Role of Platelet Interactions in Promoting Melanoma Malignancy With Insights into Proliferation, Cyclin D1...

Metastasis is a major obstacle in cancer treatment and hematogenous metastasis plays a critical role in tumor progression. Platelets have been implicated in facilitating this process by interacting with circulating tumor cells, promoting immune evasion, extravasation, and metastatic colonization.

We explored the effects of platelet interactions on the malignancy of mouse melanoma cells, focusing on cell proliferation, cyclin D1 expression, and migration.

Co-culturing melanoma cells with platelets significantly increased their proliferative capacity, an effect that was also induced by the platelet culture supernatant alone. This suggests that soluble factors released from platelets, such as transforming growth factor-β (TGF-β) and platelet derived growth factor (PDGF), mediate this effect independently of direct cell-cell interactions. Furthermore, cyclin D1, a key regulator of the G₁/S phase transition, is up-regulated in melanoma cells upon exposure to platelet-derived factors, indicating enhanced cell cycle progression. Migration assays revealed the role of platelets in melanoma cell motility, whereas pre-treatment with platelets significantly increased their migratory ability in a transwell assay. This suggests that platelets enhanced cell motility via phenotypic changes and epithelial-mesenchymal transition in mouse melanoma cells.

Platelets promote melanoma metastasis by enhancing cell proliferation and migration through soluble factor-mediated mechanisms. Targeting platelet-tumor interactions may represent a potential therapeutic strategy for mitigating metastatic progression.