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Background/Aims@#Despite the high efficacy of direct-acting antivirals (DAAs), approximately 1–3% of hepatitis C virus (HCV) patients fail to achieve a sustained virological response. We conducted a nationwide study to investigate risk factors associated with DAA treatment failure. Machine-learning algorithms have been applied to discriminate subjects who may fail to respond to DAA therapy. @*Methods@#We analyzed the Taiwan HCV Registry Program database to explore predictors of DAA failure in HCV patients. Fifty-five host and virological features were assessed using multivariate logistic regression, decision tree, random forest, eXtreme Gradient Boosting (XGBoost), and artificial neural network. The primary outcome was undetectable HCV RNA at 12 weeks after the end of treatment. @*Results@#The training (n=23,955) and validation (n=10,346) datasets had similar baseline demographics, with an overall DAA failure rate of 1.6% (n=538). Multivariate logistic regression analysis revealed that liver cirrhosis, hepatocellular carcinoma, poor DAA adherence, and higher hemoglobin A1c were significantly associated with virological failure. XGBoost outperformed the other algorithms and logistic regression models, with an area under the receiver operating characteristic curve of 1.000 in the training dataset and 0.803 in the validation dataset. The top five predictors of treatment failure were HCV RNA, body mass index, α-fetoprotein, platelets, and FIB-4 index. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the XGBoost model (cutoff value=0.5) were 99.5%, 69.7%, 99.9%, 97.4%, and 99.5%, respectively, for the entire dataset. @*Conclusions@#Machine learning algorithms effectively provide risk stratification for DAA failure and additional information on the factors associated with DAA failure.
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Background/Aims@#Chronic hepatitis C (CHC) patients who failed antiviral therapy are at increased risk for hepatocellular carcinoma (HCC). This study assessed the potential role of metformin and statins, medications for diabetes mellitus (DM) and hyperlipidemia (HLP), in reducing HCC risk among these patients. @*Methods@#We included CHC patients from the T-COACH study who failed antiviral therapy. We tracked the onset of HCC 1.5 years post-therapy by linking to Taiwan’s cancer registry data from 2003 to 2019. We accounted for death and liver transplantation as competing risks and employed Gray’s cumulative incidence and Cox subdistribution hazards models to analyze HCC development. @*Results@#Out of 2,779 patients, 480 (17.3%) developed HCC post-therapy. DM patients not using metformin had a 51% increased risk of HCC compared to non-DM patients, while HLP patients on statins had a 50% reduced risk compared to those without HLP. The 5-year HCC incidence was significantly higher for metformin non-users (16.5%) versus non-DM patients (11.3%; adjusted sub-distribution hazard ratio [aSHR]=1.51; P=0.007) and metformin users (3.1%; aSHR=1.59; P=0.022). Statin use in HLP patients correlated with a lower HCC risk (3.8%) compared to non-HLP patients (12.5%; aSHR=0.50; P<0.001). Notably, the increased HCC risk associated with non-use of metformin was primarily seen in non-cirrhotic patients, whereas statins decreased HCC risk in both cirrhotic and non-cirrhotic patients. @*Conclusions@#Metformin and statins may have a chemopreventive effect against HCC in CHC patients who failed antiviral therapy. These results support the need for personalized preventive strategies in managing HCC risk.
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Background/Aims@#Oral EDP-514 is a potent core protein inhibitor of hepatitis B virus (HBV) replication, which produced a >4-log viral load reduction in HBV-infected chimeric mice with human liver cells. This study evaluated the safety, pharmacokinetics, and antiviral activity of three doses of EDP-514 in treatment-naive viremic patients with HBeAgpositive or -negative chronic HBV infection. @*Methods@#Patients with HBsAg detectable at screening and at least 6 months previously were eligible. HBeAg-positive and -negative patients had a serum/plasma HBV DNA level ≥20,000 and ≥2,000 IU/mL, respectively. Twenty-five patients were randomized to EDP-514 200 (n=6), 400 (n=6) or 800 mg (n=7) or placebo (n=6) once daily for 28 days. @*Results@#A dose-related increase in EDP-514 exposure (AUClast and Cmax) was observed across doses. At Day 28, mean reductions in HBV DNA were –2.9, –3.3, –3.5 and –0.2 log10 IU/mL with EDP-514 200 mg, 400 mg, 800 mg, and placebo groups, respectively. The corresponding mean change from baseline for HBV RNA levels was –2.9, –2.4, –2.0, and –0.02 log10 U/mL. No virologic failures were observed. No clinically meaningful changes from baseline were observed for HBsAg, HBeAg or HBcrAg. Nine patients reported treatment emergent adverse events of mild or moderate severity with no discontinuations, serious AEs or deaths. @*Conclusions@#In treatment-naïve viremic patients, oral EDP-514 was generally safe and well-tolerated, displayed PK profile supportive of once-daily dosing, and markedly reduced HBV DNA and HBV RNA.
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The significance of 5-methylcytosine (m5C) methylation in human malignancies has become an increasing focus of investigation. Here, we show that m5C regulators including writers, readers and erasers, are predominantly upregulated in urothelial carcinoma of the bladder (UCB) derived from Sun Yat-sen University Cancer Center and The Cancer Genome Atlas cohort. In addition, NOP2/Sun RNA methyltransferase family member 2 (NSUN2) as a methyltransferase and Aly/REF export factor (ALYREF) as a nuclear m5C reader, are frequently coexpressed in UCB. By applying patient-derived organoids model and orthotopic xenograft mice model, we demonstrate that ALYREF enhances proliferation and invasion of UCB cells in an m5C-dependent manner. Integration of tanscriptome-wide RNA bisulphite sequencing (BisSeq), RNA-sequencing (RNA-seq) and RNA Immunoprecipitation (RIP)-seq analysis revealed that ALYREF specifically binds to hypermethylated m5C site in RAB, member RAS oncogene family like 6 (RABL6) and thymidine kinase 1 (TK1) mRNA via its K171 domain. ALYREF controls UCB malignancies through promoting hypermethylated RABL6 and TK1 mRNA for splicing and stabilization. Moreover, ALYREF recognizes hypermethylated m5C site of NSUN2, resulting in NSUN2 upregulation in UCB. Clinically, the patients with high coexpression of ALYREF/RABL6/TK1 axis had the poorest overall survival. Our study unveils an m5C dependent cross-regulation between nuclear reader ALYREF and m5C writer NSUN2 in activation of hypermethylated m5C oncogenic RNA through promoting splicing and maintaining stabilization, consequently leading to tumor progression, which provides profound insights into therapeutic strategy for UCB.
Subject(s)
Carcinoma, Transitional Cell , Urinary Bladder Neoplasms , Humans , Animals , Mice , Urinary Bladder Neoplasms/genetics , RNA, Messenger , RNA , Disease Models, Animal , Methyltransferases/genetics , Nuclear Proteins , Transcription Factors , RNA-Binding ProteinsABSTRACT
PURPOSE: Recurrent renal cell carcinoma(reRCC) is associated with poor prognosis and the underlying mechanism is not yet clear. A comprehensive understanding of tumor microenvironment (TME) of reRCC may aid in designing effective anticancer therapies, including immunotherapies. Single-cell transcriptomics holds great promise for investigating the TME, however, this technique has not been used in reRCC. Here, we aimed to explore the difference in the TME and gene expression pattern between primary RCC (pRCC) and reRCC at single-cell level. EXPERIMENTAL DESIGN: We performed single-cell RNA sequencing analyses of 32,073 cells from 2 pRCC, 2 reRCC, and 3 adjacent normal kidney samples. 41 pairs of pRCC and reRCC samples were collected as a validation cohort to assess differences observed in single-cell sequencing. The prognostic significance of related cells and markers were studied in 47 RCC patients underwent immunotherapy. The function of related cells and markers were validated via in vitro and in vivo experiments. RESULTS: reRCC had reduced CD8+ T cells but increased cancer-associated fibroblasts (CAFs) infiltration compared with pRCC. Reduced CD8+ T cells and increased CAFs infiltration were significantly associated with a worse response from immunotherapy. Remarkably, CAFs showed substantial expression of LGALS1 (Gal1). In vitro, CAFs could induce CD8+ T cells apoptosis via Gal1. In vivo, knockdown of Gal1 in CAFs suppressed tumor growth, increased CD8+ T cells infiltration, reduced the proportion of apoptotic CD8+ T cells and enhanced the efficacy of immunotherapy. CONCLUSIONS: We delineated the heterogeneity of reRCC and highlighted an innovative mechanism that CAFs acted as a suppressor of CD8+ T cells via Gal1. Targeting Gal1 combined with anti-PD1 showed promising efficacy in treating RCC.
Subject(s)
CD8-Positive T-Lymphocytes/metabolism , Carcinoma, Renal Cell/genetics , Immunotherapy/methods , Kidney Neoplasms/genetics , Lymphocytes, Tumor-Infiltrating/metabolism , Single-Cell Analysis/methods , Transcriptome/immunology , Translational Research, Biomedical/methods , Animals , Carcinoma, Renal Cell/pathology , Cell Line, Tumor , Female , Fibroblasts , Humans , Kidney Neoplasms/pathology , Male , Mice , Prognosis , Tumor MicroenvironmentABSTRACT
Reactive oxygen species (ROS) which are continuously generated mainly by mitochondria, have been proved to play an important role in the stress signaling of cancer cells. Moreover, pentatricopeptide repeat (PPR) proteins have been suggested to take part in mitochondrial metabolism. However, the mechanisms integrating the actions of these distinct networks in urothelial carcinoma of the bladder (UCB) pathogenesis are elusive. In this study, we found that leucine rich pentatricopeptide repeat containing (LRPPRC) was frequently upregulated in UCB and that it was an independent prognostic factor in UCB. We further revealed that LRPPRC promoted UCB tumorigenesis by regulating the intracellular ROS homeostasis. Mechanistically, LRPPRC modulates ROS balance and protects UCB cells from oxidative stress via mt-mRNA metabolism and the circANKHD1/FOXM1 axis. In addition, the SRA stem-loop interacting RNA binding protein (SLIRP) directly interacted with LRPPRC to protect it from ubiquitination and proteasomal degradation. Notably, we showed that LRPPRC modulated the tumorigenesis of UCB cells in a circANKHD1-FOXM1-dependent manner. In conclusion, LRPPRC exerts critical roles in regulating UCB redox homeostasis and tumorigenesis, and is a prognostic factor for UCB; suggesting that LRPPRC may serve as an exploitable therapeutic target in UCB.
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Background/Aims@#Real-world studies assessing the effectiveness and safety of sofosbuvir/velpatasvir (SOF/VEL) plus ribavirin (RBV) for Child-Pugh B/C hepatitis C virus (HCV)-related cirrhosis are limited. @*Methods@#We included 107 patients with Child-Pugh B/C HCV-related cirrhosis receiving SOF/VEL plus RBV for 12 weeks in Taiwan. The sustained virologic response rates at off-treatment week 12 (SVR12) for the evaluable population (EP), modified EP, and per-protocol population (PP) were assessed. Thesafety profiles were reported. @*Results@#The SVR12 rates in the EP, modified EP and PP were 89.7% (95% confidence interval [CI], 82.5–94.2%), 94.1% (95% CI, 87.8–97.3%), and 100% (95% CI, 96.2–100%). Number of patients who failed to achieve SVR12 were attributed to virologic failures. The SVR12 rates were comparable regardless of patient characteristics. One patient discontinued treatment because of adverse events (AEs). Twenty-four patients had serious AEs and six died, but none were related to SOF/VEL or RBV. Among the 96 patients achieving SVR12, 84.4% and 64.6% had improved Child-Pugh and model for endstage liver disease (MELD) scores. Multivariate analysis revealed that a baseline MELD score ≥15 was associated with an improved MELD score of ≥3 (odds ratio, 4.13; 95% CI, 1.16–14.71; P=0.02). Patients with chronic kidney disease (CKD) stage 1 had more significant estimated glomerular filtration rate declines than patients with CKD stage 2 (-0.42 mL/min/1.73 m2/month; P=0.01) or stage 3 (-0.56 mL/min/1.73 m2/month; P<0.001). @*Conclusions@#SOF/VEL plus RBV for 12 weeks is efficacious and well-tolerated for Child-Pugh B/C HCV-related cirrhosis.
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Background/Aims@#Real-world studies assessing the effectiveness and safety of sofosbuvir/velpatasvir (SOF/VEL) plus ribavirin (RBV) for Child-Pugh B/C hepatitis C virus (HCV)-related cirrhosis are limited. @*Methods@#We included 107 patients with Child-Pugh B/C HCV-related cirrhosis receiving SOF/VEL plus RBV for 12 weeks in Taiwan. The sustained virologic response rates at off-treatment week 12 (SVR12) for the evaluable population (EP), modified EP, and per-protocol population (PP) were assessed. Thesafety profiles were reported. @*Results@#The SVR12 rates in the EP, modified EP and PP were 89.7% (95% confidence interval [CI], 82.5–94.2%), 94.1% (95% CI, 87.8–97.3%), and 100% (95% CI, 96.2–100%). Number of patients who failed to achieve SVR12 were attributed to virologic failures. The SVR12 rates were comparable regardless of patient characteristics. One patient discontinued treatment because of adverse events (AEs). Twenty-four patients had serious AEs and six died, but none were related to SOF/VEL or RBV. Among the 96 patients achieving SVR12, 84.4% and 64.6% had improved Child-Pugh and model for endstage liver disease (MELD) scores. Multivariate analysis revealed that a baseline MELD score ≥15 was associated with an improved MELD score of ≥3 (odds ratio, 4.13; 95% CI, 1.16–14.71; P=0.02). Patients with chronic kidney disease (CKD) stage 1 had more significant estimated glomerular filtration rate declines than patients with CKD stage 2 (-0.42 mL/min/1.73 m2/month; P=0.01) or stage 3 (-0.56 mL/min/1.73 m2/month; P<0.001). @*Conclusions@#SOF/VEL plus RBV for 12 weeks is efficacious and well-tolerated for Child-Pugh B/C HCV-related cirrhosis.
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BACKGROUND: Muscle-invasive bladder cancer (MIBC) is a lethal disease with poor treatment response and a high death rate. Immune cells infiltrating the tumor tissues have been shown to play a vital role in tumorigenesis and tumor progression, but their prognostic significance in MIBC remains unclear. OBJECTIVES: To explore the landscape and prognostic significance of tumor-infiltrating immune cells (TIICs) in MIBC, and to develop a model to improve the prognostic predictions of MIBC. METHODS AND MATERIALS: The gene expression profile and clinical data of MIBC patients were downloaded from the Gene Expression Omnibus and The Cancer Genome Atlas portal. The fractions of 22 TIIC subtypes were calculated using the Cell Type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT) algorithm. A TIICs-based model was constructed using least absolute shrinkage and selection operator (LASSO) Cox regression in a training cohort and validated in the validation cohort. RESULTS: Ten types of TIICs demonstrated different infiltration abundance between MIBC and normal tissue. We also found 11 types of TIICs that were significantly associated with overall survival (OS). A TIICs-based model was established, consisting of 15 types of immune cells, and an immunoscore was calculated. Significant differences in OS were found between the high and low immunoscore groups, in both training (n = 343) and validation (n = 146) cohorts. The model could identify patients who would have worse OS despite having similar clinical characteristics. Furthermore, multivariate analysis identified the immunoscore as an independent risk factor (hazard ratio, 3.23; 95% confidence interval; 2.22-4.70) for OS in MIBC patients. CONCLUSION: The landscape of immune infiltration is different between MIBC and normal tissue. The TIICs-based model could provide promising predictive value to complement the existing staging system for predicting the OS of MIBC patients.
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Although 5-methylcytosine (m5C) is a widespread modification in RNAs, its regulation and biological role in pathological conditions (such as cancer) remain unknown. Here, we provide the single-nucleotide resolution landscape of messenger RNA m5C modifications in human urothelial carcinoma of the bladder (UCB). We identify numerous oncogene RNAs with hypermethylated m5C sites causally linked to their upregulation in UCBs and further demonstrate YBX1 as an m5C 'reader' recognizing m5C-modified mRNAs through the indole ring of W65 in its cold-shock domain. YBX1 maintains the stability of its target mRNA by recruiting ELAVL1. Moreover, NSUN2 and YBX1 are demonstrated to drive UCB pathogenesis by targeting the m5C methylation site in the HDGF 3' untranslated region. Clinically, a high coexpression of NUSN2, YBX1 and HDGF predicts the poorest survival. Our findings reveal an unprecedented mechanism of RNA m5C-regulated oncogene activation, providing a potential therapeutic strategy for UCB.
Subject(s)
5-Methylcytosine/metabolism , Gene Expression Regulation/genetics , Methyltransferases/genetics , Urinary Bladder Neoplasms/genetics , Y-Box-Binding Protein 1/genetics , Animals , Carcinoma, Transitional Cell/genetics , Carcinoma, Transitional Cell/metabolism , Humans , Mice , RNA, Messenger/genetics , Urinary Bladder Neoplasms/metabolism , Urinary Bladder Neoplasms/pathologyABSTRACT
Kinesin family member C1 (KIFC1) is implicated in the clustering of multiple centrosomes to maintain tumor survival and is thought to be an oncogene in several kinds of cancers. In our experiments, we first performed bioinformatics analysis to investigate the expression levels of KIFC1 in bladder cancer (BC) specimens and normal bladder epitheliums and then, using our samples, verified findings by quantitative real-time PCR and western blotting assays. All data showed that KIFC1 was significantly upregulated in BC specimens at both the mRNA and protein levels. Immunohistochemical studies in a cohort of 152 paraffin-embedded BC tissues displayed that upregulated expression of KIFC1 clearly correlated with pT status (P = .014) and recurrent status (P = .002). Kaplan-Meier survival analysis and log-rank test indicated that patients with BC with high KIFC1 expression had both shorter cancer-specific survival (P < .001) and recurrence-free survival time (P < .001) than those with low KIFC1 expression. Furthermore, ectopic downregulation of KIFC1 weakened BC cell proliferation and migration both in vitro and in vivo, whereas upregulation of KIFC1 enhanced this in vitro. Overexpression of KIFC1 phosphorylated GSK3ß and promoted Snail through activating AKT (protein kinase B0) to induce proliferation and epithelial-mesenchymal transition (EMT) and, therefore, substantially promoted BC migration and metastasis. Our study revealed an oncogenic role for KIFC1 to promote BC cell proliferation and EMT via Akt/GSK3ß signaling; KIFC1 might be a promising prognostic biomarker as well as a therapeutic target for BC.
Subject(s)
Biomarkers, Tumor/metabolism , Epithelial-Mesenchymal Transition , Glycogen Synthase Kinase 3 beta/metabolism , Kinesins/metabolism , Neoplasm Recurrence, Local/diagnosis , Urinary Bladder Neoplasms/pathology , Animals , Cell Line, Tumor , Cell Proliferation , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , Male , Mice , Mice, Nude , Middle Aged , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Phosphorylation , Prognosis , Proto-Oncogene Proteins c-akt/metabolism , Snail Family Transcription Factors/metabolism , Up-Regulation , Urinary Bladder/pathology , Urinary Bladder Neoplasms/mortality , Urothelium/pathology , Xenograft Model Antitumor AssaysABSTRACT
PURPOSE: Circular RNAs (circRNAs), a novel class of noncoding RNAs, have recently drawn lots of attention in the pathogenesis of human cancers. However, the role of circRNAs in cancer cells epithelial-mesenchymal transition (EMT) remains unclear. In this study, we aimed to identify novel circRNAs that regulate urothelial carcinoma of the bladder (UCB) cells' EMT and explored their regulatory mechanisms and clinical significance in UCBs. EXPERIMENTAL DESIGN: We first screened circRNA expression profiles using a circRNA microarray in paired UCB and normal tissues, and then studied the clinical significance of an upregulated circRNA, circPRMT5, in a large cohort of patients with UCB. We further investigated the functions and underlying mechanisms of circPRMT5 in UCB cells' EMT. Moreover, we evaluated the regulation effect of circPRMT5 on miR-30c, and its target genes, SNAIL1 and E-cadherin, in two independent cohorts from our institute and The Cancer Genome Atlas (TCGA). RESULTS: We demonstrated that upregulated expression of circPRMT5 was positively associated with advanced clinical stage and worse survival in patients with UCB. We further revealed that circPRMT5 promoted UCB cell's EMT via sponging miR-30c. Clinical analysis from two independent UCB cohorts showed that the circPRMT5/miR-30c/SNAIL1/E-cadherin pathway was essential in supporting UCB progression. Importantly, we identified that circPRMT5 was upregulated in serum and urine exosomes from patients with UCB, and significantly correlated with tumor metastasis. CONCLUSIONS: CircPRMT5 exerts critical roles in promoting UCB cells' EMT and/or aggressiveness and is a prognostic biomarker of the disease, suggesting that circPRMT5 may serve as an exploitable therapeutic target for patients with UCB.
Subject(s)
Carcinoma, Transitional Cell/genetics , Carcinoma, Transitional Cell/pathology , Epithelial-Mesenchymal Transition/genetics , MicroRNAs/genetics , Protein-Arginine N-Methyltransferases/genetics , RNA , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/pathology , Cadherins/metabolism , Carcinoma, Transitional Cell/metabolism , Cell Line, Tumor , Computational Biology/methods , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Gene Silencing , Humans , RNA Interference , RNA, Circular , Signal Transduction , Snail Family Transcription Factors/genetics , Snail Family Transcription Factors/metabolism , Urinary Bladder Neoplasms/metabolismABSTRACT
Clinically, most of human urothelial carcinoma of the bladder (UCB)-related deaths result from tumor metastasis, but the underlying molecular mechanisms are largely unknown. Recently, a growing number of tripartite motif (TRIM) family members have been suggested to be important regulators for tumorigenesis. However, the impact of most TRIM members on UCB pathogenesis is unclear. In this study, TRIM65 was first screened as an important oncogenic factor of UCB from the Cancer Genome Atlas (TCGA) database and was validated by a large cohort of clinical UCB tissues. By in vitro and in vivo experiments, we demonstrated that TRIM65 promotes UCB cell invasive and metastatic capacities. Notably, we showed that TRIM65 modulates cytoskeleton rearrangement and induces UCB cells epithelial-mesenchymal transition by the ubiquitination of ANXA2, ultimately leading to an enhanced invasiveness of UCB cells. Importantly, UCBs with high expression of TRIM65 and low expression of ANXA2 showed the poorest outcome. Collectively, our results suggest that the overexpression of TRIM65 has an essential oncogenic role via ubiquitination of ANXA2 in UCB pathogenesis, and that such could be used as a novel prognostic marker and/or therapeutic target for UCB.
Subject(s)
Annexin A2/genetics , Carcinoma, Transitional Cell/genetics , Cell Movement/genetics , Gene Expression Regulation, Neoplastic , Tripartite Motif Proteins/genetics , Ubiquitin-Protein Ligases/genetics , Urinary Bladder Neoplasms/genetics , Animals , Annexin A2/metabolism , Carcinoma, Transitional Cell/metabolism , Carcinoma, Transitional Cell/pathology , Cell Line, Tumor , Disease-Free Survival , Epithelial-Mesenchymal Transition/genetics , Female , Humans , Male , Mice, Inbred BALB C , Mice, Nude , Middle Aged , Proteolysis , Signal Transduction/genetics , Transplantation, Heterologous , Tripartite Motif Proteins/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitination , Urinary Bladder Neoplasms/metabolism , Urinary Bladder Neoplasms/pathologyABSTRACT
Chromobox homolog 8 (CBX8), also known as human polycomb 8, is a repressor that maintains the transcriptionally repressive state in various cellular genes, and has been reported to promote tumorigenesis. In the present study, we examined CBX8 expression in eight pairs of muscle invasive bladder cancer tissues and adjacent non-tumor tissues, and found that CBX8 was frequently upregulated in muscle invasive bladder cancer tissues when compared to adjacent non-tumor tissues. Analysis showed that high expression of CBX8 in 152 muscle invasive bladder cancer specimens was associated with progression of the T, N, and M stages (P = 0.004, 0.005, <0.001, respectively). Furthermore, Kaplan-Meier survival analysis and log-rank test showed that muscle invasive bladder cancer patients with high CBX8 expression had a poor rate of overall survival (P < 0.001) and 5-year recurrence-free survival (P < 0.001) compared to patients with low CBX8 expression. High CBX8 expression predicted poor overall survival and 5-year recurrence-free survival in T and N stages of muscle invasive bladder cancer patients. Moreover, knockdown of CBX8 inhibited cell proliferation of urothelial carcinoma of the bladder both in vitro and in vivo. In addition, CBX8 depletion resulted in cell cycle delay of urothelial carcinoma cells of the bladder at the G2/M phase by the p53 pathway. The data suggest that high expression of CBX8 plays a critical oncogenic role in aggressiveness of urothelial carcinoma cells of the bladder through promoting cancer cell proliferation by repressing the p53 pathway, and CBX8 could be used as a novel predictor for muscle invasive bladder cancer patients.