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Renin-Angiotensin System in the Tumor Microenvironment
Kenta Nakamura1, Ryuhei Okuyama1, Yutaka Kawakami2,3
1Department of Dermatology, Shinshu University School of Medicine, Nagano, Japan.
Advances in Experimental Medicine and Biology
|October 29, 2020
Summary
The renin-angiotensin system (RAS) in tumors suppresses immune responses, hindering immunotherapy. Inhibiting this local RAS may enhance antitumor effects and improve cancer treatment outcomes.
Area of Science:
- Oncology
- Immunology
- Cardiovascular Research
Background:
- The renin-angiotensin system (RAS) regulates systemic circulation.
- A local RAS exists within tumors, influencing the tumor microenvironment.
- Tumor-associated RAS activity can promote immunosuppression, counteracting antitumor immunity.
Purpose of the Study:
- To review the role of the local RAS in the tumor microenvironment.
- To explore how RAS signaling impacts tumor immune responses.
- To discuss the potential of RAS inhibitors in combination with immunotherapy.
Main Methods:
- Literature review of studies on RAS, tumor immunology, and immunotherapy.
- Analysis of the mechanisms by which RAS components affect immune and stromal cells within tumors.
- Synthesis of current understanding of RAS-mediated immunosuppression in cancer.
Main Results:
- RAS activation, particularly via angiotensin II type 1 receptor, inhibits anti-tumor immune responses.
- Local RAS components are present and active in various tumor types.
- Tumor cells and stromal cells contribute to the local RAS.
Conclusions:
- Targeting the local RAS presents a promising strategy to overcome immunosuppression in cancer.
- RAS inhibitors could enhance the efficacy of current immunotherapies like immune-checkpoint blockade.
- Further research into combined RAS inhibition and immunotherapy is warranted for improved cancer treatment.
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