1 Department of Haematology, Herlev and Gentofte Hospital, The Capital Region of Denmark2 Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA 15224, USA.3 University of Pittsburgh Cancer Institute, University of Pittsburgh, Pittsburgh PA 15213, USA; Department of Immunology, University of Pittsburgh, Pittsburgh PA 15213, USA.
The presence of natural killer (NK) cells in the tumor microenvironment correlates with outcome in a variety of cancers. However, the role of intratumoral NK cells is unclear. Preclinical studies have shown that, while NK cells efficiently kill circulating tumor cells of almost any origin, they seem to have very little effect against the same type of tumor cells when these have extravasated. The ability to kill extravasated tumor cells is, however, is dependent of the level of activation of the NK cells, as more recent published and unpublished studies, discussed below, have demonstrated that interleukin-2-activated NK cells are able to attack well-established solid tumors.
Critical Reviews in Oncogenesis, 2014, Vol 19, Issue 1-2, p. 91-105