Molecular Characterization of Exosomes for Subtype-Based Diagnosis of Breast Cancer

Abstract

Breast cancer is very heterogeneous and the most frequently diagnosed cancer worldwide, and precise therapy targeting specific subtypes may improve the survival rates of breast cancer patients. In this study, we designed a biomimetic vesicle by camouflaging catalytic DNA machinery with a breast cancer cell membrane, which enabled the molecular classification of circulating exosomes for subtype-based diagnosis through homotypic recognition. In addition, the vesicles specifically targeted and fused with breast cancer exosomes with phenotypic homology and manipulated the DNA machinery to amplify electrochemical signaling using exosomal RNA as an endogenous trigger. The biomimetic vesicles prepared with MCF-7 cancer cell-derived membranes were shown to recognize estrogen receptor-positive breast cancer exosomes and exhibited a low detection limit of 557 particles mL–1 with microRNA-375 used as the endogenous biomarker. Furthermore, the biomimetic vesicles prepared with MDA-MB-231 cancer cell-derived membranes displayed satisfactory performance in a homotypic analysis of triple-negative breast cancer exosomes with a potential therapeutic target, PD-L1 mRNA, used as the endogenous biomarker. Most importantly, cross-validation experiments confirmed the high accuracy and selectivity of this homotypic recognition-driven analysis for molecular subtyping of breast cancer. When applied to clinical samples of breast cancer patients, the vesicles demonstrated feasibility and reliability for evaluating the molecular features of cancer cell-derived exosomes and enabled stage-specific monitoring of breast cancer patients because the electrochemical signals showed a positive correlation with disease progression. Therefore, this work may provide new ideas for the precise diagnosis and personalized treatment of breast cancer patients throughout the whole disease process.

Recent Advances in Exosomal miRNA Biosensing for Liquid Biopsy

“…In addition to genetic engineering membranes, vesicles made from exosome-derived cell membranes were used according to the same phenotypic features. Cao et al designed a homotypic recognition method to detect exo-miRNAs based on catalytic DNA machinery enveloped by biomimetic vesicles which fuse with cancer exosomes ( Figure 6 A) [ 85 ]. In this method, two hairpin probes, electroactive MB-labeled H1 and N3-labeled H2 are camouflaged by specific biomimetic vesicles which are immobilized on anti-CD44@IMBs.…”

“…Ramshani et al identified the overexpression of miR-21 from liver cancer patients [ 73 ]. In contrast to clinical testing attempts that look solely at miRNA concentrations, the method Cao et al developed can distinguish between phenotypes [ 85 ]. The ER-positive luminal subtype of breast cancer patients was analyzed with good discrimination.…”

“…( A ) Schematic of homotypic recognition-driven membrane fusion for exo-miRNA detection. Reprinted with permission from [ 85 ]. Copyright 2022 American Chemical Society.…”

Simultaneous subset tracing and miRNA profiling of tumor-derived exosomes via dual-surface-protein orthogonal barcoding

“…Moreover, the analysis is susceptible to interference of free miRNAs in biofluids, whose abundance is several orders higher than exosomal miRNAs [22][23][24] . Alternative to the sequence amplification-based strategies, a series of in-situ exosomal miRNAs bioassays have been recently developed by directly or indirectly importing DNA probes into membrane vesicles, such as gold nanoflares (Au NFs) and molecular beacons (MBs) [25][26][27] . Zhou et al designed a virus-mimicking fusogenic vesicle-encapsulated MBs probe, which can rapidly detect extracellular vesicle miRNAs within 2 h via membrane fusion 28 .…”

Serum amino acids quantification by plasmonic colloidosome-coupled MALDI-TOF MS for triple-negative breast cancer diagnosis

“…To date, TNBC is usually diagnosed by imaging examinations and tissue biopsy, which cannot achieve early diagnosis, are invasive and associated with the risk of arousing tumor spreading [ 5 , 6 ]. Liquid biopsy based on tumor markers is an emerging technique with the advantages of non-invasive, simple operation, low cost and high throughput in analysis.…”