Natural killer cells (NK cells) are derived from bone marrow lymphoid stem cells, which are a type of lymphocytes that can non-specifically kill tumor cells and virus-infected cells without pre-sensitization. NK cells can not only directly kill malignant diseased cells, but also participate in the regulation of immune cell response and play a role in a variety of tumor immunotherapy strategies. The 2-year survival rate of NK cells combined with stem cell therapy for patients with hematological malignancies reached 36%, which is significantly higher than the 2-year survival rate (about 15%) of stem cell therapy alone, which can extend the disease-free survival period of leukemia patients by an average of 1.5 years. Relapsed and refractory leukemia can achieve a complete remission rate of up to 40%. However, NK cell therapy alone or the use of autologous NK cells to treat solid tumors is not effective. In clinical trials related to rectal cancer, esophageal cancer, kidney cancer, and gastric cancer, the clinical response of NK cell adoptive therapy is not good. A phase II clinical study found that the disease control rate of patients with ovarian cancer and breast cancer after radiotherapy and chemotherapy can reach about 60% by NK cell infusion. The main reason for the low treatment efficiency of solid tumors is related to the immunosuppressive effect of the tumor microenvironment. Combination therapy is a potential breakthrough. Researches targeting tumor immune microenvironment, targeting tumor cells and combined with NK cell therapy have shown tumor therapeutic potential. NK cells combined with IgG1 antibody treatment of gastric cancer and colon cancer in about 50% of patients with partial remission, and 17% of patients are in stable condition. In summary, the combined application of the demethylation drug DAC and NK cell infusion may be a new clinical strategy for the treatment of malignant tumors.
Natural killer cells (NK cells) are derived from bone marrow lymphoid stem cells, which are a type of lymphocytes that can non-specifically kill tumor cells and virus-infected cells without pre-sensitization. NK cells can not only directly kill malignant diseased cells, but also participate in the regulation of immune cell response and play a role in a variety of tumor immunotherapy strategies. The 2-year survival rate of NK cells combined with stem cell therapy for patients with hematological malignancies reached 36%, which is significantly higher than the 2-year survival rate (about 15%) of stem cell therapy alone, which can extend the disease-free survival period of leukemia patients by an average of 1.5 years. Relapsed and refractory leukemia can achieve a complete remission rate of up to 40%.