PB0756 - Proteomic and functional profile of platelet-derived extracellular vesicles released under physiological and tumour-associated conditions

Monday, July 11, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Mauro Vismara

PhD
University of Pavia, Pavia
Pavia, Lombardia, Italy

Co-Author(s)

MM

Marcello Manfredi

PhD
University of Piemonte Orientale
Novara, Piemonte, Italy
MZ

Marta Zarà

PhD
Centro Cardiologico Monzino IRCCS, Milano
Milano, Lombardia, Italy
LG

Luca Galgano

PhD student
University School for Advanced Studies IUSS, Pavia
Pavia, Lombardia, Italy
Silvia Maria Grazia Trivigno

PhD student
University School for Advanced Studies IUSS, Pavia
Pavia, Lombardia, Italy
AP

Andrea-Giorgia Piotti

Graduate student
University of Pavia
Pavia, Lombardia, Italy
Ilaria Canobbio, PhD

Associate Professor
University of Pavia, Pavia
Pavia, Lombardia, Italy
MT

Mauro Torti

Full Professor
University of Pavia
Pavia, Lombardia, Italy
GG

Gianni Francesco Guidetti

Associate Professor
University of Pavia, Pavia
Pavia, Lombardia, Italy

Background: Platelet-derived extracellular vesicles (PEVs) contribute to platelet-cancer crosstalk and regulate cancer progression by delivering bioactive molecules to target cells. We have recently demonstrated that breast adenocarcinoma cells are able to stimulate the release of PEVs with an efficacy comparable to the physiologic agonist thrombin. However, it is not known whether cancer cell-induced PEVs differ in composition and function from those released by thrombin-stimulated platelets.

Aims: This study aims to provide a comparative analysis of protein cargo and functional effects of PEVs released from platelets stimulated with thrombin (PEVs-THR) or stimulated with the breast cancer cell line MDA-MB-231 (PEVs-BCC).

Methods: PEVs were isolated by differential centrifugation from platelets incubated with thrombin (0.2 U/ml) or with MDA-MB-231 cells (5x104 cell/ml) for 30 minutes. The proteomic analysis was performed by liquid chromatography-tandem mass spectrometry. Migration of Jurkat cells was evaluated by trans-well assays. PEVs-induced apoptosis of MDA-MB-231 cells was investigated by flow cytometry.

Results: A total of 937 proteins were identified, with 431 found in both PEVs populations, 86 exclusively in the PEVs-THR and 420 only in the PEVs-BCC. Bioinformatic analyses indicated that the proteomic composition of the two populations may be associated to differential regulation of extravasation signalling and calcium-induced apoptosis in target cells. Both PEVs populations were equally able to potentiate invasiveness of MDA-MB-231 cells, but PEVs-BCC displayed a more pronounced proapoptotic effect on MDA-MB-231 cells compared to PEVs-THR. Interestingly, PEVs-THR and PEVs-BCC were also able to downregulate migration of Jurkat cells, suggesting a possible novel function of PEVs in the regulation of leukocyte mobility.

Conclusion(s): This study revealed that PEVs released under physiological or cancer-associated conditions differ in composition and display peculiar biological functions, suggesting that cancer cell-induced PEVs may play unique roles in the platelet-cancer crosstalk.