DTL Is a Prognostic Biomarker and Promotes Bladder Cancer Progression through Regulating the AKT/mTOR axis

Integrative transcriptomics and proteomics analysis reveal the protection of Astragaloside IV against myocardial fibrosis by regulating senescence

Myocardial fibrosis (MF) is a pivotal pathological process implicated in various cardiovascular diseases, particularly heart failure. Astragaloside IV (AS-IV), a natural compound derived from Astragalus membranaceus, possesses potent cardioprotective properties. However, the precise molecular mechanisms underlying its anti-MF effects, particularly in relation to senescence, remain elusive. Thus, this study aimed to investigate the therapeutic potential and underlying molecular mechanisms of AS-IV in treating ISO-induced MF in mice, employing transcriptomics, proteomics, in vitro, and in vivo experiments. We assessed the positive effects of AS-IV on ISO-induced MF using HE staining, Masson staining, ELISA, immunohistochemical staining, transthoracic echocardiography, transmission electron microscopy, and DHE fluorescence staining. Additionally, we elucidated the regulatory role of AS-IV in MF through comprehensive transcriptomics and proteomics analyses, complemented by Western blotting and RT-qPCR validation of pertinent molecular pathways. Our findings demonstrated that AS-IV treatment markedly attenuated ISO-induced myocardial injury and oxidative stress, concomitantly inhibiting the release of SASPs. Furthermore, integrated transcriptomics and proteomics analyses revealed that the anti-MF mechanism of AS-IV was associated with regulating cellular senescence and the p53 signaling pathway. These results highlight AS-IV exerts its anti-MF effects not only by inhibiting oxidative stress but also by modulating senescence through the p53 signaling pathway.

RUVBL1 ubiquitination by DTL promotes RUVBL1/2-β-catenin-mediated transcriptional regulation of NHEJ pathway and enhances radiation resistance in breast cancer

Radiotherapy effectiveness in breast cancer is limited by radioresistance. Nevertheless, the mechanisms behind radioresistance are not yet fully understood. RUVBL1 and RUVBL2, referred to as RUVBL1/2, are crucial AAA+ ATPases that act as co-chaperones and are connected to cancer. Our research revealed that RUVBL1, also known as pontin/TIP49, is excessively expressed in MMTV-PyMT mouse models undergoing radiotherapy, which is considered a murine spontaneous breast-tumor model. Our findings suggest that RUVBL1 enhances DNA damage repair and radioresistance in breast cancer cells both in vitro and in vivo. Mechanistically, we discovered that DTL, also known as CDT2 or DCAF2, which is a substrate adapter protein of CRL4, promotes the ubiquitination of RUVBL1 and facilitates its binding to RUVBL2 and transcription cofactor β-catenin. This interaction, in turn, attenuates its binding to acetyltransferase Tat-interacting protein 60 (TIP60), a comodulator of nuclear receptors. Subsequently, ubiquitinated RUVBL1 promotes the transcriptional regulation of RUVBL1/2-β-catenin on genes associated with the non-homologous end-joining (NHEJ) repair pathway. This process also attenuates TIP60-mediated H4K16 acetylation and the homologous recombination (HR) repair process. Expanding upon the prior study's discoveries, we exhibited that the ubiquitination of RUVBL1 by DTL advances the interosculation of RUVBL1/2-β-catenin. And, it then regulates the transcription of NHEJ repair pathway protein. Resulting in an elevated resistance of breast cancer cells to radiation therapy. From the aforementioned, it is evident that targeting DTL-RUVBL1/2-β-catenin provides a potential radiosensitization approach when treating breast cancer.

DTL promotes head and neck squamous cell carcinoma progression by mediating the degradation of ARGLU1 to regulate the Notch signaling pathway

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with a high incidence in squamous epithelium. The E3 ubiquitin ligase DTL is a component of the CRL4A complex and is widely involved in tumor progression. We aimed to analyze the role of DTL in HNSCC and to explore its mechanism of action. Through clinical analysis, we found that DTL is upregulated in HNSCC tissues and is associated with the tumor microenvironment and poor survival in patients. Through gain-of-function and loss-of-function assays, we showed that DTL promotes cell proliferation and migration in vitro and tumor growth in vivo. Mass spectrometry analysis and immunoprecipitation assays showed that DTL interacts with ARGLU1 to promote K11-linked ubiquitination-mediated degradation of ARGLU1, thereby promoting the activation of the CSL-dependent Notch signaling pathway. Furthermore, siARGLU1 blocks the inhibitory effects of DTL knockdown on HNSCC cells. In this study, we showed that DTL promotes HNSCC progression through K11-linked ubiquitination of ARGLU1 to activate the CSL-dependent Notch pathway. These findings identify a promising therapeutic target for HNSCC.

Pulse-SILAC and Interactomics Reveal Distinct DDB1-CUL4-Associated Factors, Cellular Functions, and Protein Substrates

Cullin-RING finger ligases represent the largest family of ubiquitin ligases. They are responsible for the ubiquitination of ∼20% of cellular proteins degraded through the proteasome, by catalyzing the transfer of E2-loaded ubiquitin to a substrate. Seven cullins are described in vertebrates. Among them, cullin 4 (CUL4) associates with DNA damage-binding protein 1 (DDB1) to form the CUL4-DDB1 ubiquitin ligase complex, which is involved in protein ubiquitination and in the regulation of many cellular processes. Substrate recognition adaptors named DDB1/CUL4-associated factors (DCAFs) mediate the specificity of CUL4-DDB1 and have a short structural motif of approximately forty amino acids terminating in tryptophan (W)-aspartic acid (D) dipeptide, called the WD40 domain. Using different approaches (bioinformatics/structural analyses), independent studies suggested that at least sixty WD40-containing proteins could act as adaptors for the DDB1/CUL4 complex. To better define this association and classification, the interaction of each DCAFs with DDB1 was determined, and new partners and potential substrates were identified. Using BioID and affinity purification-mass spectrometry approaches, we demonstrated that seven WD40 proteins can be considered DCAFs with a high confidence level. Identifying protein interactions does not always lead to identifying protein substrates for E3-ubiquitin ligases, so we measured changes in protein stability or degradation by pulse-stable isotope labeling with amino acids in cell culture to identify changes in protein degradation, following the expression of each DCAF. In conclusion, these results provide new insights into the roles of DCAFs in regulating the activity of the DDB1-CUL4 complex, in protein targeting, and characterized the cellular processes involved.

Integrative analyses of bulk microarray data to discover genes, pathways, and immune infiltration characteristics associated with targeting of Ewing sarcoma

PURPOSE

To explore transcriptome and immunological features of patients with Ewing sarcoma (ES) using all publicly available microarray data.

METHODS

Data of 479 ES tissues were integrated and normalized. Gene expression, immune infiltration, and cancer-specific pathways were analyzed. Genes of interest were knocked down, followed by cell proliferation and colony formation assays.

RESULTS

Consistent with the previous reports of differential expressed genes (DEGs) in ES, our analysis identified CCND1, HMCN1, and NKX2-2 were among the most highly expressed, while TWNC1, MYBPC1, and CKM were among the lowest expressed genes. GO, KEGG, and GSEA enrichment analysis identified that the DEGs related to bone and muscle functioning, those that contributed to crucial cellular, and metabolism pathways such as actin binding, apoptosis, TCA cycle, and cell cycle were also significantly enriched. Immune infiltration analysis discovered that many T cell subsets including CD4T, CD8 T, and Gamma delta T cells were highly infiltrated, while monocytes and B cells were less infiltrated in tumors. A total of 138 genes were both significantly up-regulated in tumors and associated with decreased survival, while 38 significantly down-regulated genes were associated with increased survival, many of which were previously reported as oncogenes and tumor suppressors in ES and other cancers. Silencing of four newly identified top ranked up-regulated genes with decreased survivals in ES inhibited proliferation and colony formation of ES cells.

CONCLUSION

This study may provide a clear representative transcriptome profile of ES, providing diagnostic biomarkers, pathways, and immune infiltrative characteristics targets for ES.

E3 ubiquitin ligases and deubiquitinases in bladder cancer tumorigenesis and implications for immunotherapies

With the rapidly increasing incidence of bladder cancer in China and worldwide, great efforts have been made to understand the detailed mechanism of bladder cancer tumorigenesis. Recently, the introduction of immune checkpoint inhibitor-based immunotherapy has changed the treatment strategy for bladder cancer, especially for advanced bladder cancer, and has improved the survival of patients. The ubiquitin-proteasome system, which affects many biological processes, plays an important role in bladder cancer. Several E3 ubiquitin ligases and deubiquitinases target immune checkpoints, either directly or indirectly. In this review, we summarize the recent progress in E3 ubiquitin ligases and deubiquitinases in bladder cancer tumorigenesis and further highlight the implications for bladder cancer immunotherapies.

Distinct longevity mechanisms across and within species and their association with aging

Lifespan varies within and across species, but the general principles of its control remain unclear. Here, we conducted multi-tissue RNA-seq analyses across 41 mammalian species, identifying longevity signatures and examining their relationship with transcriptomic biomarkers of aging and established lifespan-extending interventions. An integrative analysis uncovered shared longevity mechanisms within and across species, including downregulated Igf1 and upregulated mitochondrial translation genes, and unique features, such as distinct regulation of the innate immune response and cellular respiration. Signatures of long-lived species were positively correlated with age-related changes and enriched for evolutionarily ancient essential genes, involved in proteolysis and PI3K-Akt signaling. Conversely, lifespan-extending interventions counteracted aging patterns and affected younger, mutable genes enriched for energy metabolism. The identified biomarkers revealed longevity interventions, including KU0063794, which extended mouse lifespan and healthspan. Overall, this study uncovers universal and distinct strategies of lifespan regulation within and across species and provides tools for discovering longevity interventions.

Identification of key enzalutamide-resistance-related genes in castration-resistant prostate cancer and verification of RAD51 functions

Patients with castration-resistant prostate cancer (CRPC) often develop drug resistance after treatment with enzalutamide. The goal of our study was to identify the key genes related to enzalutamide resistance in CRPC and to provide new gene targets for future research on improving the efficacy of enzalutamide. Differential expression genes (DEGs) associated with enzalutamide were obtained from the GSE151083 and GSE150807 datasets. We used R software, the DAVID database, protein-protein interaction networks, the Cytoscape program, and Gene Set Cancer Analysis for data analysis. The effect of RAD51 knockdown on prostate cancer (PCa) cell lines was demonstrated using Cell Counting Kit-8, clone formation, and transwell migration experiments. Six hub genes with prognostic values were screened (RAD51, BLM, DTL, RFC2, APOE, and EXO1), which were significantly associated with immune cell infiltration in PCa. High RAD51, BLM, EXO1, and RFC2 expression was associated with androgen receptor signaling pathway activation. Except for APOE, high expression of hub genes showed a significant negative correlation with the IC50 of Navitoclax and NPK76-II-72-1. RAD51 knockdown inhibited the proliferation and migration of PC3 and DU145 cell lines and promoted apoptosis. Additionally, 22Rv1 cell proliferation was more significantly inhibited with RAD51 knockdown than without RAD51 knockdown under enzalutamide treatment. Overall, six key genes associated with enzalutamide resistance were screened (RAD51, BLM, DTL, RFC2, APOE, and EXO1), which are potential therapeutic targets for enzalutamide-resistant PCa in the future.

Pan-cancer analysis and experimental validation of DTL as a potential diagnosis, prognosis and immunotherapy biomarker

BACKGROUND

DTL has been found to be related with multiple cancers. However, comprehensive analyses, which identify the prediction value of DTL in diagnosis, prognosis, immune infiltration and treatment, have rarely been reported so far.

METHODS

Combined with the data online databases, the gene expression, gene mutation, function enrichment and the correlations with the immunity status and clinical indexes of DTL were analyzed. Expression of DTL and the degree of immune cell infiltration were examined by immunofluorescence (IF) and immunohistochemistry (IHC) and analyzed by statistical analysis. Furthermore, the influences of DTL on the cell cycle, cell proliferation and apoptosis were detected by live cell imaging, IF and flow cytometric (FC) analysis. Genomic stability assays were conducted by chromosome slide preparation.

RESULTS

DTL was widely expressed in various cells and tissues, while it was overexpressed in tumor tissues except acute myeloid leukemia (LAML). Pan-cancer bioinformatics analysis showed that the expression of DTL was correlated with the prognosis, immunotherapy, and clinical indexes in various cancers. In addition, gene set enrichment analysis (GSEA) uncovered that DTL was enriched in oocyte meiosis, pyrimidine metabolism, the cell cycle, the G2M checkpoint, mTORC1 signaling and E2F targets. Furthermore, the overexpression of DTL, and its association with immune cell infiltration and clinical indexes in liver hepatocellular carcinoma (LIHC), bladder urothelial carcinoma (BLCA) and stomach adenocarcinoma (STAD) were verified in our study. It was also verified that overexpression of DTL could regulate the cell cycle, promote cell proliferation and cause genomic instability in cultured cells, which may be the reason why DTL plays a role in the occurrence, progression and treatment of cancer.

CONCLUSIONS

Collectively, this study suggested that DTL is of clinical value in the diagnosis, prognosis and treatment of various cancers, and may be a potential biomarker in certain cancers.

NRP1 promotes prostate cancer progression via modulating EGFR-dependent AKT pathway activation

Prostate cancer (PCa) is the most common malignant tumor with a high global incidence in males. The mechanism underlying PCa progression is still not clear. This study observed that NRP1 was highly expressed in PCa and associated with poor prognosis in PCa patients. Functionally, NRP1 depletion attenuated the proliferation and migration ability of PCa cells in vitro and in vivo, while NRP1 overexpression promoted PCa cell proliferation and migration. Moreover, it was observed that NRP1 depletion induced G1 phase arrest in PCa cells. Mechanistically, HIF1α is bound to the specific promoter region of NRP1, thereby regulating its transcriptional activation. Subsequently, NRP1 interacted with EGFR, leading to EGFR phosphorylation. This study also provided evidence that the b1/b2 domain of NRP1 was responsible for the interaction with the extracellular domain of EGFR. Moreover, EGFR mediated NRP1-induced activation of the AKT signaling pathway, which promoted the malignant progression of PCa. In addition, the administration of NRP1 inhibitor EG01377 significantly inactivated the EGFR/AKT signaling axis, thereby suppressing PCa progression. In conclusion, the findings from this study highlighted the molecular mechanism underlying NRP1 expression in PCa and provide a potential predictor and therapeutic target for clinical prognosis and treatment of PCa.

YAP-mediated mechanotransduction in urinary bladder remodeling: Based on RNA-seq and CUT&Tag

Yes-associated protein (YAP) is an important transcriptional coactivator binding to transcriptional factors that engage in many downstream gene transcription. Partial bladder outlet obstruction (pBOO) causes a massive burden to patients and finally leads to bladder fibrosis. Several cell types engage in the pBOO pathological process, including urothelial cells, smooth muscle cells, and fibroblasts. To clarify the function of YAP in bladder fibrosis, we performed the RNA-seq and CUT&Tag of the bladder smooth muscle cell to analyze the YAP ablation of human bladder smooth muscle cells (hBdSMCs) and immunoprecipitation of YAP. 141 differentially expressed genes (DEGs) were identified through RNA-seq between YAP-knockdown and nature control. After matching with the results of CUT&Tag, 36 genes were regulated directly by YAP. Then we identified the hub genes in the DEGs, including CDCA5, CENPA, DTL, NCAPH, and NEIL3, that contribute to cell proliferation. Thus, our study provides a regulatory network of YAP in smooth muscle proliferation. The possible effects of YAP on hBdSMC might be a vital target for pBOO-associated bladder fibrosis.

Identification of a dysregulated CircRNA-associated gene signature for predicting prognosis, immune landscape, and drug candidates in bladder cancer

Increasing evidences have demonstrated that circular RNA (circRNAs) plays a an essential regulatory role in initiation, progression and immunotherapy resistance of various cancers. However, circRNAs have rarely been studied in bladder cancer (BCa). The purpose of this research is to explore new circRNAs and their potential mechanisms in BCa. A novel ceRNA-regulated network, including 87 differentially expressed circRNAs (DE-circRNAs), 126 DE-miRNAs, and 217 DE-mRNAs was constructed to better understanding the biological processes using Cytoscape 3.7.1 based on our previously high-throughput circRNA sequencing and five GEO datasets. Subsequently, five randomly selected circRNAs (upregulated circ_0001681; downregulated circ_0000643, circ_0001798, circ_0006117 and circ_0067900) in 20 pairs of BCa and paracancerous tissues were confirmed using qRT-PCR. Functional analysis results determined that 772 GO functions and 32 KEGG pathways were enriched in the ceRNA network. Ten genes (PFKFB4, EDNRA, GSN, GAS1, PAPPA, DTL, TGFBI, PRSS8, RGS1 and TCF4) were selected for signature construction among the ceRNA network. The Human Protein Atlas (HPA) expression of these genes were consistent with the above sequencing data. Notably, the model was validated in multiple external datasets (GSE13507, GSE31684, GSE48075, IMvigor210 and GSE32894). The immune-infiltration was evaluated by 7 published algorithms (i.e., TIMER, CIBERSORT, CIBERSORT-ABS, QUANTISEQ, MCPCOUNTER, XCELL and EPIC). Next, Correlations between riskscore or risk groups and clinicopathological data, overall survival, recognized immunoregulatory cells or common chemotherapeutic agents of BCa patients were performed using wilcox rank test, chi-square test, cox regression and spearman’s correlation analysis; and, these results are significant. According to R package “GSVA” and “clusterProfiler”, the most significantly enriched HALLMARK and KEGG pathway was separately the ‘Epithelial Mesenchymal Transition’ and ‘Ecm Receptor Interaction’ in the high- vs. low-risk group. Additionally, the functional experiments in vitro also revealed that the overexpression of has_circ_0067900 significantly impaired the proliferation, migration, and invasion capacities of BCa cells. Collectively, the results of the current study provide a novel landscape of circRNA-associated ceRNA-regulated network in BCa. The ceRNA-associated gene model which was constructed presented a high predictive performance for the prognosis, immunotherapeutic responsiveness, and chemotherapeutic sensitivity of BCa. And, has_circ_0067900 was originally proposed as tumor suppressor for patients with BCa.

Identification of Potential Biomarkers for Pan-Cancer Diagnosis and Prognosis Through the Integration of Large-Scale Transcriptomic Data

Cancer is one of the leading causes of death worldwide, bringing a significant burden to human health and society. Accurate cancer diagnosis and biomarkers that can be used as robust therapeutic targets are of great importance as they facilitate early and effective therapies. Shared etiology among cancers suggests the existence of pan-cancer biomarkers, performance of which could benefit from the large sample size and the heterogeneity of the studied patients. In this study, we conducted a systematic RNA-seq study of 9,213 tumors and 723 para-cancerous tissue samples of 28 solid tumors from the Cancer Genome Atlas (TCGA) database, and 7,008 normal tissue samples from the Genotype-Tissue Expression (GTEx) database. By differential gene expression analysis, we identified 214 up-regulated and 186 downregulated differentially expressed genes (DEGs) in more than 80% of the studied tumors, respectively, and obtained 20 highly linked up- and downregulated hub genes from them. These markers have rarely been reported in multiple tumors simultaneously. We further constructed pan-cancer diagnostic models to classify tumors and para-cancerous tissues using 10 up-regulated hub genes with an AUC of 0.894. Survival analysis revealed that these hub genes were significantly associated with the overall survival of cancer patients. In addition, drug sensitivity predictions for these hub genes in a variety of tumors obtained several broad-spectrum anti-cancer drugs targeting pan-cancer. Furthermore, we predicted immunotherapy sensitivity for cancers based on tumor mutational burden (TMB) and the expression of immune checkpoint genes (ICGs), providing a theoretical basis for the treatment of tumors. In summary, we identified a set of biomarkers that were differentially expressed in multiple types of cancers, and these biomarkers can be potentially used for diagnosis and used as therapeutic targets.