Apelin promotes lymphangiogenesis and lymph node metastasis.

Area of Science:

• Molecular Biology
• Cell Biology
• Oncology

Background:

• The G-protein-coupled APJ receptor and its ligand, apelin, are known to play a role in angiogenesis.
• The function of the apelin/APJ system in lymphangiogenesis and lymphatic metastasis remains largely unexplored.

Purpose of the Study:

• To investigate the role of the apelin/APJ system in lymphangiogenesis and lymphatic tumor progression.
• To determine if apelin can induce lymphangiogenesis and affect tumor metastasis.

Main Methods:

• Assessed APJ expression in lymphatic endothelial cells (LECs).
• Investigated apelin's effect on LEC proliferation, migration, apoptosis, spheroid formation, and in vitro capillary-like tube formation.
• Evaluated the impact of apelin on in vivo lymphatic microvessel growth using a matrigel plug assay.
• Examined the correlation between apelin overexpression in tumor cells and tumor growth, lymphangiogenesis, and metastasis.

Main Results:

• APJ is expressed in LECs and is activated by apelin.
• Apelin enhances LEC migration, survival, spheroid formation, and in vitro tube formation, but not proliferation.
• Apelin promotes in vivo lymphatic microvessel growth and is associated with accelerated tumor growth and increased lymph node metastasis.
• Apelin overexpression in malignant cells correlates with increased intratumoral lymphangiogenesis.

Conclusions:

• Apelin acts as a novel lymphangiogenic factor.
• The apelin/APJ system plays a significant role in lymphatic tumor progression and metastasis.
• Targeting lymphangiogenesis via the apelin/APJ system presents a potential strategy for novel anticancer therapies.