Blood-based liquid biopsy: insights into early detection, prediction, and treatment monitoring of bladder cancer

Predictive and Prognostic Biomarkers and Tumor Antigens for Targeted Therapy in Urothelial Carcinoma

Urothelial carcinoma (UC) is the fourth most prevalent cancer amongst males worldwide. While patients with non-muscle-invasive disease have a favorable prognosis, 25% of UC patients present with locally advanced disease which is associated with a 10-15% 5-year survival rate and poor overall prognosis. Muscle-invasive bladder cancer (MIBC) is associated with about 50% 5 year survival when treated by radical cystectomy or trimodality therapy; stage IV disease is associated with 10-15% 5 year survival. Current therapeutic modalities for MIBC include neoadjuvant chemotherapy, surgery and/or chemoradiation, although patients with relapsed or refractory disease have a poor prognosis. However, the rapid success of immuno-oncology in various hematologic and solid malignancies offers new targets with tremendous therapeutic potential in UC. Historically, there were no predictive biomarkers to guide the clinical management and treatment of UC, and biomarker development was an unmet need. However, recent and ongoing clinical trials have identified several promising tumor biomarkers that have the potential to serve as predictive or prognostic tools in UC. This review provides a comprehensive summary of emerging biomarkers and molecular tumor targets including programmed death ligand 1 (PD-L1), epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), fibroblast growth factor receptor (FGFR), DNA damage response and repair (DDR) mutations, poly (ADP-ribose) polymerase (PARP) expression and circulating tumor DNA (ctDNA), as well as their clinical utility in UC. We also evaluate recent advancements in precision oncology in UC, while illustrating limiting factors and challenges related to the clinical application of these biomarkers in clinical practice.

Sialylation on vesicular integrin β1 determined endocytic entry of small extracellular vesicles into recipient cells

BACKGROUND

Small extracellular vesicles (sEV) are closely associated with the development and metastasis of many types of mammalian cancer. Glycoconjugates are highly expressed on sEV and play important roles in sEV biogenesis and their interaction with other cells. However, the study on vesicular glycoconjugates are far behind proteins and nucleic acids. Especially, the functions of sialic acids which are the terminal components of glycoconjugates, are poorly understood in sEV.

METHODS

Sialic acid levels on sEV from plasma and bladder cancer cells were determined by ELISA and lectin blotting. Effects of sialylation on sEV uptake were determined by flow cytometry. Vesicular glycoproteins bearing sialic acids responsible for sEV uptake was identified by proteomics and density gradient centrifugation, and their site-specific sialylation functions were assayed by N-glycosylation site mutation. Effects of integrin β1 bearing sialic acids on the pro-metastatic function of sEV in vivo were explored using Balb/c nu/nu mice.

RESULTS

(1) Increased sialic acid levels were observed in sEV from malignant bladder cancer cells. (2) Elimination of sialic acids on sEV impaired sEV uptake by recipient cells. (3) Vesicular integrin β1 bearing sialic acids was identified to play a key role in sEV uptake. (4) Desialylation of the hybrid domain of vesicular integrin β1 inhibited its binding to matrix fibronectin, and reduced sEV entry into recipient cells. (5) Sialylation on integrin β1 affected pro-metastatic function of sEV in Balb/c nu/nu mice.

CONCLUSIONS

Taken together, our findings indicate important functional roles of sialic acids in sEV uptake and reprogramming plasticity of surrounding normal epithelial cells.

New Perspectives on the Role of Liquid Biopsy in Bladder Cancer: Applicability to Precision Medicine

Bladder cancer (BC) is one of the most common tumors in the world. Cystoscopy and tissue biopsy are the standard methods in screening and early diagnosis of suspicious bladder lesions. However, they are invasive procedures that may cause pain and infectious complications. Considering the limitations of both procedures, and the recurrence and resistance to BC treatment, it is necessary to develop a new non-invasive methodology for early diagnosis and multiple evaluations in patients under follow-up for bladder cancer. In recent years, liquid biopsy has proven to be a very useful diagnostic tool for the detection of tumor biomarkers. This non-invasive technique makes it possible to analyze single tumor components released into the peripheral circulation and to monitor tumor progression. Numerous biomarkers are being studied and interesting clinical applications for these in BC are being presented, with promising results in early diagnosis, detection of microscopic disease, and prediction of recurrence and response to treatment.

Disulfidptosis characterizes the tumor microenvironment and predicts immunotherapy sensitivity and prognosis in bladder cancer

Background

Bladder cancer (BLCA) is prone to metastasis and has poor prognosis with unsatisfactory treatment responsiveness. Disulfidptosis is a recently discovered, novel mode of cell death that is closely associated with human cancers. However, a comprehensive analysis of the relationship between disulfidptosis and BLCA is lacking. Therefore, this study aimed to explore the potential effect of disulfidptosis on BLCA and identify a biomarker for evaluating the prognosis and immunotherapy of patients with BLCA.

Material and methods

We acquired BLCA RNA sequencing data from The Cancer Genome Atlas Urothelial Bladder Carcinoma (TCGA-BLCA) cohort (containing 19 normal samples and 409 tumor samples) and the GES39281 cohort (containing 94 tumor samples) which were used for external validation of the signature. Initially, we performed unsupervised consensus clustering to explore disulfidptosis-related subgroups. We then conducted functional enrichment analysis on these subgroups to gain insights into their biological significance and evaluate their immunotherapy response and chemotherapy sensitivity. Next, we conducted Least Absolute Shrinkage and Selection Operator (LASSO) regression and multivariate Cox regression to construct a prognostic signature in the TCGA training set for prognosis-related differentially expressed genes (DEGs) in the disulfidptosis-related subgroups. Subsequently, we used a receiver operating characteristic (ROC) curve and independent prognostic analysis to validate the predictive performance of the signature in the TCGA testing and the GES39281 cohorts. Finally, we explored the therapeutic value of this signature in patients with BLCA, in terms of immunotherapy and chemotherapy.

Result

In this study, we obtained two subgroups: DRG-high (238 samples) and DRG-low (160 samples). The DRG-high group exhibited a poor survival rate compared to the DRG-low group and had a significant association with tumor grade, stage, and metastasis. Additionally, several pathways related to cancer and the immune system were enriched in the high-DRG group. Moreover, the DRG-high group exhibited higher expression of PD1 and CTLA4 and had a better response to immunotherapy in patients with both PD1 and CTLA4 positivity. Conversely, the DRG-high group was more sensitive to common chemotherapeutic agents. A prognostic signature was created, consisting of COL5A1, DIRAS3, NKG7, and POLR3G and validated as having a robust predictive capability. Patients in the low-risk-score group had more immune cells associated with tumor suppression and better immunotherapy outcomes.

Conclusion

This study contributes to our understanding of the characteristics of disulfidptosis-related subgroups in BLCA. Disulfidptosis-related signatures can be used to assess the prognosis and immunotherapy of patients with BLCA.

Identification of a novel ferroptosis-inducing micropeptide in bladder cancer

Bladder cancer (BC) is a common malignancy in males, and currently lacks ideal therapeutic approaches. Exploring emerging therapeutic targets from the perspective of endogenous peptides to improve the prognosis of bladder cancer patients holds promise. In this study, we have identified CTSGDP-13, a novel endogenous peptide, which demonstrates potential anti-cancer effects in BC. Our findings reveal that CTSGDP-13 can promote ferroptosis in BC cells, both in vitro and in vivo, leading to the inhibition of BC progression. Furthermore, we have identified TRIM25 as a downstream regulatory target of CTSGDP-13. The expression of TRIM25 is significantly upregulated in BC, and its inhibition of ferroptosis promotes BC progression. Mechanistic studies have shown that CTSGDP-13 promotes the ubiquitination and subsequent degradation of TRIM25 by disrupting its interaction with the deubiquitinase USP7. Further investigations indicate that CTSGDP-13 promotes ferroptosis in BC by regulating the USP7/TRIM25/KEAP1 axis. The elucidation of the functional mechanisms of natural CTSGDP-13 and TRIM25 holds promise in providing valuable therapeutic targets for BC diagnosis and treatment.

Concomitant Immunotherapy and Metastasis-Directed Radiotherapy in Upper Tract Urothelial Carcinoma: A Biomarker-Driven, Original, Case-Based Proof-of-Concept Study

Metastatic upper tract urothelial carcinoma (mUTUC) has a poor prognosis. Immune checkpoint inhibitors (ICIs) have demonstrated efficacy in patients with metastatic urothelial carcinoma. However, data supporting the use of ICIs in patients with mUTUC are limited. A promising synergy between ICI and concomitant radiotherapy (RT) has been reported in patients with mUTUC. Our research involved a case-based investigation and emphasized the successful integration of different specialists' skills. Observed after partial urethrectomy procedures for muscle-invasive upper tract urothelial carcinoma (UTUC), the radiological detection of lung metastases prompted us to implement cisplatin-based first-line chemotherapy and molecular characterization in the treatment process. We uncovered alterations in the ERBB2 and FGFR3 genes and mismatch repair deficiency at a molecular level. First-line chemotherapy treatment led to a stable disease, and the patient was started on maintenance immunotherapy with Avelumab. Subsequently, an increase in the size of the lung nodules was described, and the patient received radiotherapy for three lung lesions in combination with immunotherapy. After 3 months, a restaging CT scan reported a complete response, which is still ongoing. We discuss the mechanisms driving RT/ICI synergy and the molecular profile of mUTUC as factors that should be considered in therapeutic strategy planning. Molecular insight enhances the originality of our study, providing a nuanced understanding of the genetic landscape of mUTUC and paving the way for targeted therapeutic strategies. The therapeutic armamentarium expansion encourages the design of a multimodal and personalized approach for each mUTUC patient, taking into account tumor heterogeneity and molecular profiling.

A Large Genetic Causal Analysis of the Gut Microbiota and Urological Cancers: A Bidirectional Mendelian Randomization Study

BACKGROUND

Several observational studies and clinical trials have shown that the gut microbiota is associated with urological cancers. However, the causal relationship between gut microbiota and urological cancers remains to be elucidated due to many confounding factors.

METHODS

In this study, we used two thresholds to identify gut microbiota GWAS from the MiBioGen consortium and obtained data for five urological cancers from the UK biobank and Finngen consortium, respectively. We then performed a two-sample Mendelian randomization (MR) analysis with Wald ratio or inverse variance weighted as the main method. We also performed comprehensive sensitivity analyses to verify the robustness of the results. In addition, we performed a reverse MR analysis to examine the direction of causality.

RESULTS

Our study found that family Rikenellaceae, genus Allisonella, genus Lachnospiraceae UCG001, genus Oscillibacter, genus Eubacterium coprostanoligenes group, genus Eubacterium ruminantium group, genus Ruminococcaceae UCG013, and genus Senegalimassilia were related to bladder cancer; genus Ruminococcus torques group, genus Oscillibacter, genus Barnesiella, genus Butyricicoccus, and genus Ruminococcaceae UCG005 were related to prostate cancer; class Alphaproteobacteria, class Bacilli, family Family XI, genus Coprococcus2, genus Intestinimonas, genus Lachnoclostridium, genus Lactococcus, genus Ruminococcus torques group, and genus Eubacterium brachy group were related to renal cell cancer; family Clostridiaceae 1, family Christensenellaceae, genus Eubacterium coprostanoligenes group, genus Clostridium sensu stricto 1, and genus Eubacterium eligens group were related to renal pelvis cancer; family Peptostreptococcaceae, genus Romboutsia, and genus Subdoligranulum were related to testicular cancer. Comprehensive sensitivity analyses proved that our results were reliable.

CONCLUSIONS

Our study confirms the role of specific gut microbial taxa on urological cancers, explores the mechanism of gut microbiota on urological cancers from a macroscopic level, provides potential targets for the screening and treatment of urological cancers, and is dedicated to providing new ideas for clinical research.