Displaying publications 121 - 140 of 260 in total

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  1. Increased Expression of Phosphatidylinositol 3-Kinase p110α and Gene Amplification of PIK3CA in Nasopharyngeal Carcinoma
    Yip WK, He PY, Abdullah MA, Yusoff S, Seow HF
    Pathol Oncol Res, 2016 Apr;22(2):413-9.
    PMID: 26581613 DOI: 10.1007/s12253-015-0007-8
    Molecular alterations in PIK3CA oncogene that encodes the p110α catalytic subunit of phosphatidylinositol 3-kinase (PI3K p110α) are commonly found in human cancers. In this study, we examined the expression of PI3K p110α and PIK3CA gene amplification in 74 nasopharyngeal carcinoma (NPC) cases. Immunohistochemical staining demonstrated overexpression of PI3K p110α protein in 44.6% (33/74) of NPCs and 4.8% (2/42) of the adjacent normal nasopharyngeal mucosa. Copy number of PIK3CA gene was successfully analyzed in 51 of the total NPC cases and 19 non-malignant nasopharynx tissues by quantitative real-time PCR. Using mean + 2(standard deviation) of copy numbers in the non-malignant nasopharynx tissues as a cutoff value, PIK3CA copy number gain was found in 10 of 51 (19.6%) NPC cases. High PI3K p110α expression level was correlated with increased PIK3CA copy number (Spearman's rho =0.324, P = 0.02). PI3K p110α expression and PIK3CA copy number did not associate with Akt phosphorylation, and patient and tumor variables. This study suggests that PI3K p110α overexpression, which is attributed, at least in part, to PIK3CA gene amplification, may contribute to NPC pathogenesis. However, these molecular aberrations may not be responsible for activation of Akt signaling in NPC.
    Matched MeSH terms: Nasopharyngeal Neoplasms/genetics*; Nasopharyngeal Neoplasms/metabolism*; Nasopharyngeal Neoplasms/pathology
  2. Fulltext Potential role of oxidative stress-induced apoptosis in mediating chromosomal rearrangements in nasopharyngeal carcinoma
    Tan SN, Sim SP, Khoo AS
    Cell Biosci, 2016;6:35.
    PMID: 27231526 DOI: 10.1186/s13578-016-0103-9
    Genetic aberrations have been identified in nasopharyngeal carcinoma (NPC), however, the underlying mechanism remains elusive. There are increasing evidences that the apoptotic nuclease caspase-activated deoxyribonuclease (CAD) is one of the players leading to translocation in leukemia. Oxidative stress, which has been strongly implicated in carcinogenesis, is a potent apoptotic inducer. Most of the NPC etiological factors are known to induce oxidative stress. Although apoptosis is a cell death process, cells possess the potential to survive apoptosis upon DNA repair. Eventually, the surviving cells may carry rearranged chromosomes. We hypothesized that oxidative stress-induced apoptosis may cause chromosomal breaks mediated by CAD. Upon erroneous DNA repair, cells that survive apoptosis may harbor chromosomal rearrangements contributing to NPC pathogenesis. This study focused on the AF9 gene at 9p22, a common deletion region in NPC. We aimed to propose a possible model for molecular mechanism underlying the chromosomal rearrangements in NPC.
    Matched MeSH terms: Nasopharyngeal Neoplasms
  3. Fulltext Nutlin-3 sensitizes nasopharyngeal carcinoma cells to cisplatin-induced cytotoxicity
    Voon YL, Ahmad M, Wong PF, Husaini R, Ng WT, Leong CO, et al.
    Oncol Rep, 2015 Oct;34(4):1692-700.
    PMID: 26252575 DOI: 10.3892/or.2015.4177
    The small-molecule inhibitor of p53-Mdm2 interaction, Nutlin-3, is known to be effective against cancers expressing wild-type (wt) p53. p53 mutations are rare in nasopharyngeal carcinoma (NPC), hence targeting disruption of p53-Mdm2 interaction to reactivate p53 may offer a promising therapeutic strategy for NPC. In the present study, the effects of Nutlin-3 alone or in combination with cisplatin, a standard chemotherapeutic agent, were tested on C666-1 cells, an Epstein-Barr virus (EBV)-positive NPC cell line bearing wt p53. Treatment with Nutlin-3 activated the p53 pathway and sensitized NPC cells to the cytotoxic effects of cisplatin. The combined treatment also markedly suppressed soft agar colony growth formation and increased apoptosis of NPC cells. The effect of Nutlin-3 on NPC cells was inhibited by knockdown of p53, suggesting that its effect was p53-dependent. Extended treatment with increasing concentrations of Nutlin-3 did not result in emergence of p53 mutations in the C666-1 cells. Collectively, the present study revealed supportive evidence of the effectiveness of combining cisplatin and Nutlin-3 as a potential therapy against NPC.
    Matched MeSH terms: Nasopharyngeal Neoplasms/drug therapy*; Nasopharyngeal Neoplasms/genetics*; Nasopharyngeal Neoplasms/pathology
  4. Fulltext Systematic comparison of plasma EBV DNA, anti-EBV antibodies and miRNA levels for early detection and prognosis of nasopharyngeal carcinoma
    Tan LP, Tan GW, Sivanesan VM, Goh SL, Ng XJ, Lim CS, et al.
    Int J Cancer, 2020 04 15;146(8):2336-2347.
    PMID: 31469434 DOI: 10.1002/ijc.32656
    Nasopharyngeal carcinoma (NPC) is originated from the epithelial cells of nasopharynx, Epstein-Barr virus (EBV)-associated and has the highest incidence and mortality rates in Southeast Asia. Late presentation is a common issue and early detection could be the key to reduce the disease burden. Sensitivity of plasma EBV DNA, an established NPC biomarker, for Stage I NPC is controversial. Most newly reported NPC biomarkers have neither been externally validated nor compared to the established ones. This causes difficulty in planning for cost-effective early detection strategies. Our study systematically evaluated six established and four new biomarkers in NPC cases, population controls and hospital controls. We showed that BamHI-W 76 bp remains the most sensitive plasma biomarker, with 96.7% (29/30), 96.7% (58/60) and 97.4% (226/232) sensitivity to detect Stage I, early stage and all NPC, respectively. Its specificity was 94.2% (113/120) against population controls and 90.4% (113/125) against hospital controls. Diagnostic accuracy of BamHI-W 121 bp and ebv-miR-BART7-3p were validated. Hsa-miR-29a-3p and hsa-miR-103a-3p were not, possibly due to lower number of advanced stage NPC cases included in this subset. Decision tree modeling suggested that combination of BamHI-W 76 bp and VCA IgA or EA IgG may increase the specificity or sensitivity to detect NPC. EBNA1 99 bp could identify NPC patients with poor prognosis in early and advanced stage NPC. Our findings provided evidence for improvement in NPC screening strategies, covering considerations of opportunistic screening, combining biomarkers to increase sensitivity or specificity and testing biomarkers from single sampled specimen to avoid logistic problems of resampling.
    Matched MeSH terms: Nasopharyngeal Neoplasms/blood*; Nasopharyngeal Neoplasms/pathology; Nasopharyngeal Neoplasms/virology*
  5. A case of atypical imaging of Nasopharyngeal Carcinoma in an adolescent: A diagnostic challenge
    Teo SW, Noorafidah MD, Laili SAL
    Med J Malaysia, 2020 03;75(2):175-177.
    PMID: 32281604
    Nasopharyngeal mass in paediatric population is usually benign and malignant nasopharyngeal tumours such as carcinoma is rare. We report a case of nasopharyngeal carcinoma (NPC) in an adolescent with atypical imaging findings that mimicked a benign mass. This highlights the importance of a comprehensive review on the distinctive radiographic features of paediatric nasopharyngeal mass. We discuss the imaging features of NPC in the paediatric group, which differ from the elderly patients. By recognising these distinctive imaging features, it may help in diagnosing typical case. This case report serves as a reminder that NPC, despite being uncommon, should be considered in the differential diagnosis of a juvenile nasopharyngeal mass.
    Matched MeSH terms: Nasopharyngeal Neoplasms
  6. Activation of phosphatidylinositol 3-kinase/Akt signaling by EGF downregulates membranous E-cadherin and β-catenin and enhances invasion in nasopharyngeal carcinoma cells
    Yip WK, Seow HF
    Cancer Lett, 2012 May 28;318(2):162-72.
    PMID: 22182447 DOI: 10.1016/j.canlet.2011.12.018
    Dysregulation of E-cadherin and β-catenin function in cell-cell adhesion is common in nasopharyngeal carcinoma (NPC) and correlates with metastatic disease. In this study, we examined the role of EGF-activated phosphatidylinositol 3-kinase (PI3K)-Akt signaling in E-cadherin and β-catenin regulation. We found that reduced membranous E-cadherin and β-catenin expression was positively correlated with Akt phosphorylation in NPC tissues. EGF treatment disrupted cell-cell adhesion and resulted in mesenchymal morphological features in NPC cell lines (TW01, TW04, and TW06). Western blot analysis showed that the E-cadherin protein level was partially reduced in TW04 cells only and the β-catenin levels were not considerably affected upon EGF treatment. In contrast, quantitative real-time RT-PCR showed that the E-cadherin, but not β-catenin, mRNA levels were markedly reduced by EGF in all cell lines. Immunofluorescent staining revealed that E-cadherin and β-catenin appeared to be markedly reduced on the cell surface and more localized in the cytoplasm. Inhibition of PI3K by LY294002 did not abolish the EGF-induced downregulation of E-cadherin protein or mRNA in TW04 cells but moderately increased the β-catenin protein level in TW01 cells and mRNA level in TW06 cells. However, LY294002 substantially restored or increased cell surface E-cadherin and β-catenin in all EGF-treated cell lines, in concordance with the inhibition of cell morphological changes. Moreover, LY294002 significantly blocked EGF-driven cell invasion, correlating with the elevation of membranous E-cadherin and β-catenin levels. In conclusion, EGF-induced epithelial-to-mesenchymal transition may not be only dependent on downregulation of E-cadherin protein/mRNA but also on mislocalization of E-cadherin and β-catenin. The mechanisms involved may be related, at least in part, to the PI3K-Akt pathway.
    Matched MeSH terms: Nasopharyngeal Neoplasms/enzymology; Nasopharyngeal Neoplasms/metabolism*; Nasopharyngeal Neoplasms/pathology
  7. Fulltext Expression analysis of ribosomal protein genes, el13 and el14 in nasopharyngeal carcinoma cell lines
    Phei-Lian, Wang, Edmund Sim, Ui Hang
    Trends in Undergraduate Research, 2020;3(1):5-12.
    MyJurnal
    Increasing evidence of the association between ribosomal protein (RP) genes with nasopharyngeal carcinoma (NPC) have been derived from findings of their differential expression patterns in NPC cell lines. Nevertheless, expression data from a comprehensive list of RP gene family members is still lacking. This paper reports the assessment of two RP genes, eL13 and eL14, with regards to their expression patterns in several NPC cell lines (TW04, TW01, HK1, HONE1 and SUNE-1) relative to a non-malignant control (NP69). A conventional Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) assay was employed. Analysis of eL13 has never been explored before this, whereas investigation of eL14 represents an extended study. We found a general over-expression trend of eL14 in 40% (2 of 5; TW01 and HONE-1) of the NPC cell lines studied, with higher upregulated level in only one (TW01) of them. However, this pattern of expression level is not statistically significant. Expression of eL13 was not detected in any of the cell lines used. The inconsistency of these expression patterns demonstrates an elusive nature of RP activities in the malignancy of the nasopharynx.
    Matched MeSH terms: Nasopharyngeal Neoplasms
  8. Fulltext Establishment and analysis of the 3-dimensional (3D) spheroids generated from the Nasopharyngeal Carcinoma cell line HK1
    Muniandy, Kalaivani, Sankar, Prabu Siva, Lian, Benedict Shi Xiang, Khoo, Alan Soo-Beng, Balakrishnan, Venugopal, Mohana-Kumaran, Nethia
    Trop Life Sci Res, 2016;27(11):125-130.
    MyJurnal
    Spheroids have been shown to recapitulate the tumour in vivo with properties
    such as the tumour microenvironment, concentration gradients, and tumour phenotype. As
    such, it can serve as a platform for determining the growth and invasion behaviour pattern
    of the cancer cells as well as be utilised for drug sensitivity assays; capable of exhibiting
    results that are closer to what is observed in vivo compared to two-dimensional (2D) cell
    culture assays. This study focused on establishing a three-dimensional (3D) cell culture
    model using the Nasopharyngeal Carcinoma (NPC) cell line, HK1 and analysing its growth
    and invasion phenotypes. The spheroids will also serve as a model to elucidate their
    sensitivity to the chemotherapeutic drug, Flavopiridol. The liquid overlay method was
    employed to generate the spheroids which was embedded in bovine collagen I matrix for
    growth and invasion phenotypes observation. The HK1 cells formed compact spheroids
    within 72 hours. Our observation from the 3 days experiments revealed that the spheroids
    gradually grew and invaded into the collagen matrix, showing that the HK1 spheroids are
    capable of growth and invasion. Progressing from these experiments, the HK1 spheroids
    were employed to perform a drug sensitivity assay using the chemotherapeutic drug,
    Flavopiridol. The drug had a dose-dependent inhibition on spheroid growth and invasion.
    Matched MeSH terms: Nasopharyngeal Neoplasms
  9. Fulltext Prevalence of eosinophilic/non eosinophillic nasal polyps and analysis of their presentation in Hospital Universiti Sains Malaysia Kelantan, Malaysia
    Irfan Mohamad, Yahia Hussein Al-Hadeethi, Ramiza Ramza Ramli
    International Medical Journal Malaysia, 2017;16(2):89-92.
    MyJurnal
    Introduction: This study is aimed to examine the predominant inflammatory cells in nasal polyps (NP) in the
    local community and its correlation to the clinical presentations.

    Materials and Methods: The study was
    done retrospectively looking at patients who had undergone functional endoscopic sinus surgery (FESS) in
    Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia with a histopathological diagnosis of nasal
    polyposis (NP), between the years 2004 to 2008. Sixty two patients between the ages of 18 years to 60 years
    old were selected and data relevant to the study were collected from the patient’s folders using a specially
    created form prepared for the study. The NP histopathology report from each patient underwent FESS were
    analysed and the patients were divided into eosinophilic and non eosinophilic dominant group. Clinical
    presentations from each patient were also gathered and analysed according to the NP group.

    Results: In
    HUSM, there were a higher number of eosinophilic types NP as compared to the neutrophilic type NP which
    is contrary to other study conducted on Asian populations. The clinical symptom correlations between either
    eosinophilic or non-eosinophilic type of NP have not shown any significant associations.

    Conclusion: The
    study showed that the incidence of histological subtypes of nasal polyp in HUSM is almost the same as that
    found in other parts of the world (Europe and North America) which will reduce the possibility of racial or
    geographical influence on the pathogenesis of the nasal polyp. Clinical symptoms and presentation alone are
    not enough to differentiate the type of the nasal polyp without the histological study.
    Matched MeSH terms: Nasopharyngeal Neoplasms
  10. Fulltext The Microenvironment in Epstein-Barr Virus-Associated Malignancies
    Tan GW, Visser L, Tan LP, van den Berg A, Diepstra A
    Pathogens, 2018 04 13;7(2).
    PMID: 29652813 DOI: 10.3390/pathogens7020040
    The Epstein–Barr virus (EBV) can cause a wide variety of cancers upon infection of different cell types and induces a highly variable composition of the tumor microenvironment (TME). This TME consists of both innate and adaptive immune cells and is not merely an aspecific reaction to the tumor cells. In fact, latent EBV-infected tumor cells utilize several specific mechanisms to form and shape the TME to their own benefit. These mechanisms have been studied largely in the context of EBV+ Hodgkin lymphoma, undifferentiated nasopharyngeal carcinoma, and EBV+ gastric cancer. This review describes the composition, immune escape mechanisms, and tumor cell promoting properties of the TME in these three malignancies. Mechanisms of susceptibility which regularly involve genes related to immune system function are also discussed, as only a small proportion of EBV-infected individuals develops an EBV-associated malignancy.
    Matched MeSH terms: Nasopharyngeal Neoplasms
  11. Five-year Survival Data on the Role of Endoscopic Endonasal Nasopharyngectomy in Advanced Recurrent rT3 and rT4 Nasopharyngeal Carcinoma
    Wong EHC, Liew YT, Loong SP, Prepageran N
    Ann Otol Rhinol Laryngol, 2020 Mar;129(3):287-293.
    PMID: 31701754 DOI: 10.1177/0003489419887410
    AIM: Endoscopic endonasal nasopharyngectomy (EEN) for recurrent nasopharyngeal carcinoma (rNPC) is being increasingly used due to the added high magnification, reduced morbidities associated with open procedures and good survival outcomes. Most studies looked at usage of EEN in patients with lower recurrent staging (rT1 and rT2) although more and more surgeons are studying the outcome of EEN in advanced rNPC (rT3 and rT4). The aims of this study were to report the long-term 5-year survival outcome of EEN performed in patients with advanced rNPC, and to determine any prognostic factors for patients' survival.

    METHODS: All patients who underwent EEN for advanced rNPC between January 2003 and December 2015 inclusive were analyzed. All surgeries were performed in University Malaya Medical Centre in Kuala Lumpur and Queen Elizabeth Hospital in Sabah. We reported the 5-year overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS) and any related complications and significant prognostic factors.

    RESULTS: Twelve patients with rNPC (2 rT3 and 10 rT4) were followed-up over a mean duration of 44.8 months (range, 40-440 weeks). The 5-year OS was 50.0% (mean 44.75 months), DFS was 25.0% (mean 35.25 months) and the DSS was 58.3% (mean 43.33 months). No severe operative complications were encountered and no independent prognostic factors for survival outcome were identified.

    CONCLUSION: This is the first report in English that exclusively described the long-term 5-year survival data in patients with both rT3 and rT4 recurrent NPC after EEN. The data suggest that EEN is a feasible treatment to improve survival with minimal morbidities in patients with rT3 and rT4 recurrent NPC. However, more studies with larger patient size is recommended.

    Matched MeSH terms: Nasopharyngeal Neoplasms
  12. Long-term survival of nasopharyngeal carcinoma patients treated with adjuvant chemotherapy subsequent to conventional radical radiotherapy
    Prasad U, Wahid MI, Jalaludin MA, Abdullah BJ, Paramsothy M, Abdul-Kareem S
    Int J Radiat Oncol Biol Phys, 2002 Jul 1;53(3):648-55.
    PMID: 12062608
    To assess the long-term survival of patients with nasopharyngeal carcinoma (NPC) who were treated with conventional radical radiotherapy (RT) followed by adjuvant chemotherapy.
    Matched MeSH terms: Nasopharyngeal Neoplasms/drug therapy*; Nasopharyngeal Neoplasms/mortality; Nasopharyngeal Neoplasms/radiotherapy*
  13. Fulltext CD24, CD44 and EpCAM enrich for tumour-initiating cells in a newly established patient-derived xenograft of nasopharyngeal carcinoma
    Hoe SLL, Tan LP, Abdul Aziz N, Liew K, Teow SY, Abdul Razak FR, et al.
    Sci Rep, 2017 09 28;7(1):12372.
    PMID: 28959019 DOI: 10.1038/s41598-017-12045-8
    Subpopulations of nasopharyngeal carcinoma (NPC) contain cells with differential tumourigenic properties. Our study evaluates the tumourigenic potential of CD24, CD44, EpCAM and combination of EpCAM/CD44 cells in NPC. CD44br and EpCAMbr cells enriched for higher S-phase cell content, faster-growing tumourigenic cells leading to tumours with larger volume and higher mitotic figures. Although CD44br and EpCAMbr cells significantly enriched for tumour-initiating cells (TICs), all cells could retain self-renewal property for at least four generations. Compared to CD44 marker alone, EpCAM/CD44dbr marker did not enhance for cells with faster-growing ability or higher TIC frequency. Cells expressing high CD44 or EpCAM had lower KLF4 and p21 in NPC subpopulations. KLF4-overexpressed EpCAMbr cells had slower growth while Kenpaullone inhibition of KLF4 transcription increased in vitro cell proliferation. Compared to non-NPC, NPC specimens had increased expression of EPCAM, of which tumours from advanced stage of NPC had higher expression. Together, our study provides evidence that EpCAM is a potentially important marker in NPC.
    Matched MeSH terms: Nasopharyngeal Neoplasms/genetics; Nasopharyngeal Neoplasms/metabolism*; Nasopharyngeal Neoplasms/pathology
  14. Fulltext Nasopharyngeal carcinoma in Brunei Darussalam: low incidence among the Chinese and an evaluation of antibodies to Epstein-Barr virus antigens as biomarkers
    Yeo CH, Hsien YC, Abdullah MS, Telesinghe PU, Ramasamy R
    Singapore Med J, 2009 Apr;50(4):371-7.
    PMID: 19421680
    Little or no information is available on the prevalence of nasopharyngeal carcinoma (NPC) among different ethnic groups in Brunei, or how useful plasma IgA antibodies are against viral capsid antigen (VCA) and early antigen (EA) in the diagnosis of NPC, even though they are routinely measured in patients suspected to have NPC.
    Matched MeSH terms: Nasopharyngeal Neoplasms/ethnology*; Nasopharyngeal Neoplasms/immunology*; Nasopharyngeal Neoplasms/epidemiology
  15. Fulltext Evaluation of plasma Epstein-Barr virus DNA load as a prognostic marker for nasopharyngeal carcinoma
    Tan EL, Looi LM, Sam CK
    Singapore Med J, 2006 Sep;47(9):803-7.
    PMID: 16924363
    Nasopharyngeal carcinoma (NPC) is an important cancer in Malaysia and is one of the major causes of cancer mortality in this country. This study evaluates the diagnostic and prognostic values in the quantitative relationship between the cell-free Epstein-Barr virus (EBV) deoxyribonucleic acid (DNA) load and the tumour burden.
    Matched MeSH terms: Nasopharyngeal Neoplasms/blood; Nasopharyngeal Neoplasms/diagnosis*; Nasopharyngeal Neoplasms/virology
  16. Fulltext Late Temporal Lobe Extensive Osteoradionecrosis Post Radiation for Nasopharyngeal Carcinoma: Case Series
    Tang CL, Kumar R, Toh CJ, Azura S, Tan GC, Gendeh BS
    Indian J Otolaryngol Head Neck Surg, 2017 Sep;69(3):409-414.
    PMID: 28929077 DOI: 10.1007/s12070-015-0909-5
    Osteoradionecrosis is one of the most serious complications of radiotherapy for nasopharyngeal carcinoma. We report three cases of osteoradionecrosis in temporal lobe who presented differently few years after completion of radiotherapy. Cranial magnetic resonance image showed lesions in temporal lobe either unilateral or bilateral with mass effect. One of the cases even showed disease progression few years after the initial diagnosis of osteoradionecrosis. Diagnosis of osteoradionecrosis for all three patients was confirmed by biopsy.
    Matched MeSH terms: Nasopharyngeal Neoplasms
  17. Fulltext Wernicke's Encephalopathy in a Patient with Nasopharyngeal Carcinoma: Magnetic Resonance Imaging Findings
    Law HL, Tan S, Sedi R
    Malays J Med Sci, 2011 Jul;18(3):71-4.
    PMID: 22135604
    We report a case of Wernicke's encephalopathy in a patient with nasopharyngeal carcinoma with a 3-month history of poor oral intake related to nausea and vomiting due to chemotherapy. The patient later developed deep coma while receiving in-patient therapy. Magnetic resonance imaging of the brain revealed typical findings of Wernicke's encephalopathy. The patient was treated with thiamine injections, which resulted in subsequent partial recovery of neurological function. This paper stresses the importance of magnetic resonance imaging for prompt diagnosis of Wernicke's encephalopathy.
    Matched MeSH terms: Nasopharyngeal Neoplasms
  18. Fulltext HLA-A SNPs and amino acid variants are associated with nasopharyngeal carcinoma in Malaysian Chinese
    Chin YM, Mushiroda T, Takahashi A, Kubo M, Krishnan G, Yap LF, et al.
    Int J Cancer, 2015 Feb 1;136(3):678-87.
    PMID: 24947555 DOI: 10.1002/ijc.29035
    Nasopharyngeal carcinoma (NPC) arises from the mucosal epithelium of the nasopharynx and is constantly associated with Epstein-Barr virus type 1 (EBV-1) infection. We carried out a genome-wide association study (GWAS) of 575,247 autosomal SNPs in 184 NPC patients and 236 healthy controls of Malaysian Chinese ethnicity. Potential association signals were replicated in a separate cohort of 260 NPC patients and 245 healthy controls. We confirmed the association of HLA-A to NPC with the strongest signal detected in rs3869062 (p = 1.73 × 10(-9)). HLA-A fine mapping revealed associations in the amino acid variants as well as its corresponding SNPs in the antigen peptide binding groove (p(HLA-A-aa-site-99) = 3.79 × 10(-8), p(rs1136697) = 3.79 × 10(-8)) and T-cell receptor binding site (p(HLA-A-aa-site-145) = 1.41 × 10(-4), p(rs1059520) = 1.41 × 10(-4)) of the HLA-A. We also detected strong association signals in the 5'-UTR region with predicted active promoter states (p(rs41545520) = 7.91 × 10(-8)). SNP rs41545520 is a potential binding site for repressor ATF3, with increased binding affinity for rs41545520-G correlated with reduced HLA-A expression. Multivariate logistic regression diminished the effects of HLA-A amino acid variants and SNPs, indicating a correlation with the effects of HLA-A*11:01, and to a lesser extent HLA-A*02:07. We report the strong genetic influence of HLA-A on NPC susceptibility in the Malaysian Chinese.
    Matched MeSH terms: Nasopharyngeal Neoplasms/genetics*
  19. Application of champedak mannose-binding lectin in the glycoproteomic profiling of serum samples unmasks reduced expression of alpha-2 macroglobulin and complement factor B in patients with nasopharyngeal carcinoma
    Seriramalu R, Pang WW, Jayapalan JJ, Mohamed E, Abdul-Rahman PS, Bustam AZ, et al.
    Electrophoresis, 2010 Jul;31(14):2388-95.
    PMID: 20575108 DOI: 10.1002/elps.201000164
    The use of lectin affinity chromatography prior to 2-DE separation forms an alternative method to unmask the expression of targeted glycoproteins of lower abundance in serum samples. Reduced expression of alpha-2 macroglobulin (AMG) and complement factor B (CFB) was detected in sera of patients with nasopharyngeal carcinoma (NPC) when pooled serum samples of the patients and those of healthy individuals were subjected to affinity isolation using immobilized champedak mannose-binding lectin and analyzed by 2-DE and densitometry. The AMG and CFB spots were not detected in the 2-DE protein profiles when the same pooled serum samples were subjected to albumin and IgG depletion and neither were they detected when the depleted samples were analyzed by western blotting and lectin detection. Together with other acute-phase response proteins that were previously reported to be altered in expression in NPC patients, AMG and CFB may serve as useful complementary biomarkers for NPC.
    Matched MeSH terms: Nasopharyngeal Neoplasms/metabolism*
  20. Fulltext Mutational analysis of p53 and RB2/p130 genes in Malaysian nasopharyngeal carcinoma samples: a preliminary report
    Hoe SL, Sam CK
    Malays J Pathol, 2006 Jun;28(1):35-9.
    PMID: 17694957 MyJurnal
    This study reports the results of mutation detection of tumour suppressor genes, p53 and RB2/p130 genes in Malaysian nasopharyngeal carcinoma (NPC) studied by PCR-CSGE analysis and direct DNA sequencing method. Frequent sites of mutation in both genes (exons 5-8 of p53 and exons 19-21 of RB2/p130) were examined. Thirty-six NPC blood samples and three NPC cell lines were investigated for the presence of mutations. No mutation of p53 and RB2/p130 genes was identified in any of the blood samples. Nonetheless, there was an identical G-->4 C nucleotide change at codon 280 of p53 gene in all the cell lines. A larger study that includes biopsy tissues should be carried out to provide a more in-depth look into the pathogenesis of NPC in Malaysia.
    Matched MeSH terms: Nasopharyngeal Neoplasms/genetics*
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