71P - Exosomes isolated in plasma of non-small cell lung cancer patients contain microRNA related to the EGFR pathway: Proof of concept

Date 15 April 2016
Event European Lung Cancer Conference 2016 (ELCC) 2016
Session Poster lunch
Topics Lung and other Thoracic Tumours
Translational Research
Presenter Christian Rolfo
Citation Journal of Thoracic Oncology (2016) 11 (supplement 4): S57-S166. S1556-0864(16)X0004-4
Authors C. Rolfo1, J. Chacartegui2, M. Giallombardo2, R. Alessandro3, M. Peeters1
  • 1Department Of Oncology, U.Z.A. University Hospital Antwerp, 2650 - Edegem/BE
  • 2Oncology Unit, U.Z.A. University Hospital Antwerp, 2650 - Edegem/BE
  • 3Department Of Biopathology, Medical And Forensic Biotechnologies, University of Palermo, Palermo/IT

Abstract

Background

The exosomes have been highlighted as a promising source of new biomarkers for early diagnosis, follow-up of disease and response to therapy in non-small cell lung cancer (NSCLC). Amongst their content, microRNA has been reported in vitro to be selectively shuttled in exosomes and participate in disease progression events. Therefore, we explored whether exosomes in plasma samples of NSCLC patients contained microRNA with potential as biomarkers.

Methods

Patients with NSCLC adenocarcinoma were included in this pilot project. Their EGFR status was confirmed after inclusion. After obtention of informed consent, blood was extracted and fresh plasma was obtained as source material for exosome isolation. Exosomes were isolated for characterization through density-gradient ultracentrifugation. Characterization was performed by Western Blot analysis and imaging with scanning and transmission electron microscopy. A commercial kit was used for exosome microRNA isolation. Expression of microRNA were analyzed through RT-qPCR, using hsa-miR-1228 as endogenous control. The fold-change of expression was calculated using the 2-ΔΔCq formula.

Results

Exosome presence in the samples was confirmed both through the presence of exosome protein markers (Alix,TSG-101) and by SEM/TEM imaging, who confirmed the presence of vesicles in the size range of exosomes (30–150 nm). The microRNA hsa-miR-30b/30c shown an up-regulation in all the samples of our analysis, with the exception of one sample belonging to a patient with conflicting histology (Adenosquamous carcinoma with predominant squamous cell carcinoma). Also, one patient with confirmed EGFR exon 19 deletion showed the highest expression of 30b,30c,221 and 222, who have been reported to be related to EGFR pathway regulation.

Conclusions

This study has shown that exosomes are feasible to be obtained from plasma in NSCLC patients, and that they contain microRNA signatures that might show differences depending on the EGFR status or the histology. However, this conclusions are limited by the low number of samples. Ongoing studies with larger sample size are planned to assess the differences of the microRNA signature according to the EGFR status.

Clinical trial identification

Legal entity responsible for the study

Antwerp University Hospital.

Funding

Oncology Department. Antwerp University Hospital (UZA)

Disclosure

All authors have declared no conflicts of interest.