Tumor-derived Immunoglobulin-like transcript 4 facilitates angiogenesis of colorectal cancer

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• Current anti-angiogenic therapies for advanced colorectal cancer (CRC) have limited efficacy due to complex tumor angiogenesis.
• Tumor-derived factors contribute to angiogenesis, necessitating exploration of novel targets.
• Immunoglobulin-like transcript 4 (ILT4), found in solid tumors, is implicated in tumor progression but its role in angiogenesis is unclear.

Purpose of the Study:

• To investigate the role of tumor-derived ILT4 in colorectal cancer (CRC) angiogenesis.
• To elucidate the molecular mechanisms by which ILT4 promotes angiogenesis.
• To evaluate ILT4 inhibition as a potential therapeutic strategy, alone or in combination with existing treatments.

Main Methods:

• Correlation analysis between ILT4 expression and microvessel density in CRC tissues.
• In vitro studies assessing ILT4's effect on human umbilical vein endothelial cell (HUVEC) migration and tube formation.
• In vivo angiogenesis assays.
• Mechanistic studies involving MAPK/ERK signaling pathway analysis and assessment of VEGF-A and FGF-1 expression.
• Evaluation of ILT4 inhibition efficacy in combination with Bevacizumab in CRC models.

Main Results:

• Tumor-derived ILT4 positively correlated with microvessel density in CRC tissues.
• ILT4 promoted HUVEC migration, tube formation, and in vivo angiogenesis.
• ILT4-induced angiogenesis was mediated by MAPK/ERK signaling, leading to increased VEGF-A and FGF-1.
• Inhibition of ILT4 suppressed tumor angiogenesis and improved Bevacizumab efficacy in CRC.

Conclusions:

• Tumor-derived ILT4 is a novel driver of colorectal cancer (CRC) angiogenesis.
• ILT4 activates the MAPK/ERK pathway, upregulating VEGF-A and FGF-1, to promote tumor vascularization.
• Targeting ILT4 represents a promising therapeutic strategy and offers potential for novel combination therapies to improve CRC treatment outcomes.