Abstract 5680
Background
Increasing evidence indicates that the release of exosomes by tumor cells play a key role in tumor progression, drug resistance, immune surveillance escape, angiogenesis, tumor invasion, and metastasis. For this reason, cancer-derived exosomes are emerging as very interesting targets for early diagnosis and therapy in cancer, including breast cancer. Indeed, progresses in developing nucleic acids-based therapeutic compounds, including antisense DNAs, aptamers, short interfering/microRNAs, and short activator RNAs, have attracted great interest as emerging platforms for precise cancer treatment.
Methods
We have recently developed a novel differential SELEX (Systematic Evolution of Ligands by Exponential enrichment) strategy by using exosomes purified from epithelial BC primary cells in the positive selection step and exosome-derived from primary normal epithelial breast cell lines in the negative selection step.
Results
Three aptamers have been shown to be enriched in different families, and their ability to selectively bind BC cells-derived exosomes has been proven. Interestingly, two of them can selectively bind triple negative-derived exosomes, compared to more differentiated BC cells. To optimize the best aptamers, shortened version of aptamers (about 35mer) have been generated and their binding ability has been tested. Moreover, the aptamers showed no binding affinity for lung cancer and glioblastoma-derived exosomes. We also tested by binding assay the ability of one of the identified aptamers, named ex-50sh, to selective recognize exosomes isolated from serum of breast cancer patients. Proteomic analysis of the putative target is in progress. Immunofluorescent experiments showed that the short aptamers can also block the uptake of MDA-231-derived exosomes on MDA-231 cell lines. Moreover, ex-50sh is able to block the EMT transformation induced by MDA-231 exosomes in low malignant MCF7.
Conclusions
Altogether, the selected aptamers will provide new insights in the molecular characterization of breast cancer exosomes and, most importantly, innovative tools for early breast cancer diagnosis.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Gerolama Condorelli.
Funding
University of Naples Federico II.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4526 - Long-term outcome of neoadjuvant tyrosine kinase inhibitors (TKI) in locally advanced dermatofibrosarcoma protuberans (DFSP)
Presenter: Jessica Beaziz
Session: Poster Display session 1
Resources:
Abstract
1214 - Neo-adjuvant (NA) Imatinib for gastrointestinal stromal tumours (GISTs): What is the optimal length of treatment?
Presenter: Tom Wilson
Session: Poster Display session 1
Resources:
Abstract
2690 - Gastrointestinal Stromal Tumours (GIST) in adolescents and young adults (AYA)
Presenter: Nikki Ijzerman
Session: Poster Display session 1
Resources:
Abstract
4558 - Radiomics improves response evaluation for desmoid tumors treated with chemotherapy
Presenter: Amandine Crombe
Session: Poster Display session 1
Resources:
Abstract
2751 - Radiomics of gastrointestinal stromal tumors; risk classification based on computed tomography images – a pilot study
Presenter: Milea Timbergen
Session: Poster Display session 1
Resources:
Abstract
2737 - Differentiating well-differentiated liposarcomas from lipomas using a radiomics approach
Presenter: Melissa Vos
Session: Poster Display session 1
Resources:
Abstract
1282 - The immune landscape of chondrosarcoma reveals an anti inflammatory environment
Presenter: Iseulys Richert
Session: Poster Display session 1
Resources:
Abstract
1572 - Impact of Immunotherapy and Targeted Therapy on Tumor Growth Rate in Sarcoma
Presenter: Esmail Al-ezzi
Session: Poster Display session 1
Resources:
Abstract
3414 - DNA methylation profiles of angiosarcoma subtypes.
Presenter: Marije Weidema
Session: Poster Display session 1
Resources:
Abstract
3411 - Prognostic significance of circulating PD-1, PD-L1, pan-BTN3As and BTN3A1 in patients with metastatic gastrointestinal stromal tumors (mGISTs)
Presenter: Daniele Fanale
Session: Poster Display session 1
Resources:
Abstract