Communicate or Die - A Model for HPV+ and HPV- CSCs and Their Interactions with SDF-1α

Cancer stem cells (CSCs) are suspected of being a reason for limited therapy in head and neck squamous cell carcinoma (HNSCC). Stromal cell-derived factor-1α (SDF-1α) plays a critical role in the communication between CSCs and their microenvironment. We investigated the influence of SDF-1α on HPV+/HPV- SCC cell lines to find an approach of explanation for the superior prognosis of HPV+ HNSCCs. We evaluated the expression of CD44/CXCR4 on HPV+/HPV- SCC cell lines and monitored the influence of SDF-1α on proliferation, morphology and migration of HPV+/HPV- SCCs. HPV- SCCs showed a significant increase of podia formation and an intensified migration towards SDF-1α. HPV+ SCCs rested nearly unaffected by SDF-1α. Weakened reaction to SDF-1α in HPV+ SCC could lead to an impaired communication between CSCs and their niche, that would result in an increased exposure of CSCs to the harming influence of e.g. chemotherapeutic agents.