Phase II trial of nivolumab and metformin in patients with treatment-refractory microsatellite stable metastatic colorectal cancer.

Background: Preclinical studies showed metformin reduces exhaustion of tumor-infiltrating lymphocytes and potentiates programmed cell death protein-1 (PD-1) blockade. We hypothesized that metformin with nivolumab would elicit potent antitumor and immune modulatory activity in metastatic microsatellite stable (MSS) colorectal cancer (CRC). We evaluated this hypothesis in a phase II study.

The Intersection of Prostate Cancer and Hypertension: a Call to Action.

With improvements in treatment and survival from prostate cancer, comorbid cardiac conditions will significantly impact overall morbidity and mortality from prostate cancer. Hypertension is a well-established cardiovascular risk factor that increases the risk of heart failure, myocardial infarction, and stroke. Therapies used in the treatment of prostate cancer, including GnRH agonists, GnRH antagonists, enzalutamide, abiraterone, and others, can directly or indirectly increase the risk of hypertension.

BET Inhibition Sensitizes Immunologically Cold Rb-Deficient Prostate Cancer to Immune Checkpoint Blockade.

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.

Combined MEK/PD-L1 Inhibition Alters Peripheral Cytokines and Lymphocyte Populations Correlating with Improved Clinical Outcomes in Advanced Biliary Tract Cancer.

Purpose: Biliary tract cancers (BTC) are aggressive malignancies refractory to chemotherapy and immunotherapy. MEK inhibition (MEKi)-based regimens may have utility in this disease when combined with PD-L1 blockade. We hypothesize that dual MEK/PD-L1 inhibition alters circulating soluble and cellular immune mediators to improve clinical outcomes in patients with advanced BTC.

EZH2 inhibition activates a dsRNA-STING-interferon stress axis that potentiates response to PD-1 checkpoint blockade in prostate cancer.

Prostate cancers are considered to be immunologically 'cold' tumors given the very few patients who respond to checkpoint inhibitor (CPI) therapy. Recently, enrichment of interferon-stimulated genes (ISGs) predicted a favorable response to CPI across various disease sites. The enhancer of zeste homolog-2 (EZH2) is overexpressed in prostate cancer and known to negatively regulate ISGs.

Heat Shock Protein-90 Inhibition Alters Activation of Pancreatic Stellate Cells and Enhances the Efficacy of PD-1 Blockade in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) has a prominent fibrotic stroma, which is a result of interactions between tumor, immune and pancreatic stellate cells (PSC), or cancer-associated fibroblasts (CAF). Targeting inflammatory pathways present within the stroma may improve access of effector immune cells to PDAC and response to immunotherapy. Heat shock protein-90 (Hsp90) is a chaperone protein and a versatile target in pancreatic cancer.

Infectious Tolerance as Seen With 2020 Vision: The Role of IL-35 and Extracellular Vesicles.

Originally identified as lymphocyte regulation of fellow lymphocytes, our understanding of infectious tolerance has undergone significant evolutions in understanding since being proposed in the early 1970s by Gershon and Kondo and expanded upon by Herman Waldman two decades later. The evolution of our understanding of infectious tolerance has coincided with significant cellular and humoral discoveries. The early studies leading to the isolation and identification of Regulatory T cells (Tregs) and cytokines including TGFβ and IL-10 in the control of peripheral tolerance was a paradigm shift in our understanding of infectious tolerance.

An online repository of solvation thermodynamic and structural maps of SARS-CoV-2 targets.

SARS-CoV-2 recently jumped species and rapidly spread via human-to-human transmission to cause a global outbreak of COVID-19. The lack of effective vaccine combined with the severity of the disease necessitates attempts to develop small molecule drugs to combat the virus. COVID19_GIST_HSA is a freely available online repository to provide solvation thermodynamic maps of COVID-19-related protein small molecule drug targets.

Multicenter Phase I Trial of a DNA Vaccine Encoding the Androgen Receptor Ligand-binding Domain (pTVG-AR, MVI-118) in Patients with Metastatic Prostate Cancer.

Purpose: Preclinical studies demonstrated that a DNA vaccine (pTVG-AR, MVI-118) encoding the androgen receptor ligand-binding domain (AR LBD) augmented antigen-specific CD8 T cells, delayed prostate cancer progression and emergence of castration-resistant disease, and prolonged survival of tumor-bearing mice. This vaccine was evaluated in a multicenter phase I trial.

Patients And Methods: Patients with metastatic castration-sensitive prostate cancer (mCSPC) who had recently begun androgen deprivation therapy were randomly assigned to receive pTVG-AR on one of two treatment schedules over one year, and with or without GM-CSF as a vaccine adjuvant.

An online repository of solvation thermodynamic and structural maps of SARS-CoV-2 targets.

SARS-CoV-2 recently jumped species and rapidly spread via human-to-human transmission to cause a global outbreak of COVID-19. The lack of effective vaccine combined with the severity of the disease necessitates attempts to develop small molecule drugs to combat the virus. COVID19_GIST_HSA is a freely available online repository to provide solvation thermodynamic maps of COVID-19-related protein small molecule drug targets.

Utilizing precision medicine to modulate the prostate tumor microenvironment and enhance immunotherapy.

The last two decades of cancer research have seen two major advancements in our ability to treat cancer: precision medicine and immunotherapy. While these approaches have shown striking anticancer efficacy in numerous malignancies, they have not shown similar success and applicability in advanced prostate cancer patients. The fields of precision medicine and immunotherapy have come to realize that targeted therapies are capable of not only inhibiting tumor cell growth, but also promoting antitumor immunity by modulating the tumor microenvironment.

Mouse Models for Cancer Immunotherapy Research.

Immunotherapy has revolutionized cancer therapy, largely attributed to the success of immune-checkpoint blockade. However, there are subsets of patients across multiple cancers who have not shown robust responses to these agents. A major impediment to progress in the field is the availability of faithful mouse models that recapitulate the complexity of human malignancy and immune contexture within the tumor microenvironment.

Prostate Cancer Cells Express More Androgen Receptor (AR) Following Androgen Deprivation, Improving Recognition by AR-Specific T Cells.

Androgen deprivation is the primary therapy for recurrent prostate cancer, and agents targeting the androgen receptor (AR) pathway continue to be developed. Because androgen-deprivation therapy (ADT) has immmunostimulatory effects as well as direct antitumor effects, AR-targeted therapies have been combined with other anticancer therapies, including immunotherapies. Here, we sought to study whether an antigen-specific mechanism of resistance to ADT (overexpression of the AR) may result in enhanced AR-specific T-cell immune recognition, and whether this might be strategically combined with an antitumor vaccine targeting the AR.

Pretreatment antigen-specific immunity and regulation - association with subsequent immune response to anti-tumor DNA vaccination.

Background: Immunotherapies have demonstrated clinical benefit for many types of cancers, however many patients do not respond, and treatment-related adverse effects can be severe. Hence many efforts are underway to identify treatment predictive biomarkers. We have reported the results of two phase I trials using a DNA vaccine encoding prostatic acid phosphatase (PAP) in patients with biochemically recurrent prostate cancer.

Cabozantinib Eradicates Advanced Murine Prostate Cancer by Activating Antitumor Innate Immunity.

Several kinase inhibitors that target aberrant signaling pathways in tumor cells have been deployed in cancer therapy. However, their impact on the tumor immune microenvironment remains poorly understood. The tyrosine kinase inhibitor cabozantinib showed striking responses in cancer clinical trial patients across several malignancies.

Safety and Immunological Efficacy of a DNA Vaccine Encoding the Androgen Receptor Ligand-Binding Domain (AR-LBD).

Background: The androgen receptor (AR) is a key oncogenic driver of prostate cancer, and has been the primary focus of prostate cancer treatment for several decades. We have previously demonstrated that the AR is also an immunological target antigen, recognized in patients with prostate cancer, and targetable by means of vaccines in rodent models with delays in prostate tumor growth. The current study was performed to determine the safety and immunological efficacy of a GMP-grade plasmid DNA vaccine encoding the ligand-binding domain (LBD) of the AR, pTVG-AR.

Characteristics of retrograde amnesia for CS preexposure.

Two experiments using rats evaluated the susceptibility of CS preexposure to retrograde amnesia induced by the protein synthesis inhibitor cycloheximide and tested whether amnesia for CS preexposure shares similar characteristics with amnesia for other memories. In Experiment 1, rats received cycloheximide either immediately, 60 minutes, or 120 minutes after preexposure. Following preexposure, rats received fear conditioning.

Antitumor vaccination of prostate cancer patients elicits PD-1/PD-L1 regulated antigen-specific immune responses.

We have previously reported that tumor antigen-specific DNA vaccination in mice led to an increase in IFNγ-secreting T cells and an increase in tumor expression of PD-L1. Further, we demonstrated that increasing the encoded antigen's MHC-binding affinity led to increased PD-1 expression on antigen-specific CD8(+) T cells. Together these phenomena provided resistance to antitumor immunization that was abrogated with PD-1/PD-L1 blockade.

Generation of a C57BL/6 MYC-Driven Mouse Model and Cell Line of Prostate Cancer.

Introduction: Transgenic mouse modeling is a favorable tool to reflect human prostate tumorigenesis and interactions between prostate cancer and the microenvironment. The use of GEMMs and derived cell lines represent powerful tools to study prostate cancer initiation and progression with an associated tumor microenvironment. Notably, such models provide the capacity for rapid preclinical therapy studies including immune therapies for prostate cancer treatment.

PD-1 or PD-L1 Blockade Restores Antitumor Efficacy Following SSX2 Epitope-Modified DNA Vaccine Immunization.

DNA vaccines have demonstrated antitumor efficacy in multiple preclinical models, but low immunogenicity has been observed in several human clinical trials. This has led to many approaches seeking to improve the immunogenicity of DNA vaccines. We previously reported that a DNA vaccine encoding the cancer-testis antigen SSX2, modified to encode altered epitopes with increased MHC class I affinity, elicited a greater frequency of cytolytic, multifunctional CD8(+) T cells in non-tumor-bearing mice.

Real-time immune monitoring to guide plasmid DNA vaccination schedule targeting prostatic acid phosphatase in patients with castration-resistant prostate cancer.

Purpose: We have previously reported that a DNA vaccine encoding prostatic acid phosphatase (PAP) could elicit PAP-specific T cells in patients with early recurrent prostate cancer. In the current pilot trial, we sought to evaluate whether prolonged immunization with regular booster immunizations, or "personalized" schedules of immunization determined using real-time immune monitoring, could elicit persistent, antigen-specific T cells, and whether treatment was associated with changes in PSA doubling time (PSA DT).

Experimental Design: Sixteen patients with castration-resistant, nonmetastatic prostate cancer received six immunizations at 2-week intervals and then either quarterly (arm 1) or as determined by multiparameter immune monitoring (arm 2).

A population-based evolutionary search approach to the multiple minima problem in de novo protein structure prediction.

Background: Elucidating the native structure of a protein molecule from its sequence of amino acids, a problem known as de novo structure prediction, is a long standing challenge in computational structural biology. Difficulties in silico arise due to the high dimensionality of the protein conformational space and the ruggedness of the associated energy surface. The issue of multiple minima is a particularly troublesome hallmark of energy surfaces probed with current energy functions.

Rapid sampling of local minima in protein energy surface and effective reduction through a multi-objective filter.

Background: Many problems in protein modeling require obtaining a discrete representation of the protein conformational space as an ensemble of conformations. In ab-initio structure prediction, in particular, where the goal is to predict the native structure of a protein chain given its amino-acid sequence, the ensemble needs to satisfy energetic constraints. Given the thermodynamic hypothesis, an effective ensemble contains low-energy conformations which are similar to the native structure.

Preclinical and clinical development of DNA vaccines for prostate cancer.

Prostate cancer is the most commonly diagnosed cancer in the United States. It is also the second leading cause of cancer-related death in men, making it one of the largest public health concerns today. Prostate cancer is an ideal disease for immunotherapies because of the generally slow progression, the dispensability of the target organ in the patient population, and the availability of several tissue-specific antigens.