Cetuximab treatment alters the content of extracellular vesicles released from tumor cells

Aim: Extracellular vesicles (EVs) are attractive candidates for biomarker research, because their content reflects the parental cell status. This study aimed to examine whether tumor cell derived EVs mirrored the cellular changes caused by treatment with cetuximab, a therapeutic antibody that blocks activation of EGF receptor (EGFR). Materials & methods: A-431 cells were treated with cetuximab for 48 h. EVs were isolated using differential centrifugation and protein content was analyzed using western blotting. Results: EV levels of EGFR and phospho-EGFR were reduced after cetuximab treatment, reflecting similar changes in the parental cells. In addition, cetuximab was found associated with EVs. Conclusion: EVs could serve as biomarkers to monitor cetuximab treatment. Association of cetuximab with EVs might influence its behavior.