Displaying publications 1 - 20 of 35 in total

  1. 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*
  2. 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
  3. 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*
  4. Affandi KA, Tizen NMS, Mustangin M, Zin RRMRM
    J Pathol Transl Med, 2018 Sep;52(5):283-289.
    PMID: 30235512 DOI: 10.4132/jptm.2018.08.14
    BACKGROUND: Lung cancer is the third most common cancer worldwide. With major advances in the molecular testing of lung cancers and the introduction of targeted therapies, the distinction between adenocarcinoma and squamous cell carcinoma as well as pathologic subtyping has become important. Recent studies showed that p40 is highly specific for squamous and basal cells and is superior to p63 for diagnosing lung squamous cell carcinoma. The aim of this study was to evaluate the use of p40 immunohistochemical stain in the diagnosis of non-small cell lung carcinoma and its potential to replace current p63 antibody as the best immunohistochemical squamous marker.

    METHODS: Seventy formalin-fixed paraffin-embedded cases previously diagnosed as primary lung squamous cell carcinoma (n = 35) and lung adenocarcinoma (n = 35) from January 2008 to December 2016 were retrieved. The results of tumour cell immunoreactivity for p40 and p63 antibodies in lung squamous cell carcinoma and lung adenocarcinoma were compared.

    RESULTS: p40 was expressed in 27 cases of lung squamous cell carcinoma (77.1%). All cases of lung adenocarcinoma (35/35, 100%) were negative for p40. p63 expression was positive in 30 cases of lung squamous cell carcinoma (85.7%) and 13 cases of lung adenocarcinoma (37.1%). Reactivity for both p40 and p63 in lung squamous cell carcinoma was strong and diffuse, whereas variable reactivity was observed in lung adenocarcinoma.

    CONCLUSIONS: p40 is an excellent marker for distinguishing lung squamous cell carcinoma from adenocarcinoma, and p40 expression is equivalent to p63 expression in lung squamous cell carcinoma.

    Matched MeSH terms: Paraffin Embedding
  5. Mohd. Ridah L.J., Ismail A., A. Talib N., Muhammad N., Hussain F.A., Zainuddin N.
    Introduction: Methylation of promoter region of p16 leading to gene silencing has been implicated ina wide range of malignancies including lymphomas. In diffuse large B cell lymphoma (DLBCL) particularly, a varying percentage of epigenetic inactivation of p16 promoter region was observed ranging from 16 -54%. However, quantitative analysis of p16 promoter methylation in DLBCL has not been extensively studied in Malaysia. Objective: This study aims to quantitatively analyse p16 methylation in DLBCL samples using pyrosequencing technique. Methods: Genomic DNA was extracted from 16 formalin-fixed paraffin-embedded lymphoma tissue blocks from patients diagnosed with DLBCL. Samples were retrieved from Hospital Tengku Ampuan Afzan, Pahang and Hospital Universiti Sains Malaysia, Kelantan. Primers were designed to amplify bisulfite-treated DNA targeting p16 promoter region. Methylation status of 7 CpG sites was determined by pyrosequencing. Results: All the 16 samples studied showed promoter methylation of p16. The range of mean methylation percentage was between 18 to 81%. Conclusion: The present study has successfully measured the level of methylation of p16 in all 7 CpG sites despite the limitation in sample size. Since p16 methylation is a common event in our series of DLBCL cases, it is worth including a larger sample size in future studies to increase the chance of finding a significant correlation with clinical parameters.
    Matched MeSH terms: Paraffin Embedding
  6. Samiei G, Yip WK, Leong PP, Jabar MF, Dusa NM, Mohtarrudin N, et al.
    J Cancer Res Ther, 2018 Jun;14(Supplement):S299-S305.
    PMID: 29970680 DOI: 10.4103/0973-1482.235345
    Background: Interleukin (IL)-17A and IL-17F are inflammatory cytokines mainly produced by T helper 17 cells. IL-17A is known to be protumorigenic while IL-17F has a protective role in cancer. A number of studies have been conducted to determine the association between polymorphisms of IL-17AG197A (rs2275913) and IL-17FA7488G (rs763780) and risk of cancers. No studies have yet to be conducted to genotype the IL-17AG197A polymorphism in colorectal cancer (CRC).

    Objective: To assess the association of IL-17AG197A and IL-17FA7488G polymorphisms with CRC risk.

    Materials and Methods: We performed the genotyping by polymerase chain reaction-restriction fragment length polymorphism method on blood samples from 80 healthy individuals and paraffin-embedded tumor tissues from 70 CRC patients.

    Results: Our study showed that IL-17A197AA genotype was significantly associated with an increased CRC risk with odds ratios of 6.08 (95% confidence interval [CI]: 2.25-16.42, P < 0.001) and 2.80 (95% CI: 1.23-6.35, P = 0.014), in comparison with GG and AG genotypes, respectively. However, IL-17FA7488G polymorphism was not significantly associated with CRC risk (P = 0.102). No significant association of IL-17AG197A and IL-17FA7488G polymorphisms with patient and tumor variables was found.

    Conclusion: This report from Malaysia shows the relationship of IL-17A197AA genotype with susceptibility to CRC.

    Matched MeSH terms: Paraffin Embedding
  7. Norafiza Zainuddin, Lailatul Jalilah Mohd Ridah, Aqilah Nabihah Omar, Norlelawati A. Talib, Naznin Muhammad, Faezahtul Arbaeyah Hussain
    MGMT (O6
    -Methylguanine-DNA Methyltransferase) suppresses tumor development by removing alkyl adduct, while
    SPOCK2 (SPARC/Osteonectin CWCV and Kazal-like domains proteoglycan) abolishes the inhibition of membrane-type
    matrix metalloproteinases (MT-MMP) which leads to angiogenesis. Hence, MGMT methylation may initiate malignant cells
    transformation. In contrast, SPOCK2 methylation is hypothesized not to be a common event in diffuse large B-cell lymphoma
    (DLBCL). In this study, we examined the methylation status of MGMT and SPOCK2 in DLBCL as in Malaysia the information
    is extremely lacking. A total of 88 formalin-fixed paraffin-embedded tissue of patients diagnosed with DLBCL from the
    year 2006 to 2013 were retrieved from Hospital Universiti Sains Malaysia, Kelantan and Hospital Tengku Ampuan Afzan,
    Pahang. Methylation-specific polymerase chain reaction (MSP) was used to examine the methylation status of both genes.
    Interestingly, methylation of MGMT was detected in all the 88 DLBCL samples, whereas SPOCK2 was found to be methylated
    in 83 of 88 (94.3%) DLBCL cases. Our study showed a remarkably high percentage of promoter methylation of both
    MGMT and SPOCK2 genes. Our finding also negates initial expectation that SPOCK2 methylation would be an uncommon
    event in the majority of DLBCL cases. This study has shown a very high percentage of promoter methylation of MGMT and
    SPOCK2 in the DLBCL cases studied by MSP, using archival lymphoma tissues. Nonetheless, additional research is needed
    to quantitatively evaluate MGMT and SPOCK2 methylation, and to analyse gene expression and/or protein expression in
    order to further understand the role of MGMT and SPOCK2 methylation in the pathogenesis of DLBCL.
    Matched MeSH terms: Paraffin Embedding
  8. Rajandram R, Razack AH, Ng KL, Gobe GC
    J Kidney Cancer VHL, 2016;3(1):1-11.
    PMID: 28326275 DOI: 10.15586/jkcvhl.2016.47
    Although primary localised tumours of renal cell carcinoma (RCC) can be treated relatively successfully with surgery, metastatic RCC has poor prognosis because of late diagnosis and resistance to therapies. In the present study, we were interested in profiling the protein expression of "inhibitor of caspase-activated DNase" (ICAD), an apoptosis inhibitor, in kidney cancer and its paired normal kidney. Immunohistochemistry with automated batch staining and morphometry using digital pathology were used to compare ICAD in 121 RCC specimens with their paired normal kidney tissue. Tissue microarray of formalin-fixed, paraffin-embedded archival tissue was used. Intensity and localisation of ICAD were compared between normal and cancer samples, and against grading within the cancers. The results demonstrated that, in this cohort, ICAD was highly expressed in the proximal tubular epithelium of normal kidney, and significantly decreased in clear cell RCC tissue (p < 0.05) as well as other subtypes of RCC (p < 0.01) compared with normal kidney. There was a tendency towards nuclear localisation of ICAD in clear cell RCC, but not in other subtypes of RCC. No significant association was found between ICAD intensity and grade of RCC. In summary, down-regulation of ICAD occurs in RCC. ICAD normally inhibits DNA fragmentation and apoptosis; thus, its down-regulation was unexpected in a cancer known for its resistance to apoptosis. However, these RCC samples were from primary, not metastatic, RCC sites, and down-regulated ICAD may be part of a progressive pathway that promotes RCC metastasis.
    Matched MeSH terms: Paraffin Embedding
  9. Mohd Rohaizad Md Roduan, Norhafizah Mohtarrudin, Chong PP, Malina Osman, Noraini Mohd Dusa
    Sains Malaysiana, 2015;44:727-733.
    Inflammation plays an important role to the process of prostate carcinogenesis by increasing the rate of cell proliferation,
    which contributes to an aggressive tumour phenotype. Cyclooxygenase-2 (COX-2) has been found overexpressed in
    various types of cancer cells including prostate. The aim of this study was to investigate the COX-2 expressions in different
    types of human prostate tissues. Paraffin-embedded prostate tissues from 263 samples were examined for the expression
    of COX-2 marker by immunohistochemistry method. COX-2 was found highly expressed in prostate adenocarcinoma
    (p=0.001) as compared to benign and normal tissues. The score of COX-2 expressions in most of normal prostate was
    weak 49 (77.8%), while only 16 (16%) of BPH showed strong expression. 56 cases (56%) prostate cancer showed strong
    COX-2 expression. Prostate cancer cases showed significant differences in staining patterns as tumour grade increased.
    In addition, COX-2 expression was significantly correlated with Gleason score in cancerous tissues. This study suggests
    that COX-2 overexpression is associated with prostate cancer and higher grade tumour.
    Matched MeSH terms: Paraffin Embedding
  10. Mohd Nafi SN, Siti Azrin AH, Mat Zin AA, Othman NH, Che Jalil NA
    Malays J Pathol, 2019 Apr;41(1):33-39.
    PMID: 31025635
    INTRODUCTION: Insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) is an important component of the IGF system that regulates insulin resistance-related to tumour development. The aim of this study is to investigate the expression of IGFBP-rP1 among female cancer patients who are known or not known to have Type 2 Diabetes Mellitus (T2DM).

    MATERIALS AND METHODS: Using a cross-sectional design, cases of ovarian and breast cancer with clinical status of T2DM were selected over a 10-year period in Hospital Universiti Sains Malaysia. Immunohistochemical staining for IGFBP-rP1 was performed on paraffin-embedded tissues and the results were correlated with the patient's demographic and clinicopathological data.

    RESULTS: A total of 152 breast cancer patients were recruited into the current study with 33.5% (51/152) patients were positive T2DM. Most of the breast cancer patients with T2DM were IGFBP-rP1-negative (66.7%, 34/51). The IGFBP-rP1 expression was significantly difference between breast cancer subjects with and without T2DM (p<0.001). There was no significant association of IGFBP-rP1 expression with data on the demographic and clinicopathological profiles of patients with breast cancer. Meanwhile, positive IGFBP-rP1 expression was evident in 44 out of 108 (40.74%) ovarian cancer cases. Among these cases, 36 were T2DM. In contrast to breast cancer cases, IGFBP-rP1 was mostly expressed among ovarian cancer patients with T2DM (66.7%, 24/36, p < 0.001). However, the -positive expression was not significantly associated with any sociodemographic and clinicopathological features of ovarian cancers.

    CONCLUSIONS: Majority of breast cancer patients with T2DM did not express IGFBP-rP1. In contrast, majority of the ovarian cancer patients with T2DM expressed IGFBP-rP1.

    Matched MeSH terms: Paraffin Embedding
  11. Nenny Noorina Saaid, Reena Rahayu Md Zin, Siti Aishah Md Ali, Sharifah Noor Akmal Syed Hussain, Zulkifli Zainuddin, Zubaidah Zakaria
    Sains Malaysiana, 2014;43:1317-1326.
    The identification of chromosomal aberrations in prostate cancer has been widely studied with several known oncogenes and tumor suppressor genes have successfully been discovered. The most frequent aberrations detected in western population were losses in chromosome 5q, 6q, 8p, 13q, 16q, 17p, 18q and gains of 7p/q and 8q. The purpose of this study was to determine the chromosomal aberrations among Malaysian men of Southeast Asia population and discover those potential genes within that chromosomal aberrant region. Thirty-six formalin-fixed paraffin embedded specimens consist of eight organ-confined prostate cancer cases, five with capsular invasion, 14 showed metastasis and nine cases had no tumor stage recorded, were analyzed by array CGH technique. Chromosomal losses were frequently detected at 4q, 6q, 8p, 13q, 18q while gains at 7q, 11q, 12p, 16q and 17q. Gain of 16q24.3 was statistically significant with tumor size. Gains of 6q25.1 and Xq12 as well as losses of 3p13-p1.2 and 13q33.1-q33.3 were significantly correlated with Gleason grade whereas 12p13.31 gain was associated with bone metastasis. Several potential genes have also been found within that aberrant region which is myopodin (4q26-q27), ROBO1 (3p13-p11.2), ERCC5 (13q33.1-q33.3) and CD9 (12p13.31), suggesting that these genes may play a role in prostate cancer progression. The chromosomal aberrations identified by array CGH analysis could provide important clues to discover potential genes associated with prostate tumorigenesis of Malaysian men.
    Matched MeSH terms: Paraffin Embedding
  12. 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.
    Matched MeSH terms: Paraffin Embedding
  13. Shi Yeen TN, Pathmanathan R, Shiran MS, Ahmad Zaid FA, Cheah YK
    J. Biomed. Sci., 2013 Apr 16;20:22.
    PMID: 23590575 DOI: 10.1186/1423-0127-20-22
    BACKGROUND: Somatic mutations of the epidermal growth factor receptor (EGFR) are reportedly associated with various responses in non-small cell lung cancer (NSCLC) patients receiving the anti-EGFR agents. Detection of the mutation therefore plays an important role in therapeutic decision making. The aim of this study was to detect EGFR mutations in formalin fixed paraffin embedded (FFPE) samples using both Scorpion ARMS and high resolution melt (HRM) assay, and to compare the sensitivity of these methods.

    RESULTS: All of the mutations were found in adenocarcinoma, except one that was in squamous cell carcinoma. The mutation rate was 45.7% (221/484). Complex mutations were also observed, wherein 8 tumours carried 2 mutations and 1 tumour carried 3 mutations.

    CONCLUSIONS: Both methods detected EGFR mutations in FFPE samples. HRM assays gave more EGFR positive results compared to Scorpion ARMS.

    Matched MeSH terms: Paraffin Embedding
  14. 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
  15. 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
  16. Mabruk MJ
    Expert Rev. Mol. Diagn., 2004 Sep;4(5):653-61.
    PMID: 15347259
    In situ hybridization is a method for detecting specific nucleic acid sequences within individual cells. This technique permits visualization of viral nucleic acid or gene expression in individual cells within their histologic context. In situ hybridization is based on the complementary binding of a labeled nucleic acid probe to complementary sequences in cells or tissue sections, followed by visualization of target sequences within the cells. It has been used widely for the detection of viral nucleic acid sequences within individual cells. This review will define the technical approaches of in situ hybridization and its current application to detect viral nucleic acids within formalin-fixed, paraffin-embedded tissue samples, with special reference to the Epstein-Barr virus.
    Matched MeSH terms: Paraffin Embedding
  17. Yamada M, Shishito N, Nozawa Y, Uni S, Nishioka K, Nakaya T
    Trop Med Health, 2017;45:26.
    PMID: 29118653 DOI: 10.1186/s41182-017-0067-4
    Background: Dirofilaria ursi is a filarial nematode that parasitizes the subcutaneous tissues of the American black bear (Ursus americanus) and Japanese black bear (Ursus thiabetanus japonicus). D. ursi that has parasitized black bears has the potential to subsequently infect humans. In addition, extra-gastrointestinal anisakiasis is less common in Japan.

    Case presentation: We report a case of ventral subcutaneous anisakiasis and dorsal subcutaneous dirofilariasis that was acquired in Fukushima, in the northern part of Japan. The patient was an 83-year-old Japanese female, and subcutaneous parasitic granulomas were present on her left abdomen (near the navel) and left scapula. A pathological examination of the surgically dissected tissue sections from each region demonstrated eosinophilic granulomas containing different species of parasites. To enable the morphological and molecular identification of these parasites, DNA was extracted from paraffin-embedded sections using DEXPAT reagent, and the cytochrome oxidase 2 (COX2), internal transcribed spacer 1 (ITS1), 5.8S and ITS2 regions of the Anisakis larvae, and the 5S rRNA region of the male Dirofilaria were sequenced. The PCR products were examined and compared with DNA databases. Molecular analysis of the COX2 and 5S rRNA sequences of each worm revealed that the nematode found in the ventral region belonged to Anisakis simplex sensu stricto (s.s.) and the male Dirofilaria found in the dorsal region was classified as D. ursi.

    Conclusion: The present case showed a combined human case of D. ursi and A. simplex s.s. infections in subcutaneous tissues. The results of this study will contribute to the identification of unknown parasites in histological sections.
    Matched MeSH terms: Paraffin Embedding
  18. 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
  19. 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
  20. Briggs MT, Condina MR, Ho YY, Everest-Dass AV, Mittal P, Kaur G, et al.
    Proteomics, 2019 Jul 31.
    PMID: 31364262 DOI: 10.1002/pmic.201800482
    Epithelial ovarian cancer is one of the most fatal gynaecological malignancies in adult women. As studies on protein N-glycosylation have extensively reported aberrant patterns in the ovarian cancer tumour microenvironment, obtaining spatial information will uncover tumour-specific N-glycan alterations in ovarian cancer development and progression. MALDI mass spectrometry imaging (MSI) was employed to investigate N-glycan distribution on formalin-fixed paraffin-embedded (FFPE) ovarian cancer tissue sections from early- and late-stage patients. Tumour-specific N-glycans were identified and structurally characterised by PGC-LC-ESI-MS/MS, and then assigned to high-resolution images obtained from MALDI-MSI. Spatial distribution of 14 N-glycans was obtained by MALDI-MSI and 42 N-glycans (including structural and compositional isomers) identified and structurally characterised by LC-MS. The spatial distribution of oligomannose, complex neutral, bisecting, and sialylated N-glycan families were localised to the tumour regions of late-stage ovarian cancer patients relative to early-stage patients. Potential N-glycan diagnostic markers that emerged include the oligomannose structure, (Hex)6 + (Man)3 (GlcNAc)2 , and the complex neutral structure, (Hex)2 (HexNAc)2 (Deoxyhexose)1 + (Man)3 (GlcNAc)2 . The distribution of these markers was evaluated using a tissue microarray (TMA) of early- and late-stage patients. This article is protected by copyright. All rights reserved.
    Matched MeSH terms: Paraffin Embedding
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