMMR) was interpreted as unequivocal loss of tumor nuclear staining for any MMR protein despite immunoreactivity in the internal positive controls.
Results: CD133 was expressed in 36 (90.0%) left-sided and 28 (70.0%) right-sided tumors (p 0.05).
Conclusion: Proficient MMR correlated with high levels of CD133-marked putative cancer stem cells in both right- and left-sided tumors, whereas significantly lower levels of CD133-marked putative cancer stem cells were associated with deficient MMR status in colorectal carcinomas found on the right.

Matched MeSH terms: Paraffin Embedding
Fulltext The resin-embedded cornea prepared via rapid processing protocol : a good histomorphometric target for clinical investigation in ophthalmology and optometry

Cheah PS, Mohidin N, Mohd Ali B, Maung M, Latif AA

Malays J Med Sci, 2008 Jul;15(3):49-54.
PMID: 22570589

This study illustrates and quantifies the changes on corneal tissue between the paraffin-embedded and resin-embedded blocks and thus, selects a better target in investigational ophthalmology and optometry via light microscopy. Corneas of two cynomolgus monkeys (Macaca fascicularis) were used in this study. The formalin-fixed cornea was prepared in paraffin block via the conventional tissue processing protocol (4-day protocol) and stained with haematoxylin and eosin. The glutaraldehyde-fixed cornea was prepared in resin block via the rapid and modified tissue processing procedure (1.2-day protocol) and stained with toluidine blue. The paraffin-embedded sample exhibits various undesired tissue damage and artifact such as thinner epithelium (due to the substantial volumic extraction from the tissue), thicker stroma layer (due to the separation of lamellae and the presence of voids) and the distorted endothelium. In contrast, the resin-embedded corneal tissue has demonstrated satisfactory corneal ultrastructural preservation. The rapid and modified tissue processing method for preparing the resin-embedded is particularly beneficial to accelerate the microscopic evaluation in ophthalmology and optometry.

Matched MeSH terms: Paraffin Embedding
Endocan expression in placenta of women with hypertension

Chew BS, Ghazali R, Othman H, Ismail NAM, Othman AS, Laim NMST, et al.

J Obstet Gynaecol Res, 2018 Oct 10.
PMID: 30306675 DOI: 10.1111/jog.13836

AIM: The aim of our study was to determine the endocan-1 expression in placenta of hypertensive women, and its association with maternal and fetal outcomes.
METHODS: This was a cross-sectional study consisted of 21 pregnant women with hypertension and 23 without hypertension. The gestational age ranged from 28 to 39 weeks (hypertensive) and 32 to 40 weeks (normotensive). The paraffin embedded formalin fixed placenta tissue blocks were retrieved from the pathology archives. Endocan immunohistochemistry was performed on tissue sections of full thickness and maternal surface of the placenta. The endocan expression was determined in fetal endothelial cells, maternal endothelial cells, cytotrophoblasts, syncytiotrophoblasts and decidual cells. The differences in endocan expression in placenta between hypertensive and normotensive subjects were evaluated by Pearson chi-square test and t-test were used in the statistical analysis.
RESULTS: The endocan expression was significantly higher in fetal endothelial cells (P

Matched MeSH terms: Paraffin Embedding
Immunohistochemical Detection of Chikungunya Virus Antigens in Formalin-Fixed and Paraffin-Embedded Tissues

Chiam CW, Sam IC, Chan YF, Wong KT, Ong KC

Methods Mol Biol, 2016;1426:235-40.
PMID: 27233276 DOI: 10.1007/978-1-4939-3618-2_21

Immunohistochemistry is a histological technique that allows detection of one or more proteins of interest within a cell using specific antibody binding, followed by microscopic visualization of a chromogenic substrate catalyzed by peroxidase and/or alkaline phosphatase. Here, we describe a method to localize Chikungunya virus (CHIKV) antigens in formalin-fixed and paraffin-embedded infected mouse brain.

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Fulltext Evaluation of DNA and RNA extraction methods

Edwin Shiaw CS, Shiran MS, Cheah YK, Tan GC, Sabariah AR

Med J Malaysia, 2010 Jun;65(2):133-7.
PMID: 23756798 MyJurnal

This study was done to evaluate various DNA and RNA extractions from archival FFPE tissues. A total of 30 FFPE blocks from the years of 2004 to 2006 were assessed with each modified and adapted method. Extraction protocols evaluated include the modified enzymatic extraction method (Method A), Chelex-100 extraction method (Method B), heat-induced retrieval in alkaline solution extraction method (Methods C and D) and one commercial FFPE DNA Extraction kit (Qiagen, Crawley, UK). For RNA extraction, 2 extraction protocols were evaluated including the enzymatic extraction method (Method 1), and Chelex-100 RNA extraction method (Method 2). Results show that the modified enzymatic extraction method (Method A) is an efficient DNA extraction protocol, while for RNA extraction, the enzymatic method (Method 1) and the Chelex-100 RNA extraction method (Method 2) are equally efficient RNA extraction protocols.

Matched MeSH terms: Paraffin Embedding*
Fulltext N-glycan MALDI Imaging Mass Spectrometry on Formalin-Fixed Paraffin-Embedded Tissue Enables the Delineation of Ovarian Cancer Tissues

Everest-Dass AV, Briggs MT, Kaur G, Oehler MK, Hoffmann P, Packer NH

Mol Cell Proteomics, 2016 09;15(9):3003-16.
PMID: 27412689 DOI: 10.1074/mcp.M116.059816

Ovarian cancer is a fatal gynaecological malignancy in adult women with a five-year overall survival rate of only 30%. Glycomic and glycoproteomic profiling studies have reported extensive protein glycosylation pattern alterations in ovarian cancer. Therefore, spatio-temporal investigation of these glycosylation changes may unearth tissue-specific changes that occur in the development and progression of ovarian cancer. A novel method for investigating tissue-specific N-linked glycans is using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) on formalin-fixed paraffin-embedded (FFPE) tissue sections that can spatially profile N-glycan compositions released from proteins in tissue-specific regions. In this study, tissue regions of interest (e.g. tumor, stroma, adipose tissue and necrotic areas) were isolated from FFPE tissue sections of advanced serous ovarian cancers (n = 3). PGC-LC-ESI-MS/MS and MALDI-MSI were used as complementary techniques to firstly generate structural information on the tissue-specific glycans in order to then obtain high resolution images of the glycan structure distribution in ovarian cancer tissue. The N-linked glycan repertoires carried by the proteins in these tissue regions were structurally characterized for the first time in FFPE ovarian cancer tissue regions, using enzymatic peptide-N-glycosidase F (PNGase F) release of N-glycans. The released glycans were analyzed by porous graphitized carbon liquid chromatography (PGC-LC) and collision induced electrospray negative mode MS fragmentation analysis. The N-glycan profiles identified by this analysis were then used to determine the location and distribution of each N-glycan on FFPE ovarian cancer sections that were treated with PNGase F using high resolution MALDI-MSI. A tissue-specific distribution of N-glycan structures identified particular regions of the ovarian cancer sections. For example, high mannose glycans were predominantly expressed in the tumor tissue region whereas complex/hybrid N-glycans were significantly abundant in the intervening stroma. Therefore, tumor and non-tumor tissue regions were clearly demarcated solely on their N-glycan structure distributions.

Matched MeSH terms: Paraffin Embedding
Fulltext Programmed cell death-ligand, thymidylate synthase and deleted in colorectal carcinoma biomarkers in colorectal carcinoma

Fauzah Abd Ghani, Reena Rehavu Zin, Maha Abdullah, Norhafizah Mohtarrudin, Ebenyi Emeka Onwe

Malaysian Journal of Medicine and Health Sciences, 2019;15(108):16-16.
MyJurnal

Introduction: It is well known that cancer cells evade the immune system with the help of programmed cell death protein 1 (PD-L1) molecule to remain undetected, causing abnormal proliferation of T-cells. PD-L1 expression on the surface of neoplastic cells inhibits cytotoxic T-cell responses which lead to negative regulation of cytokines and proliferation of T-cells. The deleted in colorectal cancer (DCC) gene belongs to the immunoglobulin superfamily. It is a candidate of the tumour suppressor gene by regulating apoptosis. DCC assessment gives an insight into progno-sis in patients with advanced stages of CRC. Thymidylate synthase (TYMS) is a highly conserved enzyme involved in DNA synthesis. TYMS has been an important target for cancer chemotherapy because of its central, rate-limiting role in de novo synthesis of thymidylate. Expression of PD-L1, TYMS and DCC has been demonstrated to confer a prognostic value in CRC but none have been completely validated for patient care. This study aimed to determine the prognostic and predictive potential of PD-L1, TYMS, and DCC biomarkers in CRC. Methods: The expression of these biomarkers was evaluated immunohistochemically in 91 formalin-fixed paraffin-embedded (FFPE) archival tumour samples from patients that underwent surgical resection. Results: There was high expression of DCC in most cases; 84.6% (77/91). TYMS expression at a high level score was 46.2% (42/91) and at low level was 53.8% (49/91). Majority of cases had low PD-L1 expression in 93.4% (86/91) cases and high expression was detected in 6.6% (6/94) of cases. In addition, there was a significant association between TYMS expression with gender (P < 0.05) with distribution of TYMS expression detected at high level was 76.2% in male and 23.8% in female. The Kaplan-Meier survival plot showed mean overall survival in patients with PD-L1 with high expression to be 22 months, which pre-dicts better survival. TYMS low expression showed mean overall survival of 90 which also indicated better survival. DCC high expression showed mean overall survival of 90 which indicated better survival. The correlation between the biomarkers and overall survival were not statistically significant. Conclusion: The results from this study suggest that PD-L1, TYMS and DCC expression could be used as biomarkers to predict treatment outcome in CRC. PD-L1 overexpression predicts patients who could benefit from anti-PD-1 and anti-PD-L1 immunotherapy whilst TYMS low expression predicts patients who could benefit from 5-fluorouracil therapy. DCC high expression tumours predicts a better prognosis and overall survival compared to DCC-negative tumours in advanced CRC.

Matched MeSH terms: Paraffin Embedding
Fulltext Quantitative analysis of ERG expression and its splice isoforms in formalin-fixed, paraffin-embedded prostate cancer samples: association with seminal vesicle invasion and biochemical recurrence

Hagen RM, Adamo P, Karamat S, Oxley J, Aning JJ, Gillatt D, et al.

Am J Clin Pathol, 2014 Oct;142(4):533-40.
PMID: 25239421 DOI: 10.1309/AJCPH88QHXARISUP

The proto-oncogene ETS-related gene (ERG) is consistently overexpressed in prostate cancer. Alternatively spliced isoforms of ERG have variable biological activities; inclusion of exon 11 (72 base pairs [bp]) is associated with aggressiveness and progression of disease. Exon 10 (81 bp) has also been shown to be alternatively spliced. Within this study, we assess whether ERG protein, messenger RNA (mRNA), and ERG splice isoform mRNA expression is altered as prostate cancer progresses.

Matched MeSH terms: Paraffin Embedding
Fulltext Evaluation of Seegene Anyplex II Performance for Detection of Human Papillomavirus Genotypes in Formalin-Fixed, Paraffin-Embedded Cervical Cancer Specimens

Haqshenas G, Molano M, Phillips S, Balgovind P, Garland SM, Hawkes D, et al.

Arch Pathol Lab Med, 2024 Mar 01;148(3):353-358.
PMID: 37226838 DOI: 10.5858/arpa.2022-0317-OA

CONTEXT.—: Detection of human papillomavirus (HPV) in formalin-fixed, paraffin-embedded (FFPE) tissues may identify the cause of lesions and has value for the development of new diagnostic assays and epidemiologic studies. Seegene Anyplex II assays are widely used for HPV screening, but their performance using FFPE samples has not been fully explored.
OBJECTIVE.—: To validate Anyplex II HPV HR Detection (Anyplex II, Seegene) using FFPE samples.
DESIGN.—: We used 248 stored DNA extracts from cervical cancer FFPE samples collected during 2005-2015 that tested HPV positive using the RHA kit HPV SPF10-LiPA25, v1 (SPF10, Labo Biomedical Products) HPV genotyping assay, manufacturer-validated for FFPE samples.
RESULTS.—: Of the selected 248 samples, 243 were used in our analysis. Consistent with SPF10 genotyping results, Anyplex II detected all 12 oncogenic types and had an overall HPV detection rate of 86.4% (210 of 243 samples). Anyplex II and SPF10 showed very high agreement for the detection of the 2 most important oncogenic genotypes: HPV 16 (219 of 226; 96.9%; 95% CI, 93.7-98.75) and HPV 18 (221 of 226; 97.8%; 95% CI, 94.9-99.3).
CONCLUSIONS.—: Overall results showed that both platforms produced comparable HPV genotyping results, indicating the suitability of Anyplex II for FFPE samples. The Anyplex II assay has the added convenience of being an efficient, single-well semiquantitative polymerase chain reaction assay. Further optimization of Anyplex II may enhance its performance using FFPE samples by improving the detection limit.

Matched MeSH terms: Paraffin Embedding/methods
Fulltext Effect of the miR-96-5p inhibitor and mimic on the migration and invasion of the SW480-7 colorectal cancer cell line

He PY, Yip WK, Jabar MF, Mohtarrudin N, Dusa NM, Seow HF

Oncol Lett, 2019 Aug;18(2):1949-1960.
PMID: 31423265 DOI: 10.3892/ol.2019.10492

The objectives of the present study were to identify the aberrant expression of microRNA (miRNA) in colorectal carcinoma (CRC) tissues from published miRNA profiling studies and to investigate the effects of the identified miRNA inhibitor and mimic miR-96-5p on CRC cell migration and invasion. The altered expression of the regulators of cytoskeleton mRNA in miR-96-5p inhibitor-transfected cells was determined. The miR-96-5p expression level in five CRC cell lines, HCT11, CaCo2, HT29, SW480 and SW620, and 26 archived paraffin-embedded CRC tissues were also investigated by reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR). Cell viability in response to the miR-96-5p inhibitor and mimic transfections was determined by an MTT assay. A Matrigel invasion assay was conducted to select the invasive subpopulation designated SW480-7, by using the parental cell line SW480. The effects of miR-96-5p mimic- or inhibitor-transfected SW480-7 cells on cell migration and invasion were evaluated using the Transwell and Matrigel assays, and the change in expression of the regulators of cytoskeleton mRNAs was identified by Cytoskeleton Regulators RT2-Profiler PCR array followed by validation with RT-qPCR. CRC tissues exhibited a significant increase in miR-96-5p expression, compared with their matched normal adjacent tissues, indicating an oncogenic role for miR-96-5p. The results demonstrated that the miR-96-5p inhibitor decreased the migration of SW480-7 cells, but had no effect on invasion. This may be due to the promotion of cell invasion by Matrigel, which counteracts the blockade of cell invasion by the miR-96-5p inhibitor. The miR-96-5p mimic enhanced SW480-7 cell migration and invasion, as expected. It was determined that there was a >2.5 fold increase in the expression of genes involved in cytoskeleton regulation, myosin light chain kinase 2, pleckstrin homology like domain family B member 2, cyclin A1, IQ motif containing GTPase activating protein 2, Brain-specific angiogenesisinhibitor 1-associated protein 2 and microtubule-actin crosslinking factor 1, in miR-96-5p inhibitor-transfected cells, indicating that they are negative regulators of cell migration. In conclusion, the miR-96-5p inhibitor blocked cell migration but not invasion, and the latter may be due to the counteraction of Matrigel, which has been demonstrated to stimulate cell invasion.

Matched MeSH terms: Paraffin Embedding
Fulltext Intra-operative frozen section consultation: concepts, applications and limitations

Jaafar H

Malays J Med Sci, 2006 Jan;13(1):4-12.
PMID: 22589584

Intra-operative frozen section plays an important role in the management of surgical patients and yet it must be used prudently to avoid the indiscriminate usage of this important technique. As it is subjected to many limitations in comparison to the paraffin embedded tissue sections, this review aims to highlight the important concepts and principle of intra-operative frozen section consultation as well as discussing the limitations of this technique. This will then allow the endusers of this technique to be more informed and more selective in their decisions when requesting for a frozen section report.

Matched MeSH terms: Paraffin Embedding
ERG oncoprotein expression in prostate carcinoma patients of different ethnicities

Kelly GM, Kong YH, Dobi A, Srivastava S, Sesterhenn IA, Pathmanathan R, et al.

Molecular and clinical oncology, 2015 Jan;3(1):23-30.
PMID: 25469265

Overexpression of the erythroblast transformation-specific-related gene (ERG) oncoprotein due to transmembrane protease, serine 2 (TMPRSS2)-ERG fusion, the most prevalent genomic alteration in prostate cancer (CaP), is more frequently observed among Caucasian patients compared to patients of African or Asian descent. To the best of our knowledge, this is the first study to investigate the prevalence of ERG alterations in a multiethnic cohort of CaP patients. A total of 191 formalin-fixed paraffin-embedded sections of transrectal ultrasound-guided prostate biopsy specimens, collected from 120 patients treated at the Sime Darby Medical Centre, Subang Jaya, Malaysia, were analyzed for ERG protein expression by immunohistochemistry using the anti-ERG monoclonal antibody 9FY as a surrogate for the detection of ERG fusion events. The overall frequency of ERG protein expression in the population evaluated in this study was 39.2%. Although seemingly similar to rates reported in other Asian communities, the expression of ERG was distinct amongst different ethnic groups (P=0.004). Malaysian Indian (MI) patients exhibited exceedingly high expression of ERG in their tumors, almost doubling that of Malaysian Chinese (MC) patients, whereas ERG expression was very low amongst Malay patients (12.5%). When collectively analyzing data, we observed a significant correlation between younger patients and higher ERG expression (P=0.04). The prevalence of ERG expression was significantly different amongst CaP patients of different ethnicities. The higher number of ERG-expressing tumors among MI patients suggested that the TMPRSS2-ERG fusion may be particularly important in the pathogenesis of CaP amongst this group of patients. Furthermore, the more frequent expression of ERG among the younger patients analyzed suggested an involvement of ERG in the early onset of CaP. The results of this study underline the value of using ERG status to better understand the differences in the etiology of CaP initiation and progression between ethnic groups.

Matched MeSH terms: Paraffin Embedding
Dual variant of Epstein-Barr virus in Hodgkin/Reed-Sternberg cells: single-cell PCR study on latent membrane protein-1 gene

Kim LH, Peh SC, Poppema S

Int J Cancer, 2003 Nov 1;107(2):250-5.
PMID: 12949802

Isolation of single cells permits analysis of DNA or RNA from individual cells among heterogeneous populations. This technique is particularly useful in the study of classical Hodgkin's lymphoma (cHL) due to the scarcity of H/RS tumor cells among large numbers of reactive leukocytes. In a previous study, we found a high frequency of dual LMP-1 variant (concurrent presence of deleted and nondeleted variants) in cHL from whole-tissue sections. For the present study, we applied a single-cell isolation technique to determine the LMP-1 oncogene variant in EBV-associated H/RS cells. Five cases of EBV-infected cHL, containing nondeleted (n=1), deleted (n=1) and dual infection (n=3) based on whole-tissue section analysis, were selected for study. Paraffin-embedded tissue sections were stained with antibody to LMP-1 and positively stained H/RS cells isolated using a semiautomated micromanipulator. Each isolated single cell was subjected to PCR for amplification of the LMP-1 gene flanking the 30 bp deletion region and Xho1 restriction site. Cases with either nondeleted variant or the deleted variant showed similar LMP-1 variant expression in isolated single H/RS cells. However, 1 of the 3 cases with dual variants showed only the deleted variant in H/RS cells. The other 2 cases showed mixed patterns of deleted, nondeleted and dual LMP-1 variants in isolated single H/RS cells. All cases showed loss of the Xho1 restriction site, with the exception of the case with nondeleted LMP-1. Results of single-H/RS cell analysis of the Xho1 restriction site concur with those of whole-tissue section amplification. A mixed pattern of LMP-1 variants was observed in isolated H/RS cells, and it is speculated that this is due to the accumulation of mutation and deletion events.

Matched MeSH terms: Paraffin Embedding
Fulltext Assessment of Telomere Length in Archived Formalin-Fixed, Paraffinized Human Tissue Is Confounded by Chronological Age and Storage Duration

Kong PL, Looi LM, Lau TP, Cheah PL

PLoS One, 2016;11(9):e0161720.
PMID: 27598341 DOI: 10.1371/journal.pone.0161720

Telomeres shorten with physiological aging but undergo substantial restoration during cancer immortalization. Increasingly, cancer studies utilize the archive of formalin-fixed, paraffin-embedded (FFPE) tissues in diagnostic pathology departments. Conceptually, such studies would be confounded by physiological telomere attrition and loss of DNA integrity from prolonged tissue storage. Our study aimed to investigate these two confounding factors. 145 FFPE tissues of surgically-resected, non-diseased appendixes were retrieved from our pathology archive, from years 2008 to 2014. Cases from 2013 to 2014 were categorized by patient chronological age (0-20 years, 21-40 years, 41-60 years, > 60 years). Telomere lengths of age categories were depicted by telomere/chromosome 2 centromere intensity ratio (TCR) revealed by quantitative fluorescence in situ hybridization. Material from individuals aged 0-20 years from years 2013/2014, 2011/2012, 2009/2010, and 2008 were compared for storage effect. Telomere integrity was assessed by telomere fluorescence intensity (TFI). Epithelial TCRs (mean ± SD) for the respective age groups were 4.84 ± 2.08, 3.64 ± 1.21, 2.03 ± 0.37, and 1.93 ± 0.45, whereas corresponding stromal TCRs were 5.16 ± 2.55, 3.84 ± 1.36, 2.49 ± 1.20, and 2.93 ± 1.24. A trend of inverse correlation with age in both epithelial and stromal tissues is supported by r = -0.69, p < 0.001 and r = -0.42, p < 0.001 respectively. Epithelial TFIs (mean ± SD) of years 2013/2014, 2011/2012, 2009/2010 and 2008 were 852.60 ± 432.46, 353.04 ± 127.12, 209.24 ± 55.57 and 429.22 ± 188.75 respectively. Generally, TFIs reduced with storage duration (r = -0.42, p < 0.001). Our findings agree that age-related telomere attrition occurs in normal somatic tissues, and suggest that an age-based reference can be established for telomere studies on FFPE tissues. We also showed that FFPE tissues archived beyond 2 years are suboptimal for telomere analysis.

Matched MeSH terms: Paraffin Embedding
Immunostaining of formalin-fixed, paraffin-embedded tissues for malignant lymphomas

Lim YC, Phang KS, Cheong SK

Malays J Pathol, 1992 Dec;14(2):85-9.
PMID: 1304629

With the advent of new monoclonal antibodies that are applicable to formalin-fixed, paraffin embedded sections, immunophenotyping is becoming increasingly important in the diagnosis and classification of lymphomas. However, multiple factors such as fixation, trypsinization and even type of antibodies used have certain effects on the final outcome of the staining procedure. In this paper we report our experience and the problems encountered in our laboratory when we first tried to establish a workable immunostaining protocol for formalin-fixed, paraffin embedded tissue sections using the immunoalkaline phosphatase technique.

Matched MeSH terms: Paraffin Embedding*

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