Kelp extract reduces melanoma cell survival and downregulates PD-L1
Description
Background: Melanoma is the most aggressive form of skin cancer, accounting for most skin cancer-related deaths. Despite advances in modern therapies, its treatment remains challenging, underscoring the need for novel therapeutic approaches. The PD-1/PD-L1 pathway is a critical signaling mechanism exploited by cancer cells to evade immune surveillance. Kelp has been shown to have some anticancer effects; however, its role in melanoma is not well understood. This study investigates whether kelp has any effect on melanoma cell survival and its immunomodulatory effects on PD-1 and PD-L1.
Methods: The widely used melanoma cell line HTB-72 was treated with kelp extract (KE). Cell proliferation and survival were measured using clonogenic and proliferation assays. RT-PCR and/or IHC were used to evaluate PD-1 and PD-L1 expression in HTB-72 cells in the presence and absence of KE.
Results: After treatment with KE, the percentage of colonies of HTB-72 melanoma cells decreased significantly, paralleled by a decrease in optical density. RT-PCR showed that PD-L1, but not PD-1, was constitutively expressed in HTB-72 cells, and PD-L1 mRNA was significantly lower in KE-treated cells than in controls. IHC studies are currently underway.
Conclusions: Kelp inhibits melanoma cell growth and exerts immunomodulatory effects through downregulation of PD-L1. These findings suggest that kelp may serve as a promising natural agent with potential therapeutic value in melanoma management.
Citation Information
Champion, Parker; Abdul Qadeer, Abdul R.; Mayberry, Trenton; Cowan, Braydon; Marrah, Austin; Schmidt, Aidan A.; Wakefield, Mark R.; and Fang, Yujiang, "Kelp extract reduces melanoma cell survival and downregulates PD-L1" (2026). Office of Research DMU Research Symposium. 54.
https://digitalcommons.dmu.edu/researchsymposium/2025rs/2025abstracts/54
Kelp extract reduces melanoma cell survival and downregulates PD-L1
Background: Melanoma is the most aggressive form of skin cancer, accounting for most skin cancer-related deaths. Despite advances in modern therapies, its treatment remains challenging, underscoring the need for novel therapeutic approaches. The PD-1/PD-L1 pathway is a critical signaling mechanism exploited by cancer cells to evade immune surveillance. Kelp has been shown to have some anticancer effects; however, its role in melanoma is not well understood. This study investigates whether kelp has any effect on melanoma cell survival and its immunomodulatory effects on PD-1 and PD-L1.
Methods: The widely used melanoma cell line HTB-72 was treated with kelp extract (KE). Cell proliferation and survival were measured using clonogenic and proliferation assays. RT-PCR and/or IHC were used to evaluate PD-1 and PD-L1 expression in HTB-72 cells in the presence and absence of KE.
Results: After treatment with KE, the percentage of colonies of HTB-72 melanoma cells decreased significantly, paralleled by a decrease in optical density. RT-PCR showed that PD-L1, but not PD-1, was constitutively expressed in HTB-72 cells, and PD-L1 mRNA was significantly lower in KE-treated cells than in controls. IHC studies are currently underway.
Conclusions: Kelp inhibits melanoma cell growth and exerts immunomodulatory effects through downregulation of PD-L1. These findings suggest that kelp may serve as a promising natural agent with potential therapeutic value in melanoma management.
