Novel combinatorial approaches to tackle the immunosuppressive microenvironment of prostate cancer

Pockley, G. ORCID: 0000-0001-9593-6431, Shackelton, E., Ali, H., Stephanie, M. ORCID: 0000-0001-6929-9782 and Khan, M., 2021. Novel combinatorial approaches to tackle the immunosuppressive microenvironment of prostate cancer. Cancers, 13 (5): 1145.

1424112_Pockley.pdf - Published version

Download (4MB) | Preview


Prostate cancer (PCa) is the second-most common cancer in men worldwide and treatment options for patients with advanced or aggressive prostate cancer or recurrent disease continue to be of limited success and are rarely curative. Despite immune checkpoint blockade (ICB) efficacy in some melanoma, lung, kidney and breast cancers, immunotherapy efforts have been remarkably unsuccessful in PCa. One hypothesis behind this lack of efficacy is the generation of a distinctly immunosuppressive prostate tumor microenvironment (TME) by regulatory T cells, MDSCs, and type 2 macrophages which have been implicated in a variety of pathological conditions including solid cancers. In PCa, Tregs and MDSCs are attracted to TME by low-grade chronic inflammatory signals, while tissue-resident type 2 macrophages are induced by cytokines such as IL4, IL10, IL13, transforming growth factor beta (TGFβ) or prostaglandin E2 (PGE2) produced by Th2 cells. These then drive tumor progression, therapy resistance and the generation of castration resistance, ultimately conferring a poor prognosis. The biology of MDSC and Treg is highly complex and the development, proliferation, maturation or function can each be pharmacologically mediated to counteract the immunosuppressive effects of these cells. Herein, we present a critical review of Treg, MDSC and M2 involvement in PCa progression but also investigate a newly recognized type of immune suppression induced by the chronic stimulation of the sympathetic adrenergic signaling pathway and propose targeted strategies to be used in a combinatorial modality with immunotherapy interventions such as ICB, Sipuleucel-T or antitumor vaccines for an enhanced anti-PCa tumor immune response. We conclude that a strategic sequence of therapeutic interventions in combination with additional holistic measures will be necessary to achieve maximum benefit for PCa patients.

Item Type: Journal article
Publication Title: Cancers
Creators: Pockley, G., Shackelton, E., Ali, H., Stephanie, M. and Khan, M.
Publisher: MDPI AG
Date: 8 March 2021
Volume: 13
Number: 5
Rights: Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// 4.0/).
Divisions: Schools > School of Science and Technology
Record created by: Linda Sullivan
Date Added: 11 Mar 2021 10:35
Last Modified: 31 May 2021 15:05

Actions (login required)

Edit View Edit View


Views per month over past year


Downloads per month over past year