(-)-Oleocanthal exerts anti-melanoma activities and inhibits STAT3 signaling pathway

Area of Science:

• Oncology
• Pharmacology
• Molecular Biology

Background:

• Tumor angiogenesis, growth, and metastasis are interconnected processes crucial for cancer progression.
• Melanoma is an aggressive skin cancer with significant metastatic potential.
• Identifying novel therapeutic agents targeting these processes is a critical unmet need.

Purpose of the Study:

• To investigate the anti-melanoma effects of (-)-oleocanthal (OC).
• To explore the impact of OC on melanoma cell proliferation, migration, invasion, and apoptosis.
• To elucidate the mechanisms underlying OC's action, particularly its effect on the STAT3 signaling pathway.

Main Methods:

• In vitro studies using melanoma cell lines and human umbilical vascular endothelial cells.
• In vivo studies utilizing a subcutaneous xenograft mouse model for tumor growth and a lung metastasis model.
• Immunohistochemical staining for Ki-67 and CD31 to assess proliferation and angiogenesis.
• Western blotting and nuclear translocation assays to evaluate STAT3 signaling pathway activation and target gene expression.

Main Results:

• OC suppressed melanoma cell proliferation, migration, invasion, and induced apoptosis in vitro.
• OC inhibited proliferation, migration, invasion, and tube formation in endothelial cells, indicating anti-angiogenic effects.
• OC significantly reduced tumor growth and metastasis in vivo.
• OC downregulated STAT3 phosphorylation, nuclear localization, and transcriptional activity, leading to reduced expression of STAT3 target genes (Mcl-1, Bcl-xL, MMP-2, MMP-9, VEGF).

Conclusions:

• (-)-oleocanthal exhibits potent anti-melanoma activity by inhibiting tumor growth, angiogenesis, and metastasis.
• The anti-cancer effects of OC are mediated through the suppression of the STAT3 signaling pathway.
• OC represents a promising candidate for further development as an anti-melanoma drug.