sTLR4/MD-2 complex inhibits colorectal cancer in vitro and in vivo by targeting LPS

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• Colorectal cancer (CRC) is aggressive and linked to Toll-like receptor 4 (TLR4) and myeloid differentiation protein 2 (MD-2) signaling.
• High expression of TLR4 and MD-2 is observed in human CRC, suggesting their role in cancer progression.
• Soluble forms of TLR4 (sTLR4) and MD-2 may interfere with lipopolysaccharide (LPS) binding to cellular TLR4/MD-2 complexes.

Purpose of the Study:

• To synthesize a soluble TLR4/MD-2 (sTLR4/MD-2) complex.
• To investigate the complex's ability to inhibit LPS-TLR4/MD-2 activation.
• To evaluate the therapeutic potential of the sTLR4/MD-2 complex in preclinical models of colorectal cancer.

Main Methods:

• Synthesis of sTLR4 and MD-2 proteins and their complex formation.
• In vitro assays to assess the effect of the sTLR4/MD-2 complex on LPS-induced inflammatory cytokine production, cell cycle, migration, and invasion.
• In vivo studies using xenograft, implantation metastasis, and azoxymethane/dextran sulfate sodium salt (AOM/DSS) murine models to evaluate tumor inhibition and inflammatory markers.

Main Results:

• The sTLR4/MD-2 complex successfully attenuated LPS-induced pro-inflammatory and migration cytokine production in vitro and in vivo.
• The complex inhibited LPS effects on CRC cell cycle, migration, and invasion in vitro.
• Administration of the sTLR4/MD-2 complex protected mice from tumor growth in various models, reducing tumor size, body weight loss, and inflammatory cytokine expression.

Conclusions:

• The sTLR4/MD-2 complex effectively inhibits colorectal cancer progression by competing with LPS binding to TLR4/MD-2.
• This complex demonstrates significant anti-tumor and anti-inflammatory effects in preclinical models.
• The sTLR4/MD-2 complex holds promise as a novel preventive agent for colorectal cancer.