Extracellular vesicles as a liquid biopsy for melanoma: Are we there yet?

Predictive Factors for Sentinel Lymph Node Positivity in Melanoma Patients-The Role of Liquid Biopsy, MicroRNA and Gene Expression Profile Panels

The identification of predictive factors for sentinel lymph node (SLN) positivity in melanoma patients is crucial for accurate staging, prognosis, and personalized therapeutic decisions. This review synthesizes recent advancements in molecular and clinicopathological predictors, with a particular focus on liquid biopsy and gene expression profiling (GEP) tools. Emerging evidence highlights the significant role of miRNAs in melanoma progression, metastatic potential, and lymphatic spread. Clinicopathological factors such as Breslow thickness, ulceration, and mitotic rate remain critical, while GEP provides additional precision by uncovering tumor-specific molecular pathways. By integrating these tools, clinicians can improve risk stratification, reduce unnecessary procedures, and personalize management strategies.

BAUSSS biomarker improves melanoma survival risk assessment

BACKGROUND

The American Joint Committee on Cancer (AJCC) method of staging melanoma is dated and inaccurate. It ignores important prognostic melanoma features, especially the patient's age. BAUSSS is more accurate in determining survival risk for primary cutaneous melanoma patients who have no clinical or imaging evidence of nodal or distant metastases. BAUSSS is an algorithm incorporating analysis of Breslow thickness, Age, Ulceration, Subtype of melanoma, Sex and Site. These are the six features from the patient history along with the details from the melanoma pathology report that are most predictive of mortality outcome.

OBJECTIVE

To develop a single-page document that allows the clinician to determine BAUSSS biomarker-predicted prognosis in consultation with the patient.

METHOD

From various data sources, we developed an algorithm to predict melanoma mortality using the BAUSSS biomarker system. The single-page algorithm was made available to download at https://globalmelanoma.net/bausss-survival-chart, thus being readily available without charge to all clinicians and their patients.

RESULTS

BAUSSS method of determining melanoma prognosis is more accurate and less costly than the AJCC staging system. The only surgery the patient requires is wide local excision of the primary tumour. This method of ascertaining melanoma risk does not require added surgery, costs, hospitalization, tests and anaesthesia, such as would be required if sentinel lymph node biopsy was undertaken. BAUSSS can be a useful tool in determining which primary melanoma patients are at sufficiently high risk to be considered for adjuvant drug therapy.

CONCLUSIONS

We encourage clinicians to download and print in colour this single-page BAUSSS mortality prediction tool, laminate it, and use it face to face with the patient in consultations. Not only will the patient be able to recognize his/her long-term prognosis but will also be able to see how their tumour severity compares with others.

A scoping review of factors influencing the implementation of liquid biopsy for cancer care

BACKGROUND

Liquid biopsy (LB) offers a promising, minimally invasive alternative to traditional tissue biopsies in cancer care, enabling real-time monitoring and personalized treatment. Despite its potential, the routine implementation of LB in clinical practice faces significant challenges. This scoping review examines the barriers and facilitators influencing the implementation of liquid biopsies into standard cancer care.

METHODS

Four academic databases (PubMed, Scopus, Embase, and Web of Science) were systematically searched without language restrictions. We included peer-reviewed articles that were published between January 2019 and March 2024 that focused on the implementation of LB in cancer care or described barriers and facilitators to its implementation. Data relevant to the review objective, including key article characteristics; barriers and facilitators of implementation; and recommendations for advancement or optimisation; were extracted and analysed using thematic and visual network analyses.

RESULTS

The majority of the included articles were narrative review articles (84%), with most from China (24.2%) and the United States (20%). Thematic analysis identified four main categories and their associated barriers and facilitators to the implementation of LB in cancer care: (1) Laboratory and personnel requirements; (2) Disease specificity; (3) Biomarker-based liquid biopsy; and (4) Policy and regulation. The majority of barriers identified were concentrated in the pre-analytical phase, highlighting the lack of standardization in LB technologies and outcomes.

CONCLUSIONS

Through a thematic analysis of the barriers and facilitators to LB implementation, we present an integrated tool designed to encourage the standardization of testing methods for clinical practice guidelines in the field.

Atomic force microscopy as a nanomechanical tool for cancer liquid biopsy

Liquid biopsies have been receiving tremendous attention for their potential to reshape cancer management. Though current studies of cancer liquid biopsy primarily focus on applying biochemical assays to characterize the genetic/molecular profiles of circulating tumor cells (CTCs) and their secondary products shed from tumor sites in bodily fluids, delineating the nanomechanical properties of tumor-associated materials in liquid biopsy specimens yields complementary insights into the biology of tumor dissemination and evolution. Particularly, atomic force microscopy (AFM) has become a standard and versatile toolbox for characterizing the mechanical properties of living biological systems at the micro/nanoscale, and AFM has been increasingly utilized to probe the nanomechanical properties of various tumor-derived analytes in liquid biopsies, including CTCs, tumor-associated cells, circulating tumor DNA (ctDNA) molecules, and extracellular vesicles (EVs), offering additional possibilities for understanding cancer pathogenesis from the perspective of mechanobiology. Herein, the applications of AFM in cancer liquid biopsy are summarized, and the challenges and future directions of AFM as a nanomechanical analysis tool in cancer liquid biopsy towards clinical utility are discussed and envisioned.

Nanoscale Extracellular Vesicle-Enabled Liquid Biopsy: Advances and Challenges for Lung Cancer Detection

Lung cancer is responsible for the death of over a million people worldwide every year. With its high mortality rate and exponentially growing number of new cases, lung cancer is a major threat to public health. The high mortality and poor survival rates of lung cancer patients can be attributed to its stealth progression and late diagnosis. For a long time, intrusive tissue biopsy has been considered the gold standard for lung cancer diagnosis and subtyping; however, the intrinsic limitations of tissue biopsy cannot be overlooked. In addition to being invasive and costly, it also suffers from limitations in sensitivity and specificity, is not suitable for repeated sampling, provides restricted information about the tumor and its molecular landscape, and is inaccessible in several cases. To cope with this, advancements in diagnostic technologies, such as liquid biopsy, have shown great prospects. Liquid biopsy is an innovative non-invasive approach in which cancer-related components called biomarkers are detected in body fluids, such as blood, urine, saliva and others. It offers a less invasive alternative with the potential for applications such as routine screening, predicting treatment outcomes, evaluating treatment effectiveness, detecting residual disease, or disease recurrence. A large number of research articles have indicated extracellular vesicles (EVs) as ideal biomarkers for liquid biopsy. EVs are a heterogeneous collection of membranous nanoparticles with diverse sizes, contents, and surface markers. EVs play a critical role in pathophysiological states and have gained prominence as diagnostic and prognostic biomarkers for multiple diseases, including lung cancer. In this review, we provide a detailed overview of the potential of EV-based liquid biopsy for lung cancer. Moreover, it highlights the strengths and weaknesses of various contemporary techniques for EV isolation and analysis in addition to the challenges that need to be addressed to ensure the widespread clinical application of EV-based liquid biopsies for lung cancer. In summary, EV-based liquid biopsies present interesting opportunities for the development of novel diagnostic and prognostic platforms for lung cancer, one of the most abundant cancers responsible for millions of cancer-related deaths worldwide.

Current advance of nanotechnology in diagnosis and treatment for malignant tumors

Cancer remains a significant risk to human health. Nanomedicine is a new multidisciplinary field that is garnering a lot of interest and investigation. Nanomedicine shows great potential for cancer diagnosis and treatment. Specifically engineered nanoparticles can be employed as contrast agents in cancer diagnostics to enable high sensitivity and high-resolution tumor detection by imaging examinations. Novel approaches for tumor labeling and detection are also made possible by the use of nanoprobes and nanobiosensors. The achievement of targeted medication delivery in cancer therapy can be accomplished through the rational design and manufacture of nanodrug carriers. Nanoparticles have the capability to effectively transport medications or gene fragments to tumor tissues via passive or active targeting processes, thus enhancing treatment outcomes while minimizing harm to healthy tissues. Simultaneously, nanoparticles can be employed in the context of radiation sensitization and photothermal therapy to enhance the therapeutic efficacy of malignant tumors. This review presents a literature overview and summary of how nanotechnology is used in the diagnosis and treatment of malignant tumors. According to oncological diseases originating from different systems of the body and combining the pathophysiological features of cancers at different sites, we review the most recent developments in nanotechnology applications. Finally, we briefly discuss the prospects and challenges of nanotechnology in cancer.

Extracellular vescicles in psoriasis: from pathogenesis to possible roles in therapy

Psoriasis is a chronic inflammatory disease affecting skin and joints characterized by a chronically altered immune and inflammatory response. Several factors occur from the onset to the development of this disease due to different types of cells spatially and temporally localized in the affected area, such as, keratinocytes, macrophages, neutrophils and T helper lymphocytes. This scenario leads to the chronic release of high levels of inflammatory mediators (i.e., IL-17, IL-23, IL-22, TNF-α, S100 proteins, Defensins) and lastly parakeratosis and thickening of the stratum spinosum. Extracellular vesicles (EVs) are small double membraned biological nanoparticles that are secreted by all cell types and classified, based on dimension and biogenesis, into exosomes, microvesicles and apoptotic bodies. Their role as vessels for long range molecular signals renders them key elements in the pathogenesis of psoriasis, as well as innovative platforms for potential biomarker discovery and delivery of fine-tuned anti-inflammatory therapies. In this review, the role of EVs in the pathogenesis of psoriasis and the modulation of cellular microenvironment has been summarized. The biotechnological implementation of EVs for therapy and research for new biomarkers has been also discussed.

ALDH2 is a novel biomarker and exerts an inhibitory effect on melanoma

Melanoma is a malignant skin tumor. This study aimed to explore and assess the effect of novel biomarkers on the progression of melanoma. Differently expressed genes (DEGs) were screened from GSE3189 and GSE46517 datasets of Gene Expression Omnibus database using GEO2R. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were conducted based on the identified DEGs. Hub genes were identified and assessed using protein-protein interaction networks, principal component analysis, and receiver operating characteristic curves. Quantitative real-time polymerase chain reaction was employed to measure the mRNA expression levels. TIMER revealed the association between aldehyde dehydrogenase 2 (ALDH2) and tumor immune microenvironment. The viability, proliferation, migration, and invasion were detected by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, wound healing, and transwell assays. Total 241 common DEGs were screened out from GSE3189 and GSE46517 datasets. We determined 6 hub genes with high prediction values for melanoma, which could distinguish tumor samples from normal samples. ALDH2, ADH1B, ALDH3A2, DPT, EPHX2, and GATM were down-regulated in A375 and SK-MEL-2 cells, compared with the human normal melanin cell line (PIG1 cells). ALDH2 was selected as the candidate gene in this research, presenting a high diagnostic and predictive value for melanoma. ALDH2 had a positive correlation with the infiltrating levels of immune cells in melanoma microenvironment. Overexpression of ALDH2 inhibited cell viability, proliferation, migration, and invasion of A375/SK-MEL-2 cells. ALDH2 is a new gene biomarker of melanoma, which exerts an inhibitory effect on melanoma.

Repurposing of Antidiarrheal Loperamide for Treating Melanoma by Inducing Cell Apoptosis and Cell Metastasis Suppression In vitro and In vivo

BACKGROUND

Melanoma is the most common skin tumor worldwide and still lacks effective therapeutic agents in clinical practice. Repurposing of existing drugs for clinical tumor treatment is an attractive and effective strategy. Loperamide is a commonly used anti-diarrheal drug with excellent safety profiles. However, the affection and mechanism of loperamide in melanoma remain unknown. Herein, the potential anti-melanoma effects and mechanism of loperamide were investigated in vitro and in vivo.

METHODS

In the present study, we demonstrated that loperamide possessed a strong inhibition in cell viability and proliferation in melanoma using MTT, colony formation and EUD incorporation assays. Meanwhile, xenograft tumor models were established to investigate the anti-melanoma activity of loperamide in vivo. Moreover, the effects of loperamide on apoptosis in melanoma cells and potential mechanisms were explored by Annexin V-FITC apoptosis detection, cell cycle, mitochondrial membrane potential assay, reactive oxygen species level detection, and apoptosis-correlation proteins analysis. Furthermore, loperamide-suppressed melanoma metastasis was studied by migration and invasion assays. What's more, immunohistochemical and immunofluorescence staining assays were applied to demonstrate the mechanism of loperamide against melanoma in vivo. Finally, we performed the analysis of routine blood and blood biochemical, as well as hematoxylin- eosin (H&E) staining, in order to investigate the safety properties of loperamide.

RESULTS

Loperamide could observably inhibit melanoma cell proliferation in vitro and in vivo. Meanwhile, loperamide induced melanoma cell apoptosis by accumulation of the sub-G1 cells population, enhancement of reactive oxygen species level, depletion of mitochondrial membrane potential, and apoptosis-related protein activation in vitro. Of note, apoptosis-inducing effects were also observed in vivo. Subsequently, loperamide markedly restrained melanoma cell migration and invasion in vitro and in vivo. Ultimately, loperamide was witnessed to have an amicable safety profile.

CONCLUSION

These findings suggested that repurposing of loperamide might have great potential as a novel and safe alternative strategy to cure melanoma via inhibiting proliferation, inducing apoptosis and cell cycle arrest, and suppressing migration and invasion.

The functional and clinical roles of liquid biopsy in patient-derived models

The liquid biopsy includes the detection of circulating tumor cells (CTCs) and CTC clusters in blood, as well as the detection of, cell-free DNA (cfDNA)/circulating tumor DNA (ctDNA) and extracellular vesicles (EVs) in the patient's body fluid. Liquid biopsy has important roles in translational research. But its clinical utility is still under investigation. Newly emerged patient-derived xenograft (PDX) and CTC-derived xenograft (CDX) faithfully recapitulate the genetic and morphological features of the donor patients' tumor and patient-derived organoid (PDO) can mostly mimic tumor growth, tumor microenvironment and its response to drugs. In this review, we describe how the development of these patient-derived models has assisted the studies of CTCs and CTC clusters in terms of tumor biological behavior exploration, genomic analysis, and drug testing, with the help of the latest technology. We then summarize the studies of EVs and cfDNA/ctDNA in PDX and PDO models in early cancer diagnosis, tumor burden monitoring, drug test and response monitoring, and molecular profiling. The challenges faced and future perspectives of research related to liquid biopsy using patient-derived models are also discussed.