Extracellular vesicle-based EGFR genotyping in bronchoalveolar lavage fluid

Epidermal Growth Factor Receptor Mutations Carried in Extracellular Vesicle-Derived Cargo Mirror Disease Status in Metastatic Non-small Cell Lung Cancer

In non-small cell lung cancer (NSCLC), identifying the presence of sensitizing and resistance epidermal growth factor receptor (EGFR) mutations dictates treatment plans. Extracellular vesicles (EVs) are emerging as abundant, stable potential liquid biopsy targets that offer the potential to quantify EGFR mutations in NSCLC patients at the RNA and protein level at multiple points through treatment. In this study, we present a systematic approach for serial mutation profiling of 34 EV samples from 10 metastatic NSCLC patients with known EGFR mutations through treatment. Using western blot and droplet digital PCR (ddPCR), sensitizing (exon 19 deletion, L858R) mutations were detected in EV-Protein, and both sensitizing and resistance (T790M) mutations were quantified in EV-RNA. EGFR mutations were detected in EV-Protein from four patients at multiple time points through treatment. Using EV-RNA, tumor biopsy matched sensitizing mutations were detected in 90% of patients and resistance mutations in 100% of patients. Finally, mutation burden in EV-RNA at each time point was compared to disease status, described as either stable or progressing. For 6/7 patients who were longitudinally monitored through treatment, EV mutation burden mirrored clinical trajectory. When comparing mutation detection between EV-RNA and ctDNA using ddPCR, EVs had a better detection rate for exon 19 deletions and the L858R point mutation. In conclusion, this study demonstrates that integrating EV analysis into liquid biopsy mutation screening has the potential to advance beyond the current standard of care "rule in" test. The multi-analyte testing allows future integration of EGFR mutation monitoring with additional EV-markers for a comprehensive patient monitoring biomarker.

Novel devices for isolation and detection of bacterial and mammalian extracellular vesicles

Extracellular vesicles are spherical nanoparticles inherently released by almost all cell types. They acquire the cell's membrane and cytoplasmic characteristics offering abundant identical units that can be captured to recognize the cell of origin. The abundance of vital cell information and multifunctional roles in cellular processes has rendered them attention, particularly as promising biomarkers for disease diagnosis and use in potential drug delivery systems. This review provides insights into standard approaches towards cultivation and isolation of mammalian and bacterial extracellular vesicles. We assess gaps in conventional separation and detection technologies while also tracking developments in ongoing research. The review focuses on highlighting alternative state-of-the-art microfluidic devices that offer avenues for fast, cost-effective, precision-oriented capture and sensing of extracellular vesicles. Combining different detection technologies on an integrated "lab-on-a-chip" system has the prospective to provide customizable opportunities for clinical use of extracellular vesicles in disease diagnostics and therapeutic applications.