👤 Cheng-Hong Toh

Hepatocellular carcinoma (HCC) exhibits diverse aetiologies and molecular heterogeneity, with a median 5-year overall survival of <70% due to high recurrence rates following curative-intent surgery. This study investigated the complex tumour microenvironment (TME) in HCC and explored interactions between various cell types and their roles in disease recurrence. Using a multi-omics approach on multi-region samples of surgically resected HCC from the PLANet 1.0 cohort (NCT03267641), we performed spatial transcriptomics on 17 tissue samples from four patients and bulk RNA sequencing on 329 sectors from 90 patients. Findings were validated using immunofluorescence and multiplex immunohistochemistry. Our analysis revealed extensive intra- and intertumour gene expression heterogeneity and identified a specific subset of endothelial cells (ECs), INTS6 INTS6 The spatial co-localisation of cell types plays a significant role in the recurrence of hepatocellular carcinoma. In this study, we have pinpointed a particular group of endothelial cells, known as INTS6+ endothelial cells, which are spatially colocalised with tumour cells and enriched in microvascular invasion regions in patients experiencing recurrence. These discoveries highlight novel therapeutic targets that focus on endothelial cell interactions within the tumour microenvironment to prevent recurrence and enhance overall patient survival. Show less

Movement behaviours, including moderate-to-vigorous-intensity physical activity (MVPA), light-intensity physical activity (LPA), sedentary behaviour (SB), and sleep, influence childhood adiposity. However, their collective impact on adiposity from a sex-specific perspective remains underexplored. Our research examined the sex-specific longitudinal associations of 24-h movement behaviours with body mass index (BMI) and abdominal adiposity among children. In the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort study, we repeatedly measured 24-h movement behaviours using wrist-worn accelerometers (ActiGraph GT3x) and assessed adiposity (BMI, abdominal circumference, and MRI-based abdominal fat volumes) at three time points (ages 5.5-6, 7.5-8, and 10-10.5 years) within the same children in a longitudinal design. Compositional multivariable linear mixed-effect modelling and isotemporal substitution were used to estimate the associations. 531 children (49.5% girls) were included in the analysis. Significant interactions between movement behaviours and sex were observed across all outcomes. In girls, higher MVPA relative to other behaviours was linked to lower BMI [-0.8 (-1.5, -0.1) kg/m²] and total abdominal adiposity [-225.5 (-451.6, -2.5) mL], while in boys, longer sleep duration was associated with lower BMI [-1.6 (-3.2, -0.1) kg/m²] and total abdominal adiposity [-624.2 (-1225.6, -31.3) mL]. The isotemporal substitution model showed that replacing 30 min of LPA/SB with MVPA reduced BMI and abdominal circumference by 1-2% and MRI-measured abdominal adiposity by 6-9% in both sexes. However, replacing LPA/SB with sleep reduced BMI and abdominal circumference by 1% and MRI-measured adiposity by 3-6% only in boys, with no changes in girls. These associations were pronounced on visceral adiposity. This study highlights sex-specific associations of movement behaviours with adiposity in school-aged children, with stronger associations observed in MRI-derived measures compared to conventional adiposity indices. Replacing LPA/SB with MVPA reduced BMI and abdominal adiposity in both sexes, with particularly pronounced effects on visceral adiposity. However, sleep replacement benefits were observed only in boys, suggesting the need for gender-sensitive approaches in lifestyle interventions. Show less

Type 2 diabetes (T2D) is a complex metabolic disorder driven by genetic and environmental factors. While genome-wide association studies (GWAS) have identified numerous T2D-associated variants, many remain functionally uncharacterized. Integration of GWAS with molecular phenotyping offers a path to revealing biological relevance. We investigated the influence of GWAS-variants, including sub-threshold T2D-associated variants (GWAS p-value ≤ 0.0001), on gene and protein expression to assign functional relevance. Genetic variants associated with T2D in the GWAS Catalog and present in our whole-genome sequencing (WGS) data were used to perform expression quantitative trait loci (eQTL) analysis in 242 whole-blood mRNA-sequenced samples. The same variants were used to perform protein quantitative trait loci (pQTL) analysis in a set of 362 plasma samples profiled on the Olink platform. For each analysis, the datasets were randomly split into discovery and validation subsets. Associations between variants and mRNA or protein levels were tested by multiple linear regression, and only QTLs that reached a false discovery rate adjusted p-value ≤ 0.05 in the discovery dataset and replicated in the validation dataset (p ≤ 0.05) with same direction of effect were carried forward. QTL-linked mRNAs and proteins were subsequently evaluated for their relationship with T2D status to connect them with T2D pathophysiology. We identified 1,291 eQTLs linked to 97 mRNAs and 1,273 pQTLs linked to 22 proteins. Among these, 10 mRNAs and 5 proteins were differentially expressed between non-diabetic and diabetic individuals. Notably, LPL, APOBR, APOM (lipid metabolism), NOTCH2, TREH (β-cell/endocrine regulation), and HLA-A, OAS3 (immune response) converged on three biological axes central to T2D pathophysiology. The directionality of molecular effects was consistent with known disease mechanisms, including insulin resistance (LPL, APOBR), β-cell stress (TREH, NOTCH2), and chronic inflammation (OAS3). Our findings indicate that variants falling below conventional GWAS significance thresholds can have demonstrable effects on gene expression and protein levels. This underscores the importance of prioritizing biological relevance alongside statistical significance, rather than relying solely on rigid p-value cutoffs. Show less

Cognitive decline is a common aspect of aging, and identifying modifiable lifestyle factors, such as physical activity and sleep, is crucial for promoting healthy brain aging. While both are individually linked to cognition, few studies have simultaneously assessed their independent and combined effects using objective wearable-based data, particularly in older Asian populations. This study aimed to examine the independent and interactive effects of wearable-assessed sleep and physical activity parameters on memory performance in healthy older adults. We also explored whether age and hippocampal volume moderated these associations. This prospective cross-sectional analysis included 88 cognitively healthy community-dwelling adults (≥60 years of age) from the Integrating Systematic Data of Geriatric Medicine to Explore the Solution for Healthy Aging cohort in Taiwan. Participants underwent 12-day wrist-worn actigraphy, brain magnetic resonance imaging, and neuropsychological assessments. Light-intensity physical activity (LPA) and wake after sleep onset (WASO) were selected based on age-adjusted partial correlations with Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery memory scores. Multivariate regressions, age-stratified models (cutoff=72 years), and PROCESS moderation and mediation analyses were conducted, adjusting for age, education, daytime sleepiness, and hippocampal volume. Partial correlation analyses adjusting for age showed that higher LPA (r=0.260; P=.02) and lower WASO (r=-0.251; P=.02) were significantly associated with better memory scores. Age significantly moderated both effects: LPA was beneficial beyond 73.8 years of age, and WASO was detrimental beyond 71.1 years of age. Multivariate regression models confirmed that both WASO (β=-.044; P=.04) and LPA (β=.042; P=.01) were significant predictors of memory. In subgroup analyses (age ≥72 years), both LPA (β=.054; P=.04) and WASO (β=-.111; P=.01) remained significant predictors. Moderated mediation analyses showed that WASO was associated with reduced LPA (β=-.325; P=.03), but the indirect effect on memory via LPA was not significant. Instead, WASO exerted a direct and age-moderated effect on memory performance. Hippocampal volume moderated both associations, supporting the brain reserve hypothesis. Our findings highlight WASO and LPA, as measured by wearable devices, as modifiable behavioral factors linked to memory function in older adults. The impact of these factors intensifies with advancing age and may be influenced by hippocampal reserve. Promoting daily light physical activity and maintaining sleep continuity may serve as accessible, age-tailored strategies for preserving cognitive health in aging populations. ClinicalTrials.gov NCT04207502; https://classic.clinicaltrials.gov/ct2/show/NCT04207502. Show less

Autophagy selectively targets invading bacteria to defend cells, whereas bacterial pathogens counteract autophagy to survive in cells. The initiation of canonical autophagy involves the PIK3C3 complex, but autophagy targeting Group A Show less

Hand-foot syndrome (HFS) is a common adverse effect of capecitabine treatment. To compare the incidence and time to onset of grade 2 or greater HFS in patients receiving pyridoxine vs placebo and to identify biomarkers predictive of HFS. This single-center, randomized double-blind, placebo-controlled phase 3 trial conducted at National Cancer Centre Singapore assessed whether oral pyridoxine could prevent the onset of grade 2 or higher HFS in 210 patients scheduled to receive single-agent capecitabine chemotherapy for breast, colorectal, and other cancers. Patients were randomized to receive concurrent pyridoxine (200 mg) or placebo daily for a maximum of 8 cycles of capecitabine, with stratification by sex and use in adjuvant or neoadjuvant vs palliative setting. Patients were withdrawn from the study on development of grade 2 or higher HFS or cessation of capecitabine. Primary end point was the incidence of grade 2 or higher HFS in patients receiving pyridoxine. Secondary end points included the time to onset (days) of grade 2 or higher HFS and identification of biomarkers predictive of HFS, including baseline folate and vitamin B12 levels, as well as genetic polymorphisms with genome-wide arrays. In this cohort of 210 patients (median [range] age, 58 [26-82] years; 162 women) grade 2 or higher HFS occurred in 33 patients (31.4%) in the pyridoxine arm vs 39 patients (37.1%) in the placebo arm (P = .38). The median time to onset of grade 2 or higher HFS was not reached in both arms. In univariate analysis, the starting dose of capecitabine (odds ratio [OR], 1.99; 95% CI, 1.32-3.00; P = .001), serum folate levels (OR, 1.27; 95% CI, 1.10-1.47; P = .001), and red blood cell folate levels (OR, 1.25; 95% CI, 1.08-1.44; P = .003) were associated with increased risk of grade 2 or higher HFS. In multivariate analyses, serum folate (OR, 1.30; 95% CI, 1.12-1.52; P < .001) and red blood cell folate (OR, 1.28; 95% CI, 1.10-1.49; P = .001) were the only significant predictors of grade 2 or higher HFS. Grade 2 or higher HFS was associated with 300 DNA variants at genome-wide significance (P < 5 × 10-8), including a novel DPYD variant (rs75267292; P = 1.57 × 10-10), and variants in the MACF1 (rs183324967, P = 4.80 × 10-11; rs148221738, P = 5.73 × 10-10) and SPRY2 (rs117876855, P < 1.01 × 10-8; rs139544515, P = 1.30 × 10-8) genes involved in wound healing. Pyridoxine did not significantly prevent or delay the onset of grade 2 or higher HFS. Serum and red blood cell folate levels are independent predictors of HFS. clinicaltrials.gov Identifier: NCT00486213. Show less

The molecular basis by which proteins are transported along cytoskeletal tracts from the trans-Golgi network (TGN) to the cell periphery remains poorly understood. Previously, using human autoimmune sera, we identified and characterized a TGN protein, p230/Golgin-245, an extensively coiled-coil protein with flexible amino- and carboxyl-terminal ends, that is anchored to TGN membranes and TGN-derived vesicles by its carboxyl-terminal GRIP domain. To identify molecules that interact with the flexible amino-terminal end of p230, we used this domain as bait to screen a human brain cDNA library in a yeast two-hybrid assay. We found that this domain interacts with the carboxyl-terminal domain of MACF1, a protein that cross-links microtubules to the actin cytoskeleton. The interaction was confirmed by co-immunoprecipitation, an in vitro binding assay, double immunofluorescence images demonstrating overlapped localization in HeLa cells, and co-localization of FLAG-tagged constructs containing the interacting domains of these two proteins with their endogenous partners. Expression in HeLa cells of FLAG-tagged constructs containing the interacting domains of p230 and MACF1 disrupted transport of the glycosyl phosphatidyl inositol-anchored marker protein conjugated with yellow fluorescent protein (YFP-SP-GPI), while trafficking of the transmembrane marker protein, vesicular stomatitis virus glycoprotein conjugated with YFP (VSVG3-GL-YFP), was unaffected. Our results suggest that p230, through its interaction with MACF1, provides the molecular link for transport of GPI-anchored proteins along the microtubule and actin cytoskeleton from the TGN to the cell periphery. Show less