Podoplanin drives dedifferentiation and amoeboid invasion of melanoma

Abstract

Melanoma is an aggressive skin cancer developing from melanocytes, frequently resulting in metastatic disease. Melanoma cells utilise amoeboid migration as mode of local invasion. Amoeboid invasion is characterized by rounded cell morphology and high actomyosin contractility driven by the RhoA signalling pathway. Migrastatic drugs targeting actin polymerization and contractility to inhibit invasion and metastasis are therefore a promising treatment option. To predict amoeboid invasion and metastatic potential, there is a need for biomarkers functionally linked to contractility pathways. The glycoprotein podoplanin drives actomyosin contractility in lymphoid fibroblasts, and is overexpressed in several cancer types. Here, we show that podoplanin enhances amoeboid invasion in melanoma. Expression of podoplanin in murine melanoma models drives rounded cell morphology, increasing motility and invasion in vivo. Podoplanin expression is upregulated in a subset of dedifferentiated human melanoma, and in vitro is sufficient to suppress melanogenesis and upregulate melanoma-associated markers Mitf and Pou3f2. Together, our data indicates that podoplanin is both a potential biomarker for dedifferentiated invasive melanoma and a promising migrastatic therapeutic target.

Blebology: principles of bleb-based migration

“…Frictional forces generated due to E-cadherin cell-cell adhesion between PGCs and neighboring cells impede the retrograde actin flow in the blebs, confining the bleb-forming region at the leading edge [23,56]. Additionally, cell surface glycoproteins like CD44 [104] and podoplanin [105] are highly upregulated in blebbing cancer. These glycoproteins can interact with ECM ligands though the amount of force generated for cell migration during such interactions remains poorly understood.…”