NK Cell‐Based Cancer Immunotherapies: Current Progress, Challenges and Emerging Opportunities

Natural killer (NK) cells are vital innate immune cells that play a crucial role in cancer therapy. They are targeted by therapies designed to modulate, retain, and enhance their antitumor function in vivo. In addition to whole-cell therapy, NK cell-derived exosomes (NDEs) offer high immune safety and are easily subject to chemical, biological, and immunological modifications. This makes them suitable for use in combination with various current cancer therapies to enhance efficacy, treatment outcomes, and reduce side effects in vivo. This review aims to outline summarizes the antitumor potential of NK cells, as well as the current challenges and opportunities in NK cell-based immunotherapies such as allogeneic and autologous NK cell transplantation, CAR NK cell therapy, and the use of cytokines and monoclonal antibodies. The review also explores the dual regulatory effects of tumor exosomes on NK cells, and highlights the potential of NDEs, either alone or in combination with other antitumor therapies, to reprogram the immunosuppressive tumor microenvironment and expedite the therapeutic effects of cancer immunotherapy in future clinical research.