Related Experiment Videos
Lymphotoxin-beta receptor immune interaction promotes tumor growth by inducing angiogenesis
Thomas Hehlgans1, Benjamin Stoelcker, Peter Stopfer
1Department of Pathology/Tumor Immunology, University of Regensburg, D-93042 Regensburg, Germany.
Abstract:
Growth of solid fibrosarcoma tumors in mice was inhibited by the release of a solublelymphotoxin-beta receptor inhibitor (LTbetaR-immunoglobulin fusion protein) from the tumor cells. Tumor growth arrest in mice deficient in the ligand LTalpha1beta2 demonstrated the requirement for activation of the LTbetaR on the tumor cells by host cell-derived LTalpha1beta2. Activation of the LTbetaR resulted in enhanced release of macrophage inflammatory protein-2. Blocked angiogenesis was revealed in LTbetaR inhibitor-producing tumor nodules by immunohistochemistry and in vivo microscopy. The growth arrest of LTbetaR inhibitor-producing fibrosarcomas was overcome by forced MIP-2 expression in the tumor cells. Thus, LTbetaR activation on tumor cells by activated host lymphocytes can initiate a novel proangiogenic pathway leading to organized tumor tissue development.
Insights
Tumor growth inhibition was observed when fibrosarcoma cells released a soluble lymphotoxin-beta receptor inhibitor (LTbetaR-immunoglobulin fusion protein). LTbetaR activation on tumor cells by host lymphocytes initiates a proangiogenic pathway.
Area of Science:
- Immunology
- Cancer Biology
- Molecular Oncology
Background:
- Solid fibrosarcoma tumor growth is a complex process involving cellular interactions and signaling pathways.
- The lymphotoxin-beta receptor (LTbetaR) pathway plays a role in immune responses and tissue organization.
- Understanding the specific mechanisms of LTbetaR signaling in tumor microenvironments is crucial for developing targeted therapies.
Purpose of the Study:
- To investigate the role of LTbetaR activation on fibrosarcoma cells in regulating tumor growth and angiogenesis.
- To elucidate the downstream signaling events triggered by LTbetaR activation, including the release of inflammatory mediators.
- To determine whether LTbetaR signaling influences the tumor microenvironment and vascularization.
Main Methods:
- Utilizing a fibrosarcoma mouse model with tumor cells engineered to release an LTbetaR-immunoglobulin fusion protein inhibitor.
- Assessing tumor growth and arrest in both wild-type and LTalpha1beta2-deficient mice.
- Analyzing the expression and release of macrophage inflammatory protein-2 (MIP-2) following LTbetaR activation.
- Employing immunohistochemistry and in vivo microscopy to evaluate angiogenesis in tumor nodules.
Main Results:
- Inhibition of solid fibrosarcoma tumor growth was achieved by the release of an LTbetaR inhibitor from tumor cells.
- Tumor growth arrest was dependent on the activation of LTbetaR on tumor cells by host cell-derived LTalpha1beta2.
- LTbetaR activation led to increased release of macrophage inflammatory protein-2 (MIP-2).
- LTbetaR inhibitor-producing tumor nodules exhibited blocked angiogenesis.
Conclusions:
- LTbetaR activation on tumor cells by host lymphocytes can initiate a novel proangiogenic pathway.
- This pathway involves the release of MIP-2 and influences tumor tissue development.
- Targeting LTbetaR signaling presents a potential strategy for modulating tumor microenvironment and growth.