Metformin Promotes Antitumor Immunity via Endoplasmic-Reticulum-Associated Degradation of PD-L1.

Metformin has been reported to possess antitumor activity and maintain high cytotoxic T lymphocyte (CTL) immune surveillance. However, the functions and detailed mechanisms of metformin's role in cancer immunity are not fully understood. Here, we show that metformin increases CTL activity by reducing the stability and membrane localization of programmed death ligand-1 (PD-L1). Furthermore, we discover that AMP-activated protein kinase (AMPK) activated by metformin directly phosphorylates S195 of PD-L1. S195 phosphorylation induces abnormal PD-L1 glycosylation, resulting in its ER accumulation and ER-associated protein degradation (ERAD). Consistently, tumor tissues from metformin-treated breast cancer patients exhibit reduced PD-L1 levels with AMPK activation. Blocking the inhibitory signal of PD-L1 by metformin enhances CTL activity against cancer cells. Our findings identify a new regulatory mechanism of PD-L1 expression through the ERAD pathway and suggest that the metformin-CTLA4 blockade combination has the potential to increase the efficacy of immunotherapy.

Multigenerational adversity impacts on human gut microbiome composition and socioemotional functioning in early childhood.

Adversity exposures in the prenatal and postnatal period are associated with an increased risk for psychopathology, which can be perpetuated across generations. Nonhuman animal research highlights the gut microbiome as a putative biological mechanism underlying such generational risks. In a sample of 450 mother-child dyads living in Singapore, we examined associations between three distinct adversity exposures experienced across two generations-maternal childhood maltreatment, maternal prenatal anxiety, and second-generation children's exposure to stressful life events-and the gut microbiome composition of second-generation children at 2 y of age. We found distinct differences in gut microbiome profiles linked to each adversity exposure, as well as some nonaffected microbiome features (e.g., beta diversity). Remarkably, some of the microbial taxa associated with concurrent and prospective child socioemotional functioning shared overlapping putative functions with those affected by adversity, suggesting that the intergenerational transmission of adversity may have a lasting impact on children's mental health via alterations to gut microbiome functions. Our findings open up a new avenue of research into the underlying mechanisms of intergenerational transmission of mental health risks and the potential of the gut microbiome as a target for intervention.

Trajectories of lifestyle patterns from 2 to 8 years of age and cardiometabolic risk in children: the GUSTO study.

BACKGROUND: Tracking combinations of lifestyle behaviours during childhood ("lifestyle pattern trajectories") can identify subgroups of children that might benefit from lifestyle interventions aiming to improve health outcomes later in life. However, studies on the critical transition period from early to middle childhood are limited. We aimed to describe lifestyle patterns trajectories in children from 2 to 8 years of age and evaluated their associations with cardiometabolic risk markers at age 8 years in a multi-ethnic Asian cohort. METHODS: Twelve lifestyle behaviours related to child's diet, physical activity, screen use, and sleep were ascertained using questionnaires at ages 2, 5, and 8 years. Age-specific lifestyle patterns were derived using principal component analysis and trajectories were determined using group-based multi-trajectory modelling. Child cardiometabolic risk markers were assessed at age 8 years, and associations with trajectories examined using multiple regression, adjusted for confounders. RESULTS: Among 546 children, two lifestyle patterns "healthy" and "unhealthy" were observed at ages 2, 5, and 8 years separately. Three trajectory groups from 2 to 8 years were identified: consistently healthy (11%), consistently unhealthy (18%), and mixed pattern (71%). Children in the consistently unhealthy group (vs. mixed pattern) had increased odds of pre-hypertension (OR = 2.96 [95% CI 1.18-7.41]) and higher levels of diastolic blood pressure (ß = 1.91 [0.27-3.55] mmHg), homeostasis model assessment of insulin resistance (ß = 0.43 [0.13-0.74]), triglycerides (ß = 0.11 [0.00-0.22] mmol/L), and metabolic syndrome score (ß = 0.85 [0.20-1.49]), but not with BMI z-score or any anthropometric measurements. The consistently healthy group showed no differences in cardiometabolic outcomes compared to the mixed pattern group. CONCLUSION: Three distinct lifestyle pattern trajectories were identified from early to middle childhood. Children in the consistently unhealthy lifestyle group did not have a raised BMI but was associated with several elevated cardiometabolic risk markers. These findings suggest the potential benefits of initiating holistic lifestyle interventions to improve children's health and well-being from an early age. TRIAL REGISTRATION: Trial registration number: NCT01174875. Name of registry: ClinicalTrials.gov. URL of registry: https://classic. CLINICALTRIALS: gov/ct2/show/NCT01174875 . Date of registration: August 4, 2010. Date of enrolment of the first participant to the trial: June 2009.

Efficacy and Safety of Avapritinib in Treating Unresectable or Metastatic Gastrointestinal Stromal Tumors: A Phase I/II, Open-Label, Multicenter Study.

BACKGROUND: Avapritinib is a type 1 kinase inhibitor designed to potently and selectively inhibit oncogenic KIT/PDGFRA mutants by targeting the kinase active conformation. This multicenter, single-arm, open-label, phase I/II bridging study of NAVIGATOR in Chinese patients evaluated the safety and the antineoplastic activity of avapritinib in Chinese patients with unresectable/metastatic gastrointestinal stromal tumors (GIST). METHODS: Phase I comprised dose escalation for safety and phase II dose determination. Phase II comprised dose expansion for safety/efficacy evaluations in patients with PDGFRA D842V mutations or patients having received at least 3 lines of therapy without PDGFRA D842V mutations. The primary endpoints were recommended phase II dose, safety, and Independent Radiology Review Committee (IRRC)-assessed objective response rate (ORR). RESULTS: No dose-limiting toxicities occurred (n = 10); the recommended phase II dose was avapritinib 300 mg once daily orally. Fifty-nine patients initially received avapritinib 300 mg. Common grade ≥3 treatment-related adverse events were anemia, decreased white blood cell count, increased blood bilirubin levels, and decreased neutrophil count. In patients with PDGFRA D842V mutations, IRRC- and investigator-assessed ORRs were 75% and 79%, respectively; clinical benefit rates were both 86%. Median duration of response/progression-free survival were not reached. IRCC- and investigator-assessed ORRs in patients in the fourth- or later-line setting were 22% and 35%, respectively. Median progression-free survivals were 5.6 months for both. Overall survival data were immature and not calculated. CONCLUSION: Avapritinib was generally well tolerated and showed marked anti-tumor activity in Chinese patients with GIST bearing PDGFRA D842V mutations and notable efficacy as fourth- or later-line monotherapy (ClinicalTrials.gov Identifier: NCT04254939).

ALKBH5-mediated CHAC1 depletion promotes malignant progression and decreases cisplatin-induced oxidative stress in gastric cancer.

The m6a demethyltransferase ALKBH5 dynamically modulates gene expression and intracellular metabolic molecules by modifying RNA m6a in cancer cells. However, ALKBH5's function in gastric cancer (GC) has remained controversial. This study demonstrates that ALKBH5 is highly expressed in GC. Silencing ALKBH5 hampers proliferation, and metastatic potential, and induces cell death in GC cells. Through a comprehensive analysis of the transcriptome and m6A sequencing, alterations in certain ALKBH5 target genes, including CHAC1, were identified. ALKBH5's demethylation effect regulates CHAC1 RNA stability, leading to reduced CHAC1 expression. Moreover, CHAC1 modulates intracellular ROS levels, influencing the chemotherapy sensitivity of gastric cancer. In summary, our study unveils the pivotal role of the ALKBH5-CHAC1-ROS axis and highlights the significance of m6A methylation in gastric cancer.

Mid-pregnancy and postpartum maternal mental health and infant sleep in the first year of life.

Perinatal depression and anxiety are common and associated with sleep problems in the offspring. Depression and anxiety are commonly comorbid, yet often studied independently. Our study used an integrative measure of anxiety and depressive symptoms to examine the associations of maternal mental health (mid-pregnancy and postnatal) with infant sleep during the first year of life. A total of 797 mother-child dyads from the 'Growing Up in Singapore Towards healthy Outcome' cohort study provided infant sleep data at 3, 6, 9 and 12 months of age, using the caregiver reported Brief Infant Sleep Questionnaire. Maternal mental health was assessed at 26-28 weeks gestation and 3 months postpartum using the Edinburgh Postnatal Depression Scale, Beck Depression Inventory and State-Trait Anxiety Inventory. Bifactor modelling with the individual questionnaire items produced a general affect factor score that provided an integrated measure of anxiety and depressive symptoms. Linear mixed models were used to model the sleep outcomes, with adjustment for maternal age, education, parity, ethnicity, sex of the child and maternal sleep quality concurrent with maternal mental health assessment. We found that poorer mid-pregnancy, but not postpartum, maternal mental health was associated with longer wake after sleep onset duration across the first year of life (ß = 49, 95% confidence interval 13-85 min). Poor maternal mental health during mid-pregnancy is linked to longer period of night awakening in the offspring during infancy. Interventions that aim to improve maternal antenatal mental health should examine infant sleep outcomes.

Nutrient trajectories during infancy and their associations with childhood neurodevelopment.

PURPOSE: To examine the associations between infants' dietary nutrient trajectories and subsequent neurodevelopment during childhood in the Growing Up in Singapore Towards healthy Outcomes study. METHODS: One-day food records were collected at ages 6, 9 and 12 months, whilst Bayley Scales of Infant and Toddler Development-III and Kaufman Brief Intelligence Test-2 were conducted at ages 24 and 54 months respectively. Nutrient trajectories were constructed using multi-level mixed modelling and associations with neurodevelopment (24 months: n = 484; 54 months: n = 444) were examined using adjusted multivariable linear regression. RESULTS: At age 24 months, higher protein intake (at 6 months) and increasing rate of intake (from 6 to 12 months) were associated with higher fine motor score [ß = 0.17 SD (95% CI 0.03, 0.31) and 0.62 SD (0.10, 1.14) respectively]. Higher fat intake was associated with higher receptive language score [0.04 SD (0.003, 0.07)], but increasing rate of intake was associated with lower expressive language [- 0.20 SD (- 0.39, - 0.01)] and fine motor [- 0.29 SD (- 0.48, - 0.10)] scores. Higher carbohydrate intake was associated with lower gross motor score [- 0.07 SD (- 0.14, - 0.005)], but increasing rate of intake was associated with higher receptive language [0.44 SD (0.08, 0.81)] and fine motor [0.56 SD (0.18, 0.93)] scores. Increasing rate of dietary fibre intake was associated with higher fine motor scores [0.63 SD (0.16, 1.10)]. No significant associations were observed with neurodevelopment at 54 months. CONCLUSION: Our findings provide greater understanding of how nutrition over time could have varying effects on child neurodevelopment.

Single-cell RNA-seq dissecting heterogeneity of tumor cells and comprehensive dynamics in tumor microenvironment during lymph nodes metastasis in gastric cancer.

Lymph node metastasis is the common metastasis route of gastric cancer. However, until now, heterogeneities of tumor cells and tumor microenvironment in primary tumors (PT) and metastatic lymph nodes (MLN) of gastric cancer (GC) remains uncharacterized. In our study, single cell RNA sequencing was performed on tissues from PT and MLN of gastric cancer. Trajectory analysis and function enrichment analyses were conducted to decode the underlying mechanisms contributing to LN metastasis of gastric cancer. Heterogeneous composition of immune cells and distinct intercellular interactions in PT and MLN were analyzed. Based on the generated single cell transcriptome profiles, dynamics of gene expressions in cancer cells between PT and MLN were characterized. Moreover, we reconstructed the developmental trajectory of GC cells' metastasis to LN and identified two subtypes of GC cells with distinct potentials of having malignant biological behaviors. We characterized the repression of neutrophil polarization associated genes, like LCN2, which would contribute to LN metastasis, and histochemistry experiments validated our findings. Additionally, heterogeneity in neutrophils, rather than macrophages, was characterized. Immune checkpoint associated interaction of SPP1 was found active in MLN. In conclusion, we decode the dynamics of tumor cells during LN metastasis in GC and to identify a subtype of GC cells with potentials of LN metastasis. Our data indicated that the disordering the neutrophils polarization and maturation and the activation of immune checkpoint SPP1 might contribute to LN metastasis in GC, providing a novel insight on the mechanism and potential therapeutic targets of LN metastasis in GC.

Family-focused contextual factors associated with lifestyle patterns in young children from two mother-offspring cohorts: GUSTO and EDEN.

BACKGROUND: Integrated patterns of energy balance-related behaviours of preschool children in Asia are sparse, with few comparative analyses. PURPOSE: Using cohorts in Singapore (GUSTO) and France (EDEN), we characterized lifestyle patterns of children and investigated their associations with family-focused contextual factors. METHODS: Ten behavioural variables related to child's diet, walking, outdoor play and screen time were ascertained by parental questionnaires at age 5-6 years. Using principal component analysis, sex-specific lifestyle patterns were derived independently for 630 GUSTO and 989 EDEN children. Contextual variables were organised into distal (family socio-economics, demographics), intermediate (parental health, lifestyle habits) and proximal (parent-child interaction factors) levels of influence and analysed with hierarchical linear regression. RESULTS: Three broadly similar lifestyle patterns were identified in both cohorts: "discretionary consumption and high screen time", "fruit, vegetables, and low screen time" and "high outdoor playtime and walking". The latter two patterns showed small differences between cohorts and sexes. The "discretionary consumption and high screen time" pattern was consistently similar in both cohorts; distal associated factors were lower maternal education (EDEN boys), no younger siblings (GUSTO boys) and Malay/Indian ethnicity (GUSTO), while intermediate and proximal associated factors in both cohorts and sexes were poor maternal diets during pregnancy, parents allowing high child control over food intake, snacking between meals and having television on while eating. CONCLUSIONS: Three similar lifestyle patterns were observed among preschool children in Singapore and France. There were more common associated proximal factors than distal ones. Cohort specific family-focused contextual factors likely reflect differences in social and cultural settings. Findings will aid development of strategies to improve child health.