miRNAs in Serum Exosomes for Differential Diagnosis of Brain Metastases

Abstract

Circulating miRNAs are increasingly studied and proposed as tumor markers with the aim of investigating their role in monitoring the response to therapy as well as the natural evolution of primary or secondary brain tumors. This study aimed to evaluate the modulation of the expression of three miRNAs, miR-21, miR-222 and miR-124-3p, in the serum exosomes of patients with high-grade gliomas (HGGs) and brain metastases (BMs) to verify their usefulness in the differential diagnosis of brain masses; then, it focused on their variations following the surgical and/or radiosurgical treatment of the BMs. A total of 105 patients with BMs from primary lung or breast cancer, or melanoma underwent neurosurgery or radiosurgery treatment, and 91 patients with HGGs were enrolled, along with 30 healthy controls. A significant increase in miR-21 expression in serum exosomes was observed in both HGGs and BMs compared with healthy controls; on the other hand, miR-124-3p was significantly decreased in BMs, and it was increased in HGGs. After the surgical or radiosurgical treatment of patients with BMs, a significant reduction in miR-21 was noted with both types of treatments. This study identified a signature of exosomal miRNAs that could be useful as a noninvasive complementary analysis both in the differential diagnosis of BMs from glial tumors and in providing information on tumor evolution over time.

Highly Effective Detection of Exosomal miRNAs in Plasma Using Liposome-Mediated Transfection CRISPR/Cas13a

“…9,10 Therefore, exosomal miRNAs are considered as more promising non-invasive biomarkers to detect and monitor diseases. 11 Exosomal miRNAs are commonly quantified by traditional methods, such as real-time quantitative polymerase chain reaction (RT-qPCR). 12,13 Recently, electrochemical biosensors, 14−16 surface-enhanced Raman spectroscopy (SERS), 17 and hybridization chain reaction (HCR) 18 have also been applied to measure exosomal miRNAs.…”

“…Exosomes, small extracellular vesicles (EV) with diameters of 40–150 nm, are released by a large variety of cells into biofluids. , They carry various functional biomolecules from their parental cells, including proteins, microRNAs (miRNAs), mRNAs, and DNAs, which could reflect the physiological condition of the original host cell because their cargos often vary under various pathological conditions. − Among various cargos, the aberrant miRNA expression is closely associated with multiple diseases, including cancer. , Besides, RNAs encapsulated inside exosomes are highly stable even in the presence of RNase. , Therefore, exosomal miRNAs are considered as more promising non-invasive biomarkers to detect and monitor diseases …”

Tumor microenvironment and exosomes in brain metastasis: Molecular mechanisms and clinical application

“…As a target system, exosomes are expected to effectively promote the development of medical oncology. The relationship between exosomes and brain metastases needs to be explored further to understand the intrinsic mechanisms of exosome structure and their interactions with regulatory proteins ( 165 – 167 ). Along with the in-depth study of exosomes in brain metastases, their monitoring can aid the screening of susceptible or high-risk groups, clinical diagnosis, molecular staging, prognosis assessment, recurrence or metastasis prediction, and efficacy evaluation.…”

Therapeutic and Diagnostic Potential of Exosomes as Drug Delivery Systems in Brain Cancer

“…Cancer surgical removal resulted in a significant reduction in miR-21. Therefore, elevated levels of miR-21 and reduced levels of miR-124-3p in serum exosomes is characteristic molecular evidence of BMs [ 128 ].…”