Related Experiment Video
Updated: Sep 28, 2025
Exosomal miRNA Analysis in Non-small Cell Lung Cancer NSCLC Patients' Plasma Through qPCR: A Feasible Liquid Biopsy Tool
Published on: May 27, 2016
ALK-Fusion Transcripts Can Be Detected in Extracellular Vesicles (EVs) from Nonsmall Cell Lung Cancer Cell Lines and
Estela Sánchez-Herrero1,2, Carmen Campos-Silva3, Yaiza Cáceres-Martell3
1Liquid Biopsy Laboratory, Medical Oncology Department, Instituto de Investigación Sanitaria Puerta de Hierro-Segovia de Arana, Majadahonda, Spain.
Background:
ALK rearrangements are present in 5% of nonsmall cell lung cancer (NSCLC) tumors and identify patients who can benefit from ALK inhibitors. ALK fusions testing using liquid biopsies, although challenging, can expand the therapeutic options for ALK-positive NSCLC patients considerably. RNA inside extracellular vesicles (EVs) is protected from RNases and other environmental factors, constituting a promising source for noninvasive fusion transcript detection.
Methods:
EVs from H3122 and H2228 cell lines, harboring EML4-ALK variant 1 (E13; A20) and variant 3 (E6a/b; A20), respectively, were successfully isolated by sequential centrifugation of cell culture supernatants. EVs were also isolated from plasma samples of 16 ALK-positive NSCLC patients collected before treatment initiation.
Results:
Purified EVs from cell cultures were characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and flow cytometry. Western blot and confocal microscopy confirmed the expression of EV-specific markers as well as the expression of EML4-ALK-fusion proteins in EV fractions from H3122 and H2228 cell lines. In addition, RNA from EV fractions derived from cell culture was analyzed by digital PCR (dPCR) and ALK-fusion transcripts were clearly detected. Similarly, plasma-derived EVs were characterized by NTA, flow cytometry, and the ExoView platform, the last showing that EV-specific markers captured EV populations containing ALK-fusion protein. Finally, ALK fusions were identified in 50% (8/16) of plasma EV-enriched fractions by dPCR, confirming the presence of fusion transcripts in EV fractions.
Conclusions:
ALK-fusion transcripts can be detected in EV-enriched fractions. These results set the stage for the development of EV-based noninvasive ALK testing.
