Abstract
Harnessing natural killer (NK) cell activity, either endogenous NK or NK-cell-based therapy, is in the forefront development for many tumor types. There are compelling clinical evidence demonstrating the significant relevance of loss of NK cell activity with prostate cancer (PCa) disease progression to the lethal phenotype, metastatic castration-resistant PCa (mCRPC). Given that mCRPC is generally regarded as a "cold" tumor and has only elicited marginal response to immune checkpoint blockade therapy to revive CD8 T cell activity, NK cell targeted therapy may present a viable opportunity not only to directly target mCRPC and also to "fire up" the cold mCRPC tumor. However, current efforts on harnessing NK cell activity for treating mCRPC is very limited with only one open NK-cell-based clinical trial. This minireview will present the clinical significance of NK cell activity in controlling metastatic PCa and provide perspectives on harnessing NK cell activity for treating mCRPC.