Prostanoid induces premetastatic niche in regional lymph nodes

Area of Science:

• Oncology
• Immunology
• Cell Biology

Background:

• Lymph node metastasis (LNM) is crucial for cancer progression and patient prognosis.
• The lymphatic system facilitates cancer cell dissemination.
• Understanding the mechanisms of premetastatic niche formation is vital for developing targeted therapies.

Purpose of the Study:

• To investigate the role of COX-2-derived PGE2 in forming a premetastatic niche and LNM.
• To explore the signaling pathways involved in COX-2-mediated LNM.
• To evaluate the therapeutic potential of targeting the COX-2/PGE2 axis.

Main Methods:

• Utilized a murine model of Lewis lung carcinoma (LLC) metastasis.
• Administered COX-2 inhibitors, SDF-1 antagonists, and CXCR4 neutralizing antibodies.
• Analyzed gene and protein expression in dendritic cells (DCs) and lymph nodes.
• Investigated LNM in mice with genetic deficiencies in the PGE2 receptor EP3.
• Assessed the impact on regulatory T cells (Tregs) and lymphangiogenesis.

Main Results:

• COX-2 expression in DCs preceded LLC cell infiltration in lymph nodes.
• COX-2 inhibition significantly reduced mediastinal LNM.
• Elevated Stromal cell-derived factor-1 (SDF-1) in DCs was linked to LNM.
• Targeting COX-2, SDF-1, or CXCR4 pathways reduced LNM.
• Mice lacking the PGE2 receptor EP3 showed reduced LNM.
• EP3 signaling in DCs promoted SDF-1 production.
• COX-2/EP3 signaling influenced Treg accumulation and lymph node lymphangiogenesis.

Conclusions:

• DCs induce a premetastatic niche in LNM via COX-2/EP3-dependent SDF-1 induction.
• Targeting the COX-2/EP3/SDF-1 signaling axis is a promising strategy to suppress LNM.
• This pathway represents a potential therapeutic target for preventing cancer metastasis.