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

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.