Role of heme oxygenase-1 in tumor immune escape

Abstract

The inducible enzyme heme oxygenase 1 (HO-1) plays a pivotal role in cell defense against different kind of stressors, from oxidative stress to hypoxia. For this reason, HO-1 overexpression has been correlated to cancer aggressiveness in different tumors, being one of the molecular mechanisms used by tumor cells to become resistant to therapies. In addition, HO-1 has a well-recognized role in restraining immune response and in maintaining tolerance. In this context, the possibility that HO-1 induction in immune cells can reduce immune response to cancer and impair cancer immune therapy becomes a hot topic in cancer research. In this review, the most recent evidence pointing out the role of HO-1 in generating a permissive tumor microenvironment has been discussed as well as the most promising therapeutic approaches to increase effectiveness of immune therapies.