Protein Biomarker Discovery Studies on Urinary sEV Fractions Separated with UF-SEC for the First Diagnosis and Detection of Recurrence in Bladder Cancer Patients

The latest applications of exosome-mediated drug delivery in anticancer therapies

In recent years, the significant role of anticancer drugs in cancer treatment has garnered considerable attention. However, the application of these drugs is largely limited by their short half-life in blood circulation, low cellular uptake efficiency, and off-target effects. Exosomes, which serve as crucial messengers in intercellular communication, exhibit unique advantages in molecular delivery compared to traditional synthetic carriers, thereby offering new possibilities for modern drug delivery systems. Exosomes possess organotropic functions and are naturally produced by cells, making them promising candidates for natural drug delivery systems with organotropic properties and minimal side effects. These naturally derived carriers can achieve stable, efficient, and selective delivery of anticancer drugs, thereby enhancing the efficacy and potential of anticancer agents in cancer immunotherapy. This review provides a concise overview of the unique characteristics of exosomes related to anticancer drug delivery, strategies for utilizing exosomes as carriers in cancer therapy, and the latest advancements in the field.

New biomarkers for diagnosis of bladder cancer: a bibliometric analysis

BACKGROUND/OBJECTIVES

Bladder cancer is a multifactorial disease, ranking as the 10th most common cancer globally and the fourth most common cancer in men and the ninth in women in the Western world. This bibliometric analysis aims to identify and evaluate scientific literature addressing new biomarkers for bladder cancer diagnosis, as well as to identify the most prolific organizations, authors, journals, countries, and keywords within this research domain.

METHODS

An electronic search was conducted using Elsevier's Scopus database. From a total of 940 retrieved papers (published between 2019 and 2024), 493 were selected. For data analysis and visualization, the titles of articles, year of publication, countries, authors, journals, articles, and keywords were analyzed using Microsoft Excel, VOSviewer, and Biblioshiny.

RESULTS

China published the most papers (200 articles) and received the highest number of citations, followed by the USA. While some countries, such as Egypt and India, published exclusively Single Country Publications (SCPs), others demonstrated a higher level of international collaboration, with at least half of their publications being Multi-Country Publications (MCPs). Countries with higher rates of MCPs were Greece (66.6%), Italy (53.8%), Korea, and France (50%). The journals that produced the most publications and received the highest number of citations were Cancers, International Journal of Molecular Sciences, and Frontiers in Oncology, confirming their role in producing high-impact research.

CONCLUSIONS

The consistent distribution of publications over the years considered indicates a sustained interest in this field.

Protein profile in urinary extracellular vesicles is a marker of malignancy and correlates with muscle invasiveness in urinary bladder cancer

Urinary Bladder Cancer (UBC) ranks among the most prevalent cancers worldwide, has a high recurrence rate and unpredictable treatment responses. Thus, biomarkers are urgently needed. Extracellular vesicles (EVs) are released from both cancer- and immune cells and provide a snapshot of the originating cell. They are abundant in urine and are therefore candidate biomarkers for UBC. Isolated urinary EVs from 39 UBC patients were compared with EVs from healthy controls, prostate cancer patients and whole urine. Samples were from bladder urine at time of both transurethral resection of the bladder tumour (TURB) and cystectomy, as well as urine taken from the ureter at cystectomy. EVs were isolated by tangential flow filtration and differential ultracentrifugation and their protein composition was detected by Proximity Extension Assay (PEA; Olink, immuno-oncology panel). In UBC patients, the proteomic signature of bladder urine EVs differed from ureter urine EVs from the same individuals, and from bladder urine derived EVs of both healthy and prostate cancer controls. Pairwise comparison was performed with matched whole urine revealing proteins solely detected in isolated vesicles. Additionally, a distinct signature was identified in bladder urine EVs correlating with muscle invasiveness, and a trained classifier could predict UBC with 92 % accuracy. Some differentially expressed proteins, HO-1 and MMP7, were analysed by bead-based flow cytometry, where HO-1 was detected on the EV surface. Taken together, these results strengthen the rationale of using EVs as non-invasive biomarkers and prognostic tools for UBC.

Bladder cancer biomarkers: current approaches and future directions

Bladder cancer is a significant health concern worldwide, necessitating effective diagnostic and monitoring strategies. Biomarkers play a crucial role in the early detection, prognosis, and treatment of this disease. This review explores the current landscape of bladder cancer biomarkers, including FDA-approved molecular biomarkers and emerging ones. FDA-approved molecular biomarkers, such as BTA stat, BTA TRAK, and NMP22, have been instrumental in diagnosing and monitoring bladder cancer. These biomarkers are derived from urinary samples and are particularly useful due to their sensitivity and specificity. As we move forward, we should continue to seek ways to optimize our processes and outcomes, these markers remain seriously challenged in the detection of early bladder cancer due to their limited sensitivity and specificity. For instance, sensitivities of BTA stat in bladder tumor detection have varied between 40-72%, while its specificities vary from 29-96%. In the same way, 70% sensitivity and 80% specificity have been recorded for BTA TRAK, while 11-85.7% sensitivity and 77-100% specificity have been documented for NMP22 BladderChek. The given variations, especially the low sensitivity in the diagnosis of bladder cancer at an early stage call for the invention of better diagnostic systems. Moreover, different sample collection and handling procedures applied in different laboratories further contribute to inconsistent results obtained. Extracellular vesicles (EVs) and exosomes, which carry a vast number of proteins, are being considered as potential biomarkers. Although these markers show promise, challenges remain due to non-standardized isolation techniques and lack of reproducibility across studies. Moreover, the discovery of new potential biomarkers is ongoing. For instance, the UBC® Rapid test and UBC ELISA kit, the XPERT BC Monitor, BC UroMark, TaqMan® Arrays, Soluble FAS (sFAS), Bladder tumor fibronectin (BTF), and IGF2 and MAGE-A3 are among the newest biomarkers under investigation. In conclusion, while bladder cancer biomarkers have shown great promise, more research is needed to standardize the testing procedures and validate these biomarkers in a clinical setting. This will pave the way for more accurate and efficient diagnosis and monitoring of bladder cancer, ultimately improving patient outcomes.

Comprehensive Urinary Proteome Profiling Analysis Identifies Diagnosis and Relapse Surveillance Biomarkers for Bladder Cancer

Bladder cancer (BCa) is the predominant malignancy of the urinary system. Herein, a comprehensive urine proteomic feature was initially established for the noninvasive diagnosis and recurrence monitoring of bladder cancer. 279 cases (63 primary BCa, 87 nontumor controls (NT), 73 relapsed BCa (BCR), and 56 nonrelapsed BCa (BCNR)) were collected to screen urinary protein biomarkers. 4761 and 3668 proteins were qualified and quantified by DDA and sequential window acquisition of all theoretical mass spectra (SWATH-MS) analysis in two discovery sets, respectively. Upregulated proteins were validated by multiple reaction monitoring (MRM) in two independent combined sets. Using the multi-support vector machine-recursive feature elimination (mSVM-RFE) algorithm, a model comprising 13 proteins exhibited good performance between BCa and NT with an AUC of 0.821 (95% CI: 0.675-0.967), 90.9% sensitivity (95% CI: 72.7-100%), and 73.3% specificity (95% CI: 53.3-93.3%) in the diagnosis test set. Meanwhile, an 11-marker classifier significantly distinguished BCR from BCNR with 75.0% sensitivity (95% CI: 50.0-100%), 81.8% specificity (95% CI: 54.5-100%), and an AUC of 0.784 (95% CI: 0.609-0.959) in the test cohort for relapse surveillance. Notably, six proteins (SPR, AK1, CD2AP, ADGRF1, GMPS, and C8A) of 24 markers were newly reported. This paper reveals novel urinary protein biomarkers for BCa and offers new theoretical insights into the pathogenesis of bladder cancer (data identifier PXD044896).

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.