A body map of somatic mutagenesis in morphologically normal human tissues.

Somatic mutations that accumulate in normal tissues are associated with ageing and disease1,2. Here we performed a comprehensive genomic analysis of 1,737 morphologically normal tissue biopsies of 9 organs from 5 donors. We found that somatic mutation accumulations and clonal expansions were widespread, although to variable extents, in morphologically normal human tissues. Somatic copy number alterations were rarely detected, except for in tissues from the oesophagus and cardia. Endogenous mutational processes with the SBS1 and SBS5 mutational signatures are ubiquitous among normal tissues, although they exhibit different relative activities. Exogenous mutational processes operate in multiple tissues from the same donor. We reconstructed the spatial somatic clonal architecture with sub-millimetre resolution. In the oesophagus and cardia, macroscopic somatic clones that expanded to hundreds of micrometres were frequently seen, whereas in tissues such as the colon, rectum and duodenum, somatic clones were microscopic in size and evolved independently, possibly restricted by local tissue microstructures. Our study depicts a body map of somatic mutations and clonal expansions from the same individual.

Associations between temporal eating patterns and body composition in young adults: a cross-sectional study.

PURPOSE: The aim of this study was to examine the associations between body composition and temporal eating patterns, including time of first eating occasion, time of last eating occasion, eating window, and eating jet lag (the variability in meal timing between weekdays and weekends). METHODS: A total of 131 participants were included in the study. Temporal eating pattern information was collected through consecutive 7-day eat timing questionnaires and photographic food records. Body composition was assessed by bioelectrical impedance analysis. Multiple linear regression models were used to evaluate the relationships of temporal eating patterns with body composition, and age was adjusted. Eating midpoint was additionally adjusted in the analysis of eating window. RESULTS: On weekdays, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with lower body fat percentage. On weekends, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with higher FFMI. Longer first eating occasion jet lag was associated with lower lean mass. CONCLUSION: Our study suggested that earlier and more regular eating patterns may have a benefit on body composition.

Oral administration of punicalagin attenuates imiquimod-induced psoriasis by reducing ROS generation and inflammation via MAPK/ERK and NF-κB signaling pathways.

Psoriasis, an immune-mediated chronic inflammatory skin disease, imposes a huge mental and physical burden on patients and severely affects their quality of life. Punicalagin (PU), the most abundant ellagitannin in pomegranates, has become a research hotspot owing to its diverse biological activities. However, its effects on psoriasis remain unclear. We explored the impact and molecular mechanism of PU on M5-stimulated keratinocyte cell lines and imiquimod (IMQ)-induced psoriasis-like skin inflammation in BABL/c mice using western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), hematoxylin and eosin (H&E) stain, immunohistochemistry, and immunofluorescent. Administration of PU-enriched pomegranate extract at dosages of 150 and 250 mg/kg/day markedly attenuated psoriatic severity, abrogated splenomegaly, and reduced IMQ-induced abnormal epidermal proliferation, CD4+ T-cell infiltration, and inflammatory factor expression. Moreover, PU could decrease expression levels of pro-inflammatory cytokines, such as IL-1ß, IL-1α, IL-6, IL-8, TNF-α, IL-17A, IL-22, IL-23A, and reactive oxygen species (ROS), followed by keratinocyte proliferation inhibition in the M5-stimulated cell line model of inflammation through inhibition of mitogen-activated protein kinases/extracellular regulated protein kinases (MAPK/ERK) and nuclear factor kappaB (NF-κB) signaling pathways. Our results indicate that PU may serve as a promising nutritional intervention for psoriasis by ameliorating cellular oxidative stress and inflammation.

What Aimed Movement Models Fit Distal Pointing With Varying Depth?

OBJECTIVE: With the rapid improvements in drone technology, there is an increasing interest in distal pointing to diffuse drones. This study investigated the effect of depth on distal pointing when the hand does not traverse the entire distance from start to target so that the most suitable mathematical model can be assessed. BACKGROUND: Starting from the Fitts paradigm, researchers have proposed different models to predict movement time when the distance to the target is variable. They do consider distance, but they are based on statistical modeling rather than the underlying control mechanisms. METHODS: Twenty-four participants volunteered for an experiment in a full-factorial Fitts' paradigm task (3 levels of movement amplitude *7 levels of target width *3 levels of distance from participant to screen). Movement time and the number of errors were the dependent variables. RESULTS: Depth has a significant effect when the target width is small, but depth has no effect when the target width is large. The angular version of the two-part model is superior to the one-part Fitts' model at larger distances. Besides, Index of difficulty for distal pointing, IDDP with adjustable k achieves the best fit even though the model is very sensitive to the value of k and the complexity of the model could be resulting in an overfitting. The result implies that the effects of movement amplitude and target width are not comparable and grouping them to form a dependent index of difficulty can be misleading especially when distance is an added variable. CONCLUSION: The angular version of the two-part model is a viable and meaningful description for distal pointing. Even though the IDDP with adjustable k is the best predictor for movement time when depth is an added variable, there is no physical interpretation for it. APPLICATION: A reasonable predictive model for performance assessments and predictions in distal pointing.

Abnormal expression and role of MicroRNA-214-3p/SLC8A1 in neonatal Hypoxic-Ischaemic encephalopathy.

Neonatal hypoxic-ischaemic encephalopathy (HIE) refers to brain damage caused by intra-uterine distress and asphyxia/hypoxia during the perinatal and neonatal periods. MicroRNA (MiR)-214-3p plays a critical role in cell growth and apoptosis. The aim of this study was to investigate the expression and role of miR-214-3p in neonatal HIE development, and to explore the underlying mechanisms. The expression of miR-214-3p was significantly down-regulated, while that of Slc8a1, a direct target of miR-214-3p, was significantly up-regulated, in the brain tissue of neonatal HIE rats. The over-expression of miR-214-3p promoted the proliferation and inhibited the apoptosis of neurones, while its down-regulation had the opposite effect. Our results indicate that miR-214-3p expression was down-regulated in neonatal HIE rats, and the up-regulation of miR-214-3p expression protected against HIE development by inhibiting neuronal apoptosis.

Application of the PGT-M strategy using single sperm and/or affected embryos as probands for linkage analysis in males with hereditary tumor syndromes without family history.

Hereditary tumor syndromes have garnered substantial attention due to their adverse effects on both the physical and psychological health of patients, as well as the elevated risk of transmission to subsequent generations. This has prompted a growing interest in exploring preimplantation genetic testing (PGT) as a treatment option to mitigate and eliminate these impacts. Several studies have demonstrated that de novo variants have become a great cause of many hereditary tumor syndromes, which introduce certain difficulties to PGT. In the absence of adequate genetic linkage information (parents and offspring), haplotype construction seems unrealizable. In the study, researchers used single sperm or affected embryos as proband to perform single-nucleotide polymorphism linkage analysis for cases with de novo variants. For complicated variants, the strategy that sperm combined with embryo detection will increase accuracy while avoiding the limitations and potential failures of using a single detection material. The study recruited 11 couples with male de novo carriers, including 3 tumor types and 4 genes. To date, 4 couples have been clinically confirmed as pregnant and three healthy babies have been born. The results of amniocentesis or umbilical cord blood verification were consistent with the results of PGT-M. The study aims to introduce the application of the PGT-M strategy in hereditary tumor syndromes.

Aging-induced pseudouridine synthase 10 impairs hematopoietic stem cells.

Aged hematopoietic stem cells (HSC) exhibit compromised reconstitution capacity and differentiation-bias towards myeloid lineage, however, the molecular mechanism behind it remains not fully understood. In this study, we observed that the expression of pseudouridine (Ψ) synthase 10 is increased in aged hematopoietic stem and progenitor cells (HSPC) and enforced protein of Ψ synthase 10 (PUS10) recapitulates the phenotype of aged HSC, which is not achieved by its Ψ synthase activity. Consistently, we observed no difference of transcribed RNA pseudouridylation profile between young and aged HSPC. No significant alteration of hematopoietic homeostasis and HSC function is observed in young Pus10-/- mice, while aged Pus10-/- mice exhibit mild alteration of hematopoietic homeostasis and HSC function. Moreover, we observed that PUS10 is ubiquitinated by E3 ubiquitin ligase CRL4DCAF1 complex and the increase of PUS10 in aged HSPC is due to aging-declined CRL4DCAF1- mediated ubiquitination degradation signaling. Taken together, this study for the first time evaluated the role of PUS10 in HSC aging and function, and provided a novel insight into HSC rejuvenation and its clinical application.

Enhancing HCC Treatment: innovatively combining HDAC2 inhibitor with PD-1/PD-L1 inhibition.

Hepatocellular carcinoma (HCC) is a malignancy with high morbidity and mortality but lacks effective treatments thus far. Although the emergence of immune checkpoint inhibitors in recent years has shed light on the treatment of HCC, a considerable number of patients are still unable to achieve durable and ideal clinical benefits. Therefore, refining the combination of immune checkpoint inhibitors (ICIs) to enhance the therapeutic effect has become a global research hotspot. Several histone deacetylase 2 inhibitors have shown advantages in ICIs in many solid cancers, except for HCC. Additionally, the latest evidence has shown that histone deacetylase 2 inhibition can regulate PD-L1 acetylation, thereby blocking the nuclear translocation of PD-L1 and consequently enhancing the efficacy of PD-1/PD-L1 inhibitors and improving anti-cancer immunity. Moreover, our team has recently discovered a novel HDAC2 inhibitor (HDAC2i), valetric acid (VA), that possesses great potential in HCC treatment as a monotherapy. Thus, a new combination strategy, combining HDAC2 inhibitors with ICIs, has emerged with significant development value. This perspective aims to ignite enthusiasm for exploring the application of ideal HDAC2 inhibitors with solid anti-tumor efficacy in combination with immunotherapy for HCC.

Higher serum lipocalin 2 is associated with post-stroke depression at discharge.

BACKGROUND AND AIMS: Post-stroke depression (PSD), as one of the common complications after stroke, seriously affects the physical and mental health and functional prognosis of patients. Previous studies have shown that the increase of inflammatory mediators is associated with the occurrence of PSD. Lipocalin 2 (LCN2), as an acute phase protein, is involved in the development of acute ischemic stroke (AIS), and its expression is up-regulated in patients with depression, suggesting that there is a potential correlation between serum LCN2 and depression. The aim of this study was to explore the relationship between serum LCN2 at admission and PSD at discharge. METHODS: A total of 358 AIS patients were retrospectively included. All patients had fasting venous blood taken within 24 h of admission to detect serum LCN2. The patients were evaluated by 17-item Hamilton Depression Scale (HAMD) before discharge. Patients with HAMD score > 7 were diagnosed with PSD. The correlation between serum LCN2 and PSD was tested using binary logistic regression analysis. RESULTS: In our study, 92 (25.7%) patients were diagnosed with PSD at discharge. According to the serum LCN2 value, the patients were divided into three layers (Tertile1 ≤ 105.24ng/ml; Tertile2: 105.24-140.12ng/ml; Tertile3 ≥ 140.12ng/ml), with T1 layer (the lowest levels) as a reference, after adjusting for multiple potential confounding factors, T3 layer (the highest levels) was independently associated with the occurrence of PSD (odds ratio [OR] = 2.639, 95% confidence interval [CI]: 1.317-5.287, P = 0.006). Similar results were found when the serum LCN2 was analyzed as a continuous variable. The optimal cut-off value of serum LCN2 at admission to predict PSD at discharge was 117.60ng/ml, at this threshold, the sensitivity was 77.2%, and the specificity was 53.4%. CONCLUSIONS: High serum LCN2 levels at admission are an independent risk factor for PSD in patients with AIS at discharge.

Countermeasure to the side effect of polarization demultiplexing in Stokes space.

We propose a new method to solve the side effect of polarization demultiplexing in Stokes space. The scheme calculates the phase difference between the two polarization states according to the boundary of the projection of the signal on the S2-S3 plane in Stokes space and completes the compensation by a phase retarder. According to the analysis results, this scheme can effectively solve the side effect caused by polarization demultiplexing in Stokes space. At the same time, the use of the scheme can save one carrier phase recovery module in the subsequent digital signal processing, which effectively reduces the implementation complexity of the system.

Reconfigurable AWGR based on LNOI with a tunable central wavelength and bandwidth used in elastic optical networking.

Elastic optical networking introduces elasticity and adaptation into the optical domain, which highly depends on reconfigurable optical devices. In this paper, a tunable 4×4 arrayed waveguide grating router based on lithium niobate on insulator is designed. By using the electro-optic effect of lithium niobate, we design electrode regions with specific shapes in the array waveguide region to realize the tuning of the routing wavelength and bandwidth of the third output channel. The designed arrayed waveguide grating router (AWGR) has a dense channel spacing of 0.8 nm, and the minimum insertion loss is 2.3 dB. Experiments show that the tuning range of the central wavelength can reach 3.2 nm, and the 3 dB bandwidth can be expanded from 0.2 to 0.6 nm.

A novel embryo biopsy morphological analysis and genetic integrality criterion system significantly improves the outcome of preimplantation genetic testing.

PURPOSE: While efforts have been made to establish blastocyst grading systems in the past decades, little research has examined the quality of biopsy specimens. This study is the first to correlate the morphology of biopsied trophectoderm (TE) cells to their quality and subsequent genetic testing results of preimplantation genetic testing (PGT), through an innovative Morphological Analysis and Genetic Integrality Criterion (MAGIC) system. METHODS: Biopsied TE cells were first evaluated according to the MAGIC procedure, followed by whole-genome amplification (WGA) and library construction, and then sequenced using the Illumina X Ten Platform. Copy number variation (CNV) and allele drop-out (ADO) rates as well as test failure rates were compared and analyzed. RESULTS: Our data explores the relationship between TE cell morphology and its quality and final genetic testing outcome, which is established based on the MAGIC system. MAGIC guarantees that only high- or good-quality TE cells are used for genetic testing to generate excellent data uniformity and lower ADO rates. Low-quality cells containing biopsied TE cell mass are responsible for the "background noise" of CNV analysis. CONCLUSION: The MAGIC application has effectively decreased the false-positive mosaicism, hence to ensure the stability and veracity of detection results, to avoid misdiagnoses, and to improve accuracy, as well as to avoid re-biopsy procedures. The study also contributes to understand how the IVF laboratory and the molecular biology laboratory depend on each other to achieve good-quality PGT results, which are clinically relevant for the patients.

Effects of different dietary protein levels on intestinal aquaporins in weaned piglets.

This study was conducted to investigate the relationship between changes in intestinal aquaporins (AQPs) in piglets fed diets with different protein levels and nutritional diarrhoea in piglets. Briefly, 96 weaned piglets were randomly divided into four groups fed diets with crude protein (CP) levels of 18%, 20%, 22% and 24%. The small intestines and colons of the weaned piglets were collected, and several experiments were conducted. In the small intestine, AQP4 protein expression was higher in weaned piglets fed the higher-CP diets (22% and 24% CP) than in those fed the 20% CP diet except at 72 h (p < 0.01). At 72 h, the AQP4 protein expression in the small intestine was lower in the 18% group than in the other three groups (p < 0.01). Under 20% CP feeding, AQP2, AQP4 and AQP9 protein expression in the colons of piglets peaked at certain time points. The AQP2 and AQP4 mRNA levels in the colon and the AQP4 and AQP4 mRNA levels in the distal colon were approximately consistent with the protein expression levels. However, the AQP9 mRNA content in the colon was highest in the 18% group, and the AQP2 mRNA content in the distal colon was significantly higher in the 24% group than in the 20% group. AQP2 and AQP4 were expressed mainly around columnar cells in the upper part of the smooth colonic intestinal villi, and AQP9 was expressed mainly on columnar cells and goblet cells in the colonic mucosa. In conclusion, 20% CP is beneficial to the normal expression of AQP4 in the small intestine, AQP2, AQP4 and AQP9 in the colon of weaned piglets, which in turn maintains the balance of intestinal water absorption and secretion in piglets.

Supra-Cyanines: Ultrabright Cyanine-Based Fluorescent Supramolecular Materials in Solution and in the Solid State.

Fluorescent materials with high brightness play a crucial role in the advancement of various technologies such as bioimaging, photonics, and OLEDs. While significant efforts are dedicated to designing new organic dyes with improved performance, enhancing the brightness of existing dyes holds equal importance. In this study, we present a simple supramolecular strategy to develop ultrabright cyanine-based fluorescent materials by addressing long-standing challenges associated with cyanine dyes, including undesired cis-trans photoisomerization and aggregation-caused quenching. Supra-cyanines are obtained by incorporating cyanine moieties in a cyclic peptide-based supramolecular scaffold, and exhibit high fluorescence quantum yields (up to 50 %) in both solution and in the solid state. These findings offer a versatile approach for constructing highly emissive cyanine-based supramolecular materials.

Quantitative Proteomics Reveals That the Protein Components of Outer Membrane Vesicles (OMVs) in Aeromonas hydrophila Play Protective Roles in Antibiotic Resistance.

In recent years, the intracellular mechanisms that contribute to antibiotic resistance have received increasing attention, and outer membrane vesicles (OMVs) have been reported to be related to antibiotic resistance in several Gram-negative bacterial species. However, the intrinsic molecular mechanisms and the form of such antibiotic resistance are still largely unknown. In this study, OMVs from an oxytetracycline (OXY) sensitive aquatic pathogen, Aeromonas hydrophila (OXY-S), were found with significantly increased OXY resistance. Interestingly, the OXY-resistant strain (OXY-R) had a more protective role in OXY resistance. Therefore, a DIA-based quantitative proteomics analysis was performed to compare the differential expression of OMV proteins between OXY-R (OMVsR) and OXY-S (OMVsS). The results showed that seven proteins increased and five proteins decreased in OMVsR vs OMVsS. A subsequent antibiotics susceptibility assay showed that the deletion of icd, rpsF, and iscS significantly increased OXY sensitivity. Moreover, the exogenous addition of the crude OMV fractions of overexpressed recombinant proteins in E. coli with rRpsF, rIcd, rIscS, rOmpA, rPepA, rFrdA, and rRplQ demonstrated that these proteins promoted the OXY resistance of A. hydrophila. Overall, our results indicate the important protective role of OMVs in antibiotic resistance in A. hydrophila and provide novel insights on bacterial antibiotic resistance mechanisms.

Kynureninase contributes to the pathogenesis of psoriasis through pro-inflammatory effect.

Kynureninase (KYNU) is a key enzyme in the tryptophan metabolism pathway with elevated expression in psoriatic lesions relative to normal skin. However, whether KYNU contributes to the pathogenesis of psoriasis remains unknown. We sought to investigate the role of KYNU in psoriasis and its possible regulation mechanism. In the results, KYNU is upregulated in psoriatic skin samples from patients or animal models compared with normal skin control which was assayed in psoriatic patient samples, IMQ-induced psoriasis-like skin inflammation in BABL/c mice and M5-stimulated keratinocyte cell lines by immunohistochemistry (IHC). KYNU knockdown had a trivial impact on keratinocyte proliferation, but significantly inhibited the production of inflammatory cytokines in HaCaT, HEKα, and HEKn cells by quantitative reverse-transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and western blot analysis. The 3'-untranslated region of KYNU contains a conserved target site of a skin-specific microRNA (miRNA), miR-203a, as predicted by TargetScan software. Furthermore, miR-203a exhibited an inversed expression kinetics to KYNU during the development of IMQ-induced psoriasis-like skin inflammation in BABL/c mice. Overexpression of miR-203 subsequently leading to the inhibition of KYNU, could significantly reduce the production of M5-induced, psoriasis-related inflammatory factors in keratinocytes. Finally, KYNU inhibitors could alleviate the pathological phenotypes in IMQ-mice. Our study supported the contributive role of KYNU in the development of psoriasis and provided preliminary evidence for KYNU as a potential therapeutic target in psoriasis.

Preimplantation genetic testing for structural rearrangement based on low-coverage next-generation sequencing accurately discriminates between normal and carrier embryos for patients with translocations.

RESEARCH QUESTION: Can preimplantation genetic testing for structural rearrangement (PGT-SR) based on low-coverage next-generation sequencing (NGS) accurately discriminate between normal and carrier embryos of reciprocal translocation (RecT) and Robertsonian translocation (RobT)? DESIGN: A total of 109 couples with RecT or RobT were included in this study. The ages, bad obsteric histories (BOH), blood karyotype and IVF cycle information, including the number of cumulus-oocyte complexes, metaphase II oocytes, two pronuclei oocytes and blastocysts were recorded. 0.1 × whole genome sequencing (WGS) of embryos followed by copy number variation (identifying unbalanced/balanced) and 2 × WGS of parents and embryos followed by haplotype analysis (discriminating between normal and carrier) were carried out in PGT-SR cycles. The embryos without translocation were transferred and clinical outcomes evaluated. RESULTS: Among all the couples in this study, 67 patients had RecT and 42 had RobT. After unbalanced and balanced detection, 103 balanced embryos underwent a further normal and carrier discrimination procedure, and 53 normal embryos were identified. Finally, 32 normal embryos were transferred, with an ongoing pregnancy rate of 46.88% (15/32). All ongoing pregnancies underwent amniocentesis, and the amninocentesis karyotyping results showed 100% concordance with PGT-SR diagnosis. CONCLUSIONS: Our low-coverage NGS-based PGT-SR method can accurately discriminate between normal and carrier status of balanced embryos. The method is cost-effective and has broad clinical applicability.

Associations of walking impairment with visual impairment, depression, and cognitive function in U.S. older adults: NHANES 2013-2014.

BACKGROUND: Walking impairment, a common health problem among older adults, has been linked to poor vision and mental health. This study aimed to investigate the associations of walking impairment with visual impairment, depression, and cognitive function in older adults. METHODS: A total of 1,489 adults aged 60 years and older who had participated in the National Health and Examination Survey (NHANES) 2013-2014 in the United States were included. Multivariate logistic regression models were used to examine the associations of walking impairment with visual impairment, depression, and four subdomains of cognitive function. Sample weights were used to ensure the generalizability of the results. RESULTS: Among all the participants (median age = 68 years; 53.7% women), 17.5% reported walking impairment. Walking impairment was significantly associated with visual impairment (adjusted odds ratio [aOR] = 2.76; 95% CI: 1.47-5.20) and depression (aOR = 4.66; 95% CI: 3.11-6.99). Walking impairment was only associated with the Digit Symbol Substitution (DSST) subdomain of cognitive function in total participants (aOR = 0.97; 95% CI: 0.95-0.99) and in non-Hispanic white adults (aOR = 0.96; 95% CI: 0.94-0.98). Participants with two or three impairment indicators had a higher OR of walking impairment (aOR = 3.64, 95% CI = 2.46-5.38) than those with 0-1 (reference group) impairment indicator. CONCLUSIONS: Walking impairment was associated with visual impairment, depression, and cognitive impairment in American older adults and also positively associated with the number of impairment indicators. The association between walking impairment and cognitive impairment varied according to race. Evaluations of vision, cognition, and depression should be conducted among older adults with walking impairment, and the needs of older adults should be provided in the evaluations alongside information on the biological aspects of their particular race.

Profile of protein lysine propionylation in Aeromonas hydrophila and its role in enzymatic regulation.

Protein lysine propionylation (Kpr) modification is a novel post-translational modification (PTM) of prokaryotic cells that was recently discovered; however, it is not clear how this modification regulates bacterial life. In this study, the protein Kpr modification profile in Aeromonas hydrophila was identified by high specificity antibody-based affinity enrichment combined with high resolution LC MS/MS. A total of 98 lysine-propionylated peptides with 59 Kpr proteins were identified, most of which were associated with energy metabolism, transcription and translation processes. To further understand the role of Kpr modified proteins, the K168 site on malate dehydrogenase (MDH) and K608 site on acetyl-coenzyme A synthetase (AcsA) were subjected to site-directed mutation to arginine (R) and glutamine (Q) to simulate deacylation and propionylation, respectively. Subsequent measurement of the enzymatic activity showed that the K168 site of Kpr modification on MDH may negatively regulate the MDH enzymatic activity while also affecting the survival of mdh derivatives when using glucose as the carbon source, whereas Kpr modification of K608 of AcsA does not. Overall, the results of this study indicate that protein Kpr modification plays an important role in bacterial biological functions, especially those involved in the activity of metabolic enzymes.

Bufalin suppresses tumour microenvironment-mediated angiogenesis by inhibiting the STAT3 signalling pathway.

BACKGROUND: Antiangiogenic therapy has increasingly become an important strategy for the treatment of colorectal cancer. Recent studies have shown that the tumour microenvironment (TME) promotes tumour angiogenesis. Bufalin is an active antitumour compound whose efficacy has been indicated by previous studies. However, there are very few studies on the antiangiogenic effects of bufalin. METHODS: Herein, human umbilical vein endothelial cell (HUVEC) tube formation, migration and adhesion tests were used to assess angiogenesis in vitro. Western blotting and quantitative PCR were used to detect relevant protein levels and mRNA expression levels. A subcutaneous xenograft tumour model and a hepatic metastasis model were established in mice to investigate the influence of bufalin on angiogenesis mediated by the TME in vivo. RESULTS: We found that angiogenesis mediated by cells in the TME was significantly inhibited in the presence of bufalin. The results demonstrated that the proangiogenic genes in HUVECs, such as VEGF, PDGFA, E-selectin and P-selectin, were downregulated by bufalin and that this downregulation was mediated by inhibition of the STAT3 pathway. Overexpression of STAT3 reversed the inhibitory effects of bufalin on angiogenesis. Furthermore, there was little reduction in angiogenesis when bufalin directly acted on the cells in the tumour microenvironment. CONCLUSION: Our findings demonstrate that bufalin suppresses tumour microenvironment-mediated angiogenesis by inhibiting the STAT3 signalling pathway in vascular endothelial cells, revealing that bufalin may be used as a new antiangiogenic adjuvant therapy medicine to treat colorectal cancer.