Tumor Anti-Angiogenesis Therapy and Its Influence on Immune Cell Function in the Tumor Microenvironment

Vascular normalization, one promising anti-angiogenic strategy, has the potential to enhance vascular perfusion and elevate the infiltration of immune cells into tumors by rectifying aberrant tumor blood vessels. This results in the enhancement of immunotherapy. Immunotherapy has been identified as an effective treatment option for various types of cancer. However, it has become increasingly evident that the benefits of immunotherapy are less than expected, as recognized by the fact that only a small percentage of cancer patients respond positively to it. The structurally and functionally abnormal tumor vasculature, a characteristic feature of most solid tumors, contributes to the creation of an immunosuppressive microenvironment. This poses a significant challenge for immunotherapy. On the other hand, tumor antiangiogenic therapy could remodel the immune microenvironment by interfering with the function of immune cells, improving the anti-tumor efficacy. In this review, we primarily discuss the current research progress of anti-tumor angiogenesis drugs and the effects of tumor vasculature on immune cells in the tumor microenvironment (TME). We further emphasize advances recently in the clinical setting of anti-angiogenic therapy combined with immunotherapies, demonstrating that targeting both tumor blood vessels and immune cells provides a resultful approach for the cancer treatment.