Mechanosensitive protein polycystin-1 promotes periosteal stem/progenitor cells osteochondral differentiation in fracture healing.

Background: Mechanical forces are indispensable for bone healing, disruption of which is recognized as a contributing cause to nonunion or delayed union. However, the underlying mechanism of mechanical regulation of fracture healing is elusive. Methods: We used the lineage-tracing mouse model, conditional knockout depletion mouse model, hindlimb unloading model and single-cell RNA sequencing to analyze the crucial roles of mechanosensitive protein polycystin-1 (PC1, Pkd1) promotes periosteal stem/progenitor cells (PSPCs) osteochondral differentiation in fracture healing. Results: Our results showed that cathepsin (Ctsk)-positive PSPCs are fracture-responsive and mechanosensitive and can differentiate into osteoblasts and chondrocytes during fracture repair. We found that polycystin-1 declines markedly in PSPCs with mechanical unloading while increasing in response to mechanical stimulus. Mice with conditional depletion of Pkd1 in Ctsk+ PSPCs show impaired osteochondrogenesis, reduced cortical bone formation, delayed fracture healing, and diminished responsiveness to mechanical unloading. Mechanistically, PC1 facilitates nuclear translocation of transcriptional coactivator TAZ via PC1 C-terminal tail cleavage, enhancing osteochondral differentiation potential of PSPCs. Pharmacological intervention of the PC1-TAZ axis and promotion of TAZ nuclear translocation using Zinc01442821 enhances fracture healing and alleviates delayed union or nonunion induced by mechanical unloading. Conclusion: Our study reveals that Ctsk+ PSPCs within the callus can sense mechanical forces through the PC1-TAZ axis, targeting which represents great therapeutic potential for delayed fracture union or nonunion.

Associations of Combined Exposure to Metabolic and Inflammatory Indicators with Thyroid Nodules in Adults: A Nested Case-Control Study.

Objective: To explore associations of combined exposure to metabolic/inflammatory indicators with thyroid nodules. Methods: We reviewed personal data for health screenings from 2020 to 2021. A propensity score matching method was used to match 931 adults recently diagnosed with thyroid nodules in a 1 : 4 ratio based on age and gender. Conditional logistic regression and Bayesian kernel machine regression (BKMR) were used to explore the associations of single metabolic/inflammatory indicators and the mixture with thyroid nodules, respectively. Results: In the adjusted models, five indicators (ORQ4 vs. Q1: 1.30, 95% CI: 1.07-1.58 for fasting blood glucose; ORQ4 vs. Q1: 1.30, 95% CI: 1.08-1.57 for systolic blood pressure; ORQ4 vs. Q1: 1.26, 95% CI: 1.04-1.53 for diastolic blood pressure; ORQ4 vs. Q1: 1.23, 95% CI: 1.02-1.48 for white blood cell; ORQ4 vs. Q1: 1.28, 95% CI: 1.07-1.55 for neutrophil) were positively associated with the risk of thyroid nodules, while high-density lipoproteins (ORQ3 vs. Q1: 0.75, 95% CI: 0.61-0.91) were negatively associated with the risk of thyroid nodules. Univariate exposure-response functions from BKMR models showed similar results. Moreover, the metabolic and inflammatory mixture exhibited a significant positive association with thyroid nodules in a dose-response pattern, with systolic blood pressure being the greatest contributor within the mixture (conditional posterior inclusion probability of 0.82). No interaction effects were found among the five indicators. These associations were more prominent in males, participants with higher age (≥40 years old), and individuals with abnormal body mass index status. Conclusions: Levels of the metabolic and inflammatory mixture have a linear dose-response relationship with the risk of developing thyroid nodules, with systolic blood pressure levels being the most important contributor.

COVID-19 in patients with myasthenia gravis: a single-center retrospective study in China.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has been a great concern since 2019. Patients with myasthenia gravis (MG) may be at higher risk of COVID-19 and a more severe disease course. We examined the associations between COVID-19 and MG. METHODS: This single-center retrospective cohort study involved 134 patients who were diagnosed with MG from June 2020 to November 2022 and followed up until April 2023. They were divided into a COVID-19 group and non-COVID-19 group. Logistic regression analysis was used to detect factors potentially associating COVID-19 with MG. RESULTS: Of the 134 patients with MG, 108 (80.6%) had COVID-19. A higher number of comorbidities was significantly associated with an increased risk of COVID-19 (p = 0.040). A total of 103 patients (95.4%) had mild/moderate COVID-19 symptoms, and 4 patients (3.7%) were severe/critical symptoms (including 2 deaths). Higher age (p = 0.036), use of rituximab (p = 0.037), tumors other than thymoma (p = 0.031), Hashimoto's thyroiditis (p = 0.011), more comorbidities (p = 0.002), and a higher baseline MG activities of daily living (MG-ADL) score (p = 0.006) were risk factors for severe COVID-19 symptoms. The MG-ADL score increased by ≥ 2 points in 16 (15.7%) patients. Dry cough and/or expectoration (p = 0.011), use of oral corticosteroids (p = 0.033), and use of more than one kind of immunosuppressant (p = 0.017) were associated with the increase of the post-COVID-19 MG-ADL score. CONCLUSION: Most patients with MG have a mild course of COVID-19. However, patients with older age, many comorbidities, a high MG-ADL score, and use of a variety of immunosuppressants during COVID-19 may be more prone to severe symptoms.

Hi-C, a chromatin 3D structure technique advancing the functional genomics of immune cells.

The functional performance of immune cells relies on a complex transcriptional regulatory network. The three-dimensional structure of chromatin can affect chromatin status and gene expression patterns, and plays an important regulatory role in gene transcription. Currently available techniques for studying chromatin spatial structure include chromatin conformation capture techniques and their derivatives, chromatin accessibility sequencing techniques, and others. Additionally, the recently emerged deep learning technology can be utilized as a tool to enhance the analysis of data. In this review, we elucidate the definition and significance of the three-dimensional chromatin structure, summarize the technologies available for studying it, and describe the research progress on the chromatin spatial structure of dendritic cells, macrophages, T cells, B cells, and neutrophils.

Exploration of Streptomyces fradiae J1-021 as a Potential Host for the Heterologous Production of Spinosad.

Spinosad is a potent insecticide produced by Saccharopolyspora spinosa. However, it harbors certain limitations of a low growing rate and unfeasible genetic manipulation that can be overcome by adopting a superior platform, such as Streptomyces. Herein, we exploited the industrial tylosin-producing Streptomyces fradiae J1-021 for the heterologous production of spinosad. An engineered strain (HW01) with deletion of the tylosin biosynthetic gene cluster (BGC) was constructed and then transformed with the natural spinosad BGC. The distribution and expression levels of the tylosin BGC operons were assessed to construct a natural promoter library. The rate-limiting steps of spinosad biosynthesis were identified by analyzing the transcriptional expression of the spinosad biosynthetic genes. The stepwise engineering work involved the overexpression of the biosynthetic genes participating in rate-limiting pathways using strong promoters, affording an increase in spinosad production to 112.4 µg/L. These results demonstrate that strain HW01 has the potential to be used as a chassis for the heterologous production of polyketides.

Egalitarian penalty or reward? A longitudinal study of adolescent gender attitudes and adulthood income.

Studies often attribute the persistent gender pay gap to different labor force experiences between men and women. Yet, attitudes formed in earlier life stages also critically shape individual outcomes. Using longitudinal data from Taiwan, this study examines whether and how adolescents' gender attitudes are related to income in young adulthood. We test two pathways that mediate this relationship at different time points: the attitude continuity pathway from adolescence to young adulthood, hypothesized by the path-dependence theory, and the occupational pathway during young adulthood, hypothesized by the gender socialization perspective. The findings show that girls with egalitarian attitudes are rewarded, as both pathways facilitate higher income in adulthood. However, boys with egalitarian attitudes are simultaneously rewarded and penalized based on different occupational characteristics, resulting in an overall null effect. This study highlights the importance of adolescent gender attitudes and the differential consequences for men and women in the labor market.

High-Performance Contact-Doped WSe2 Transistors Using TaSe2 Electrodes.

Two-dimensional (2D) transitional metal dichalcogenides (TMDs) have garnered significant attention due to their potential for next-generation electronics, which require device scaling. However, the performance of TMD-based field-effect transistors (FETs) is greatly limited by the contact resistance. This study develops an effective strategy to optimize the contact resistance of WSe2 FETs by combining contact doping and 2D metallic electrode materials. The contact regions were doped using a laser, and the metallic TaSe2 flakes were stacked on doped WSe2 as electrodes. Doping the contact areas decreases the depletion width, while introducing the TaSe2 contact results in a lower Schottky barrier. This method significantly improves the electrical performance of the WSe2 FETs. The doped WSe2/TaSe2 contact exhibits an ultralow Schottky barrier height of 65 meV and a contact resistance of 11 kΩ·µm, which is a 50-fold reduction compared to the conventional Cr/Au contact. Our method offers a way on fabricating high-performance 2D FETs.

Roles of mechanosensitive ion channel PIEZO1 in the pathogenesis of brain injury after experimental intracerebral hemorrhage.

Secondary brain injury after intracerebral hemorrhage (ICH) is the main cause of poor prognosis in ICH patients, but the underlying mechanisms remain less known. The involvement of Piezo1 in brain injury after ICH was studied in a mouse model of ICH. ICH was established by injecting autologous arterial blood into the basal ganglia in mice. After vehicle, Piezo1 blocker, GsMTx4, Piezo1 activator, Yoda-1, or together with mannitol (tail vein injection) was injected into the left lateral ventricle of mouse brain, Piezo1 level and the roles of Piezo1 in neuronal injury, brain edema, and neurological dysfunctions after ICH were determined by the various indicated methods. Piezo1 protein level in neurons was significantly upregulated 24 h after ICH in vivo (human and mice). Piezo1 protein level was also dramatically upregulated in HT22 cells (a murine neuron cell line) cultured in vitro 24 h after hemin treatment as an in vitro ICH model. GsMTx4 treatment or together with mannitol significantly downregulated Piezo1 and AQP4 levels, markedly increased Bcl2 level, maintained more neurons alive, considerably restored brain blood flow, remarkably relieved brain edema, substantially decreased serum IL-6 level, and almost fully reversed the neurological dysfunctions at ICH 24 h group mice. In contrast, Yoda-1 treatment achieved the opposite effects. In conclusion, Piezo1 plays a crucial role in the pathogenesis of brain injury after ICH and may be a target for clinical treatment of ICH.

Development and validation of a novel biomarker panel for Crohn's disease and rheumatoid arthritis diagnosis and treatment.

BACKGROUND: Crohn's disease (CD) and rheumatoid arthritis (RA) are immune-mediated inflammatory diseases. However, the molecular mechanisms linking these two diseases remain unclear. METHODS: To identify shared core genes between CD and RA, we employed differential gene analysis and the least absolute shrinkage and selection operator (LASSO) algorithm. Functional annotation of these core biomarkers was performed using consensus clustering and gene set enrichment analysis. We also constructed a protein-protein network and a miRNA-mRNA network using multiple databases, and potential therapeutic agents targeting the core biomarkers were predicted. Finally, we confirmed the expression of the genes in the biomarker panel in both CD and RA using quantitative PCR. RESULTS: A total of five shared core genes, namely C-X-C motif chemokine ligand 10 (CXCL10), C-X-C motif chemokine ligand 9 (CXCL9), aquaporin 9 (AQP9), secreted phosphoprotein 1 (SPP1), and metallothionein 1M (MT1M), were identified as core biomarkers. These biomarkers activate classical pro-inflammatory and immune signaling pathways, influencing immune cell aggregation. Additionally, testosterone was identified as a potential therapeutic agent targeting the biomarkers identified in this study. The expression of genes in the biomarker panel in CD and RA was confirmed through quantitative PCR. CONCLUSION: Our study revealed some core genes shared between CD and RA and established a novel biomarker panel with potential implications for the diagnosis and treatment of these diseases.

Multi-step strategies for synergistic treatment of urinary tract infections based on D-xylose-decorated antimicrobial peptide carbon dots.

Urinary tract infections (UTIs) caused by Uropathogenic Escherichia coli (UPEC), often reoccur due to the formation of intracellular bacterial colonies (IBCs) and antibiotic resistance. Given the significance of YadC for UPEC infection in our previous study, we developed D-xylose-decorated ɛ-poly-L-lysine (εPL)-based carbon dots (D-xyl@εPLCDs) that can be traced, and employed multi-step approaches to elucidate the functional roles of D-xyl@εPLCDs in UPEC infection. Compared to undecorated particles, D-xyl@εPLCDs demonstrate YadC-dependent bacterial targeting and exhibit enhanced bactericidal activities both intracellularly and extracellularly. Moreover, pre-treatment of D-xyl@εPLCDs before infection blocked the subsequent adhesion and invasion of UPEC to bladder epithelial cells 5637. Increase of ROS production and innate immune responses were observed in bladder epithelial cells 5637 treated with D-xyl@εPLCDs. In addition, treatment of D-xyl@εPLCDs post-infection facilitated clearance of UPEC in the bladders of the UTI mouse model, and reduced ultimate number of neutrophils, macrophages and inflammatory responses raised by invaded bacteria. Collectively, we presented a comprehensive evaluating system to show that D-xyl@εPLCDs exhibits superior bactericidal effects against UPEC, making them a promising candidate for drug development in clinical UTI therapeutics.

The impact of regional policy implementation on the decoupling of carbon emissions and economic development.

The contradiction between economic growth demands and the achievement of the "dual-carbon" goals at the regional level is a pressing issue in China. As a significant economic and cultural center in the western region of China, the Guanzhong Plain urban agglomeration has experienced rapid development and urbanization, making it one of the key areas for national development. Therefore, greater attention should be given to carbon emission reduction in this region. This study focuses on the dataset from 2010 to 2019 in the Guanzhong Plain urban agglomeration, utilizing an input-output table to construct a carbon dioxide emission inventory. The research investigates the impact of regional classification on carbon emission levels within the Guanzhong Plain urban agglomeration. Furthermore, the Tapio decoupling analysis method is employed to assess the decoupling coefficient between regional economic development and carbon emissions. Additionally, the Theil index inequality analysis method is utilized to measure the disparities in per capita carbon emissions among cities within the region. Research findings indicate the following: 1) The regional classification of the Guanzhong Plain urban agglomeration is an effective policy for reducing regional carbon emissions and promoting carbon emissions reduction. 2) There exist variations in energy and industrial structures among cities within the urban agglomeration, necessitating tailored measures for low-carbon transition based on the specific circumstances of each city. 3) The regional classification of the urban agglomeration significantly influences the degree of decoupling between economic development and carbon emissions, with a trend towards stronger decoupling. The study suggests that cities within the Guanzhong Plain urban agglomeration should adopt measures aligned with their natural conditions and economic characteristics to achieve a low-carbon transition. Leveraging the regional cooperation capacity of the urban agglomeration is crucial to decouple economic development from carbon emissions, thereby promoting sustainable economic growth and environmental protection in a mutually beneficial manner.

The EIF3H-HAX1 axis increases RAF-MEK-ERK signaling activity to promote colorectal cancer progression.

Eukaryotic initiation translation factor 3 subunit h (EIF3H) plays critical roles in regulating translational initiation and predicts poor cancer prognosis, but the mechanism underlying EIF3H tumorigenesis remains to be further elucidated. Here, we report that EIF3H is overexpressed in colorectal cancer (CRC) and correlates with poor prognosis. Conditional Eif3h deletion suppresses colorectal tumorigenesis in AOM/DSS model. Mechanistically, EIF3H functions as a deubiquitinase for HAX1 and stabilizes HAX1 via antagonizing ßTrCP-mediated ubiquitination, which enhances the interaction between RAF1, MEK1 and ERK1, thereby potentiating phosphorylation of ERK1/2. In addition, activation of Wnt/ß-catenin signaling induces EIF3H expression. EIF3H/HAX1 axis promotes CRC tumorigenesis and metastasis in mouse orthotopic cancer model. Significantly, combined targeting Wnt and RAF1-ERK1/2 signaling synergistically inhibits tumor growth in EIF3H-high patient-derived xenografts. These results uncover the important roles of EIF3H in mediating CRC progression through regulating HAX1 and RAF1-ERK1/2 signaling. EIF3H represents a promising therapeutic target and prognostic marker in CRC.

Experimental Ischemic Stroke Induces Secondary Bihemispheric White Matter Degeneration and Long-Term Cognitive Impairment.

Clinical studies have identified widespread white matter degeneration in ischemic stroke patients. However, contemporary research in stroke has predominately focused on the infarct and periinfarct penumbra regions. The involvement of white matter degeneration after ischemic stroke and its contribution to post-stroke cognitive impairment and dementia (PSCID) has remained less explored in experimental models. In this study, we examined the progression of locomotor and cognitive function up to 4 months after inducing ischemic stroke by middle cerebral artery occlusion in young adult rats. Despite evident ongoing locomotor recovery, long-term cognitive and affective impairments persisted after ischemic stroke, as indicated by Morris water maze, elevated plus maze, and open field performance. At 4 months after stroke, multimodal MRI was conducted to assess white matter degeneration. T2-weighted MRI (T2WI) unveiled bilateral cerebroventricular enlargement after ischemic stroke. Fluid Attenuated Inversion Recovery MRI (FLAIR) revealed white matter hyperintensities in the corpus callosum and fornix across bilateral hemispheres. A positive association between the volume of white matter hyperintensities and total cerebroventricular volume was noted in stroke rats. Further evidence of bilateral white matter degeneration was indicated by the reduction of fractional anisotropy and quantitative anisotropy at bilateral corpus callosum in diffusion-weighted MRI (DWI) analysis. Additionally, microglia and astrocyte activation were identified in the bilateral corpus callosum after stroke. Our study suggests that experimental ischemic stroke induced by MCAO in young rat replicate long-term cognitive impairment and bihemispheric white matter degeneration observed in ischemic stroke patients. This model provides an invaluable tool for unraveling the mechanisms underlying post-stroke secondary white matter degeneration and its contribution to PSCID.

Tuning the Flat Band in Bi2O2Se by Pressure to Induce Superconductivity.

The discovery of superconductivity in twisted bilayer graphene has reignited enthusiasm in the field of flat-band superconductivity. However, important challenges remain, such as constructing a flat-band structure and inducing a superconducting state in materials. Here, we successfully achieved superconductivity in Bi2O2Se by pressure-tuning the flat-band electronic structure. Experimental measurements combined with theoretical calculations reveal that the occurrence of pressure-induced superconductivity at 30 GPa is associated with a flat-band electronic structure near the Fermi level. Moreover, in Bi2O2Se, a van Hove singularity is observed at the Fermi level alongside pronounced Fermi surface nesting. These remarkable features play a crucial role in promoting strong electron-phonon interactions, thus potentially enhancing the superconducting properties of the material. These findings demonstrate that pressure offers a potential experimental strategy for precisely tuning the flat band and achieving superconductivity.

Identification of Key Ubiquitination Sites Involved in the Proteasomal Degradation of AtACS7 in Arabidopsis.

The gaseous hormone ethylene plays pivotal roles in plant growth and development. The rate-limiting enzyme of ethylene biosynthesis in seed plants is 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS). ACS proteins are encoded by a multigene family and the expression of ACS genes is highly regulated, especially at a post-translational level. AtACS7, the only type III ACS in Arabidopsis, is degraded in a 26S proteasome-dependent pathway. Here, by using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) analysis, two lysine residues of AtACS7, lys285 (K285) and lys366 (K366), were revealed to be ubiquitin-modified in young, light-grown Arabidopsis seedlings but not in etiolated seedlings. Deubiquitylation-mimicking mutations of these residues significantly increased the stability of the AtACS7K285RK366R mutant protein in cell-free degradation assays. All results suggest that K285 and K366 are the major ubiquitination sites on AtACS7, providing deeper insights into the post-translational regulation of AtACS7 in Arabidopsis.

Association between oxidative balance score and self-reported severe headache or migraine based on NHANES 1999 to 2004 data: A cross-sectional study.

Purpose: The pathophysiological mechanisms underlying migraine remain elusive, with oxidative stress hypothesized as a potential etiological factor. The Oxidative Balance Score (OBS) is a comprehensive tool for assessing the impact of diet and lifestyle on oxidative stress, thereby gauging an individual's overall antioxidant capacity. In this cross-sectional study, we explored the correlation between OBS and migraine prevalence among a cohort of US adults. Methods: We analyzed data from 6195 participants aged 20 years and above, drawn from the National Health and Nutrition Examination Survey (NHANES) conducted between 1999 and 2004. We employed multiple logistic regression, coupled with sensitivity analyses, to investigate the relationship between OBS and migraine. Subsequent subgroup analyses and interaction tests were performed to assess the consistency of this association across the population. Results: Multiple logistic regression revealed an inverse relationship between OBS and the likelihood of experiencing migraines. Specifically, individuals in the highest OBS quartile exhibited a significantly reduced migraine risk compared to those in the lowest quartile (OR = 0.98, 95% Confidence Interval (CI): 0.97-0.99, P = 0.0001). Furthermore, restricted cubic spline curves indicated a non-linear association between dietary OBS and migraine incidence (non-linear P = 0.0258). Discussion: Our findings suggest that adherence to an antioxidant-rich diet may be an effective strategy for mitigating migraine, potentially by influencing oxidative balance.

Fluorescence complementation-based FRET imaging reveals centromere assembly dynamics.

Visualization of specific molecules and their assembly in real time and space is essential to delineate how cellular dynamics and signaling circuit are orchestrated during cell division cycle. Our recent studies reveal structural insights into human centromere-kinetochore core CCAN complex. Here we introduce a method for optically imaging trimeric and tetrameric protein interactions at nanometer spatial resolution in live cells using fluorescence complementation-based Förster resonance energy transfer (FC-FRET). Complementary fluorescent protein molecules were first used to visualize dimerization followed by FRET measurements. Using FC-FRET, we visualized centromere CENP-SXTW tetramer assembly dynamics in live cells, and dimeric interactions between CENP-TW dimer and kinetochore protein Spc24/25 dimer in dividing cells. We further delineated the interactions of monomeric CENP-T with Spc24/25 dimer in dividing cells. Surprisingly, our analyses revealed critical role of CDK1 kinase activity in the initial recruitment of Spc24/25 by CENP-T. However, interactions between CENP-T and Spc24/25 during chromosome segregation is independent of CDK1. Thus, FC-FRET provides a unique approach to delineate spatiotemporal dynamics of trimerized and tetramerized proteins at nanometer scale and establishes a platform to report the precise regulation of multimeric protein interactions in space and time in live cells.

Construction of immune-related molecular diagnostic and predictive models of hepatocellular carcinoma based on machine learning.

Background: To exploit hepatocellular carcinoma (HCC) diagnostic substances, we identify potential predictive markers based on machine learning and to explore the significance of immune cell infiltration in this pathology. Method: Three HCC gene expression datasets were used for weighted gene co-expression network analysis (WGCNA) and differential expression analysis. Least Absolute Shrinkage and Selection Operator (LASSO) and Random Forest were applied to identify candidate biomarkers. The diagnostic value of HCC diagnostic gene biomarkers was further assessed by the area under the ROC curve observed in the validation dataset. CIBERSORT was used to analyze 22 immune cell fractions from HCC patients and to analyze their correlation with diagnostic markers. In addition, the prognostic value of the markers and the sensitivity of the drugs were analyzed. Result: WGCNA and differential expression analysis were used to screen 396 distinct gene signatures in HCC tissues. They were mostly engaged in cytoplasmic fusion and the cell division cycle, according to gene enrichment analyses. Five genes were shown to have a high diagnostic value for use as diagnostic biomarkers for HCC, including EFHD1 (AUC = 0.77), KIF4A (AUC = 0.97), UBE2C (AUC = 0.96), SMYD3 (AUC = 0.91), and MCM7 (AUC = 0.93). T cells, NK cells, macrophages, and dendritic cells were found to be related to diagnostic markers in HCC tissues by immune cell infiltration analysis, indicating that these cells are intimately linked to the onset and spread of HCC. Concurrently, these five genes and their constructed models have considerable prognostic value. Conclusion: These five genes (EFHD1, KIF4A, UBE2C, SMYD3, and MCM7) may serve as new candidate molecular markers for HCC, providing new insights for future diagnosis, prognosis, and molecular therapy of HCC.

A Novel KIF4A-Related Model for Predicting Immunotherapy Response and Prognosis in Kidney Renal Clear Cell Carcinoma.

BACKGROUND: The efficacy of chemotherapy in treating Kidney Renal Clear Cell Carcinoma (KIRC) is limited, whereas immunotherapy has shown some promising clinical outcomes. In this context, KIF4A is considered a potential therapeutic target for various cancers. Therefore, identifying the mechanism of KIF4A that can predict the prognosis and immunotherapy response of KIRC would be of significant importance. METHODS: Based on the TCGA Pan-Cancer dataset, the prognostic significance of the KIF4A expression across 33 cancer types was analyzed by univariate Cox algorithm. Furthermore, overlapping differentially expressed genes (DEGs1) between the KIF4A high- and lowexpression groups and DEGs2 between the KIRC and normal groups were also analyzed. Machine learning and Cox regression algorithms were performed to obtain biomarkers and construct a prognostic model. Finally, the role of KIF4A in KIRC was analyzed using quantitative real-time PCR, transwell assay, and EdU experiment. RESULTS: Our analysis revealed that KIF4A was significant for the prognosis of 13 cancer types. The highest correlation with KIF4A was found for KICH among the tumour mutation burden (TMB) indicators. Subsequently, a prognostic model developed with UBE2C, OTX1, PPP2R2C, and RFLNA was obtained and verified with the Renal Cell Cancer-EU/FR dataset. There was a positive correlation between risk score and immunotherapy. Furthermore, the experiment results indicated that KIF4A expression was considerably increased in the KIRC group. Besides, the proliferation, migration, and invasion abilities of KIRC tumor cells were significantly weakened after KIF4A was knocked out. CONCLUSION: We identified four KIF4A-related biomarkers that hold potential for prognostic assessment in KIRC. Specifically, early implementation of immunotherapy targeting these biomarkers may yield improved outcomes for patients with KIRC.