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63
result(s) for
"Simon Y. Law"
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Circulating microRNAs as Specific Biomarkers for Breast Cancer Detection
2013
We previously showed microRNAs (miRNAs) in plasma are potential biomarkers for colorectal cancer detection. Here, we aimed to develop specific blood-based miRNA assay for breast cancer detection.
TaqMan-based miRNA profiling was performed in tumor, adjacent non-tumor, corresponding plasma from breast cancer patients, and plasma from matched healthy controls. All putative markers identified were verified in a training set of breast cancer patients. Selected markers were validated in a case-control cohort of 170 breast cancer patients, 100 controls, and 95 other types of cancers and then blindly validated in an independent set of 70 breast cancer patients and 50 healthy controls. Profiling results showed 8 miRNAs were concordantly up-regulated and 1 miRNA was concordantly down-regulated in both plasma and tumor tissue of breast cancer patients. Of the 8 up-regulated miRNAs, only 3 were significantly elevated (p<0.0001) before surgery and reduced after surgery in the training set. Results from the validation cohort showed that a combination of miR-145 and miR-451 was the best biomarker (p<0.0001) in discriminating breast cancer from healthy controls and all other types of cancers. In the blind validation, these plasma markers yielded Receiver Operating Characteristic (ROC) curve area of 0.931. The positive predictive value was 88% and the negative predictive value was 92%. Altered levels of these miRNAs in plasma have been detected not only in advanced stages but also early stages of tumors. The positive predictive value for ductal carcinoma in situ (DCIS) cases was 96%.
These results suggested that these circulating miRNAs could be a potential specific biomarker for breast cancer screening.
Journal Article
Cancer cell-secreted IGF2 instigates fibroblasts and bone marrow-derived vascular progenitor cells to promote cancer progression
2017
Local interactions between cancer cells and stroma can produce systemic effects on distant organs to govern cancer progression. Here we show that IGF2 secreted by inhibitor of differentiation (Id1)-overexpressing oesophageal cancer cells instigates VEGFR1-positive bone marrow cells in the tumour macroenvironment to form pre-metastatic niches at distant sites by increasing VEGF secretion from cancer-associated fibroblasts. Cancer cells are then attracted to the metastatic site via the CXCL5/CXCR2 axis. Bone marrow cells transplanted from nude mice bearing Id1-overexpressing oesophageal tumours enhance tumour growth and metastasis in recipient mice, whereas systemic administration of VEGFR1 antibody abrogates these effects. Mechanistically, IGF2 regulates VEGF in fibroblasts via miR-29c in a p53-dependent manner. Analysis of patient serum samples showed that concurrent elevation of IGF2 and VEGF levels may serve as a prognostic biomarker for oesophageal cancer. These findings suggest that the Id1/IGF2/VEGF/VEGFR1 cascade plays a critical role in tumour-driven pathophysiological processes underlying cancer progression.
Cancer cells can affect cancer progression by producing systemic effects. Here, the authors show that IGF2 produced by oesophageal cancer cells increases secretion of VEGF from cancer-associated fibroblasts resulting in systemic mobilization of bone marrow-derived cells and increased metastases.
Journal Article
The somatic mutation landscape of normal gastric epithelium
2025
The landscapes of somatic mutation in normal cells inform us about the processes of mutation and selection operative throughout life, providing insight into normal ageing and the earliest stages of cancer development
1
. Here, by whole-genome sequencing of 238 microdissections
2
from 30 individuals, including 18 with gastric cancer, we elucidate the developmental trajectories of normal and malignant gastric epithelium. We find that gastric glands are units of monoclonal cell populations that accrue roughly 28 somatic single-nucleotide variants per year, predominantly attributable to endogenous mutational processes. In individuals with gastric cancer, metaplastic glands often show elevated mutation burdens due to acceleration of mutational processes linked to proliferation and oxidative damage. Unusually for normal cells, gastric epithelial cells often carry recurrent trisomies of specific chromosomes, which are highly enriched in a subset of individuals. Surveying 829 polyclonal gastric microbiopsies by targeted sequencing, we find somatic ‘driver’ mutations in a distinctive repertoire of known cancer genes, including
ARID1A
,
ARID1B
,
ARID2
,
CTNNB1
and
KDM6A
. The prevalence of mutant clones increases with age to occupy roughly 8% of the gastric epithelial lining by age 60 years and is significantly increased by the presence of severe chronic inflammation. Our findings provide insights into intrinsic and extrinsic influences on somatic evolution in the gastric epithelium in healthy, precancerous and malignant states.
Whole-gene sequencing of microdissected gastric glands from individuals with and without gastric cancer reveals distinct patterns of somatic mutations and provides insights into influences on the somatic evolution of the gastric epithelium.
Journal Article
Divergent lineage trajectories and genetic landscapes in human gastric intestinal metaplasia organoids associated with early neoplastic progression
2025
BackgroundGastric intestinal metaplasia (IM) is a precancerous stage spanning a morphological spectrum that is poorly represented by human cell line models.ObjectiveWe aim to establish and characterise human IM cell models to better understand IM progression along the cancer spectrum.DesignA large human gastric IM organoid (IMO) cohort (n=28), their clonal derivatives and normal gastric organoids (n=42) for comparison were established. Comprehensive multi-omics profiling and functional characterisation were performed.ResultsSingle-cell transcriptomes revealed IMO cells spanning a spectrum from hybrid gastric/intestinal to advanced intestinal differentiation. Their lineage trajectories connected different cycling and quiescent stem and progenitors, highlighting differences in gastric to IM transition and the potential origin of IM from STMN1 cycling isthmus stem cells. Hybrid IMOs showed impaired differentiation potential, high lineage plasticity beyond gastric or intestinal fates and reactivation of a fetal gene programme.Cell populations in gastric IM and cancer tissues were highly similar to those derived from IMOs and exhibited a fetal signature. Genomically, IMOs showed elevated mutation burden, frequent chromosome 20 gain and epigenetic deregulation of many intestinal and gastric genes. Functionally, IMOs were FGF10 independent and showed downregulated FGFR2. Several IMOs exhibited a cell-matrix adhesion independent subpopulation that displayed chromosome 20 gain but lacked key cancer driver mutations, potentially representing the earliest neoplastic precursor of IM-induced gastric cancer.ConclusionsOverall, our IMO biobank captured the heterogeneous nature of IM, revealing mechanistic insights on IM pathogenesis and progression, offering an ideal platform for studying early gastric neoplastic transformation and chemoprevention.
Journal Article
MicroRNA‐338‐5p reverses chemoresistance and inhibits invasion of esophageal squamous cell carcinoma cells by targeting Id‐1
2019
5‐Fluorouracil (5‐FU) is a chemotherapeutic agent commonly used to treat esophageal squamous cell carcinoma (ESCC), but acquisition of chemoresistance frequently occurs and the underlying mechanisms are not fully understood. We found that microRNA (miR)‐338‐5p was underexpressed in ESCC cells with acquired 5‐FU chemoresistance. Forced expression of miR‐338‐5p in these cells resulted in downregulation of Id‐1, and restoration of both in vitro and in vivo sensitivity to 5‐FU treatment. The effects were abolished by reexpression of Id‐1. In contrast, miR‐338‐5p knockdown induced 5‐FU resistance in chemosensitive esophageal cell lines, and knockdown of both miR‐338‐5p and Id‐1 resensitized the cells to 5‐FU. In addition, miR‐338‐5p had suppressive effects on migration and invasion of ESCC cells. Luciferase reporter assay confirmed a direct interaction between miR‐338‐5p and the 3′‐UTR of Id‐1. We also found that miR‐338‐5p was significantly downregulated in tumor tissue and serum samples of patients with ESCC. Notably, low serum miR‐338‐5p expression level was associated with poorer survival and poor response to 5‐FU/cisplatin‐based neoadjuvant chemoradiotherapy. In summary, we found that miR‐338‐5p can modulate 5‐FU chemoresistance and inhibit invasion‐related functions in ESCC by negatively regulating Id‐1, and that serum miR‐338‐5p could be a novel noninvasive prognostic and predictive biomarker in ESCC. We found that microRNA (miR)‐338‐5p was underexpressed in esophageal squamous cell carcinoma cells with acquired 5‐fluorouracil (5‐FU) chemoresistance, and that reexpression of miR‐338‐5p could resensitize them to 5‐FU treatment through targeting Id‐1. MicroRNA‐338‐5p was significantly downregulated in tumor tissue and serum of patients with esophageal squamous cell carcinoma. Low serum miR‐338‐5p was predictive of poor response to 5‐FU/cisplatin‐based neoadjuvant chemoradiotherapy.
Journal Article
Escape from cell-cell and cell-matrix adhesion dependence underscores disease progression in gastric cancer organoid models
2023
ObjectiveCell-cell (CC) and cell-matrix (CM) adhesions are essential for epithelial cell survival, yet dissociation-induced apoptosis is frequently circumvented in malignant cells.DesignWe explored CC and CM dependence in 58 gastric cancer (GC) organoids by withdrawing either ROCK inhibitor, matrix or both to evaluate their tumorigenic potential in terms of apoptosis resistance, correlation with oncogenic driver mutations and clinical behaviour. We performed mechanistic studies to determine the role of diffuse-type GC drivers: ARHGAP fusions, RHOA and CDH1, in modulating CC (CCi) or CM (CMi) adhesion independence.Results97% of the tumour organoids were CMi, 66% were CCi and 52% were resistant to double withdrawal (CCi/CMi), while normal organoids were neither CMi nor CCi. Clinically, the CCi/CMi phenotype was associated with an infiltrative tumour edge and advanced tumour stage. Moreover, the CCi/CMi transcriptome signature was associated with poor patient survival when applied to three public GC datasets. CCi/CMi and CCi phenotypes were enriched in diffuse-type GC organoids, especially in those with oncogenic driver perturbation of RHO signalling via RHOA mutation or ARHGAP fusions. Inducible knockout of ARHGAP fusions in CCi/CMi tumour organoids led to resensitisation to CC/CM dissociation-induced apoptosis, upregulation of focal adhesion and tight junction genes, partial reversion to a more normal cystic phenotype and inhibited xenograft formation. Normal gastric organoids engineered with CDH1 or RHOA mutations became CMi or CCi, respectively.ConclusionsThe CCi/CMi phenotype has a critical role in malignant transformation and tumour progression, offering new mechanistic information on RHO-ROCK pathway inhibition that contributes to GC pathogenicity.
Journal Article
Divergent trends of hospitalizations for upper and lower gastrointestinal bleeding based on population prescriptions of aspirin, proton pump inhibitors and Helicobacter pylori eradication therapy
2021
Background With the increasing use of medications that alter the risk of gastrointestinal bleeding (GIB), comprising aspirin, proton pump inhibitors (PPIs), and Helicobacter pylori eradication therapies, the trends of GIB are evolving. Objective The aim of this study is to determine and predict the trends of GIB and to evaluate the effects of population prescriptions of these medications on GIB incidences. Methods We retrieved patients hospitalized for GIB in all public hospitals in Hong Kong between 2009 and 2019. Monthly age‐ and sex‐standardized GIB data were fitted and predicted, based on population prescriptions of aspirin, nonsteroidal anti‐inflammatory drugs (NSAIDs), anticoagulants, other antiplatelet drugs, PPIs, and H. pylori therapies, using autoregressive integrated moving average model for time series analysis. Results The incidence of upper GIB (UGIB) showed a clear declining trend while lower GIB (LGIB) decreased slightly. Older population (>80 years) had the greatest decline in UGIB but was associated with an increase in LGIB. Prescriptions of PPIs and aspirin increased significantly with time. PPIs prescriptions were negatively associated with UGIB incidence (coefficient log(PPIs) −4.58; 95% confidence interval [CI]: −5.69, −3.47). H. pylori eradication in the previous month showed a nonsignificant trend on UGIB (coefficient −0.14; 95% CI: −0.30, 0.02). In contrast, aspirin increased the incidences of UGIB (coefficient 0.06; 95% CI: 0.04, 0.07) and LGIB (coefficient 0.04; 95% CI: 0.03, 0.05). NSAIDs, anticoagulants, and other antiplatelet drugs were not significantly associated with the trend of either UGIB or LGIB. UGIB is predicted to decline continuously but LGIB is projected to rise, particularly with increasing use of aspirin. Conclusions UGIB incidences were decreasing and had been surpassed by LGIB. Based on population prescriptions of aspirin and PPIs, divergent trends of upper and lower GIB are expected, especially in elderly. Key summary Summarize the established knowledge on this subject With increasing use of proton pump inhibitors (PPIs) and Helicobacter pylori eradication therapy, the incidences of upper gastrointestinal bleeding (UGIB) are declining. The increasing use of antiplatelets and anticoagulants, however, increases the risk of both UGIB and lower gastrointestinal bleeding (LGIB). The dynamic contribution of these factors on the incidences of UGIB and LGIB at population level remains uncertain. What are the significant and/or new findings of this study? The incidences of UGIB showed a clear declining trend while LGIB decreased slightly over the past decade in Hong Kong. LGIB had actually surpassed UGIB as the leading source of GIB, especially among older population. The increasing PPIs prescription was associated with the falling incidences of UGIB, whereas the rising use of aspirin was associated with both an increase in UGIB and LGIB. With the increasing use of aspirin and the lack of effective prevention preventive strategies, LGIB would become a major health challenge.
Journal Article
International Expert Consensus on Semantics of Multimodal Esophageal Cancer Treatment: Delphi Study
by
Yin-Kai Chao
,
Geert-Jan Creemers
,
Rutger Quispel
in
Cancer therapies
,
Chemoradiotherapy
,
Chemotherapy
2024
Background
Recent developments in esophageal cancer treatment, including studies exploring active surveillance following chemoradiotherapy, have led to a need for clear terminology and definitions regarding different multimodal treatment options.
Objective
The aim of this study was to reach worldwide consensus on the definitions and semantics of multimodal esophageal cancer treatment.
Methods
In total, 72 experts working in the field of multimodal esophageal cancer treatment were invited to participate in this Delphi study. The study comprised three Delphi surveys sent out by email and one online meeting. Input for the Delphi survey consisted of terminology obtained from a systematic literature search. Participants were asked to respond to open questions and to indicate whether they agreed or disagreed with different statements. Consensus was reached when there was ≥75% agreement among respondents.
Results
Forty-nine of 72 invited experts (68.1%) participated in the first online Delphi survey, 45 (62.5%) in the second survey, 21 (46.7%) of 45 in the online meeting, and 39 (86.7%) of 45 in the final survey. Consensus on neoadjuvant and definitive chemoradiotherapy with or without surgery was reached for 27 of 31 items (87%). No consensus was reached on follow-up after treatment with definitive chemoradiotherapy.
Conclusion(s)
Consensus was reached on most statements regarding terminology and definitions of multimodal esophageal cancer treatment. Implementing uniform criteria facilitates comparison of studies and promotes international research collaborations.
Journal Article
Hospital Authority audit of the outcome of endoscopic resection of superficial upper gastro-intestinal lesions in Hong Kong
2015
To review the short-term outcome of endoscopic resection of superficial upper gastro-intestinal lesions in Hong Kong.
Historical cohort study.
All Hospital Authority hospitals in Hong Kong.
This was a multicentre retrospective study of all patients who underwent endoscopic resection of superficial upper gastro-intestinal lesions between January 2010 and June 2013 in all government-funded hospitals in Hong Kong.
Indication of the procedures, peri-procedural and procedural parameters, oncological outcomes, morbidity, and mortality.
During the study period, 187 lesions in 168 patients were resected. Endoscopic mucosal resection was performed in 34 (18.2%) lesions and endoscopic submucosal dissection in 153 (81.8%) lesions. The mean size of the lesions was 2.6 (standard deviation, 1.8) cm. The 30-day morbidity rate was 14.4%, and perforations and severe bleeding occurred in 4.3% and 3.2% of the patients, respectively. Among patients who had dysplasia or carcinoma, R0 resection was achieved in 78% and the piecemeal resection rate was 11.8%. Lateral margin involvement was 14% and vertical margin involvement was 8%. Local recurrence occurred in 9% of patients and 15% had residual disease. The 2-year overall survival rate and disease-specific survival rate was 90.6% and 100%, respectively.
Endoscopic mucosal resection and endoscopic submucosal dissection were introduced in low-to-moderate-volume hospitals with acceptable morbidity rates. The short-term survival was excellent. However, other oncological outcomes were higher than those observed in high-volume centres and more secondary procedures were required.
Journal Article