Harnessing the Power of Memory-like NK Cells to Fight Cancer.

Natural killer (NK) cells possess the innate ability to eliminate cancerous cells effectively. Their crucial role in immunosurveillance has been widely recognised and exploited for therapeutic intervention. Despite the fast-acting nature of NK cells, NK adoptive cell transfer lacks favourable response in some patients. Patient NK cells often display diminished phenotype in preventing cancer progression resulting in poor prognosis. Tumour microenvironment play a significant role in causing the downfall of NK cells in patients. The release of inhibitory factors by tumour microenvironment hinders normal function of NK cells against tumour. In order to overcome this challenge, therapeutic strategies such as cytokine stimulation and genetic manipulation are being investigated to improve NK tumour killing capacity. One of the promising approaches include generation of more competent NK cells via ex-vivo cytokines activation and proliferation. Cytokine induced ML-NK demonstrated phenotypic alterations such as enhanced expression of activating receptors which help elevate their antitumour response. Previous preclinical studies showed enhanced cytotoxicity and IFNγ production in ML-NK cells compared to normal NK cells against malignant cells. Similar effects are shown in clinical studies in which MK-NK demonstrated encouraging results in treating haematological cancer. However, there is still lack of in-depth studies using ML-NK in treating different types of tumours and cancers. With convincing preliminary response, this cell-based approach could be used to complement other therapeutic modalities to achieve better clinical outcome.