Study of the effects of NK-tumor cell interaction by proteomic analysis and imaging

Abstract

Natural Killer (NK) cells play a pivotal role in the elimination of tumor cells. The interactions that NK cells can establish with cancer cells in the tumor microenvironment (TME) are crucial for the outcome of the anti-tumor response, possibly resulting in mechanisms able to modulate NK cell effector functions on the one side, and to modify tumor cell phenotype and properties on the other side. This chapter will describe two different experimental approaches for the evaluation of NK-tumor cell interactions. First, a detailed protocol for the setting up of NK-tumor cell co-cultures will be illustrated, followed by information on cell imaging techniques, useful for assessing cell morphology and cytoskeletal changes. The second part will be focused on the description of a proteomic approach aimed at investigating the effect of this crosstalk from another point of view, i.e., characterizing the cellular and molecular pathways modulated in tumor cells following interaction with NK cells. The chapter centers on the interaction between NK and melanoma cells and refers to experimental approaches we set up to study the effects of this cross-talk on the process of the Epithelial-to-Mesenchymal Transition (EMT). Nevertheless, the described protocols can be quite easily adapted to study the interaction of NK cells with adherent tumor cell lines of different origin and histotype, as in our original study, we also analyzed possible NK-induced morphologic changes in the cervix adenocarcinoma HeLa cells and the colon cancer HT29 cells.

Keywords: Cell imaging; EMT; Natural Killer cells; Proteomics; Tumor cells.