Dataset Information

Suppression of tumor cell lactate-generating signaling pathways eradicates murine PTEN/p53-deficient aggressive-variant prostate cancer via macrophage phagocytosis.

ABSTRACT:

Purpose

PTEN loss-of-function/PI3K pathway hyperactivation occurs in ∼50% of metastatic, castrate-resistant prostate cancer patients, resulting in poor therapeutic outcomes and resistance to immune checkpoint inhibitors across multiple malignancies. Our prior studies in prostate-specific PTEN/p53-deleted genetically engineered mice (Pb-Cre;PTEN ^fl/fl Trp53 ^fl/fl GEM) with aggressive-variant prostate cancer (AVPC) demonstrated feedback Wnt/β-catenin signaling activation in 40% mice resistant to androgen deprivation therapy (ADT)/PI3K inhibitor (PI3Ki)/PD-1 antibody (aPD-1) combination, resulting in restoration of lactate cross-talk between tumor-cells and tumor-associated macrophages (TAM), histone lactylation (H3K18lac) and phagocytic suppression within TAM. Here, we targeted immunometabolic mechanism(s) of resistance to ADT/PI3Ki/aPD-1 combination, with the goal of durable tumor control in PTEN/p53-deficient PC.

Experimental design

Pb-Cre;PTEN ^fl/fl Trp53 ^fl/fl GEM were treated with either ADT (degarelix), PI3Ki (copanlisib), aPD-1, MEK inhibitor (trametinib) or Porcupine inhibitor (LGK 974) as single agents or their combinations. MRI was used to monitor tumor kinetics and immune/proteomic profiling/ ex vivo co-culture mechanistic studies were performed on prostate tumors or established GEM-derived cell lines.

Results

We tested whether Wnt/β-catenin pathway inhibition with LGK 974 addition to degarelix/copanlisib/aPD-1 therapy enhances tumor control in GEM, and observed de novo resistance due to feedback activation of MEK signaling. Based on our observation that degarelix/aPD-1 treatment resulted in partial inhibition of MEK signaling, we substituted trametinib for degarelix/aPD-1 treatment, and observed a durable tumor growth control of PI3Ki/MEKi/PORCNi in 100% mice via H3K18lac suppression and complete TAM activation within TME.

Conclusions

Abrogation of lactate-mediated cross-talk between cancer cells and TAM results in durable ADT-independent tumor control in PTEN/p53-deficient AVPC, and warrants further investigation in clinical trials.

Statement of translational relevance

PTEN loss-of-function occurs in ∼50% of mCRPC patients, and associated with poor prognosis, and immune checkpoint inhibitor resistance across multiple malignancies. Our prior studies have demonstrated that ADT/PI3Ki/PD-1 triplet combination therapy controls PTEN/p53-deficient PC in 60% of mice via enhancement of TAM phagocytosis. Here, we discovered that resistance to ADT/PI3K/PD-1 therapy occurred via restoration of lactate production via feedback Wnt/MEK signaling following treatment with PI3Ki, resulting in inhibition of TAM phagocytosis. Critically, co-targeting of PI3K/MEK/Wnt signaling pathways using an intermittent dosing schedule of corresponding targeted agents resulted in complete tumor control and significantly prolonged survival without significant long-term toxicity. Collectively, our findings provide "proof-of-concept" that targeting lactate as a macrophage phagocytic checkpoint controls growth of murine PTEN/p53-deficient PC and warrant further investigation in AVPC clinical trials.

SUBMITTER: Chaudagar K

PROVIDER: S-EPMC10245812 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature

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Publications

Suppression of tumor cell lactate-generating signaling pathways eradicates murine PTEN/p53-deficient aggressive-variant prostate cancer via macrophage phagocytosis.

Chaudagar Kiranj K Hieromnimon Hanna M HM Kelley Anne A Labadie Brian B Shafran Jordan J Rameshbabu Srikrishnan S Drovetsky Catherine C Bynoe Kaela K Solanki Ani A Markiewicz Erica E Fan Xiaobing X Loda Massimo M Patnaik Akash A

bioRxiv : the preprint server for biology 20230523

<h4>Purpose</h4>PTEN loss-of-function/PI3K pathway hyperactivation occurs in ∼50% of metastatic, castrate-resistant prostate cancer patients, resulting in poor therapeutic outcomes and resistance to immune checkpoint inhibitors across multiple malignancies. Our prior studies in prostate-specific PTEN/p53-deleted genetically engineered mice (Pb-Cre;PTEN <sup>fl/fl</sup> Trp53 <sup>fl/fl</sup> GEM) with aggressive-variant prostate cancer (AVPC) demonstrated feedback Wnt/β-catenin signaling activat ...[more]

PMID: 37292972

Similar Datasets

Project description:PurposePhosphatase and tensin homolog (PTEN) loss of function occurs in approximately 50% of patients with metastatic castrate-resistant prostate cancer (mCRPC), and is associated with poor prognosis and responsiveness to standard-of-care therapies and immune checkpoint inhibitors. While PTEN loss of function hyperactivates PI3K signaling, combinatorial PI3K/AKT pathway and androgen deprivation therapy (ADT) has demonstrated limited anticancer efficacy in clinical trials. Here, we aimed to elucidate mechanism(s) of resistance to ADT/PI3K-AKT axis blockade, and to develop rational combinatorial strategies to effectively treat this molecular subset of mCRPC.Experimental designProstate-specific PTEN/p53-deficient genetically engineered mice (GEM) with established 150-200 mm3 tumors, as assessed by ultrasound, were treated with either ADT (degarelix), PI3K inhibitor (copanlisib), or anti-PD-1 antibody (aPD-1), as single agents or their combinations, and tumors were monitored by MRI and harvested for immune, transcriptomic, and proteomic profiling, or ex vivo co-culture studies. Single-cell RNA sequencing on human mCRPC samples was performed using 10X Genomics platform.ResultsCoclinical trials in PTEN/p53-deficient GEM revealed that recruitment of PD-1-expressing tumor-associated macrophages (TAM) thwarts ADT/PI3Ki combination-induced tumor control. The addition of aPD-1 to ADT/PI3Ki combination led to TAM-dependent approximately 3-fold increase in anticancer responses. Mechanistically, decreased lactate production from PI3Ki-treated tumor cells suppressed histone lactylation within TAM, resulting in their anticancer phagocytic activation, which was augmented by ADT/aPD-1 treatment and abrogated by feedback activation of Wnt/β-catenin pathway. Single-cell RNA-sequencing analysis in mCRPC patient biopsy samples revealed a direct correlation between high glycolytic activity and TAM phagocytosis suppression.ConclusionsImmunometabolic strategies that reverse lactate and PD-1-mediated TAM immunosuppression, in combination with ADT, warrant further investigation in patients with PTEN-deficient mCRPC.

Project description:Purpose: PTEN loss-of-function occurs in ~50% of metastatic, castrate-resistant prostate cancer (mCRPC) patients, and associated with poor prognosis and responsiveness to standard-of-care therapies and immune checkpoint inhibitors. While PTEN loss-of-function hyperactivates PI3K signaling, combinatorial PI3K/AKT pathway and androgen deprivation therapy (ADT) has demonstrated limited anti-cancer efficacy in clinical trials. Here, we aimed to elucidate mechanism(s) of resistance to ADT/PI3K-AKT axis blockade, and to develop rational combinatorial strategies to effectively treat this molecular subset of mCRPC. Experimental design: Prostate-specific PTEN/p53-deficient genetically engineered mice (GEM) with established 150-200 mm3 tumors, as assessed by ultrasound, were treated with either ADT (degarelix), PI3K inhibitor (copanlisib), or anti-PD-1 antibody (aPD-1), as single agents or their combinations, and tumors were monitored by MRI and harvested for immune, transcriptomic and proteomic profiling, or ex vivo co-culture studies. Single-cell RNAseq on human mCRPC samples was performed using 10X Genomics platform. Results: Co-clinical trials in PTEN/p53-deficient GEM revealed that recruitment of PD-1-expressing tumor-associated macrophages (TAM) thwarts ADT/PI3Ki combination-induced tumor control. The addition of aPD-1 to ADT/PI3Ki combination led to TAM-dependent ~3-fold increase in anti-cancer responses. Mechanistically, decreased lactate production from PI3Ki-treated tumor cells suppressed histone lactylation within TAM, resulting in their anti-cancer phagocytic activation, which was augmented by ADT/aPD-1 treatment and abrogated by feedback activation of Wnt/β-catenin pathway. Single-cell RNA-sequencing analysis in mCRPC patient biopsy samples revealed a direct correlation between high glycolytic activity and TAM phagocytosis suppression. Conclusions: Immunometabolic strategies that reverse lactate and PD-1-mediated TAM immunosuppression, in combination with ADT, warrant further investigation in PTEN-deficient mCRPC patients.

Dataset Information

Suppression of tumor cell lactate-generating signaling pathways eradicates murine PTEN/p53-deficient aggressive-variant prostate cancer via macrophage phagocytosis.

Purpose

Experimental design

Results

Conclusions

Statement of translational relevance

Publications

Suppression of tumor cell lactate-generating signaling pathways eradicates murine PTEN/p53-deficient aggressive-variant prostate cancer via macrophage phagocytosis.

Similar Datasets

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