Beyond immune checkpoint blockade: new approaches to targeting host-tumor interactions in prostate cancer: report from the 2014 Coffey-Holden prostate cancer academy meeting

Disrupting prostate cancer research: Challenge accepted; report from the 2023 Coffey-Holden Prostate Cancer Academy Meeting

INTRODUCTION

The 2023 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, themed "Disrupting Prostate Cancer Research: Challenge Accepted," was convened at the University of California, Los Angeles, Luskin Conference Center, in Los Angeles, CA, from June 22 to 25, 2023.

METHODS

The 2023 marked the 10th Annual CHPCA Meeting, a discussion-oriented scientific think-tank conference convened annually by the Prostate Cancer Foundation, which centers on innovative and emerging research topics deemed pivotal for advancing critical unmet needs in prostate cancer research and clinical care. The 2023 CHPCA Meeting was attended by 81 academic investigators and included 40 talks across 8 sessions.

RESULTS

The central topic areas covered at the meeting included: targeting transcription factor neo-enhancesomes in cancer, AR as a pro-differentiation and oncogenic transcription factor, why few are cured with androgen deprivation therapy and how to change dogma to cure metastatic prostate cancer without castration, reducing prostate cancer morbidity and mortality with genetics, opportunities for radiation to enhance therapeutic benefit in oligometastatic prostate cancer, novel immunotherapeutic approaches, and the new era of artificial intelligence-driven precision medicine.

DISCUSSION

This article provides an overview of the scientific presentations delivered at the 2023 CHPCA Meeting, such that this knowledge can help in facilitating the advancement of prostate cancer research worldwide.

CD44 is a potential immunotherapeutic target and affects macrophage infiltration leading to poor prognosis

CD44 plays a key role in the communication of CSCs with the microenvironment and the regulation of stem cell properties. UALCAN was used to analyze the expression of CD44 in bladder cancer (BLCA) and normal tissue. The UALCAN was utilized to analyze the prognostic value of CD44 in BLCA. The TIMER database was used to explore the relationship between CD44 and PD-L1; CD44 and tumor-infiltrating immune cells. The regulatory effect of CD44 on PD-L1 was verified by cell experiments in vitro. IHC confirmed the results of the bioinformatics analysis. GeneMania and Metascape were used to analyze protein-protein interaction (PPI) investigations and functional enrichment analysis. We found that BLCA patients with high CD44 expression had worse survival than those with low CD44 expression (P < 0.05). IHC and the TIMER database results showed that CD44 expression was positively correlated with PD-L1 expression (P < 0.05). At the cellular level, the expression of PD-L1 was significantly inhibited after CD44 expression was inhibited by siRNA. Immune infiltration analysis showed that CD44 expression levels in BLCA were significantly correlated with immune infiltration levels of different immune cells. IHC staining results further confirmed that the expression of CD44 in tumor cells was positively associated with the number of CD68⁺ macrophages and CD163⁺ macrophages (P < 0.05). Our results suggest that CD44 is a positive regulator of PD-L1 in BLCA and may be a key regulator of tumor macrophages infiltration and may be involved in M2 macrophage polarization. Our study provided new insights into the prognosis and immunotherapy of BLCA patients through macrophage infiltration and immune checkpoints.

Exploring new frontiers in prostate cancer research: Report from the 2022 Coffey-Holden prostate cancer academy meeting

INTRODUCTION

The 2022 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Exploring New Frontiers in Prostate Cancer Research," was held from June 23 to 26, 2022, at the University of California, Los Angeles, Luskin Conference Center, in Los Angeles, CA.

METHODS

The CHPCA Meeting is an annual discussion-oriented scientific conference organized by the Prostate Cancer Foundation, that focuses on emerging and next-step topics deemed critical for making the next major advances in prostate cancer research and clinical care. The 2022 CHPCA Meeting included 35 talks over 10 sessions and was attended by 73 academic investigators.

RESULTS

Major topic areas discussed at the meeting included: prostate cancer diversity and disparities, the impact of social determinants on research and patient outcomes, leveraging real-world and retrospective data, development of artificial intelligence biomarkers, androgen receptor (AR) signaling biology and new strategies for targeting AR, features of homologous recombination deficient prostate cancer, and future directions in immunotherapy and nuclear theranostics.

DISCUSSION

This article summarizes the scientific presentations from the 2022 CHPCA Meeting, with the goal that dissemination of this knowledge will contribute to furthering global prostate cancer research efforts.

Prostate cancer research in the 21st century; report from the 2021 Coffey-Holden prostate cancer academy meeting

INTRODUCTION

The 2021 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Prostate Cancer Research in the 21st Century," was held virtually, from June 24-25, 2021.

METHODS

The CHPCA Meeting is organized by the Prostate Cancer Foundation as a unique discussion-oriented meeting focusing on critical topics in prostate cancer research envisioned to bridge the next major advances in prostate cancer biology and treatment. The 2021 CHPCA Meeting was virtually attended by 89 investigators and included 31 talks over nine sessions.

RESULTS

Major topic areas discussed at the meeting included: cancer genomics and sequencing, functional genomic approaches to studying mediators of plasticity, emerging signaling pathways in metastatic castration resistant prostate cancer, Wnt signaling biology and the challenges of targeted therapy, clonal hematopoiesis, neuroendocrine cell plasticity and antitumor immunity, cancer immunotherapy and its synergizers, and imaging the tumor microenvironment and metabolism.

DISCUSSION

This meeting report summarizes the research presented at the 2021 CHPCA Meeting. We hope that publication of this knowledge will accelerate new understandings and the development of new biomarkers and treatments for prostate cancer.

Prostate cancer research: The next generation; report from the 2019 Coffey-Holden Prostate Cancer Academy Meeting

INTRODUCTION

The 2019 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Prostate Cancer Research: The Next Generation," was held 20 to 23 June, 2019, in Los Angeles, California.

METHODS

The CHPCA Meeting is an annual conference held by the Prostate Cancer Foundation, that is uniquely structured to stimulate intense discussion surrounding topics most critical to accelerating prostate cancer research and the discovery of new life-extending treatments for patients. The 7th Annual CHPCA Meeting was attended by 86 investigators and concentrated on many of the most promising new treatment opportunities and next-generation research technologies.

RESULTS

The topics of focus at the meeting included: new treatment strategies and novel agents for targeted therapies and precision medicine, new treatment strategies that may synergize with checkpoint immunotherapy, next-generation technologies that visualize tumor microenvironment (TME) and molecular pathology in situ, multi-omics and tumor heterogeneity using single cells, 3D and TME models, and the role of extracellular vesicles in cancer and their potential as biomarkers.

DISCUSSION

This meeting report provides a comprehensive summary of the talks and discussions held at the 2019 CHPCA Meeting, for the purpose of globally disseminating this knowledge and ultimately accelerating new treatments and diagnostics for patients with prostate cancer.

Tumor cell heterogeneity and resistance; report from the 2018 Coffey-Holden Prostate Cancer Academy Meeting

INTRODUCTION

The 2018 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Tumor Cell Heterogeneity and Resistance," was held in Los Angeles, California from June 21 to 24, 2018.

METHODS

The CHPCA Meeting is a unique, discussion-oriented scientific conference convened annually by the Prostate Cancer Foundation (PCF), which focuses on the most critical topics in need of further study to advance the treatment of lethal prostate cancer. The 6th Annual CHPCA Meeting was attended by 70 investigators and concentrated on prostate cancer heterogeneity and treatment resistance.

RESULTS

The meeting focused on topics including: recognition of tumor heterogeneity, molecular drivers of heterogeneity, the role of the tumor microenvironment, the role of heterogeneity in disease progression, metastasis and treatment resistance, clinical trials designed to target resistance and tumor heterogeneity, and immunotherapeutic approaches to target and overcome tumor heterogeneity.

DISCUSSION

This review article summarizes the presentations and discussions from the 2018 CHPCA Meeting in order to share this knowledge with the scientific community and encourage new studies that will lead to improved treatments and outcomes for men with prostate cancer.

STAT3 Inhibition Combined with CpG Immunostimulation Activates Antitumor Immunity to Eradicate Genetically Distinct Castration-Resistant Prostate Cancers

PURPOSE

Prostate cancers show remarkable resistance to emerging immunotherapies, partly due to tolerogenic STAT3 signaling in tumor-associated myeloid cells. Here, we describe a novel strategy combining STAT3 inhibition with Toll-like Receptor 9 (TLR9) stimulation to unleash immune response against prostate cancers regardless of the genetic background.

EXPERIMENTAL DESIGN

We developed and validated a conjugate of the STAT3 antisense oligonucleotide (ASO) tethered to immunostimulatory TLR9 agonist (CpG oligonucleotide) to improve targeting of human and mouse prostate cancer and myeloid immune cells, such as myeloid-derived suppressor cells (MDSC).

RESULTS

CpG-STAT3ASO conjugates showed improved biodistribution and potency of STAT3 knockdown in target cells in vitro and in vivo. Systemic administration of CpG-STAT3ASO (5 mg/kg) eradicated bone-localized, Ras/Myc-driven, and Pten^{pc -/-} Smad4^{pc -/-} Trp53^{c -/-} prostate tumors in the majority of treated mice. These antitumor effects were primarily immune-mediated and correlated with an increased ratio of CD8⁺ to regulatory T cells and reduced pSTAT3⁺/PD-L1⁺ MDSCs. Both innate and adaptive immunity contributed to systemic antitumor responses as verified by the depletion of Gr1⁺ myeloid cells and CD8⁺ and CD4⁺ T cells, respectively. Importantly, only the bifunctional CpG-STAT3ASO, but not control CpG oligonucleotides, STAT3ASO alone, or the coinjection of both oligonucleotides, succeeded in recruiting neutrophils and CD8⁺ T cells into tumors. Thus, the concurrence of TLR9 activation with STAT3 inhibition in the same cellular compartment is indispensable for overcoming tumor immune tolerance and effective antitumor immunity against prostate cancer.

CONCLUSIONS

The bifunctional, immunostimulatory, and tolerance-breaking design of CpG-STAT3ASO offers a blueprint for the development of effective and safer oligonucleotide strategies for treatment of immunologically "cold" human cancers.

Beyond the androgen receptor II: New approaches to understanding and treating metastatic prostate cancer; Report from the 2017 Coffey-Holden Prostate Cancer Academy Meeting

INTRODUCTION

The 2017 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Beyond the Androgen Receptor II: New Approaches to Understanding and Treating Metastatic Prostate Cancer," was held in Carlsbad, California from June 14-17, 2017.

METHODS

The CHPCA is an annual scientific conference hosted by the Prostate Cancer Foundation (PCF) that is uniquely designed to produce extensive and constructive discussions on the most urgent and impactful topics concerning research into the biology and treatment of metastatic prostate cancer. The 2017 CHPCA Meeting was the 5th meeting in this annual series and was attended by 71 investigators focused on prostate cancer and a variety of other fields including breast and ovarian cancer.

RESULTS

The discussions at the meeting were concentrated on topics areas including: mechanisms and therapeutic approaches for molecular subclasses of castrate resistant prostate cancer (CRPC), the epigenetic landscape of prostate cancer, the role of DNA repair gene mutations, advancing the use of germline genetics in clinical practice, radionuclides for imaging and therapy, advances in molecular imaging, and therapeutic strategies for successful use of immunotherapy in advanced prostate cancer.

DISCUSSION

This article reviews the presentations and discussions from the 2017 CHPCA Meeting in order to disseminate this knowledge and accelerate new biological understandings and advances in the treatment of patients with metastatic prostate cancer.

Beyond Seed and Soil: Understanding and Targeting Metastatic Prostate Cancer; Report From the 2016 Coffey-Holden Prostate Cancer Academy Meeting

INTRODUCTION

The 2016 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Beyond Seed and Soil: Understanding and Targeting Metastatic Prostate Cancer," was held from June 23 to June 26, 2016, in Coronado, California.

METHODS

For the 4th year in a row, the Prostate Cancer Foundation (PCF) hosted the CHPCA Meeting, a think tank-structured scientific conference, which focuses on a specific topic of critical unmet need on the biology and treatment of advanced prostate cancer. The 2016 CHPCA Meeting was attended by 71 investigators from prostate cancer and other fields, who discussed the biology, study methodologies, treatment strategies, and critical unmet needs concerning metastatic prostate cancer, with the ultimate goal of advancing strategies to treat and eliminate this disease.

RESULTS

The major topics of discussion included: the molecular landscape and molecular heterogeneity of metastatic prostate cancer, the role of the metastatic microenvironment, optimizing immunotherapy in metastatic prostate cancer, learning from exceptional responders and non-responders, targeting DNA repair deficiency in advanced prostate cancer, developing and applying novel biomarkers and imaging techniques, and potential roles for the microbiome in prostate cancer.

DISCUSSION

This article reviews the topics presented and discussions held at the CHPCA Meeting, with a focus on the unknowns and next steps needed to advance our understanding of the biology and most effective treatment strategies for metastatic prostate cancer. Prostate 77:123-144, 2017. © 2016 Wiley Periodicals, Inc.

The Relationship between Obesity, Prostate Tumor Infiltrating Lymphocytes and Macrophages, and Biochemical Failure

BACKGROUND

Obesity reflects a chronic inflammatory environment that may contribute to prostate cancer progression and poor treatment outcomes. However, it is not clear which mechanisms drive this association within the tumor microenvironment. The aim of this pilot study was to examine prostatic inflammation via tumor infiltrating lymphocytes and macrophages characterized by obesity and cancer severity.

METHODS

We studied paraffin-embedded prostatectomy tissue from 99 participants (63 non-obese and 36 obese) from the Study of Clinical Outcomes, Risk and Ethnicity (University of Pennsylvania). Pathologists analyzed the tissue for type and count of lymphocytes and macrophages, including CD3, CD8, FOXP3, and CD68. Pathology data were linked to clinical and demographic variables. Statistical analyses included frequency tables, Kruskal-Wallis tests, Spearman correlations, and multivariable models.

RESULTS

We observed positive univariate associations between the number of CD68 cells and tumor grade (p = 0.019). In multivariable analysis, CD8 counts were associated with time to biochemical failure (HR = 1.09, 95% CI = 1.004-1.192, p-value = 0.041.) There were no differences in lymphocytes or macrophages by obesity status or BMI.

CONCLUSIONS

The number of lymphocytes and macrophages in the tumor microenvironment did not differ by obesity status. However, these inflammation markers were associated with poor prostate cancer outcomes. Further examination of underlying mechanisms that influence obesity-related effects on prostate cancer outcomes is warranted. Such research will guide immunotherapy protocols and weight management as they apply to diverse patient populations and phenotypes.

New advances in genitourinary cancer: evidence gathered in 2014

This review provides updated information published in 2014 regarding advances and major achievements in genitourinary cancer. Sections include the best in prostate cancer, renal cancer, bladder cancer, and germ cell tumors. In the field of prostate cancer, data related to treatment approach of hormone-sensitive disease, castrate-resistant prostate cancer, mechanisms of resistance, new drugs, and molecular research are presented. In relation to renal cancer, relevant aspects in the treatment of advanced renal cell carcinoma, immunotherapy, and molecular research, including angiogenesis and von Hippel-Lindau gene, molecular biology of non-clear cell histologies, and epigenetics of clear renal cell cancer are described. New strategies in the management of muscle-invasive localized bladder cancer and metastatic disease are reported as well as salient findings of biomolecular research in urothelial cancer. Some approaches intended to improve outcomes in poor prognosis patients with metastatic germ cell cancer are also reported. Results of clinical trials in these areas are discussed.

Multidisciplinary intervention of early, lethal metastatic prostate cancer: Report from the 2015 Coffey-Holden Prostate Cancer Academy Meeting

BACKGROUND

The 2015 Coffey-Holden Prostate Cancer Academy Meeting, themed: "Multidisciplinary Intervention of Early, Lethal Metastatic Prostate Cancer," was held in La Jolla, California from June 25 to 28, 2015.

METHODS

The Prostate Cancer Foundation (PCF) sponsors an annual, invitation-only, action-tank-structured meeting on a critical topic concerning lethal prostate cancer. The 2015 meeting was attended by 71 basic, translational, and clinical investigators who discussed the current state of the field, major unmet needs, and ideas for addressing earlier diagnosis and treatment of men with lethal prostate cancer for the purpose of extending lives and making progress toward a cure.

RESULTS

The questions addressed at the meeting included: cellular and molecular mechanisms of tumorigenesis, evaluating, and targeting the microenvironment in the primary tumor, advancing biomarkers for clinical integration, new molecular imaging technologies, clinical trials, and clinical trial design in localized high-risk and oligometastatic settings, targeting the primary tumor in advanced disease, and instituting multi-modal care of high risk and oligometastatic patients.

DISCUSSION

This article highlights the current status, greatest unmet needs, and anticipated field changes that were discussed at the meeting toward the goal of optimizing earlier interventions to potentiate cures in high-risk and oligometastatic prostate cancer patients.

Delivery of cancer therapeutics to extracellular and intracellular targets: Determinants, barriers, challenges and opportunities

Advances in molecular medicine have led to identification of worthy cellular and molecular targets located in extracellular and intracellular compartments. Effectiveness of cancer therapeutics is limited in part by inadequate delivery and transport in tumor interstitium. Parts I and II of this report give an overview on the kinetic processes in delivering therapeutics to their intended targets, the transport barriers in tumor microenvironment and extracellular matrix (TME/ECM), and the experimental approaches to overcome such barriers. Part III discusses new concepts and findings concerning nanoparticle-biocorona complex, including the effects of TME/ECM. Part IV outlines the challenges in animal-to-human translation of cancer nanotherapeutics. Part V provides an overview of the background, current status, and the roles of TME/ECM in immune checkpoint inhibition therapy, the newest cancer treatment modality. Part VI outlines the development and use of multiscale computational modeling to capture the unavoidable tumor heterogeneities, the multiple nonlinear kinetic processes including interstitial and transvascular transport and interactions between cancer therapeutics and TME/ECM, in order to predict the in vivo tumor spatiokinetics of a therapeutic based on experimental in vitro biointerfacial interaction data. Part VII provides perspectives on translational research using quantitative systems pharmacology approaches.