Effect of secretory DKK3 on circulating CD56bright natural killer cells in patients with liver cancer

Background Liver cancer seriously threatens human health. Natural killer (NK) cells are an important part of the innate immune system and have strong anti-tumor ability. Immunotherapy based on NK cells has become a hot topic in the treatment of liver cancer. Methods In this study, we checked the serum DKK3 (sDKK3) and circulating CD56(bright) NK cells using ELISA and flow cytometry, respectively, in the blood of liver cancer patients. The effect on recombinant human DKK3 (rhDKK3) on CD56(bright) NK cells was analyzed in vitro. Results We found low levels of sDKK3 in liver cancer patients and a negative correlation between sDKK3 and circulating CD56(bright) NK cells. In addition, we found that DKK3 induced the differentiation and improved the cytotoxicity of CD56(bright) NK cells for the first time. It could be used as an agonist for NK cell-based immunotherapy. Conclusions Improving the clinical efficacy of NK cells through DKK3 will become a new strategy for cancer immunotherapy.