Natural killer cells phenotypic characterization as an outcome predictor of HCV-linked HCC after curative treatments

NK-cell number and function have been associated with cancer progression. A detailed analysis of phenotypic and functional characteristics of NK-cells in HCC is still lacking. NK-cell function is regulated by activating and inhibitory receptors determined by genetic factors and engagement with cognate ligands on transformed or infected cells. We evaluated phenotypic and functional characteristic of NK-cells in HCC patients undergoing curative treatment in relation to clinical outcome. NK-cells from 70 HCC patients undergoing resection or ablative treatment, 18 healthy volunteers and 12 cirrhotic patients with HCV-infection (controls) were phenotypically characterized. Unsupervised clustering based on the frequency of cells expressing different phenotypic NK-cell markers segregated HCC patients into different cohorts that were compared for outcome. NK-cell cytokine production and cytotoxicity were compared between cohorts with different overall survival (OS) and time to disease recurrence (TTR). By multivariate analysis, age, Child-Pugh class and NK-cell phenotypic clustering could independently identify patients with significantly different OS. NK-cells from patients with better outcome expressed higher levels of cytotoxic granules and CD3 zeta and lower levels of natural cytotoxic receptors (NCRs) that were co-expressed with the inhibitory receptor NKG2A known to negatively regulate NCR function. Cytotoxic function and IFN gamma production were significantly lower in the cohort of patients with worse outcome compared to controls (p < 0.05). Our results show a role for NK-cells in the control of HCC progression and survival providing the basis for the development of immunotherapeutic strategies to potentiate NK-cell response.