American Association for Cancer Research
Browse

Supplementary Figure 10 from BET Inhibition Sensitizes Immunologically Cold Rb-Deficient Prostate Cancer to Immune Checkpoint Blockade

Download (247.7 kB)
journal contribution
posted on 2023-06-01, 08:20 authored by Brian M. Olson, Kiranj Chaudagar, Riyue Bao, Sweta Sharma Saha, Christina Hong, Marguerite Li, Srikrishnan Rameshbabu, Raymond Chen, Alison Thomas, Akash Patnaik

JQ-1 treatment in vivo increases PD-L1 expression on myeloid suppressive cells.

Funding

NCI Prostate SPORE

Prostate Cancer Foundation (PCF)

American Cancer Society (ACS)

Winship Cancer Research Institute

Department of Defense Prostate Cancer Research Program

National Center for Georgia Clinical & Translational Science Alliance of the National Institutes of Health

National Cancer Institute (NCI)

United States Department of Health and Human Services

Find out more...

History

ARTICLE ABSTRACT

Non–T-cell–inflamed immunologically “cold” tumor microenvironments (TME) are associated with poor responsiveness to immune checkpoint blockade (ICB) and can be sculpted by tumor cell genomics. Here, we evaluated how retinoblastoma (Rb) tumor-suppressor loss-of-function (LOF), one of the most frequent alterations in human cancer and associated with lineage plasticity, poor prognosis, and therapeutic outcomes, alters the TME, and whether therapeutic strategies targeting the molecular consequences of Rb loss enhance ICB efficacy. We performed bioinformatics analysis to elucidate the impact of endogenous Rb LOF on the immune TME in human primary and metastatic tumors. Next, we used isogenic murine models of Rb-deficient prostate cancer for in vitro and in vivo mechanistic studies to examine how Rb loss and bromodomain and extraterminal (BET) domain inhibition (BETi) reprograms the immune landscape, and evaluated in vivo therapeutic efficacy of BETi, singly and in combination with ICB and androgen deprivation therapy. Rb loss was enriched in non–T-cell–inflamed tumors, and Rb-deficient murine tumors demonstrated decreased immune infiltration in vivo. The BETi JQ1 increased immune infiltration into the TME through enhanced tumor cell STING/NF-κB activation and type I IFN signaling within tumor cells, resulting in differential macrophage and T-cell–mediated tumor growth inhibition and sensitization of Rb-deficient prostate cancer to ICB. BETi can reprogram the immunologically cold Rb-deficient TME via STING/NF-κB/IFN signaling to sensitize Rb-deficient prostate cancer to ICB. These data provide the mechanistic rationale to test combinations of BETi and ICB in clinical trials of Rb-deficient prostate cancer.

Usage metrics

    Molecular Cancer Therapeutics

    Categories

    Keywords

    Licence

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC