PEP06 polypeptide 30 is a novel cluster-dissociating agent inhibiting α v integrin/FAK/Src signaling in oral squamous cell carcinoma cells.

Collectively migrating tumor cells have been recently implicated in enhanced metastasis of epithelial malignancies. In oral squamous cell carcinoma (OSCC), α v integrin is a crucial mediator of multicellular clustering and collective movement in vitro ; however, its contribution to metastatic spread remains to be addressed. According to the emerging therapeutic concept, dissociation of tumor clusters into single cells could significantly suppress metastasis-seeding ability of carcinomas. This study aimed to investigate the anti-OSCC potential of novel endostatin-derived polypeptide PEP06 as a cluster-dissociating therapeutic agent in vitro . Firstly, we found marked enrichment of α v integrin in collectively invading multicellular clusters in human OSCCs. Our study revealed that metastatic progression of OSCC was associated with augmented immunostaining of α v integrin in cancerous lesions. Following PEP06 treatment, cell clustering on fibronectin, migration, multicellular aggregation, anchorage-independent survival and colony formation of OSCC were significantly inhibited. Moreover, PEP06 suppressed α v integrin/FAK/Src signaling in OSCC cells. PEP06-induced loss of active Src and E-cadherin from cell-cell contacts contributed to diminished collective migration of OSCC in vitro . Overall, these results suggest that PEP06 polypeptide 30 inhibiting α v integrin/FAK/Src signaling and disrupting E-cadherin-based intercellular junctions possesses anti-metastatic potential in OSCC by acting as a cluster-dissociating therapeutic agent.
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