ORCID Profile
0000-0002-7997-331X
Current Organisation
The University of Hong Kong
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Springer Science and Business Media LLC
Date: 07-11-2018
DOI: 10.1038/S41467-018-06889-5
Abstract: The lack of representative nasopharyngeal carcinoma (NPC) models has seriously h ered research on EBV carcinogenesis and preclinical studies in NPC. Here we report the successful growth of five NPC patient-derived xenografts (PDXs) from fifty-eight attempts of transplantation of NPC specimens into NOD/SCID mice. The take rates for primary and recurrent NPC are 4.9% and 17.6%, respectively. Successful establishment of a new EBV-positive NPC cell line, NPC43, is achieved directly from patient NPC tissues by including Rho-associated coiled-coil containing kinases inhibitor (Y-27632) in culture medium. Spontaneous lytic reactivation of EBV can be observed in NPC43 upon withdrawal of Y-27632. Whole-exome sequencing (WES) reveals a close similarity in mutational profiles of these NPC PDXs with their corresponding patient NPC. Whole-genome sequencing (WGS) further delineates the genomic landscape and sequences of EBV genomes in these newly established NPC models, which supports their potential use in future studies of NPC.
Publisher: Wiley
Date: 26-08-2019
DOI: 10.1002/IJC.32619
Abstract: Esophageal squamous cell carcinoma (ESCC) occurs with highest frequency in China with over 90% mortality, highlighting the need for early detection and improved treatment strategies. We aimed to identify ESCC cancer predisposition gene(s). Our study included 4,517 in iduals. The discovery phase using whole-exome sequencing (WES) included 186 familial ESCC patients from high-risk China. Targeted gene sequencing validation of 598 genes included 3,289 Henan and 1,228 moderate-risk Hong Kong Chinese. A WES approach identified BRCA2 loss-of-function (LOF) mutations in 3.23% (6/186) familial ESCC patients compared to 0.21% (9/4300) in the ExAC East Asians (odds ratio [OR] = 15.89, p = 2.48 × 10
Publisher: Springer Science and Business Media LLC
Date: 04-2016
Publisher: MDPI AG
Date: 26-05-2020
Abstract: (1) Background: Early predictive markers to track treatment responses are needed for advanced esophageal squamous cell carcinoma (ESCC) patients. We examined the prognostication and risk stratification role of liquid biopsy serial monitoring for this deadly cancer. (2) Methods: Circulating tumor cells (CTCs) and plasma cell-free DNA (cfDNA) were isolated from 60 ESCC patients treated by chemotherapy (CT) at five serial timepoints: baseline (CTC1/cfDNA1), CT pre-cycle III (CTC2/cfDNA2), CT post-cycle IV, end of CT and relapse. (3) Results: In 45/57 ESCC patients with evaluable CTC counts at CT pre-cycle III, positive CTC2 (≥3 CTCs) is independently associated with response at interim reassessment and progression-free survival (PFS) in multivariate analysis. In 42/57 ESCC patients with changes of CTC1/CTC2 and cfDNA1/cfDNA2, patients categorized into four risk groups based on the number of favorable and unfavorable changes of CTC1/CTC2 and cfDNA1/cfDNA2, were independently associated with overall survival (OS) by multivariate analysis. (4) Conclusions: CTC counts at pre-cycle III are independently associated with response at interim reassessment and PFS. Combined changes of CTC counts and cfDNA levels from baseline to pre-cycle III are independently associated with OS. Longitudinal liquid biopsy serial monitoring provides complementary information for prediction and prognosis for CT responses in advanced ESCC.
Publisher: MDPI AG
Date: 29-01-2023
Abstract: We aim to reveal the clinical significance and potential usefulness of dynamic monitoring of CTCs to track therapeutic responses and improve survival for advanced ESCC patients. Peripheral blood (PB) (n = 389) and azygos vein blood (AVB) (n = 13) s lings were recruited prospectively from 88 ESCC patients undergoing curative surgery from 2017 to 2022. Longitudinal CTC enumeration was performed with epithelial (EpCAM an-cytokeratins/MUC1) and mesenchymal (vimentin) markers at 12 serial timepoints at any of the pre-treatment, all of the post-treatments re-surgery, post-surgery follow-ups for 3-year, and relapse. Longitudinal real-time CTC analysis in PB and AVB suggests more CTCs are released early at pre-surgery and 3-month post-surgery into the circulation from the CTRT group compared to the up-front surgery group. High CTC levels at pre-treatments, 1-/3-month post-surgery, unfavorable changes of CTC levels between all post-treatment re-surgery and 1-month or 3-month post-surgery (Hazard Ratio (HR) = 6.662, p 0.001), were independent prognosticators for curative treatment. The unfavorable pre-surgery CTC status was independent prognostic and predictive for neoadjuvant treatment efficacy (HR = 3.652, p = 0.035). The aggressive CTC clusters were more frequently observed in AVB compared to PB. Its role as an independent prognosticator with relapse was first reported in ESCC (HR = 2.539, p = 0.068). CTC clusters and longitudinal CTC monitoring provide useful prognostic information and potential predictive biomarkers to help guide clinicians in improving disease management.
Publisher: Springer Science and Business Media LLC
Date: 19-10-2022
DOI: 10.1038/S41416-022-01995-0
Abstract: The patients with dual oesophageal squamous cell carcinoma (ESCC) and hypopharyngeal cancer (HPC) have poor prognosis their underlying genetic pathogenesis is unclear. We hypothesise that development of synchronous ESCC/HPC depends on multicentricity or independent origin, rather than multifocality due to local or lateral spreading. Multiple region whole-exome sequencing (M-WES) and clonality analysis were used to assess clonal relationship and spatial inter- or intra-tumour heterogeneity (ITH) in 62 tumour regions from eight dual ESCC/HPC and ten ESCC patients. All synchronous ESCC/HPC patients had COSMIC 16 mutation signatures, compared to only 40% ESCC in the current study ( p = 0.013) and public data set ( n = 165, p = 0.003). This alcohol consumption-related mutation signature 16, commonly involved in multiple alcohol-related cancers, was significantly associated with drinking and alcohol metabolism-related ADH1B rs1229984. The mutational landscape and copy number profiles were completely distinct between the two primary tumours clonality analysis further suggested the two primary tumours shared no or only one clone accompanying independent subclone evolution. M-WES strategy demonstrated higher sensitivity and accuracy for detection of mutational prevalence and the late branch mutations among different regions in the ESCC tumours, compared to traditional sequencing analysis based on single biopsy strategy. Patients with high ITH assessed by cancer cell fraction analysis after M-WES were significantly associated with both relapse and survival. Our hypothesis-generating M-WES ITH assessment data have implications for prognostication. Collectively, our findings support multicentric independent clonal evolution, the field cancerisation theory, and suggest novel insights implicating an aetiologic role of alcohol metabolism in dual ESCC/HPC carcinogenesis.
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1053/J.GASTRO.2015.08.025
Abstract: The DnaJ (Hsp40) homolog, subfamily B, member 6 (DNAJB6) is part of a family of proteins that regulates chaperone activities. One of its isoforms, DNAJB6a, contains a nuclear localization signal and regulates β-catenin signaling during breast cancer development. We investigated the role of DNAJB6 in the pathogenesis of esophageal squamous cell carcinoma (ESCC). We performed immunohistochemical analyses of primary ESCC s les and lymph node metastases from a cohort of 160 patients who underwent esophagectomy with no preoperative chemoradiotherapy at Hong Kong Queen Mary Hospital. Data were collected on patient outcomes over a median time of 12.1 ± 2.9 months. Retrospective survival association analyses were performed. Wild-type and mutant forms of DNAJB6a were overexpressed in cancer cell lines (KYSE510, KYSE 30TSI, KYSE140, and KYSE70TS), which were analyzed in proliferation and immunoblot assays, or injected subcutaneously into nude mice. Levels of DNAJB6 were knocked down in ESCC cell lines (KYSE450 and T.Tn), immortalized normal esophageal epithelial cell lines (NE3 and NE083), and other cells with short hairpin RNAs, or by genome engineering. Bimolecular fluorescence complementation was used to study interactions between proteins in living cells. In primary ESCC s les, patients whose tumors had high nuclear levels of DNAJB6 had longer overall survival times (19.2 ± 1.8 months 95% confidence interval [CI], 15.6-22.8 mo) than patients whose tumors had low nuclear levels of DNAJB6 (12.6 ± 1.4 mo 95% CI, 9.8-15.4 mo P = .004, log-rank test). Based on Cox regression analysis, patients whose tumors had high nuclear levels of DNAJB6 had a lower risk of death than patients with low levels (hazard ratio, 0.562 95% CI, 0.379-0.834 P = .004). Based on log-rank analysis and Cox regression analysis, the combination of the nuclear level of DNAJB6 and the presence of lymph node metastases at diagnosis could be used to stratify patients into groups with good or bad outcomes (P < .0005 for both analyses). There was a negative association between the nuclear level of DNAJB6 and the presence of lymph node metastases (P = .022 Pearson χ(2) test). Cancer cell lines that overexpressed DNAJB6a formed tumors more slowly in nude mice than control cells or cells that expressed a mutant form of DNAJB6a that did not localize to the nucleus. DNAJB6 knockdown in cancer cell lines promoted their growth as xenograft tumors in mice. A motif of histidine, proline, and aspartic acid in the J domain of DNAJB6a was required for its tumor-suppressive effects and signaling via AKT1. Loss of DNAJB6a resulted in up-regulation of AKT signaling in cancer cell lines and immortalized esophageal epithelial cells. Expression of a constitutively active form of AKT1 restored proliferation to tumor cells that overexpressed DNAJB6a, and DNAJB6a formed a complex with AKT1 in living cells. The expression of DNAJB6a reduced the sensitivity of ESCC to AKT inhibitors the expression level of DNAJB6a affected AKT signaling in multiple cancer cell lines. Nuclear localization of DNAJB6 is associated with longer survival times of patients with ESCC. DNAJB6a reduces AKT signaling, and DNAJB6 expression in cancer cells reduces their proliferation and growth of xenograft tumors in mice. DNAJB6a might be developed as a biomarker for progression of ESCC.
Publisher: Impact Journals, LLC
Date: 25-10-2016
Publisher: Proceedings of the National Academy of Sciences
Date: 07-03-2016
Abstract: Nasopharyngeal carcinoma (NPC) is a valuable cancer model to study the interaction of host genetics, viral infection, and environment in tumorigenesis. Little is known about the genetic basis for the remarkably distinct geographical distribution of NPC. We used a whole-exome sequencing approach to identify the genetic alterations associated with NPC susceptibility and revealed a strong link between macrophage-stimulating 1 receptor ( MST1R ) and NPC early-age onset (age of ≤20 y). MST1R is critical for innate immunity and plays an important role for host defense against viral infection. We further discovered that an interaction network involved in the MST1R/14-3-3 complex was frequently deregulated by genetic alterations in NPC. Our findings provide new insights in the pathogenesis of NPC by highlighting the involvement of the MST1R-mediated signaling pathways.
Publisher: Wiley
Date: 12-07-2017
DOI: 10.1002/PATH.4925
Abstract: Oesophageal squamous cell carcinoma (ESCC) is one of the most lethal cancers, owing to a high frequency of metastasis. However, little is known about the genomic landscape of metastatic ESCC. To identify the genetic alterations that underlie ESCC metastasis, whole-exome sequencing was performed for 41 primary tumours and 15 lymph nodes (LNs) with metastatic ESCCs. Eleven cases included matched primary tumours, synchronous LN metastases, and non-neoplastic mucosa. Approximately 50-76% of the mutations identified in primary tumours appeared in the synchronous LN metastases. Metastatic ESCCs harbour frequent mutations of TP53, KMT2D, ZNF750, and IRF5. Importantly, ZNF750 was recurrently mutated in metastatic ESCC. Combined analysis from current and previous genomic ESCC studies indicated more frequent ZNF750 mutation in diagnosed cases with LN metastasis than in those without metastasis (14% versus 3.4%, n = 629, P = 1.78 × 10
Publisher: Elsevier BV
Date: 12-2018
No related grants have been discovered for Josephine Ko.