Publications by authors named "Shoa-Nian Choo"

Primary Epstein-Barr virus (EBV)-positive nodal T/NK-cell lymphoma (PTCL-EBV) is a poorly understood disease which shows features resembling extranodal NK/T-cell lymphoma (ENKTL) and is currently not recognized as a distinct entity but categorized as a variant of primary T-cell lymphoma not otherwise specified (PTCL-NOS). Herein, we analyzed copynumber aberrations (n=77) with a focus on global measures of genomic instability and homologous recombination deficiency and performed gene expression (n=84) and EBV miRNA expression (n=24) profiling as well as targeted mutational analysis (n=16) to further characterize PTCL-EBV in relation to ENKTL and PTCL-NOS. Multivariate analysis revealed that patients with PTCL-EBV had a significantly worse outcome compared to patients with PTCL-NOS (P=0.

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Objectives: To investigate plasma and urinary kynurenine (KYN)-tryptophan (TRP) ratios in bladder cancer, expression of indoleamine 2,3-dioxygenase 1 (IDO1) in relation to tryptophan 2,3-dioxygenase (TDO2) in bladder tumour, and the correlation of KYN-TRP ratio with bladder tumour burden.

Methods: Metabotyping of the TRP-KYN metabolic axis was performed via a clinical case-control study. Expression of IDO1 and TDO2 was measured in human biopsied tissues.

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Immunohistochemistry (IHC) provides clinically useful information on protein expression in cancer cells. However, quantification of colocalizing signals using conventional IHC and visual scores is challenging. Here we describe the application of quantitative immunofluorescence in angioimmunoblastic T-cell lymphoma (AITL), a peripheral T-cell lymphoma characterized by cellular heterogeneity that impedes IHC interpretation and quantification.

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The molecular biology of primary nodal T- and NK-cell lymphoma and its relationship with extranodal NK/T-cell lymphoma, nasal type is poorly understood. In this study, we assessed the relationship between nodal and extranodal Epstein-Barr virus-positive T/NK-cell lymphomas using gene expression profiling and copy number aberration analyses. We performed gene expression profiling and copy number aberration analysis on 66 cases of Epstein-Barr virus-associated T/NK-cell lymphoma from nodal and extranodal sites, and correlated the molecular signatures with clinicopathological features.

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Introduction: Sporadic colorectal cancers with BRAF mutations constitute two distinct subgroups of colorectal cancers. Recent studies have linked the presence of the BRAF mutation to a familial inheritance pattern. This was a proof-of-concept study that aimed to examine: (a) the extent of field change in sporadic colorectal cancers with BRAF mutation; and (b) the extent of resection margins required and the pattern of DNA mismatch repair protein loss in these tumours.

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Background: EBV-associated T/NK-cell lymphoproliferative diseases (TNKLPD) is a rare spectrum of disease that occurs more commonly in Asia, and Central and South America. It commonly affects children and young adults and is an aggressive disease that is poorly understood with no known biologic markers that can predict prognosis. The systemic form of TNKLPD includes chronic active EBV infection of T/NK type, aggressive NK cell leukemia and systemic EBV + T-cell lymphoproliferative disease of childhood.

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We performed gene expression profiling in Epstein-Barr virus (EBV)-associated T/natural killer (NK)-cell lymphoproliferative disorder in children and young adults (TNKLPDC) in order to understand the molecular pathways deregulated in this disease and compared it with nasal-type NK/T-cell lymphoma (NKTL). The molecular and phenotypic signature of TNKLPDC is similar to NKTL, with overexpression of p53, survivin and EZH2. Down-regulation of EZH2 in TNKLPDC cell lines led to an increase in apoptosis and decrease in tumor viability, suggesting that EZH2 may be important for the survival of TNKLPDC cells and hence potentially a useful therapeutic target.

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The role of enhancer of zeste homolog 2 (EZH2) in cancer is complex and may vary depending on the cellular context. We found that EZH2 is aberrantly overexpressed in the majority of natural killer/T-cell lymphoma (NKTL), an aggressive lymphoid malignancy with very poor prognosis. We show that EZH2 upregulation is mediated by MYC-induced repression of its regulatory micro RNAs and EZH2 exerts oncogenic properties in NKTL.

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A 74-year-old woman had carcinoma of her right breast for which surgery was performed. Four weeks following the start of tamoxifen therapy, she developed papules and plaques over her face, trunk and limbs. A skin biopsy showed perivascular and periadnexal mixed inflammatory cellular infiltrate with fibroplasia.

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Background: Ovarian cancer is a leading cause of gynaecological cancer-related morbidity and mortality. There has been increasing interest in the potential utility of anti-human epidermal growth factor receptor 2 (anti-HER2) agents in the treatment of this disease, with the attendant need to identify suitable predictive biomarkers of response to treatment.

Aims/methods: The authors studied the prevalence of HER2 genomic amplification and overexpression in 85 ovarian tumours in the local patient cohort of this study, as well as the concordance rate between immunohistochemistry, fluorescent in situ hybridisation (FISH) and a dual-colour HER2/chromosome 17 centromere chromogenic in situ hybridisation (CISH) assay.

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Background: Determination of HER2 protein expression by immunohistochemistry (IHC) and genomic status by fluorescent in situ hybridisation (FISH) are important in identifying a subset of high HER2-expressing gastric cancers that might respond to trastuzumab. Although FISH is considered the standard for determination of HER2 genomic status, brightfield ISH is being increasingly recognised as a viable alternative. Also, the impact of HER2 protein expression/genomic heterogeneity on the accuracy of HER2 testing has not been well studied in the context of gastric biopsy samples.

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