Cisplatin-induced antitumor immunomodulation: A review of preclinical and clinical evidence
Contrary to the long held belief that chemotherapy is immunosuppressive, emerging evidence indicates that the anticancer activity of cisplatin is not limited to its ability to inhibit mitosis, but that cisplatin also has important immunomodulatory effects. We therefore methodically examined the relevant preclinical literature and identified four main mechanisms of cisplatin-induced antitumor immunomodulation: (i) MHC class I expression upregulation; (ii) recruitment and proliferation of effector cells; (iii) upregulation of the lytic activity of cytotoxic effectors; and (iv) downregulation of the immunosuppressive microenvironment. Cisplatin-based combination chemotherapy's antitumor immunomodulatory effects are also beginning to be harnessed in the clinic; we therefore additionally reviewed the applicable clinical literature and discussed how monitoring various components of the immune system (and their responses to cisplatin) can add new levels of sophistication to disease monitoring and prognostication. In summation, this growing body of literature on cisplatin-induced antitumor immunomodulation ultimately highlights the therapeutic potential of synergistic strategies that combine traditional chemotherapy with immunotherapy.