A genomic and epigenomic atlas of prostate cancer in Asian populations.

Prostate cancer is the second most common cancer in men worldwide1. Over the past decade, large-scale integrative genomics efforts have enhanced our understanding of this disease by characterizing its genetic and epigenetic landscape in thousands of patients2,3. However, most tumours profiled in these studies were obtained from patients from Western populations. Here we produced and analysed whole-genome, whole-transcriptome and DNA methylation data for 208 pairs of tumour tissue samples and matched healthy control tissue from Chinese patients with primary prostate cancer. Systematic comparison with published data from 2,554 prostate tumours revealed that the genomic alteration signatures in Chinese patients were markedly distinct from those of Western cohorts: specifically, 41% of tumours contained mutations in FOXA1 and 18% each had deletions in ZNF292 and CHD1. Alterations of the genome and epigenome were correlated and were predictive of disease phenotype and progression. Coding and noncoding mutations, as well as epimutations, converged on pathways that are important for prostate cancer, providing insights into this devastating disease. These discoveries underscore the importance of including population context in constructing comprehensive genomic maps for disease.

LRP5 competes for SPOP binding to enhance tumorigenesis mediated by Daxx and PD-L1 in prostate cancer.

Genetic factors coordinate with environmental factors to drive the pathogenesis of prostate adenocarcinoma (PRAD). SPOP is one of the most mutated genes and LRP5 mediates lipid metabolism that is abnormally altered in PRAD. Here, we investigated the potential cross-talk between SPOP and LRP5 in PRAD. We find a negative correlation between SPOP and LRP5 proteins in PRAD. SPOP knockdown increased LRP5 protein while SPOP overexpression resulted in LRP5 reduction that was fully rescued by proteasome inhibitors. LRP5 intracellular tail has SPOP binding site and the direct interaction between LRP5 and SPOP was confirmed by Co-IP and GST-pulldown. Moreover, LRP5 competed with Daxx for SPOP-mediated degradation, establishing a dynamic balance among SPOP, LRP5 and Daxx. Overexpression of LRP5 tail could shift this balance to enhance Daxx-mediated transcriptional inhibition, and inhibit T cell activity in a co-culture system. Further, we generated human and mouse prostate cancer cell lines expressing SPOP variants (F133V, A227V, R368H). SPOP-F133V and SPOP-A227V have specific effects in up-regulating the protein levels of PD-1 and PD-L1. Consistently, SPOP-F133V and SPOP-A227V show robust inhibitory effects on T cells compared to WT SPOP in co-culture. This is further supported by the mouse syngeneic model showing that SPOP-F133V and SPOP-A227V enhance tumorigenesis of prostate cancer in in-vivo condition. Taken together, our study provides evidence that SPOP-LRP5 crosstalk plays an essential role, and the genetic variants of SPOP differentially modulate the expression and activity of immune checkpoints in prostate cancer.

Enhanced Artificial Intelligence Strategies in Renal Oncology: Iterative Optimization and Comparative Analysis of GPT 3.5 Versus 4.0.

BACKGROUND: The rise of artificial intelligence (AI) in medicine has revealed the potential of ChatGPT as a pivotal tool in medical diagnosis and treatment. This study assesses the efficacy of ChatGPT versions 3.5 and 4.0 in addressing renal cell carcinoma (RCC) clinical inquiries. Notably, fine-tuning and iterative optimization of the model corrected ChatGPT's limitations in this area. METHODS: In our study, 80 RCC-related clinical questions from urology experts were posed three times to both ChatGPT 3.5 and ChatGPT 4.0, seeking binary (yes/no) responses. We then statistically analyzed the answers. Finally, we fine-tuned the GPT-3.5 Turbo model using these questions, and assessed its training outcomes. RESULTS: We found that the average accuracy rates of answers provided by ChatGPT versions 3.5 and 4.0 were 67.08% and 77.50%, respectively. ChatGPT 4.0 outperformed ChatGPT 3.5, with a higher accuracy rate in responses (p < 0.05). By counting the number of correct responses to the 80 questions, we then found that although ChatGPT 4.0 performed better (p < 0.05), both versions were subject to instability in answering. Finally, by fine-tuning the GPT-3.5 Turbo model, we found that the correct rate of responses to these questions could be stabilized at 93.75%. Iterative optimization of the model can result in 100% response accuracy. CONCLUSION: We compared ChatGPT versions 3.5 and 4.0 in addressing clinical RCC questions, identifying their limitations. By applying the GPT-3.5 Turbo fine-tuned model iterative training method, we enhanced AI strategies in renal oncology. This approach is set to enhance ChatGPT's database and clinical guidance capabilities, optimizing AI in this field.

A novel clinically significant prostate cancer prediction system with multiparametric MRI and PSA: P.Z.A. score.

PURPOSE: This study aims to establish and validate a new diagnosis model called P.Z.A. score for clinically significant prostate cancer (csPCa). METHODS: The demographic and clinical characteristics of 956 patients were recorded. Age, prostate-specific antigen (PSA), free/total PSA (f/tPSA), PSA density (PSAD), peripheral zone volume ratio (PZ-ratio), and adjusted PSAD of PZ (aPSADPZ) were calculated and subjected to receiver operating characteristic (ROC) curve analysis. The nomogram was established, and discrimination abilities of the new nomogram were verified with a calibration curve and area under the ROC curve (AUC). The clinical benefits of P.Z.A. score were evaluated by decision curve analysis and clinical impact curves. External validation of the model using the validation set was also performed. RESULTS: The AUCs of aPSADPZ, age, PSA, f/tPSA, PSAD and PZ-ratio were 0.824, 0.672, 0.684, 0.715, 0.792 and 0.717, respectively. The optimal threshold of P.Z.A. score was 0.41. The nomogram displayed excellent net benefit and better overall calibration for predicting the occurrence of csPCa. In addition, the number of patients with csPCa predicted by P.Z.A. score was in good agreement with the actual number of patients with csPCa in the high-risk threshold. The validation set provided better validation of the model. CONCLUSION: P.Z.A. score (including PIRADS(P), aPSADPZ(Z) and age(A)) can increase the detection rate of csPCa, which may decrease the risk of misdiagnosis and reduce the number of unnecessary biopsies. P.Z.A. score contains data that is easy to obtain and is worthy of clinical replication.

Anlotinib combined with the PD-L1 blockade exerts the potent anti-tumor immunity in renal cancer treatment.

Anlotinib have shown certain therapeutic effects of renal cell carcinoma (RCC), but drug resistance during treatment leads to the fact that the therapeutic effect is unsatisfactory. Herein, we investigated the tumor immune microenvironment about resistance mechanisms when application of Anlotinib and further improved its therapeutic effect. Our results showed that Anlotinib suppressed cell proliferation and promoted cell apoptosis in RCC cells. Meanwhile, the significantly up-regulated expression of PD-L1 was observed in Anlotinib-treated RCC cells by the concentration and time-dependent manner. Further study showed that Anlotinib-induced PD-L1 expression was regulated by autocrine IL-6 mediated JAK2/STAT3 signaling pathways. Interestingly, Anlotinib combined with PD-L1 blockade increased the infiltration of IFN-γ+CD8+ T cells and natural killer (NK) cells, also decreased the quantity of Treg cells and MDSCs in vivo. Likewise, the therapy above showed significantly synergistic therapeutic effect as demonstrated by reduced tumor volume and weight. These results indicated that the drug resistance might be attributed to the Anlotinib induced-PD-L1 mediated immunosuppression in renal cancer treatment. Anlotinib combined anti-PDL-1 treatment exerts the potential anti-tumor effect by promoting the induction and activation of immune killer cells. The therapeutic strategy of Anlotinib combined anti-PDL-1 could be a potential and promising approach for the therapy of renal cancer or other malignant tumors.

LINC00624/TEX10/NF-κB axis promotes proliferation and migration of human prostate cancer cells.

Prostate cancer (PCa) is a malignant epithelial tumor with a high rate of biochemical or local recurrence. Studies have suggested that LINC00624 plays an important oncogenic role in liver cancer. However, whether it exerts similar effects in PCa progression remains unknown. In this study, we explored the effects of LINC00624 on the malignant progression of PCa and sought to identify the relevant signaling pathways. The results showed that LINC00624 was highly expressed in PCa tissues and cells and was associated with poor prognosis in PCa patients. In vitro and in vivo assays further showed that LINC00624 knockdown could decrease the proliferative and migratory ability of PCa cells. Mechanistically, we found that LINC00624 and TEX10 formed a co-regulatory axis that stimulated NF-κB activity. Our data suggest that LINC00624 acts as an oncogene in PCa progression and has potential as a novel biomarker for PCa.

A Supramolecular Self-Assembling Nanoagent by Inducing Intracellular Aggregation of PSMA for Prostate Cancer Molecularly Targeted Theranostics.

Prostate cancer (PCa) with prostate-specific membrane antigen (PSMA)-specific high expression is well suited for molecularly targeted theranostics. PSMA expression correlates with the malignancy of PCa, and its dimeric form can promote tumor progression by exerting enzymatic activity to activate downstream signal transduction. However, almost no studies have shown that arresting the procancer signaling of the PSMA receptors themselves can cause tumor cell death. Meanwhile, supramolecular self-assembling peptides are widely used to design anticancer agents due to their unique and excellent properties. Here, a PSMA-targeting supramolecular self-assembling nanotheranostic agent, DBT-2FFGACUPA, which actively targets PSMA receptors on PCa cell membranes and induces them to enter the cell and form large aggregates, is developed. This process not only selectively images PSMA-positive tumor cells but also suppresses the downstream procancer signals of PSMA, causing tumor cell death. This work provides an alternative approach and an advanced agent for molecularly targeted theranostics options in PCa that can induce tumor cell death without relying on any reported anticancer drugs.

Aberrant FBXW7-mediated ubiquitination and degradation of ZMYND8 enhances tumor progression and stemness in bladder cancer.

ZMYND8, an epigenetic regulator, was identified as a common oncogene across various tumors. However, little was reported about the association between ZMYND8 and bladder cancer. Besides, aberrant mechanisms that contribute to abnormal ZMYND8 expressions still remain unclear. In the current study, we first found that ZMYND8 protein levels were significantly elevated in Bca samples versus normal tissues, but not the mRNA levels. We then utilized the Cell Counting Kit-8 (CCK-8) assay, clone formation assay and transwell analysis to confirm that ZMYND8 could remarkably promote the tumor progression in vitro, including growth capacity and migration. Bioinformatic predictive analysis revealed that E3 ubiquitin ligase FBXW7 interacts directly with ZMYND8 and degrades ZMYND8 in a polyubiquitination manner. Low FBXW7 was a hazard factor for promoting and depending on accumulated ZMYND8 proteins to promote Bca progression. Gene set enrichment analysis (GSEA) further indicated that ZMYND8 was notably associated with stemness process, which was well functionally validated. Lastly, ZMYND8 deficiency was observed to inhibit tumor growth of Bca in vivo, revealing a promising translational significance in Bca treatment. In conclusion, our study for the first time provided evidence for a novel mechanism of FBXW7/ZMYND8 axis in Bca, providing therapeutic vulnerability for individualized cancer treatment.

FOXD1-AS1 promotes malignant behaviours of prostate cancer cells via the miR-3167/YWHAZ axis.

Herein, the effect of long noncoding RNA forkhead box D1 antisense RNA 1 (FOXD1-AS1) on malignant phenotypes of prostate cancer (PCa) cells was investigated. FOXD1-AS1 presented high expression in PCa cells according to the results of RT-qPCR. As shown by cell counting kit-8 assays, colony formation assays, wound-healing assays, Transwell assays and flow cytometry analyses, silenced FOXD1-AS1 suppressed PCa cell viability, proliferation, migration and invasion and enhanced cell apoptosis. Additionally, FOXD1-AS1 was primarily localised in cytoplasm of PCa cells. RNA immunoprecipitation assays and luciferase reporter assays revealed that FOXD1-AS1 interacted with miR-3167 in PCa cells. MiR-3167 functioned as an anti-oncogene in PCa and miR-3167 overexpression suppressed cell proliferation while promoted cell apoptosis. Moreover, the downstream target of miR-3167 is mRNA YWHAZ. FOXD1-AS1 elevated the expression of YWHAZ by binding with miR-3167. The suppressive effect of miR-3167 on YWHAZ expression was reversed by FOXD1-AS1 overexpression. Furthermore, overexpressed YWHAZ reversed the suppressive effect of FOXD1-AS1 deficiency on malignant behaviours of PCa cells. Overall, FOXD1-AS1 facilitates malignant phenotypes of PCa cells by up-regulating YWHAZ via miR-3167. The study first reveals the molecular mechanism of FOXD1-AS1 in PCa, suggesting that FOXD1-AS1 and its downstream molecules might be prognostic biomarkers before medical treatment.

Insights into the Allosteric Effect of SENP1 Q597A Mutation on the Hydrolytic Reaction of SUMO1 via an Integrated Computational Study.

Small ubiquitin-related modifier (SUMO)-specific protease 1 (SENP1) is a cysteine protease that catalyzes the cleavage of the C-terminus of SUMO1 for the processing of SUMO precursors and deSUMOylation of target proteins. SENP1 is considered to be a promising target for the treatment of hepatocellular carcinoma (HCC) and prostate cancer. SENP1 Gln597 is located at the unstructured loop connecting the helices α4 to α5. The Q597A mutation of SENP1 allosterically disrupts the hydrolytic reaction of SUMO1 through an unknown mechanism. Here, extensive multiple replicates of microsecond molecular dynamics (MD) simulations, coupled with principal component analysis, dynamic cross-correlation analysis, community network analysis, and binding free energy calculations, were performed to elucidate the detailed mechanism. Our MD simulations showed that the Q597A mutation induced marked dynamic conformational changes in SENP1, especially in the unstructured loop connecting the helices α4 to α5 which the mutation site occupies. Moreover, the Q597A mutation caused conformational changes to catalytic Cys603 and His533 at the active site, which might impair the catalytic activity of SENP1 in processing SUMO1. Moreover, binding free energy calculations revealed that the Q597A mutation had a minor effect on the binding affinity of SUMO1 to SENP1. Together, these results may broaden our understanding of the allosteric modulation of the SENP1-SUMO1 complex.

Metformin exerts anti-AR-negative prostate cancer activity via AMPK/autophagy signaling pathway.

BACKGROUND: Encouraged by the goal of developing an effective treatment strategy for prostate cancer, this study explored the mechanism involved in metformin-mediated inhibition of AR-negative prostate cancer. METHODS: Cell behaviors of DU145 and PC3 cells were determined by CCK8 test, colony formation experiment and scratch test. Flow cytometry was used to detect cell cycle distribution. Cell autophagy was induced with metformin, and an autophagy inhibitor, 3-MA, was used to assess the level of autophagy. Detection of LC3B by immunofluorescence was conducted to determine autophagy level. Cell proliferation, autophagy and cell cycle were examined by performing Western blot. DU145 and PC3 cell lines were transfected with AMPK siRNA targeting AMPK-α1 and AMPK-α2. Tumor formation experiment was carried out to evaluate the anti-prostate cancer effect of metformin in vivo. RESULTS: The inhibitory effect of metformin on the proliferation of prostate cancer cell lines was confirmed in this study, and the mechanism of such an effect was related to autophagy and the block of cell cycle at G0/G1 phase. Metformin also induced the activation of AMPK, markedly promoted expression of LC3II, and down-regulated the expression of p62/SQSTM1. Animal experiments showed that the tumor volume of metformin group was smaller, meanwhile, the levels of p-AMPK (Thr172) and LC3B were up-regulated and the Ki-67 level was down-regulated, without abnormalities in biochemical indicators. CONCLUSION: This study found that autophagy induction might be the mechanism through which metformin suppressed the growth of AR-negative prostate cancer. Moreover, the activation of AMPK/autophagy pathway might be a therapeutically effective for treating AR-negative prostate cancer in the future.

miR-499a inhibits the proliferation and apoptosis of prostate cancer via targeting UBE2V2.

BACKGROUND: Prostate cancer is one of the malignant tumors of the urinary system and ranks second among the fatal cancers in men. And with age, the incidence of prostate cancer will increase linearly. METHODS: In this study, we measured the expression of Ubiquitin Conjugating Enzyme E2 V2 (UBE2V2) in prostate cancer tissues and cell lines by WB and explored the effect of UBE2V2 on the proliferation characteristics of prostate cancer by MTT and colony formation test. RESULTS: In our research, we found that the UBE2V2 protein level in prostate cancer cell lines was significantly higher than the UBE2V2 protein level in normal prostate cells, and the mRNA expression level did not change significantly compared with normal prostate tissue cells. At the same time, we found that miR-499a combined with UBE2V2 inhibited the expression of UBE2V2 in prostate cancer cells. CONCLUSIONS: In conclusion, our results indicate that miR-499a inhibits the proliferation of human prostate cancer cells by targeting UBE2V2, which will provide a potential target for the treatment of prostate cancer.

Overexpression of Capns1 Predicts Poor Prognosis and Correlates with Tumor Progression in Renal Cell Carcinoma.

INTRODUCTION: Calpain small subunit 1 (Capns1) has shown its correlation with the metastasis and invasion of hepatocellular carcinoma and intrahepatic cholangiocarcinoma. However, the expression and function of Capns1 in human renal cell carcinoma (RCC) have not been clarified. This study aimed to examine the expression of Capns1 in RCC tissues and cell lines and to assess its role performed in RCC. METHODS: Capns1 expression was evaluated in 75 pairs of RCC and matched adjacent non-tumor tissues by immunohistochemistry. The prognostic value of Capns1 in RCC was assessed by Kaplan-Meier and Cox regression analyses. The action of Capns1 in the proliferation, adhesion, migration, and invasion of RCC cells and the effects on matrix metalloproteinase (MMP) 2 and 9 expression were evaluated after Capns1 silence. RESULTS: Capns1 expression was significantly higher in RCC tissues compared with the adjacent non-tumor tissues. Multivariate analysis showed that Capns1 overexpression was an independent poor prognostic marker in RCC. The silencing of Capns1 prohibited cell adhesion and impaired the migration and invasion ability of 786-O cells in vitro. Furthermore, Capns1 silence reduced MMP2 and MMP9 expression. CONCLUSION: Capns1 overexpression predicts poor prognosis and correlates with tumor progression in RCC. Capns1 expression might serve a prognostic marker and therapeutic target for RCC.

Antibody-induced vascular inflammation skews infiltrating macrophages to a novel remodeling phenotype in a model of transplant rejection.

HLA donor-specific antibodies (DSAs) binding to vascular endothelial cells of the allograft trigger inflammation, vessel injury, and antibody-mediated rejection (AMR). Accumulation of intragraft-recipient macrophages is a histological characteristic of AMR, which portends worse outcome. HLA class I (HLA I) DSAs enhance monocyte recruitment by activating endothelial cells and engaging FcγRs, but the DSA-activated donor endothelial influence on macrophage differentiation is unknown. In this study, we explored the consequence of DSA-activated endothelium on infiltrating monocyte differentiation. Here we show that cardiac allografts from murine recipients treated with MHC I DSA upregulated genes related to monocyte transmigration and Fc receptor stimulation. Human monocytes co-cultured with HLA I IgG-stimulated primary human endothelium promoted monocyte differentiation into CD68+ CD206+ CD163+ macrophages (M(HLA I IgG)), whereas HLA I F(ab')2 stimulated endothelium solely induced higher CD206 (M(HLA I F(ab')2 )). Both macrophage subtypes exhibited significant changes in discrete cytokines/chemokines and unique gene expression profiles. Cross-comparison of gene transcripts between murine DSA-treated cardiac allografts and human co-cultured macrophages identified overlapping genes. These findings uncover the role of HLA I DSA-activated endothelium in monocyte differentiation, and point to a novel, remodeling phenotype of infiltrating macrophages that may contribute to vascular injury.

Data-driven translational prostate cancer research: from biomarker discovery to clinical decision.

Prostate cancer (PCa) is a common malignant tumor with increasing incidence and high heterogeneity among males worldwide. In the era of big data and artificial intelligence, the paradigm of biomarker discovery is shifting from traditional experimental and small data-based identification toward big data-driven and systems-level screening. Complex interactions between genetic factors and environmental effects provide opportunities for systems modeling of PCa genesis and evolution. We hereby review the current research frontiers in informatics for PCa clinical translation. First, the heterogeneity and complexity in PCa development and clinical theranostics are introduced to raise the concern for PCa systems biology studies. Then biomarkers and risk factors ranging from molecular alternations to clinical phenotype and lifestyle changes are explicated for PCa personalized management. Methodologies and applications for multi-dimensional data integration and computational modeling are discussed. The future perspectives and challenges for PCa systems medicine and holistic healthcare are finally provided.

TRIM13 inhibits cell migration and invasion in clear-cell renal cell carcinoma.

TRIM13, a member of the TRIM family, is a RING domain containing E3 ubiquitin ligase which plays critical roles in diverse cellular processes including cell death, cancer and antiviral immunity. However, its expression and molecular mechanism on renal cell carcinoma (RCC) have not been characterized. This study explored the clinical significance and biological function of TRIM13 in human RCC. Western blot analyses and Immunohistochemical were performed in RCC tissues. The clinical relevance of TRIM13 in RCC was evaluated by immunohistochemical staining using tissue microarray. The role of TRIM13 in migration was studied in renal cell carcinoma cell lines of 786-O through knocking down TRIM13 with siRNA and over-expression of TRIM13. The regulation of TRIM13 on migration and invasion were determined by wound-healing and transwell assays. Western blot analyses showed that TRIM13 expression was dramatically decreased in RCC tissues compared with adjacent non-tumorous tissues. Up-regulation of TRIM13 in 786-O cells resulted in decreased NF-kB, MMP-9 and p-AKT levels and the capability for migration and invasion. In contrast, the ectopic expression of TRIM13 decreased the migration and invasion ability of 786-O cells. These findings indicate that TRIM13 decreases RCC metastasis and invasion may serve as a candidate RCC prognostic marker and a potential therapeutic target.

The prognostic value and potential mechanism of Matrix Metalloproteinases among Prostate Cancer.

Background: Matrix Metalloproteinases (MMPs) play an indispensable role in the initial alteration and development of PCa. We tried to generate an MMP-related prognostic signature (MMPS) in prostate cancer (PCa). Methods: TCGA-PRAD, MSKCC/GSE21032, GSE116918, GSE70769 cohorts were enrolled to assess the prognostic value of MMPs. The least absolute shrinkage and selection operator (LASSO) Cox regression was employed to generate the MMPS signature. The log-rank test and Kaplan-Meier (K-M) survival curve were applied to show the difference RFS, The receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) was plotted to predict the accuracy of signature. CIBERSORT was conducted to analyze the different immune infiltration in MMPS-H and MMPS-L groups. Potential signaling pathways activated in the MMPS-H groups by Metascape. Results: MMP1, MMP7, MMP11, MMP24 and MMP26 were selected by LASSO regression and established the MMPS predict signature. The MMPS showed the high prognostic value in TCGA-PRAD training cohort (AUC=0.714) and validation cohorts (GSE116918: AUC=0.976, GSE70769: AUC=0.738, MSKCC: AUC=0.793). Pid integrin1 pathway, G2M checkpoint, and response to growth factor signaling pathways were activated in MMPS-H group, patients with the high MMPS risk score and low M2 macrophage showed the worst recurrence-free survival (RFS). Conclusion: MMPs involved and played an essential role in the tumorigenesis and biochemical recurrence in PCa patients. The MMPS signature could accurately predict the recurrence of PCa patients and validated in several cohorts.

Preoperative Anemia as a Simple Prognostic Factor in Patients with Urinary Bladder Cancer.

BACKGROUND To evaluate the incidence of preoperative anemia and its prognostic role in patients with urinary bladder cancer (BC). MATERIAL AND METHODS A total of 317 patients diagnosed with BC were enrolled in this retrospective cohort study. Univariate and multivariate analysis was used to identify independent prognostic factors and Kaplan-Meier survival analysis was applied to examine the influence of anemia on survival. RESULTS 109 patients (34.4%) were anemic with a median preoperative hemoglobin of 114 g/L (interquartile range 104 to 122.5). After a median of 6 years follow-up (range: 2 to 8 years), the median recurrence-free survival (RFS), progression-free survival (PFS), and overall survival (OS) in anemic patients were significantly lower than non-anemic patients (p≤0.001). Multivariate Cox analysis indicated that anemia remained an independent predictor of RFS and OS (p=0.010, 0.007). CONCLUSIONS Anemic patients with BC are likely to have a shorter RFS and OS than non-anemic patients, and anemia is an independent predictor of RFS and OS.

Different expression of B7-H3 in the caput, corpus, and cauda of the epididymis in mouse.

BACKGROUND: B7-H3, a member of the B7 family of the Ig superfamily of proteins, has been detected in the epididymis, which is a storage organ related to sperm maturation. However, the characteristics of its expression in different regions of the epididymis remain unknown. Our aim was to investigate the expression of B7-H3 in the caput, corpus, and cauda of the epididymis. METHODS: We extracted epididymis specimens from adult male C57BL/6 mice. The expression of B7-H3 was then measured with immunohistochemistry, enzyme-linked immunosorbent assay (ELISA) and western blotting. RESULTS: B7-H3 protein was predominantly detected on the membrane and in the cytoplasm of the principal cells in the epididymis. Moreover, the level of B7-H3 in the corpus of the mouse epididymis was significantly higher than that in the caput (p < 0.05) or the cauda of the epididymis (P < 0.05). However, there was no remarkable difference in the level of B7-H3 between the caput and the cauda (p > 0.05). CONCLUSIONS: The caput, corpus, and cauda of the mouse epididymis all expressed B7-H3 protein. However, the levels of B7-H3 were different in the three regions of the epididymis.