Immunogenicity of prostate cancer is augmented by BET bromodomain inhibition

Epitherapy and immune checkpoint blockade: using epigenetic reinvigoration of exhausted and dysfunctional T cells to reimburse immunotherapy response

BACKGROUND

Cancer cells subvert natural immunosuppression by upregulating the expression of checkpoint proteins and their ligands. For example, tumor cells expressing programmed death-ligand 1 (PD-L1) induce immune cell tolerance to cancers, thereby facilitating tumor progression. The recent clinical success of immunotherapy, particularly checkpoint blockade, represents a significant advance in cancer therapy. However, many cancers develop resistance to immunotherapies, and the underlying mechanisms and how these might be exploited to overcome resistance still need to be determined.

METHODS

T cell dysfunction, in part caused by chronic T cell receptor stimulation, diminishes the capacity for durable responses to checkpoint blockade. Furthermore, T cell populations are phenotypically and functionally heterogeneous, resulting in varying responses to checkpoint blockade. Recent molecular studies of T cell heterogeneity have shown that checkpoint blockade on its own does not alter the epigenetic landscape of T cells, despite epigenetic changes governing T cell phenotype.

CONCLUSION

Here we argue that epigenetic modifiers can be used to prime and sensitize T cells to immunotherapy. Administering epitherapy in conjunction with checkpoint blockade could decrease T cell exhaustion and immunotherapy resistance in many cancer types.

Targeting the Immune system and Epigenetic Landscape of Urological Tumors

In the last years, we have witnessed remarkable advances in targeted therapies for cancer patients. There is a growing effort to either replace or reduce the dose of unspecific, systemic (chemo)therapies, given the associated short- and long-term side effects, by introducing more specific targeted therapies as single or combination agents. Due to the well-known implications of the immune system and epigenetic landscape in modulating cancer development, both have been explored as potential targets in several malignancies, including those affecting the genitourinary tract. As the immune system function is also epigenetically regulated, there is rationale for combining both strategies. However, this is still rather underexplored, namely in urological tumors. We aim to briefly review the use of immune therapies in prostate, kidney, bladder, and testicular cancer, and further describe studies providing supporting evidence on their combination with epigenetic-based therapies.