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Adaptive proteomic remodeling and eNOS upregulation in luminal endothelium and perivascular adipose tissue of patent saphenous vein grafts after CABG.

OBJECTIVE: Long-term patency of saphenous vein grafts (SVGs) remains a significant challenge in coronary artery bypass grafting (CABG). The biological factors underlying successful human grafts are poorly understood. We aimed to characterize the structural and molecular features associated with successful graft function. METHODS: Patent and occluded SVG and internal thoracic artery (ITA) grafts were obtained from explanted hearts of CABG patients undergoing heart transplantation for end-stage heart failure not attributable to graft failure, along with freshly harvested ITA and SVG controls. Samples underwent histomorphological analysis, immunohistochemistry (IHC), and liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics. RESULTS: Patent ITA (ITA-P) showed minimal intimal hyperplasia with medial reinforcement, whereas patent SVGs (SVG-P) had organized, α-smooth muscle actin (αSMA)-positive myofibroblast-rich neointima. Endothelial nitric oxide synthase (eNOS) was markedly upregulated in patent grafts at two sites-the luminal endothelium and adventitial microvessels within perivascular adipose tissue (PVAT)-and lost at both sites in occluded SVG (SVG-O). Adventitial CD31-positive microvessels were significantly increased in patent grafts. Proteomically, ITA-P and SVG-P shared a largely common adaptive proteome enriched in translation, RNA processing, and extracellular matrix (ECM) organization, with shared upstream activation of NR4A3, EGFR, and STAT1, and conduit-specific signatures (IGF-1/RUNX2 in ITA-P; RETN/SRC/PTGES in SVG-P). PTGES was strongly expressed in the adventitia of SVG-P. CONCLUSIONS: Patent arterial and venous bypass grafts exhibited a shared adaptive phenotype characterized by dual-site upregulation of eNOS in both the luminal endothelium and the perivascular microvessels/PVAT. In SVG-P, PTGES was co-upregulated alongside eNOS, indicating a mechanistic link between the proteomic and IHC findings. These findings highlight the perivascular compartment as a site of adaptive, eNOS-associated changes in patent vein grafts.

Humans↗

Upregulation versus loss of function of NTRK2 in 44 affected individuals leads to 2 distinct neurodevelopmental disorders.

PURPOSE: Heterozygous pathogenic variants in NTRK2 (HGNC: 8032) have been associated with global developmental delay. However, only scattered cases have been described in small or general studies. The aim of our work was to consolidate our understanding of NTRK2-related disorders and to delineate the clinical presentation. METHODS: We reported an extended cohort of 44 affected individuals, of whom 19 are from the literature and 25 were previously unreported. RESULTS: Our analysis led to splitting the cohort into 2 entities. CONCLUSION: One group had variants in the cholesterol-binding motif of the transmembrane domain, with most of these being the recurrent variant c.1301A>G p.(Tyr434Cys). These variants probably lead to upregulation of tropomyosin receptor kinase B activity and to a severe phenotype of developmental delay/intellectual disability, muscular hypotonia, therapy-refractory epilepsy, visual impairment and blindness, and feeding difficulties. The second group had truncating variants or variants that presumably disturb the 3D structure of the protein leading to loss of function. These individuals had a remarkably milder phenotype of developmental delay, obesity, and hyperphagia.

Humans↗

IGF2BP1-Mediated m⁶A Modification Stabilizes HMGA2 mRNA to Promote Intrahepatic Cholangiocarcinoma Progression.

BACKGROUND & AIMS: Intrahepatic cholangiocarcinoma (iCCA) remains a lethal malignancy with a lack of effective therapies, underscoring the critical need to identify novel therapeutic targets. The high-mobility group protein A2 (HMGA2) is an oncogenic architectural transcription factor aberrantly overexpressed in multiple cancers; yet its function and regulatory mechanisms in iCCA are poorly defined. This study aimed to elucidate the clinical significance and molecular mechanism of HMGA2 in iCCA progression. METHODS: We integrated analyses across 4 independent iCCA cohorts (The Cancer Genome Atlas, 2 Zhongshan Hospital cohorts, and our 192-patient institutional cohort). Functional investigations were conducted using iCCA cell lines and multiple mouse models, including xenograft, syngeneic, YAP/AKT-driven spontaneous iCCA, and metastasis models. RESULTS: We demonstrated that HMGA2 was significantly upregulated in iCCA, correlating with poor survival, and exhibited sexually dimorphic prognostic effects with a female-specific link to perineural invasion. Functionally, HMGA2 depletion suppressed iCCA cell proliferation, migration, in vivo tumor growth and metastasis. Mechanistically, HMGA2 expression was positively regulated by the N6-methyladenosine reader insulin-like growth factor 2 messenger RNA-binding protein 1 (IGF2BP1), which directly bound to and stabilized HMGA2 messenger RNA via its KH3-4 domains in an N6-methyladenosine-dependent manner. High IGF2BP1 expression predicted poor iCCA prognosis, was required for HMGA2-driven progression, and the axis promoted PI3K-AKT pathway activation. CONCLUSIONS: Our results reveal a critical role for the IGF2BP1-HMGA2 axis in iCCA pathogenesis, thereby highlighting its potential as a therapeutic target.

Cholangiocarcinoma↗

miR-503-3p promotes epithelial-mesenchymal transition in breast cancer by directly targeting SMAD2 and E-cadherin.

Although progress in clinical and basic research has significantly increased our understanding of breast cancer, little is known about the molecular mechanism underlying breast cancer metastasis. Identification of effective therapeutic targets to prevent breast cancer metastasis is urgently needed. The function of miR-503-3p has been investigated in other cancers, but its role in breast cancer remains undefined. Here, we found that miR-503-3p was overexpressed in breast cancer tissue and plasma compared with adjacent normal breast tissue and with plasma from healthy individuals. Moreover, we identified miR-503-3p to be an oncogene of breast cancer cell proliferation, migration and invasion. Upregulation of miR-503-3p in breast cancer cells inhibited expression of epithelial-mesenchymal transition (EMT)-related protein SMAD2 and the epithelial marker protein E-cadherin by directly binding to their mRNA 3' untranslated region, whereas increased expression of mesenchymal marker proteins, including vimentin and N-cadherin. Taken together, our findings support a critical role for miR-503-3p in induction of breast cancer EMT and suggest that plasma miR-503-3p may be a useful diagnostic biomarker for breast cancer.

Base Sequence↗

Low-Grade Myofibroblastic Sarcoma Represents an Epigenetically Distinct Myofibroblastic Tumor With USP6 Upregulation and Stable Genome.

Low-grade myofibroblastic sarcoma (LGMS) is a rare, indolent mesenchymal neoplasm exhibiting myofibroblastic differentiation, with a propensity for local recurrence. The molecular basis of LGMS and its precise relationship with other histological mimics have remained largely undefined. To address this gap, we conducted the first comprehensive multiomics analysis of 6 LGMS cases, integrating whole-exome sequencing, RNA sequencing, and Illumina Methylation EPICv2 array profiling with comparative analysis against public sarcoma methylation cohorts and related fibroblastic tumors. Clinically, patients (median age 35.5 years) presented with small tumors (median size 1.45 cm), predominantly located in the head and neck, displaying classic histological features of diffusely infiltrative spindle cell fascicles with patchy mononuclear inflammation. Two of the 5 patients with follow-up developed local recurrence, and none metastasized (median follow-up duration 92.5 months). Genomically, all LGMS exhibited a low tumor mutational burden (median 2.31 mut/Mb) and a minimal fraction of genome altered, with TP53 and TSC2 deletions and NTRK1 and ERBB3 amplifications found in a subset of cases. No pathogenic fusions were detected. Transcriptomic profiling revealed a distinct signature featuring prominent USP6 overexpression and upregulation of inflammatory and immune-related genes, including CD274 (PD-L1), and enrichment of inflammatory and interferon-gamma response signatures. Epigenetically, LGMS formed a unique methylation cluster closest to inflammatory myofibroblastic tumor, with numerous differentially methylated regions and higher immune infiltration, particularly monocytes, compared with other fibroblastic tumors. These findings establish LGMS as a genomically stable, epigenetically distinct myofibroblastic sarcoma driven by USP6 overexpression and an inflammation-enriched transcriptome. They support its recognition as a standalone entity, facilitate integration into methylation-based sarcoma classifiers for improved diagnostic precision, and nominate USP6-associated pathways and immune checkpoint blockade as promising therapeutic strategies for recurrent or unresectable disease.

Humans↗

Neuropilin-2 upregulation by stromal TGFβ1 induces lung disseminated tumor cells dormancy escape and promotes metastasis outgrowth.

Metastasis is the main cause of death from solid tumors. Therefore, identifying the mechanisms that govern metastatic growth poses a major biomedical challenge. Tumor microenvironment signals regulate the fate and survival of disseminated tumor cells (DTCs) in secondary organs. However, very little is known about the role of nervous system mediators in this process. We have previously reported that neuropilin-2 (NRP2) expression in breast cancer correlates with poor prognosis. Here, we show that NRP2 positively regulates the proliferation, invasion, and survival of breast and head and neck cancer cells in vitro. NRP2 deletion in tumor cells inhibits tumor growth in vivo and decreases the number and size of lung metastases by promoting lung DTCs quiescence. NRP2 deletion upregulates dormancy and cell cycle regulators expression and promotes DTCs reprograming into quiescence. Moreover, lung fibroblasts and macrophages induce NRP2 upregulation in DTCs through the secretion of TGFβ1. NRP2 facilitates lung DTC interaction with the extracellular matrix and promotes lung DTCs activation and metastasis. Therefore, we conclude that the TGFβ1-NRP2 axis is a new key dormancy-awakening inducer that promotes DTCs proliferation and lung metastasis development.

Neuropilin-2↗

Upregulation of Endogenous Serine Proteinases by SVMPs Contributes to Muscle Damage Induced by Bothrops atrox Venom.

In Brazil, approximately 25,000 snakebites occur annually, with Bothrops atrox responsible for most cases. Local morbidity is high, driven primarily by snake venom metalloproteases (SVMPs). The major SVMPs in B. atrox venom, Atroxlysin-Ia (ATXL) and Batroxrhagin (BATX), efficiently hydrolyze extracellular matrix proteins, inducing rapid hemorrhage and dermonecrosis. Thus, we characterized the composition of the exudate produced after SVMPs injection into the mice gastrocnemius muscle using proteomics. Muscle damage was evaluated by histological analysis. The composition of the exudate was analyzed by mass spectrometry. The SVMPs induced disorganization of muscle fibers and inflammatory cell migration. However, ATXL-induced a significantly higher neutrophil influx compared to BATX, likely triggered by an increase in CXCL16, suggesting a superior inflammatory capacity. In summary, despite being metalloproteases, these toxins exhibit distinct pathological profiles: ATXL is predominantly inflammatory, while BATX is more hemorrhagic. Interestingly, while endogenous serine proteinase levels were similar in both exudates, BATX showed significantly higher levels of proteinase inhibitors. Furthermore, identification of peptide bond cleavage sites revealed a pattern consistent with trypsin-like serine proteinases. These findings suggest that SVMPs not only damage tissue directly but also associate with the activation of host endogenous proteinases, which may contribute to the complex pathology of B. atrox envenomation, although direct causation remains to be established.

Animals↗

Jarid2 is induced by TCR signalling and controls iNKT cell maturation.

Jarid2 is a reported component of three lysine methyltransferase complexes, polycomb repressive complex 2 (PRC2) that methylates histone 3 lysine 27 (H3K27), and GLP-G9a and SETDB1 complexes that methylate H3K9. Here we show that Jarid2 is upregulated upon TCR stimulation and during positive selection in the thymus. Mice lacking Jarid2 in T cells display an increase in the frequency of IL-4-producing promyelocytic leukemia zinc finger (PLZF)(hi) immature invariant natural killer T (iNKT) cells and innate-like CD8(+) cells; Itk-deficient mice, which have a similar increase of innate-like CD8(+) cells, show blunted upregulation of Jarid2 during positive selection. Jarid2 binds to the Zbtb16 locus, which encodes PLZF, and thymocytes lacking Jarid2 show increased PLZF and decreased H3K9me3 levels. Jarid2-deficient iNKT cells perturb Th17 differentiation, leading to reduced Th17-driven autoimmune pathology. Our results establish Jarid2 as a novel player in iNKT cell maturation that regulates PLZF expression by modulating H3K9 methylation.

Animals↗

Modulating the PPARγ pathway upregulates NECTIN4 and enhances chimeric antigen receptor (CAR) T cell therapy in bladder cancer.

With the approval of the antibody-drug conjugate enfortumab vedotin (EV), NECTIN4 has emerged as a bona fide therapeutic target in urothelial carcinoma (UC). Here, we report the development of a NECTIN4-directed chimeric antigen receptor (CAR) T cell, which exhibits reactivity across cells expressing a range of endogenous NECTIN4, with enhanced activity in high expressors. We demonstrate that the PPARγ pathway, critical for luminal differentiation, transcriptionally controls NECTIN4, and that the PPARγ agonist rosiglitazone primes and augments NECTIN4 expression, thereby increasing sensitivity to NECTIN4-CAR T cell-mediated killing. NECTIN4-CAR T cells have potent anti-tumor activity even against EV resistant cells, which largely retain NECTIN4 expression, including in a post-EV biopsy cohort. Our results elucidate a therapeutically actionable mechanism that UC cells use to control NECTIN4 expression and suggest therapeutic approaches that leverage PPARγ agonists for rational combinations with NECTIN4-targeting agents in UC, as well as future potential treatment options for EV-refractory patients.

Humans↗

COXFA4L2 upregulation preserves residual cytochrome c oxidase activity in COXFA4-related Leigh-like encephalopathy.

Primary mitochondrial diseases (PMDs) affect approximately 1 in 4300 individuals and cause early-onset neuromuscular and multisystem dysfunction with reduced lifespan. They result from pathogenic variants in mitochondrial or nuclear DNA that impair oxidative phosphorylation. Cytochrome c oxidase (COX; complex IV) deficiency is a well-established cause of PMD, leading to a broad spectrum of phenotypes. COXFA4 (cytochrome c oxidase subunit FA4), formerly NDUFA4, is a nuclear-encoded COX subunit, but its role in disease remains poorly defined. We report the largest genetically confirmed cohort of COXFA4-related PMD to date, comprising 13 individuals from 12 families with biallelic pathogenic COXFA4 variants. All present with Leigh-like encephalopathy and complete loss of COXFA4 protein; however, patient-derived fibroblasts retain residual COX activity, with upregulation of COXFA4L2 (cytochrome c oxidase subunit FA4-like 2), a poorly characterised paralog. Here, we show that COXFA4 is a late-stage COX assembly subunit and identify a paralog-mediated compensatory mechanism with translational potential.

Humans↗

PPRC1 is a prognostic biomarker and key regulator of mitochondrial oxidative phosphorylation in multiple myeloma.

BACKGROUND: Multiple myeloma (MM) remains an incurable haematological malignancy, underscoring the need for novel prognostic biomarkers and therapeutic targets. This study aimed to investigate the clinical and biological significance of peroxisome proliferator-activated receptor gamma coactivator-related protein 1 (PPRC1) in MM. METHODS: Expression and clinical data were obtained from public databases and an independent local cohort. Kaplan-Meier and Cox regression analyses were performed to evaluate prognostic value. Differential expression analysis, pathway enrichment analysis and single-cell RNA-seq data analysis were used to explore biological functions. PPRC1 was silenced in MM cell lines using siRNA to assess its effects on cell survival and oxidative phosphorylation. RESULTS: PPRC1 was significantly upregulated in MM and was associated with advanced disease stage and poor overall survival. Multivariate Cox analysis identified PPRC1 as an independent prognostic factor. A nomogram incorporating PPRC1 and revised-ISS improved survival prediction. Functional analyses revealed that PPRC1 was positively correlated with oxidative phosphorylation and oncogenic signalling pathways. A potential connection between PPRC1 expression and immune cell infiltration was observed. PPRC1 knockdown inhibited cell proliferation, induced cell cycle arrest and apoptosis and impaired oxidative phosphorylation in MM. CONCLUSIONS: PPRC1 acts as a prognostic biomarker and metabolic regulator in MM by sustaining mitochondrial oxidative phosphorylation. These findings highlight PPRC1 as a potential therapeutic target in MM.

Humans↗

TMEM176B is co-expressed with TMEM176A and upregulated in peripheral blood monocytes of patients with primary Sjögren's syndrome.

OBJECTIVES: This study aims to determine the role of acid‑sensitive nonspecific cation channels transmembrane protein 176A (TMEM176A) and TMEM176B in autoimmune diseases, with a focus on primary Sjögren's Syndrome (pSS). METHODS: We examined the expression patterns of TMEM176A and TMEM176B across tissues and cells utilizing bulk RNA-seq and scRNA-seq datasets. Immunophenotyping analysis was performed by flow cytometry to compare CD62L expression between TMEM176B⁺ and TMEM176B⁻ monocytes. The proportion of TMEM176B+ cells in monocytes was interrogated in both pSS patients and healthy controls. Clinical correlations of TMEM176B with anti‑SSB antibody and complement C4 levels were also evaluated. RESULTS: TMEM176A and TMEM176B showed conserved co‑expression and were significantly upregulated in autoimmune diseases. TMEM176B⁺ monocytes displayed higher CD62L positivity rate than TMEM176B- monocytes. In pSS patients, the proportion of TMEM176B⁺ monocytes was elevated in total monocytes, classical monocytes (cMo) and intermediate monocytes (iMo). The proportion of TMEM176B+ monocytes positively correlated with anti‑SSB levels, while several TMEM176B-associated monocyte subset markers inversely correlated with C4. CONCLUSION: TMEM176A and TMEM176B are highly correlated. TMEM176B expression in monocytes is linked to pSS and may serve as a novel auxiliary diagnostic biomarker.

Humans↗

Rice ETHYLENE RESPONSE FACTOR 101 increases leaf angle by upregulating BRASSINOSTEROID UPREGULATED 1.

The leaf angle (LA) is a critical component of plant architecture that directly influences photosynthetic efficiency and grain yield. In the present study, we found that ETHYLENE RESPONSE FACTOR 101 (OsERF101), an APETALA2/ethylene response factor, plays a role in LA formation. A null mutation in OsERF101 resulted in reduced LA, whereas transgenic plants overexpressing OsERF101 (OsERF101-OEs) exhibited increased LA. OsERF101 increased the development of the adaxial lamina joint (LJ). Transactivation assays and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis indicated that OsERF101 activated BRASSINOSTEROID UPREGULATED 1 (OsBU1) transcription by directly binding to its promoter. However, OsERF101 expression was suppressed by exogenous brassinosteroid (BR) treatment and elevated endogenous brassinolide (BL) levels during LJ development. Additionally, OsERF101 downregulated the expression of BR biosynthesis genes, including Brassinosteroid-deficient dwarf2 (OsBRD2) and CYP90B2/OsDWARF4, leading to reduced levels of endogenous BL, the most active BR, in OsERF101-OEs. These findings suggested that OsERF101 mediates a negative feedback loop that balances endogenous BR levels and signaling. Collectively, rice plants have evolved diverse regulatory mechanisms involving OsERF101 to tune LA formation and optimize plant architecture finely.

Oryza↗

Integrative Pan-Cancer Characterization of lncRNA UPK1A-AS1 and Its Role in Hypoxia-Associated Sorafenib Resistance in Hepatocellular Carcinoma.

Long noncoding RNAs (lncRNAs) are emerging as critical regulators of tumor initiation and progression through transcriptional and posttranscriptional mechanisms. UPK1A antisense RNA 1 (UPK1A-AS1), a cancer-associated lncRNA, has been reported to participate in oncogenic processes; however, its overall landscape across human malignancies and its biological role in therapy resistance remain poorly understood. Given the increasing importance of identifying functional lncRNAs with prognostic and therapeutic potential, this study presents a comprehensive multiomics characterization of UPK1A-AS1 and its experimental validation in hepatocellular carcinoma (HCC). We integrated datasets from The Cancer Genome Atlas (TCGA), the Genotype-Tissue Expression Project (GTEx), the cancer immunology data engine (CIDE), and the cBioPortal for cancer genomics (cBioPortal) to systematically assess its expression pattern, genomic alterations, clinical significance, and immunological associations. Our analyses revealed that UPK1A-AS1 is significantly upregulated in multiple tumor types, with copy-number amplification as the predominant genomic alteration driving its overexpression. Elevated UPK1A-AS1 expression was correlated with advanced disease stage, poor differentiation, immune exclusion, and unfavorable prognosis, supporting its potential as a cancer type-dependent biomarker. In parallel, functional studies demonstrated that hypoxia transcriptionally induces UPK1A-AS1 in HCC, where it promotes sorafenib resistance by suppressing apoptosis. Silencing UPK1A-AS1 restored apoptotic and enhanced sorafenib efficacy both in vitro and in vivo. Collectively, our findings suggest that UPK1A-AS1 is a hypoxia-inducible oncogenic lncRNA that plays dual roles in cancer, with cancer type-dependent associations with progression and immune modulation across malignancies and mechanistically mediating hypoxia-associated drug resistance in HCC.

Humans↗

MEIS1 knockdown upregulates WNT signaling pathway genes in esophageal squamous cell carcinoma.

BACKGROUND: The transcription factor MEIS1 belongs to the 3-amino acid loop extension (TALE) family of homeodomain proteins which plays various functions in normal and tumor cell progression. The canonical WNT/β-catenin pathway governs a plethora of biological processes including cell proliferation, differentiation, and tumor development. In the present study, the effect of MEIS1 gene silencing was assessed on WNT pathway genes in esophageal squamous cell carcinoma (ESCC) cells. MATERIALS AND METHODS: Along with the packaging plasmids, the pLKO.1-MEIS1 plasmid was cotransfected into HEK293T to generate lentiviral particles, followed by transduction of a semi-confluent KYSE-30 cell culture. After total RNA extraction and cDNA synthesis, comparative real-time PCR was applied to assess the efficiency of MEIS1 knockdown and the expression of genes related to the WNT signaling pathway. RESULTS: The results revealed effective downregulation of MEIS1 in KYSE-30 cells. Interestingly, MEIS1 silencing led to a substantial overexpression of WNT pathway key components while the expression of negative regulators of this pathway was substantially decreased. CONCLUSIONS: Our data suggest that MEIS1 gene probably induces WNT/β-catenin pathway deactivation in ESCC cells. Consequently, the inverse correlation of MEIS1 expression and WNT signaling pathway activation may introduce a new molecular linkage through ESCC progression and aggressiveness.

Humans↗

Elevated triglyceride-glucose index and risk of thymoma-associated myasthenia gravis: a prospective analysis from the UK Biobank.

BACKGROUND: Thymoma-associated myasthenia gravis (MG) is a clinically significant but uncommon condition, affecting up to half of thymoma patients and associated with worse outcomes than either disease alone. Reliable biomarkers for early risk stratification remain scarce. The triglyceride-glucose (TyG) index and triglyceride-to-high-density lipoprotein cholesterol (TG/HDL-C) ratio are established biomarkers reflecting insulin resistance and dyslipidemia. However, their clinical associations with thymoma-associated MG remain incompletely characterized. METHODS: A total of 501,954 UK Biobank participants were included. After exclusions, 422,397 (313 cases) were analyzed for TyG index and 422,691 (314 cases) for TG/HDL-C ratio. Exposures were stratified into quartiles, and assessed continuously per unit increase. Cox proportional hazards models estimated hazard ratios (HRs), restricted cubic splines (RCS) assessed non-linear associations, and subgroup analyses were stratified by body mass index (BMI). Sensitivity analyses examined TyG index and MG alone. RESULTS: An elevated TyG index was associated with increased risk of thymoma-associated MG. Compared to Q1, Q4 had higher risk (HR = 1.66, 95% CI: 1.20-2.31, P = 0.003); the overall HR per unit increase was 1.42 (95% CI: 1.17-1.73, P = 0.0005). TG/HDL-C ratio showed similar patterns: Q4 vs Q1 HR = 1.54 (95% CI: 1.11-2.15, P = 0.01); overall HR per unit increase was 1.06 (95% CI: 1.02-1.10, P = 0.002). Non-linear relationships were observed, with suggested inflection points at TyG index 8.7 and TG/HDL-C ratio 2.8, rather than strict thresholds. Subgroup analyses revealed stronger associations in normal-weight and obese participants, although tests for interaction were not statistically significant. Sensitivity analyses confirmed consistent associations between TyG index and MG risk, including for isolated MG. CONCLUSION: Elevated TyG index and TG/HDL-C ratio were independently associated with higher thymoma-associated MG risk in this large prospective cohort, with evidence of non-linear relationships and BMI-related heterogeneity. These findings provide novel epidemiologic evidence linking metabolic markers of insulin resistance with thymoma-associated MG, but clinical translation requires further validation.

Humans↗

FMRP promotes gastric cancer progression via m6A-dependent stabilization of DVL2 and activation of the Wnt/PCP-JNK pathway.

BACKGROUND: N6-methyladenosine (m6A) modification has emerged as a critical regulator in gastric cancer progression. Fragile X messenger ribonucleoprotein 1 (FMRP), an RNA-binding protein with tumorigenic potential, remains poorly characterized in gastric cancer. METHODS: FMRP expression in gastric cancer was assessed through bioinformatic analyses and tissue microarray-based immunohistochemistry. Its biological functions were examined through loss-of-function experiments in vitro and in vivo. Mechanistic investigations, including RNA interaction, m6A site mutation, and RNA stability analyses, were performed to identify downstream targets and pathways regulated by FMRP. RESULTS: Bioinformatic analyses and tissue microarray-based immunohistochemistry showed that FMRP was significantly upregulated in gastric cancer tissues. FMRP depletion suppressed tumor growth and metastasis. Subsequently, Dishevelled segment polarity protein 2 (DVL2) was identified as a candidate downstream target of FMRP. DVL2 was also significantly upregulated in gastric cancer tissues, and its expression positively correlated with FMRP expression. Mechanistically, FMRP bound to DVL2 mRNA and enhanced its stability in an m6A-dependent manner. Among the candidate sites tested, mutation of 1271A attenuated FMRP-mediated regulation of DVL2 reporter activity, supporting the involvement of this site. Functionally, FMRP promoted activation of the noncanonical Wnt/planar cell polarity (PCP) signaling pathway and enhanced the proliferative, migratory, and invasive capacities of gastric cancer cells via DVL2. CONCLUSIONS: These results define FMRP as an oncogenic driver in gastric cancer that operates via the DVL2/Wnt/PCP axis. Targeting this pathway may provide a potential therapeutic strategy for gastric cancer.

Stomach Neoplasms↗

Genetic analysis of pathways regulated by the von Hippel-Lindau tumor suppressor in Caenorhabditis elegans.

The von Hippel-Lindau (VHL) tumor suppressor functions as a ubiquitin ligase that mediates proteolytic inactivation of hydroxylated alpha subunits of hypoxia-inducible factor (HIF). Although studies of VHL-defective renal carcinoma cells suggest the existence of other VHL tumor suppressor pathways, dysregulation of the HIF transcriptional cascade has extensive effects that make it difficult to distinguish whether, and to what extent, observed abnormalities in these cells represent effects on pathways that are distinct from HIF. Here, we report on a genetic analysis of HIF-dependent and -independent effects of VHL inactivation by studying gene expression patterns in Caenorhabditis elegans. We show tight conservation of the HIF-1/VHL-1/EGL-9 hydroxylase pathway. However, persisting differential gene expression in hif-1 versus hif-1; vhl-1 double mutant worms clearly distinguished HIF-1-independent effects of VHL-1 inactivation. Genomic clustering, predicted functional similarities, and a common pattern of dysregulation in both vhl-1 worms and a set of mutants (dpy-18, let-268, gon-1, mig-17, and unc-6), with different defects in extracellular matrix formation, suggest that dysregulation of these genes reflects a discrete HIF-1-independent function of VHL-1 that is connected with extracellular matrix function.

Animals↗