Long-term outcomes of 1-2 cm rectal neuroendocrine tumors after local excision or radical resection: A population-based multicenter study.

Objectives: Studies on rectal neuroendocrine tumors (R-NETs) that are 1-2 cm in size are limited, and the optimal treatment for these tumors is not well established. Methods: Data from patients with primary localized R-NETs 1-2 cm in size were retrospectively collected from 17 large-scale referral medical centers in China. Long-term prognosis, quality of life (QOL), and fecal incontinence were evaluated, and the effects of local excision (LE) or radical resection (RR) were elucidated using propensity score matching (PSM). Results: A total of 272 patients were included in this study; 233 underwent LE, and the remaining 39 underwent RR. Patients in the LE group showed lower tumor location, fewer postoperative Clavien-Dindo III-V complications, more G1 tumors, and lower tumor stage. There were no significant differences in the relapse-free survival or overall survival (OS) between the LE and RR groups after PSM. Patients in the LE group reported superior physical, role, emotional, social, and cognitive functions, global QOL, and Wexner fecal incontinence scores compared with those in the RR group (all P < 0.050). Eighteen (6.6%) patients had lymph node metastases. Multivariable analysis revealed that tumor location (odds ratio [OR] = 3.19, 95% confidence interval [CI] 1.04-10.07, P = 0.010), neutrophil-to-lymphocyte ratio (NLR) > 1.80 (OR = 4.50, 1.46-15.89, P = 0.012), and T3-T4 (OR = 36.31, 95% CI 7.85-208.62, P < 0.001) were independent risk factor for lymph node metastasis. Conclusions: R-NETs measuring 1-2 cm generally have a favorable prognosis, and there is no difference in postoperative survival between LE and RR. For patients without lymph node metastasis, LE should be the preferred choice; however, for patients with a higher tumor location, preoperative NLR >1.8 or T3/T4 tumors, RR should be considered.

Single-Cell and Spatial Transcriptome Profiling Identifies the Transcription Factor BHLHE40 as a Driver of EMT in Metastatic Colorectal Cancer.

Colorectal cancer (CRC) is one of the most common malignant tumors in humans, with liver metastasis being the primary cause of mortality. The epithelial-mesenchymal transition (EMT) process endows cancer cells with enhanced metastatic potential. To elucidate the cellular mechanisms driving EMT in CRC, we analyzed single-cell RNA-sequencing (scRNA-seq) data from 11 non-metastatic primary tumors (TnM) and 11 metastatic primary tumors (TM) from CRC patients. Compared to TnM group, the TM samples showed elevated numbers of malignant epithelial cell and cancer-associated fibroblast (CAF) subsets that displayed enrichments of EMT, angiogenesis, and TGF-ß signaling pathways. One specific TM-enriched subgroup of malignant epithelial cells underwent EMT to trans-differentiate into CXCL1+ CAFs that subsequently differentiated into SFRP2+ CAFs, which was validated by spatial transcriptomic and pseudotime trajectory analyses. Furthermore, cell-cell communication analysis identified BHLHE40 as a probable key transcription factor driving EMT that was associated with poor prognosis. Finally, in vitro and in vivo experiments functionally substantiated that BHLHE40 promoted the proliferation, invasion, migration, EMT, and liver metastasis of CRC cells. In summary, this study identified BHLHE40 as a key transcription factor regulating EMT that promotes liver metastasis in CRC.

Local Excision Versus Radical Resection for Grade 2 Rectal Neuroendocrine Tumors: A Multicenter Propensity Score-Matched Analysis.

BACKGROUND: Studies on the grade 2 rectal neuroendocrine tumors are limited and the optimal treatment for these tumors is not well established. OBJECTIVE: To compare the oncologic results of local excision versus radical resection for the treatment of grade 2 rectal neuroendocrine tumors. DESIGN: Retrospective multicenter propensity score-matched study to minimize heterogeneity between groups and focus on the difference between surgery strategies. SETTINGS: Seventeen Chinese large-scale medical centers participated in this study. PATIENTS: A total of 144 patients with pathologically confirmed grade 2 rectal neuroendocrine tumors were retrospectively analyzed. MAIN OUTCOME MEASURES: Cancer-specific survival and relapse-free survival were assessed to compare surgery strategies. RESULTS: A total of 144 patients with grade 2 rectal neuroendocrine tumors were enrolled in this study. Twenty-seven patients underwent endoscopic resection, 55 underwent transanal excision, 50 underwent radical resection, and 12 underwent palliative surgery or biopsy for distant metastasis. Of the 50 patients who underwent radical resection, 30 (60.0%) had clinically positive lymph nodes based on the histopathology results. The optimal cutoff value for tumor size to predict cancer-specific survival was 1.5 cm. In patients with grade 2 rectal neuroendocrine tumors ≤ 1.5 cm, there were no significant differences in cancer-specific survival and relapse-free survival between local excision and radical resection groups (P >0.05). In patients with grade 2 rectal neuroendocrine tumors > 1.5 cm, relapse-free survival was significantly lower in the local excision group than in the radical resection group (P = 0.04). LIMITATIONS: The nature of retrospective review and relatively short follow-up period are limitations of this study. CONCLUSIONS: Grade 2 rectal neuroendocrine tumors have a nonnegligible rate of lymph node metastasis. Local excision is a feasible choice for tumors ≤ 1.5 cm without metastasis, while radical resection is more beneficial in those > 1.5 cm. See Video Abstract.

Discovery of Novel 5,6-Dihydro-4H-pyrido[2,3,4-de]quinazoline Irreversible Inhibitors Targeting Both Wild-Type and A775_G776insYVMA Mutated HER2 Kinases.

HER2 mutations were seen in 4% of non-small-cell lung cancer (NSCLC) patients. Most of these mutations (90%) occur as an insertion mutation within the exon 20 frame, leading to the downstream activation of the PI3K-AKT and RAS/MAPK pathways. However, no targeted therapies have yet been approved worldwide. Here a novel series of highly potent HER2 inhibitors with a pyrido[2,3,4-de]quinazoline core were designed and developed. The derivatives with the pyrido[2,3,4-de]quinazoline core displayed superior efficacy of antiproliferation in BaF3 cells harboring HER2insYVMA mutation compared with afatinib and neratinib. Rat studies showed that 8a and 9a with the newly developed core have good pharmacokinetic properties with an oral bioavailability of 41.7 and 42.0%, respectively. Oral administration of 4a and 10e (30 mg/kg, QD) displayed significant antitumor efficacy in an in vivo xenograft model. We proposed promising strategies for the development of HER2insYVMA mutant inhibitors in this study.

Integration of photothermal water evaporation with photocatalytic microplastics upcycling via nanofluidic thermal management.

Photothermal heating and photocatalytic treatment are two solar-driven water processing approaches by harnessing NIR and UV-vis light, respectively, which can fully utilize solar energy if integrated. However, it remains a challenge to achieve high performance in both approaches when integrated in a material due to uncontrollable heat diffusion. Here, we report a demonstration of heat confinement on photothermal sites and fluid cooling on photocatalysis sites at the nanoscale, within a well-designed heat and fluid confinement nanofiber reactor. Photothermal and photocatalytic nanostructures were alternatively aligned in electrospun nanofibers for on-demand nanofluidic thermal management as well as easy folding into 3D structures with enhanced light utilization and mass transfer. Such a design showed simultaneously high photothermal evaporation rate (2.59 kg m-2 h-1, exceeding the limit rate) and efficient photocatalytic upcycling of microplastics pollutant into valued products. Enabled by controlled photothermal heating, the valued main product (i.e., methyl acetate) can be evaporated out with 100% selectivity by in situ separation.

Evaluating AI in medicine: a comparative analysis of expert and ChatGPT responses to colorectal cancer questions.

Colorectal cancer (CRC) is a global health challenge, and patient education plays a crucial role in its early detection and treatment. Despite progress in AI technology, as exemplified by transformer-like models such as ChatGPT, there remains a lack of in-depth understanding of their efficacy for medical purposes. We aimed to assess the proficiency of ChatGPT in the field of popular science, specifically in answering questions related to CRC diagnosis and treatment, using the book "Colorectal Cancer: Your Questions Answered" as a reference. In general, 131 valid questions from the book were manually input into ChatGPT. Responses were evaluated by clinical physicians in the relevant fields based on comprehensiveness and accuracy of information, and scores were standardized for comparison. Not surprisingly, ChatGPT showed high reproducibility in its responses, with high uniformity in comprehensiveness, accuracy, and final scores. However, the mean scores of ChatGPT's responses were significantly lower than the benchmarks, indicating it has not reached an expert level of competence in CRC. While it could provide accurate information, it lacked in comprehensiveness. Notably, ChatGPT performed well in domains of radiation therapy, interventional therapy, stoma care, venous care, and pain control, almost rivaling the benchmarks, but fell short in basic information, surgery, and internal medicine domains. While ChatGPT demonstrated promise in specific domains, its general efficiency in providing CRC information falls short of expert standards, indicating the need for further advancements and improvements in AI technology for patient education in healthcare.

The Uridylyl Transferase TUT7-Mediated Accumulation of Exosomal miR-1246 Reprograms TAMs to Support CRC Progression.

Tumor-associated macrophages (TAMs) play a crucial role in promoting tumor growth and dissemination, motivating a search for key targets to interfere with the activation of TAMs or reprogram TAMs into the tumor-suppressive type. To gain insight into the mechanisms of macrophage polarization, a designed co-culture system is established, allowing for the education of macrophages in a manner that closely mimics the intricacies of TAMs in the tumor immune microenvironment (TIME). Through database mining, exosomal miR-1246 is identified and is then validated. Exosomal miR-1246-driven polarization of TAMs disrupts the infiltration and function of CD8+ T cells. Mechanically, the amassment of exosomal miR-1246 stems from TUT7-mediated degradation of small noncoding RNA, a process stabilized by SNRPB, but not the precursor of miR-1246. Moreover, an Exo-motif is present in the exosomal miR-1246 sequence, enabling it to bind with the exosomal sorting protein hnRNPA2B1. RNA-seq analysis reveals that exogenous miR-1246 modulates the polarization of TAMs at a post-transcriptional level, emphasizing the pivotal role of the NLRP3 in macrophage polarization. In conclusion, the findings underscore the importance of exosomal miR-1246 as a trigger of macrophage reprogramming and uncover a novel mechanism for its enhanced presence in the TIME.

Interaction between intratumoral microbiota and tumor mediates the response of neoadjuvant therapy for rectal cancer.

Background: Previous observations have demonstrated that the response to neoadjuvant chemoradiotherapy (nCRT) is highly variable in patients with locally advanced rectal cancer (LARC). Recent studies focusing on the intratumoral microbiota of colorectal cancer have revealed its role in oncogenesis and tumor progression. However, limited research has focused on the influence of intratumoral microbiota on the nCRT of LARC. Methods: We explored the microbial profiles in the tumor microenvironment of LARC using RNA-seq data from a published European cohort. Microbial signatures were characterized in pathological complete response (pCR) and non-pCR groups. Multi-omics analysis was performed between intratumor microbiomes and transcriptomes. Results: Microbial α and ß diversity were significantly different in pCR and non-pCR groups. Twelve differential microbes were discovered between the pCR and non-pCR groups, six of which were related to subclusters of cancer-associated fibroblasts (CAFs) associated with extracellular matrix formation. A microbial risk score based on the relative abundance of seven differential microbes had predictive value for the nCRT response (AUC = 0.820, p < 0.001). Conclusion: Our study presents intratumoral microbes as potential independent predictive markers for the response of nCRT to LARC and demonstrates the underlying mechanism by which the interaction between intratumoral microbes and CAFs mediates the response to nCRT.

Distinct laccase expression and activity profiles of Trametes versicolor facilitate degradation of benzo[a]pyrene.

A Trametes versicolor isolate from the Changbai Mountain showed promising activity in degrading benzo[a]pyrene (BaP), which is a high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH) compound. It was hypothesized that the T. versicolor isolate encode BaP-degrading enzymes, among which laccase is mostly sought after due to significant commercial potential. Genome of the T. versicolor isolate was sequenced and assembled, and seven laccase homologues were identified (TvLac1-7) as candidate genes potentially contributing to BaP degradation. In order to further identify the BaP responsive laccases, time-course transcriptomic and proteomic analyses were conducted in parallel on the T. versicolor isolate upon BaP treatment. Homologous laccases showed distinct expression patterns. Most strikingly, TvLac5 was rapidly induced in the secreted proteomes (secretomes), while TvLac2 was repressed. Recombinant laccase expression and biochemical characterization further showed corresponding enzymatic activity profiles, where TvLac5 was 21-fold more effective in BaP degradation compared to TvLac2. Moreover, TvLac5 also showed 3.6-fold higher BaP degrading activity compared to a commercial laccase product of T. versicolor origin. Therefore, TvLac5 was concluded to be a BaP-responsive enzyme from T. versicolor showing effective BaP degradation activity.

Lymph node ratio and hematological parameters predict relapse-free survival in patients with high grade rectal neuroendocrine neoplasms after radical resection: a multicenter prognostic study.

BACKGROUND: The prognostic nutritional index (PNI), alkaline phosphatase (ALP), and lymph node ratio (LNR) are reportedly related to prognosis. The aim of this study was to elucidate the clinical importance of the LNR and hematological parameters in patients with high grade rectal neuroendocrine neoplasms (HG-RNENs) who were undergoing radical resection. METHODS: We reviewed the medical records of patients with HG-RNENs from 17 large-scale medical centers in China (January 1, 2010-April 30, 2022). A nomogram was constructed by using a proportional hazard model. Bootstrap method was used to draw calibration plots to validate the reproducibility of the model. Concordance index (C-Index), decision curve analysis (DCA), and time-dependent area under the receiver operating characteristic curve (TD-AUC) analysis were used to compare the prognostic predictive power of the new model with American Joint Committee on Cancer (AJCC) TNM staging and European Neuroendocrine Tumor Society (ENETS) TNM staging. RESULTS: A total of 85 patients with HG-RNENs were enrolled in this study. In the 45 patients with HG-RNENs who underwent radical resection, PNI ≤ 49.13 (HR: 3.997, 95% CI: 1.379-11.581, P = 0.011), ALP > 100.0 U/L (HR: 3.051, 95% CI: 1.011-9.205, P = 0.048), and LNR > 0.40 (HR: 6.639, 95% CI: 2.224-19.817, P = 0.0007) were independent predictors of relapse-free survival. The calibration plots suggested that the nomogram constructed based on the three aforementioned factors had good reproducibility. The novel nomogram revealed a C-index superior to AJCC TNM staging (0.782 vs 0.712) and ENETS TNM staging (0.782 vs 0.657). Also, the new model performed better compared to AJCC TNM staging and ENETS TNM staging in DCA and TD-AUC analyses. CONCLUSIONS: LNR, ALP, and PNI were independent prognostic factors in patients with HG-RNENs after radical resection, and the combined indicator had better predictive efficacy compared with AJCC TNM staging and ENETS TNM staging.

Wettability and morphology of proboscises interweave with hawkmoth evolutionary history.

Hovering hawkmoths expend significant energy while feeding, which should select for greater feeding efficiency. Although increased feeding efficiency has been implicitly assumed, it has never been assessed. We hypothesized that hawkmoths have proboscises specialized for gathering nectar passively. Using contact angle and capillary pressure to evaluate capillary action of the proboscis, we conducted a comparative analysis of wetting and absorption properties for 13 species of hawkmoths. We showed that all 13 species have a hydrophilic proboscis. In contradistinction, the proboscises of all other tested lepidopteran species have a wetting dichotomy with only the distal ∼10% hydrophilic. Longer proboscises are more wettable, suggesting that species of hawkmoths with long proboscises are more efficient at acquiring nectar by the proboscis surface than are species with shorter proboscises. All hawkmoth species also show strong capillary pressure, which, together with the feeding behaviors we observed, ensures that nectar will be delivered to the food canal efficiently. The patterns we found suggest that different subfamilies of hawkmoths use different feeding strategies. Our comparative approach reveals that hawkmoths are unique among Lepidoptera and highlights the importance of considering the physical characteristics of the proboscis to understand the evolution and diversification of hawkmoths.

Insole Systems for Disease Diagnosis and Rehabilitation: A Review.

Some chronic diseases, including Parkinson's disease (PD), diabetic foot, flat foot, stroke, elderly falling, and knee osteoarthritis (KOA), are related to orthopedic organs, nerves, and muscles. The interaction of these three parts will generate a comprehensive result: gait. Furthermore, the lesions in these regions can produce abnormal gait features. Therefore, monitoring the gait features can assist medical professionals in the diagnosis and analysis of these diseases. Nowadays, various insole systems based on different sensing techniques have been developed to monitor gait and aid in medical research. Hence, a detailed review of insole systems and their applications in disease management can greatly benefit researchers working in the field of medical engineering. This essay is composed of the following sections: the essay firstly provides an overview of the sensing mechanisms and parameters of typical insole systems based on different sensing techniques. Then this essay respectively discusses the three stages of gait parameters pre-processing, respectively: pressure reconstruction, feature extraction, and data normalization. Then, the relationship between gait features and pathogenic mechanisms is discussed, along with the introduction of insole systems that aid in medical research; Finally, the current challenges and future trends in the development of insole systems are discussed.

Promotion of colorectal cancer progression by immune-related lnc-SOX9-4 via suppression of YBX1 poly-ubiquitination and degradation.

BACKGROUND: Recent research has highlighted the versatile functions of long non-coding RNAs (lncRNAs) in the onset and progression of various malignancies. Still, insufficient knowledge is available on how lnc-SOX9-4 functions in colorectal cancer (CRC) progression. METHODS: Bioinformatics analysis was used to identify a novel lncRNA (lnc-SOX9-4), and the expression pattern of the RNA in CRC was verified using qRT-PCR. Gene ontology (GO) term analysis and Gene set enrichment analysis (GSEA) were implemented for the identification of the related mechanisms and roles of lnc-SOX9-4. Immune infiltration analysis was conducted for assessment of how lnc-SOX9-4 is linked to tumor immune cell infiltration level. Both in vitro and in vivo phenotype analyses were conducted for scrutinizing how lnc-SOX9-4 impacts the proliferation and metastasis of CRC. RNA pulldown, mass spectrometry analysis, fluorescent in situ hybridization (FISH), western blotting, and RIP assay aided in verifying lnc-SOX9-4 mechanisms linked to CRC progression. RESULTS: An upregulation of lnc-SOX9-4 was observed in the sample CRC cells and tissues. Elevated lnc-SOX9-4 levels showed a positive association with poor clinical prognosis. Lnc-SOX9-4 was closely correlated to several types of immune infiltrating cells. Functionally, the knockdown of lnc-SOX9-4 significantly inhibited CRC cell proliferation, migration, and invasion abilities. Mechanistically, YBX1 was identified as lnc-SOX9-4, specifically interacting protein in the nucleus. Lnc-SOX9-4 could stabilize YBX1 protein levels by inhibiting poly-ubiquitination and degradation of YBX1. Furthermore, phenotype rescue experiments reveal that lnc-SOX9-4 enhanced the CRC cellular potential to proliferate and metastasize by regulating YBX1 levels. CONCLUSIONS: Lnc-SOX9-4 promoted CRC progression by suppressing cytoplasmic translocation and promoting protein levels of YBX1 can serve as novel treatment targets for diagnosing and treating CRC.

Intratumoural microbiome can predict the prognosis of hepatocellular carcinoma after surgery.

BACKGROUND: The dismal prognosis of hepatocellular carcinoma (HCC) is closely associated with characteristics of the tumour microenvironment (TME). Recent studies have confirmed the presence and potential influence of the microbiome in TME on cancer progression. Elucidating the relationship between microbes in the TME and cancer could provide valuable insights into novel diagnostic markers and therapeutic strategies for HCC and thus warrants a closer investigation of the role of intratumoural microbiome in the HCC TME. METHODS: We determined the presence of intratumoural microbiome using fluorescence in situ hybridisation, and explored the microbial community profiles in the HCC TME in paired tumour and adjacent normal tissues using 16S rDNA sequencing. Microbial signatures were characterised in the paired group, and their correlation with clinical characteristics was further investigated. We clustered the microbial signatures of tumour tissues by hepatotypes, and further analysis was performed to elucidate the independent prognostic value of the hepatotypes. RESULTS: This study revealed that microbial profiles and community networks differed notably between tumours and adjacent normal tissues. Proteobacteria and Actinobacteria were the most abundant phyla in the HCC TME. The TME microbial profiles also revealed heterogeneities between individuals and between multiple tumour lesions. Clustering of the microbial profiles into two hepatotypes revealed different microbial network patterns. Additionally, the hepatotypes were revealed to be independent prognostic factors in patients with resected HCC. CONCLUSIONS: Our study illuminates the microbial profiles in the TME of HCC and presents the hepatotype as a potential independent biomarker for the prognostic prediction of HCC after surgery.

A Prognostic Model of Angiogenesis and Neutrophil Extracellular Traps Related Genes Manipulating Tumor Microenvironment in Colon Cancer.

Colon adenocarcinoma (COAD) is one of the most common carcinomas worldwide. The main causes of cancer-related mortality of COAD are metastases. The fundamental processes for how angiogenesis and neutrophil extracellular traps (NETs) contributing to tumor progression and metastasis are still uncertain. In our study, The Cancer Genome Atlas (TCGA)-COAD dataset (train set) and GSE17536 (test set) were analyzed. Angiogenesis potential index (API) and NETs potential index (NPI) based on angiogenesis and NETs-related genes were respectively built using bioinformatic methods and machine learning algorithms. Subjects were split into groups with low API/NPI or high API/NPI. Survival analysis showed the high API and high NPI patients with the worst survival compared with the others. Between the high API/NPI group and the other groups, differentially expressed genes (DEGs) were found. A four-gene signature (TIMP1, FSL3, CALB2, and FABP4) was included in a risk model based on least absolute shrinkage and selection operator (LASSO) analysis. Additionally, the model displayed a significant association with many immune microenvironment characteristics. Finally, we verified the clinical significance of CALB2 expression and its role to promote the invasion and migration of colon cancer cells in vitro.

Hierarchical triphase diffusion photoelectrodes for photoelectrochemical gas/liquid flow conversion.

Photoelectrochemical device is a versatile platform for achieving various chemical transformations with solar energy. However, a grand challenge, originating from mass and electron transfer of triphase-reagents/products in gas phase, water/electrolyte/products in liquid phase and catalyst/photoelectrode in solid phase, largely limits its practical application. Here, we report the simulation-guided development of hierarchical triphase diffusion photoelectrodes, to improve mass transfer and ensure electron transfer for photoelectrochemical gas/liquid flow conversion. Semiconductor nanocrystals are controllably integrated within electrospun nanofiber-derived mat, overcoming inherent brittleness of semiconductors. The mechanically strong skeleton of free-standing mat, together with satisfactory photon absorption, electrical conductivity and hierarchical pores, enables the design of triphase diffusion photoelectrodes. Such a design allows photoelectrochemical gas/liquid conversion to be performed continuously in a flow cell. As a proof of concept, 16.6- and 4.0-fold enhancements are achieved for the production rate and product selectivity of methane conversion, respectively, with remarkable durability.

GPR176 Promotes Cancer Progression by Interacting with G Protein GNAS to Restrain Cell Mitophagy in Colorectal Cancer.

GPR176 belongs to the G protein-coupled receptor superfamily, which responds to external stimuli and regulates cancer progression, but its role in colorectal cancer (CRC) remains unclear. In the present study, expression analyses of GPR176 are performed in patients with colorectal cancer. Genetic mouse models of CRC coupled with Gpr176-deficiency are investigated, and in vivo and in vitro treatments are conducted. A positive correlation between GPR176 upregulation and the proliferation and poor overall survival of CRC is demonstrated. GPR176 is confirmed to activate the cAMP/PKA signaling pathway and modulate mitophagy, promoting CRC oncogenesis and development. Mechanistically, the G protein GNAS is recruited intracellularly to transduce and amplify extracellular signals from GPR176. A homolog model tool confirmed that GPR176 recruits GNAS intracellularly via its transmembrane helix 3-intracellular loop 2 domain. The GPR176/GNAS complex inhibits mitophagy via the cAMP/PKA/BNIP3L axis, thereby promoting the tumorigenesis and progression of CRC.

Interaction of bioactive kaempferol with HMGB1: Investigation by multi-spectroscopic and molecular simulation methods.

Chronic and persistent inflammation associated with excessive high mobility group protein 1 (HMGB1) is a risk factor for various diseases. Dietary intake of kaempferol has been proven to be effective in reducing HMGB1 levels and the degree of inflammation, but the structural mechanism remains unclear. In this context, we first investigated the interaction between bioactive kaempferol and HMGB1 using multi-spectroscopic and molecular simulation techniques. The surface plasmon resonance (SPR) data indicated that kaempferol binds directly to HMGB1 with a Kd value of 2.89 × 10-5 M. Binding of kaempferol with HMGB1 led to the intrinsic fluorescence quenching and modest secondary structure change of HMGB1 supported by fluorescence spectrometry and circular dichroism (CD). Using dynamic light scattering (DLS), it was found that kaempferol induced the aggregation of HMGB1 protein complex to form larger particles. On HMGB1-activated RAW264.7 cells, kaempferol co-incubation exhibited a remarkable inhibitory effect on nitric oxide (NO) release with an IC50 value of 5.02 µM, which was lower than that of quercetin. In silico, kaempferol binds to HMGB1 mainly through hydrogen bonds and hydrophobic forces. Collectively, our study showed kaempferol as a potential HMGB1 inhibitor, mainly acting by direct binding to HMGB1 and inducing its conformational changes, which provides clues for the treatment of chronic inflammation by kaempferol.