Inhibition of MELK produces potential anti-tumour effects in bladder cancer by inducing G1/S cell cycle arrest via the ATM/CHK2/p53 pathway.

We aimed to investigate the biological function of MELK and the therapeutic potential of OTSSP167 in human bladder cancer (BCa). First, we observed overexpression of MELK in BCa cell lines and tissues and found that it was associated with higher tumour stage and tumour grade, which was consistent with transcriptome analysis. High expression of MELK was significantly correlated with poor prognosis in BCa patients, and MELK was found to have a role in the cell cycle, the G1/S transition in mitosis, and DNA repair and replication. Furthermore, BCa cells presented significantly decreased proliferation capacity following silencing of MELK or treatment with OTSSP167 in vitro and in vivo. Functionally, reduction in MELK or treatment of cells with OTSSP167 could induce cell cycle arrest and could suppress migration. In addition, these treatments could activate phosphorylation of ATM and CHK2, which would be accompanied by down-regulated MDMX, cyclin D1, CDK2 and E2F1; however, p53 and p21 would be activated. Opposite results were observed when MELK expression was induced. Overall, MELK was found to be a novel oncogene in BCa that induces cell cycle arrest via the ATM/CHK2/p53 pathway. OTSSP167 displays potent anti-tumour activities, which may provide a new molecule-based strategy for BCa treatment.

Epigenetic signature predicts overall survival clear cell renal cell carcinoma.

BACKGROUND: Recently, increasing study have found that DNA methylation plays an important role in tumor, including clear cell renal cell carcinoma (ccRCC). METHODS: We used the DNA methylation dataset of The Cancer Genome Atlas (TCGA) database to construct a 31-CpG-based signature which could accurately predict the overall survival of ccRCC. Meanwhile, we constructed a nomogram to predict the prognosis of patients with ccRCC. RESULT: Through LASSO Cox regression analysis, we obtained the 31-CpG-based epigenetic signature which were significantly related to the prognosis of ccRCC. According to the epigenetic signature, patients were divided into two groups with high and low risk, and the predictive value of the epigenetic signature was verified by other two sets. In the training set, hazard ratio (HR) = 13.0, 95% confidence interval (CI) 8.0-21.2, P < 0.0001; testing set: HR = 4.1, CI 2.2-7.7, P < 0.0001; entire set: HR = 7.2, CI 4.9-10.6, P < 0.0001, Moreover, combined with clinical indicators, the prediction of 5-year survival of ccRCC reached an AUC of 0.871. CONCLUSIONS: Our study constructed a 31-CpG-based epigenetic signature that could accurately predicted overall survival of ccRCC and staging progression of ccRCC. At the same time, we constructed a nomogram, which may facilitate the prediction of prognosis for patients with ccRCC.

PPARγ inhibition regulates the cell cycle, proliferation and motility of bladder cancer cells.

Peroxisome proliferator-activated receptor gamma (PPARγ) is a member of the nuclear receptor family of ligand-activated transcription factors and plays an important role in regulating cell proliferation, inflammation and lipid and glucose homeostasis. Our results revealed that PPARγ was up-regulated in human bladder cancer (BCa) tissues both at transcriptional and translational levels. Moreover, down-regulation of PPARγ mRNA or inhibition of PPARγ function (using GW9662, antagonist of PPARγ) could significantly suppress the proliferation of BCa cells. Furthermore, the cell cycle arrested in G0/G1 phase was also induced by the down-regulated PPARγ possibly through AKT-mediated up-regulation of p21/p27, whereas no significant transformation of apoptosis was observed. In addition, knockdown or inhibition of PPARγ might reduce the invasion and migration of BCa cells by affecting epithelial-mesenchymal transition-related proteins through AKT/GSK3ß signalling pathway. Additionally, in vivo studies showed that BCa cell proliferation was significantly suppressed by GW9662. In conclusion, our results indicated that PPARγ might be crucial for BCa tumorigenesis by interfering with the motility and viability of BCa cells.

Fifteen hub genes associated with progression and prognosis of clear cell renal cell carcinoma identified by coexpression analysis.

Renal cell carcinoma (RCC) is the most common type of renal tumor, and the clear cell renal cell carcinoma (ccRCC) is the most frequent subtype. In this study, our aim is to identify potential biomarkers that could effectively predict the prognosis and progression of ccRCC. First, we used The Cancer Genome Atlas (TCGA) RNA-sequencing (RNA-seq) data of ccRCC to identify 2370 differentially expressed genes (DEGs). Second, the DEGs were used to construct a coexpression network by weighted gene coexpression network analysis (WGCNA). Moreover, we identified the yellow module, which was strongly related to the histologic grade and pathological stage of ccRCC. Then, the functional annotation of the yellow module and single-samples gene-set enrichment analysis of DEGs were performed and mainly enriched in cell cycle. Subsequently, 18 candidate hub genes were screened through WGCNA and protein-protein interaction (PPI) network analysis. After verification of TCGA's ccRCC data set, Gene Expression Omnibus (GEO) data set (GSE73731) and tissue validation, we finally identified 15 hub genes that can actually predict the progression of ccRCC. In addition, by using survival analysis, we found that patients of ccRCC with high expression of each hub gene were more likely to have poor prognosis than those with low expression. The receiver operating characteristic curve showed that each hub gene could effectively distinguish between localized and advanced ccRCC. In summary, our study indicates that 15 hub genes have great predictive value for the prognosis and progression of ccRCC, and may contribute to the exploration of the pathogenesis of ccRCC.

Fatty acid oxidation inhibitor etomoxir suppresses tumor progression and induces cell cycle arrest via PPARγ-mediated pathway in bladder cancer.

Tumor cells rely on aerobic glycolysis as their main energy resource (Warburg effect). Recent research has highlighted the importance of lipid metabolism in tumor progression, and certain cancers even turn to fatty acids as the main fuel. Related studies have identified alterations of fatty acid metabolism in human bladder cancer (BCa). Our microarray analysis showed that fatty acid metabolism was activated in BCa compared with normal bladder. The free fatty acid (FFA) level was also increased in BCa compared with paracancerous tissues. Inhibition of fatty acid oxidation (FAO) with etomoxir caused lipid accumulation, decreased adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH) levels, suppressed BCa cell growth in vitro and in vivo, and reduced motility of BCa cells via affecting epithelial-mesenchymal transition (EMT)-related proteins. Furthermore, etomoxir induced BCa cell cycle arrest at G0/G1 phase through peroxisome proliferator-activated receptor (PPAR) γ-mediated pathway with alterations in fatty acid metabolism associated gene expression. The cell cycle arrest could be reversed by PPARγ antagonist GW9662. Taken together, our results suggest that inhibition of FAO with etomoxir may provide a novel avenue to investigate new therapeutic approaches to human BCa.

TRAIP suppresses bladder cancer progression by catalyzing K48-linked polyubiquitination of MYC.

TRAF-interacting protein (TRAIP), an E3 ligase containing a RING domain, has emerged as a significant contributor to maintaining genome integrity and is closely associated with cancer. Our study reveals that TRAIP shows reduced expression in bladder cancer (BLCA), which correlates with an unfavorable prognosis. In vitro and in vivo, TRAIP inhibits proliferation and migration of BLCA cells. MYC has been identified as a novel target for TRAIP, wherein direct interaction promotes K48-linked polyubiquitination at neighboring K428 and K430 residues, ultimately resulting in proteasome-dependent degradation and downregulation of MYC transcriptional activity. This mechanism effectively impedes the progression of BLCA. Restoring MYC expression reverses suppressed proliferation and migration of BLCA cells induced by TRAIP. Moreover, our results suggest that MYC may bind to the transcriptional start region of TRAIP, thereby exerting regulatory control over TRAIP transcription. Consequently, this interaction establishes a negative feedback loop that regulates MYC expression, preventing excessive levels. Taken together, this study reveals a mechanism that TRAIP inhibits proliferation and migration of BLCA by promoting ubiquitin-mediated degradation of MYC.

USP43 stabilizes c-Myc to promote glycolysis and metastasis in bladder cancer.

A hallmark of tumor cells, including bladder cancer (BLCA) cells, is metabolic reprogramming toward aerobic glycolysis (Warburg effect). The classical oncogene MYC, which is crucial in regulating glycolysis, is amplified and activated in BLCA. However, direct targeting of the c-Myc oncoprotein, which regulates glycolytic metabolism, presents great challenges and necessitates the discovery of a more clarified regulatory mechanism to develop selective targeted therapy. In this study, a siRNA library targeting deubiquitinases identified a candidate enzyme named USP43, which may regulate glycolytic metabolism and c-Myc transcriptional activity. Further investigation using functional assays and molecular studies revealed a USP43/c-Myc positive feedback loop that contributes to the progression of BLCA. Moreover, USP43 stabilizes c-Myc by deubiquitinating c-Myc at K148 and K289 primarily through deubiquitinase activity. Additionally, upregulation of USP43 protein in BLCA increased the chance of interaction with c-Myc and interfered with FBXW7 access and degradation of c-Myc. These findings suggest that USP43 is a potential therapeutic target for indirectly targeting glycolytic metabolism and the c-Myc oncoprotein consequently enhancing the efficacy of bladder cancer treatment.

Integrative Single Cell Atlas Revealed Intratumoral Heterogeneity Generation from an Adaptive Epigenetic Cell State in Human Bladder Urothelial Carcinoma.

Intratumor heterogeneity (ITH) of bladder cancer (BLCA) contributes to therapy resistance and immune evasion affecting clinical prognosis. The molecular and cellular mechanisms contributing to BLCA ITH generation remain elusive. It is found that a TM4SF1-positive cancer subpopulation (TPCS) can generate ITH in BLCA, evidenced by integrative single cell atlas analysis. Extensive profiling of the epigenome and transcriptome of all stages of BLCA revealed their evolutionary trajectories. Distinct ancestor cells gave rise to low-grade noninvasive and high-grade invasive BLCA. Epigenome reprograming led to transcriptional heterogeneity in BLCA. During early oncogenesis, epithelial-to-mesenchymal transition generated TPCS. TPCS has stem-cell-like properties and exhibited transcriptional plasticity, priming the development of transcriptionally heterogeneous descendent cell lineages. Moreover, TPCS prevalence in tumor is associated with advanced stage cancer and poor prognosis. The results of this study suggested that bladder cancer interacts with its environment by acquiring a stem cell-like epigenomic landscape, which might generate ITH without additional genetic diversification.

Decreased Nrf2 protein level and low sperm quality in intractable spermatocystitis.

ABSTRACT: To investigate the molecular etiology of low sperm quality in patients with intractable spermatocystitis, spermatozoa samples from patients with persistent hematospermia undergoing transurethral seminal vesiculoscopy and healthy volunteers were utilized. Spermatozoa samples were collected from the seminal vesicles through transurethral seminal vesiculoscopy or by masturbation ejaculation. Sperm quality was analyzed by a WLJY-9000 color semen analysis system. Measurement of tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) in the seminal plasma was performed using enzyme-linked immunosorbent assay (ELISA). Measurement of H2O2 in the seminal plasma was performed with a hydrogen peroxide kit. The protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and phosphorylated-Nrf2 (p-Nrf2) were measured by western blot analysis and immunofluorescence assays. Low sperm quality parameters and increased levels of inflammatory cytokines (TNFα, IL-6, and H2O2) in the seminal plasma were detected among the semen samples from the patients with persistent hematospermia. Nrf2 and p-Nrf2 were strongly expressed in the nucleus and periphery of human sperm cells, according to the results of the immunofluorescence assays. The protein levels of Nrf2 and p-Nrf2 were significantly lower in the spermatozoa samples from patients with persistent hematospermia than in those from healthy volunteers with normal sperm motility. The results suggested that Nrf2 signaling might play a role in the low sperm quality of patients with intractable spermatocystitis.

DNA polymerase POLD1 promotes proliferation and metastasis of bladder cancer by stabilizing MYC.

To date, most studies on the DNA polymerase, POLD1, have focused on the effect of POLD1 inactivation mutations in tumors. However, the implications of high POLD1 expression in tumorigenesis remains elusive. Here, we determine that POLD1 has a pro-carcinogenic role in bladder cancer (BLCA) and is associated to the malignancy and prognosis of BLCA. Our studies demonstrate that POLD1 promotes the proliferation and metastasis of BLCA via MYC. Mechanistically, POLD1 stabilizes MYC in a manner independent of its' DNA polymerase activity. Instead, POLD1 attenuates FBXW7-mediated ubiquitination degradation of MYC by directly binding to the MYC homology box 1 domain competitively with FBXW7. Moreover, we find that POLD1 forms a complex with MYC to promote the transcriptional activity of MYC. In turn, MYC increases expression of POLD1, forming a POLD1-MYC positive feedback loop to enhance the pro-carcinogenic effect of POLD1-MYC on BLCA. Overall, our study identifies POLD1 as a promotor of BCLA via a MYC driven mechanism and suggest its potential as biomarker for BLCA.

Development and Validation of a Six-Gene Prognostic Signature for Bladder Cancer.

Human bladder cancer (BCa) is the most common urogenital system malignancy. Patients with BCa have limited treatment efficacy in clinical practice. Novel biomarkers could provide more crucial information conferring to cancer diagnosis, treatment, and prognosis. Here, we aimed to explore and identify novel biomarkers associated with cancer-specific survival of patients with BCa to build a prognostic signature. Based on univariate Cox regression, Lasso regression, and multivariate Cox regression analysis, we conducted an integrated analysis in the training set (GSE32894) and established a six-gene signature to predict the cancer-specific survival for human BCa. The six genes were Cyclin Dependent Kinase 4 (CDK4), E2F Transcription Factor 7 (E2F7), Collagen Type XI Alpha 1 Chain (COL11A1), Bradykinin Receptor B2 (BDKRB2), Yip1 Interacting Factor Homolog B (YIF1B), and Zinc Finger Protein 415 (ZNF415). Then, we validated the prognostic value of the model by using two other datasets (GSE13507 and TCGA). Also, we conducted univariate and multivariate Cox regression analyses, and results indicated that the six-gene signature was an independent prognostic factor of cancer-specific survival of patients with BCa. Functional analysis was performed based on the differentially expressed genes of low- and high-risk patients, and we found that they were enriched in lipid metabolic and cell division-related biological processes. Meanwhile, the gene set enrichment analysis (GSEA) revealed that high-risk samples were enriched in cell cycle and cancer-related pathways [G2/M checkpoint, E2F targets, mitotic spindle, mTOR signaling, spermatogenesis, epithelial-mesenchymal transition (EMT), DNA repair, PI3K/AKT/mTOR signaling, unfolded protein response (UPR), and MYC targets V2]. Lastly, we detected the relative expression of each signature in BCa cell lines by quantitative real-time PCR (qRT-PCR). As far as we know, currently, the present study is the first research that developed and validated a cancer-specific survival prognostic index based on three independent cohorts. The results revealed that this six-gene signature has a predictive ability for cancer-specific prognosis. Moreover, we also verified the relative expression of these six signatures between the bladder cell line and four BCa cell lines by qRT-PCR. Nevertheless, experiments to further explore the function of six genes are lacking.

Wild-type IDH1 inhibits the tumor growth through degrading HIF-α in renal cell carcinoma.

The purpose of our study was to explore the effect and intrinsic mechanism of wild-type IDH1 and its substrate α-KG on renal cell carcinoma (RCC). IDH1 was observed lower expression in RCC cell lines. Phenotype experiment was carried out in the wild-type IDH1 and mutant IDH1R132H plasmid treated cell line. The results showed that the wild-type IDH1 could significantly inhibit the proliferation, migration and promote the apoptosis of RCC cell lines, which were consistent with the IDH1's substrate α-KG. The mutant IDH1R132H was found to lose this biological function of IDH1. Moreover, we verified the proliferation inhibition of IDH1 in vivo. In addition, we verified the correlation between IDH1 and hypoxia signal-related proteins in vitro and in vivo, specifically, IDH1 overexpression could significantly reduce the expression of HIF-1α and HIF-2α proteins and its downstream proteins (VEGF, TGF-α). Furthermore, we preliminarily verified the possibility of α-KG in the RCC's treatment by injecting α-KG into the xenograft model. α-KG significantly reduced tumor size and weight in tumor-bearing mice. This study provided a new therapeutic target and small molecule for the study of the treatment and mechanism of RCC.

Tumor mutational burden related classifier is predictive of response to PD-L1 blockade in locally advanced and metastatic urothelial carcinoma.

BACKGROUND: Immunotherapy has made encouraging progress in the treatment of urothelial carcinoma, but only a small percentage of patients respond effectively to the immune checkpoint blockade (ICB). Our study aims to develop a classifier could effectively predict the response to ICB. METHODS: Support vector machines recursive feature elimination (SVM-RFE) algorithm was used to feature selection, then compared nine common binary classification algorithms through machine learning, we selected the classifier with the highest prediction performance (LASSO logistics classifier). Ten-fold cross-validation was used to avoid the overfitting effect. RESULTS: We developed a classifier on a urothelial carcinoma cohort treated with PD-L1 inhibitor Atzolizumab (IMvigor210 cohort, n = 272) and calculated a tumor mutational burden-related LASSO score (TLS) using the LASSO algorithm, which was significantly correlated with Tumor mutational burden (TMB) and neoantigen burden. We validated the efficacy of TLS in predicting prognosis and immunotherapy benefit in internal (IMvigor210) and external validation set (TCGA-BLCA, n = 406), respectively. CONCLUSIONS: After in-depth analysis, we provide a new idea for stratified treatment of such patients, that is, patients with high TLS should use ICB and also may benefit from hormone therapy, while patients with low TLS respond poorly to ICB and maybe benefit from targeting TGFß.

Immune-related signature predicts the prognosis and immunotherapy benefit in bladder cancer.

BACKGROUND: There is no good prognostic model that could predict the prognosis of bladder cancer (BCa) and the benefit of immunotherapy. METHODS: Through the least absolute shrinkage and selection operator (LASSO) algorithm, we constructed a 13-mRNA immune signature from the TCGA cohort (n = 406). We validated its prognostic value and predictive value for the benefit of immunotherapy with four independent validation cohort (GSE13507 [n = 256], GSE31684 [n = 93], GSE32894 [n = 308], and IMvigor210 cohort [n = 298]). RESULTS: Our results indicating that high-risk group with higher inhibitory immune cell infiltration (regulatory T cells [Tregs] and macrophage, etc), higher expression of immune checkpoints, and more T cell suppressive pathways (transforming growth factor ß [TGF-ß], epithelial-mesenchymal transition [EMT], etc) were activated. Besides, the immune signature showed a good predictive value for the benefit of immunotherapy in a cohort of urothelial carcinoma patients treated with PD-L1. CONCLUSIONS: The immune signature constructed is convenient to classify the immunotherapeutic susceptibility of patients with BCa, so as to achieve precision immunotherapy for BCa.

A novel germline EGFR variant p.R831H causes predisposition to familial CDK12-mutant prostate cancer with tandem duplicator phenotype.

5-10% of total prostate cancer (PCa) cases are hereditary. Particularly, immune checkpoint inhibitor-sensitive tandem duplicator phenotype (TDP) accounts for 6.9% of PCa cases, whereas genetic susceptibility genes remain completely unknown. We identified a Chinese family with two PCa patients, in which the PCa phenotype co-segregated with a rare germline variant EGFRR831H. Patient-derived conditionally reprogrammed cells (CRC) exhibited increased EGFR and AKT phosphorylation, and a sensitivity to EGFR antagonist Afatinib in migration assays, suggesting the EGFR allele was constitutively active. Both EGFRR831H-mutant tumours contained biallelic CDK12 inactivation, together with prominent tandem duplication across the genome. These somatic mutations could be detected in urine before surgery. Analysis of public databases showed a significant correlation between the mutation status of EGFR and CDK12. Taken together, our genetic and functional analyses identified a previously undescribed link between EGFR and PCa.

Establishing the prediction models for recurrence and progression of T1G3 bladder urothelial carcinoma.

We aim to determine clinical recurrence and progression risk factors of T1G3 bladder cancer (BCa), and to establish recurrence and progression prediction models. 5-year follow-up records of 106 T1G3 BCa patients from January 2012 to December 2016 were analyzed for recurrence and progression. Two-sample T-test, Chi-square test, Mann-Whitney test, Kaplan-Meier curves, Cox univariate and multivariate analyses were performed to determine the independent risk factors. Effective prognostic nomograms were established to provide individualized prediction, and the calibration curves were founded to evaluate the agreements of the predicted probability with the actual observed probability. Receiver operating characteristic (ROC) curves were generated for the recurrence and progression prediction models. The stability of prediction models was validated with an external cohort included 61 T1G3 BCa patients. Of the 106 T1G3 BCa patients, 77 were males (72.6%) and 29 were females (27.4%), with median age 70 years. Within 5 years, recurrence was identified in 67 cases (63.2%), and progression was identified in 31 cases (29.2%). The results showed that large size of tumor, multifocal tumors, recrudescent tumor, non-BCG perfusion therapy were the independent risk factors for recurrence, and large size of tumor, multifocal tumors, recrudescent tumor, concomitant carcinoma in situ (CIS) were the independent risk factors for progression. However, no evidence shown that tumor location or operative method was independent risk factors for recurrence and progression. Based on the results of Cox regression analyses, the independent risk factors were used to establish the prediction nomograms to calculate the recurrence and progression probability of each T1G3 BCa patient. Calibration curves, ROC curves and external validation displayed that the nomograms had great value of prediction.

Novel Biomarkers Associated With Progression and Prognosis of Bladder Cancer Identified by Co-expression Analysis.

Our study's goal was to screen novel biomarkers that could accurately predict the progression and prognosis of bladder cancer (BC). Firstly, we used the Gene Expression Omnibus (GEO) dataset GSE37815 to screen differentially expressed genes (DEGs). Secondly, we used the DEGs to construct a co-expression network by weighted gene co-expression network analysis (WGCNA) in GSE71576. We then screened the brown module, which was significantly correlated with the histologic grade (r = 0.85, p = 1e-12) of BC. We conducted functional annotation on all genes of the brown module and found that the genes of the brown module were mainly significantly enriched in "cell cycle" correlation pathways. Next, we screened out two real hub genes (ANLN, HMMR) by combining WGCNA, protein-protein interaction (PPI) network and survival analysis. Finally, we combined the GEO datasets (GSE13507, GSE37815, GSE31684, GSE71576). Oncomine, Human Protein Atlas (HPA), and The Cancer Genome Atlas (TCGA) dataset to confirm the predict value of the real hub genes for BC progression and prognosis. A gene-set enrichment analysis (GSEA) revealed that the real hub genes were mainly enriched in "bladder cancer" and "cell cycle" pathways. A survival analysis showed that they were of great significance in predicting the prognosis of BC. In summary, our study screened and confirmed that two biomarkers could accurately predict the progression and prognosis of BC, which is of great significance for both stratification therapy and the mechanism study of BC.