Melanoma exosomal hsa-miR-221-5p suppresses keratinocyte LL-37 to promote tumor progression.

Melanoma exosomal hsa-miR-221-5p suppresses keratinocyte LL-37, promoting tumor progression by impairing immune defenses and enhancing invasion.

• Why it matters: Understanding how melanoma interacts with surrounding skin tissue is crucial for developing therapies that can prevent or slow tumor growth and metastasis, addressing gaps in knowledge about tumor-epidermal communication.
• What they did: The study analyzed clinical specimens and used exosome treatments to demonstrate that melanoma-derived exosomal hsa-miR-221-5p downregulates LL-37 in keratinocytes, impairing EGFR signaling and tumor suppression.
• The result: Suppressing LL-37 facilitates melanoma invasion and immune evasion, suggesting that boosting LL-37 signaling could be a promising therapeutic approach to counteract melanoma progression.