Inhibition of Cyclin Dependent Kinase 4/6 Overcomes Primary Resistance to Programmed Cell Death 1 Blockade in Malignant Mesothelioma.

BACKGROUND: Despite the profound number of malignant pleural mesothelioma (MPM) patients now treated with programmed cell death 1 (PD-1) blockade, insight into the underpinnings of rational therapeutic strategies to treat resistance to checkpoint immunotherapy remains unrealized. Our objective was to develop a novel therapeutic approach to overcome primary resistance to PD-1 blockade in MPM. METHODS: We generated a transcriptome signature of resistance to PD-1 blockade in MPM patients treated with nivolumab (4 responders and 4 nonresponders). We used The Cancer Genome Atlas MPM cohort (n = 73) to determine what genomic alterations were associated with the resistance signature. We tested whether regulation of identified molecules could overcome resistance to PD-1 blockade in an immunocompetent mouse malignant mesothelioma model. RESULTS: Immunogenomic analysis by applying our anti-PD-1 resistance signature to The Cancer Genome Atlas cohort revealed that deletion of cyclin dependent kinase inhibitor 2A (CDKN2A) was highly associated with primary resistance to PD-1 blockade. Under the hypothesis that resistance to PD-1 blockade can be overcome by cyclin dependent kinase 4/6 (CDK4/6) inhibition, we tested whether CDK4/6 inhibitors could overcome resistance to PD-1 blockade in subcutaneous tumors derived from Cdkn2a-/- AB1 malignant mesothelioma cells, which were resistant to PD-1 blockade. The combination of daily oral administration of CDK4/6 inhibitors (abemaciclib or palbociclib) and intraperitoneal anti-PD-1 treatment markedly suppressed tumor growth compared with anti-PD-1 or CDK4/6 inhibitor alone. CONCLUSIONS: We identified a therapeutic target, CDK4/6, to overcome primary resistance to PD-1 blockade through comprehensive immunogenomic approaches. These data provide a rationale for undertaking clinical trials of CDK4/6 inhibitors in more than 40% of patients with MPM who demonstrate loss of CDKN2A.

Cholesterol-Lowering Intervention Decreases mTOR Complex 2 Signaling and Enhances Antitumor Immunity.

PURPOSE: There is a need for strategies to prevent prostate cancer. Cholesterol-lowering interventions are employed widely and safely to reduce risk of cardiovascular disease and has been proposed for chemoprevention. Using preclinical models and a window-of-opportunity clinical trial, we describe an adaptive antitumor immunity resulting from cholesterol lowering. EXPERIMENTAL DESIGN: Statins do not reliably lower serum cholesterol in mice. Therefore, oral ezetimibe was administered to mice to lower serum cholesterol to clinically relevant levels and evaluated the final adaptive immune response. T-lymphocytes-specific mTORC2 knockout mice were used to evaluate mTOR signaling and antitumor immunity. Pretreatment and posttreatment prostate tumors and lymphocytes were examined from a window-of-opportunity clinical trial where men with prostate cancer were treated with 2 to 6 weeks of aggressive cholesterol-lowering intervention prior to radical prostatectomy. RESULTS: Mice treated with oral ezetimibe exhibited enhanced antitumor immunity against syngeneic cancers in a CD8+ lymphocyte-dependent manner, produced immunity that was transferrable through lymphocytes, and had enhanced central CD8+ T-cell memory. In mice and in patients undergoing prostatectomy, lowering serum cholesterol inhibited mTORC2 signaling in lymphocytes and increased infiltration of CD8+ lymphocytes into prostate tumors. T-lymphocyte-specific mTORC2 knockout mice demonstrated enhanced CD8+ lymphocyte function and antitumor capacity. In patients, cholesterol-lowering intervention prior to prostatectomy decreased the proliferation of normal prostate and low-grade adenocarcinomas. CONCLUSIONS: Lowering serum cholesterol decreased signaling through mTORC2 and enhanced antitumor CD8+ T-cell memory. We provide a rationale for large-scale clinical testing of cholesterol lowering strategies for prostate cancer chemoprevention.

Robot-Assisted Surgery for Upper Tract Urothelial Carcinoma.

Upper tract urothelial carcinoma is a rare malignancy for which surgery provides definitive management. Open radical nephroureterectomy was the gold standard treatment, but laparoscopic and robot-assisted approaches are alternative options. Kidney-sparing approaches are feasible for carefully selected patients with ureteral cancer. This article discusses the evaluation of patients with upper tract urothelial carcinoma and definitive management using robot-assisted surgical approaches. Patients with urothelial carcinoma of the upper tract can be treated with robot-assisted nephroureterectomy, distal ureterectomy, and segmental ureterectomy.

Uncoiling of a Cook Resonance Metallic Ureteral Stent.

Introduction and Background: The Cook Resonance® metallic ureteral stent's unique configuration allows adequate urine drainage while providing improved resistance to external ureteral compression. We report a case in which a stent broke and subsequently uncoiled during stent removal under cystoscopy. Case Presentation: A 46-year-old woman with a history of cervical carcinoma treated with radiation therapy and chemotherapy and bilateral ureteral strictures presented for cystoscopic removal of bilateral Cook Resonance ureteral stents. During removal of the right ureteral stent, a snap was felt with subsequent uncoiling of the stent. Firm tension to the inner wire and outside curls allowed eventual complete removal of the stent without any retained fragments. Discussion: The all-metal Cook Resonance stent is an attractive alternative to polymeric stents because of reduced frequency of stent exchange and resistance to external compression. However, the metal stent possesses risks such as increased urothelial hyperplasia and stent embedment.

Underrepresentation of functional conditions of the lower urinary tract in adults in US federal research funding.

AIMS: Evaluation and treatment of functional conditions of the lower urinary tract (fcLUT), a subset of benign urinary tract conditions, is highly subjective due to overlapping symptomatology. Despite high prevalence and socioeconomic cost, there has been little improvement in their treatment and lack of progress in understanding their pathophysiology. This study investigates trends in quantity, monetary amounts, and awardees' characteristics of federally funded research awards for fcLUT compared to nonurologic benign conditions (NUBCs) and urologic malignancies. METHODS: Data were extracted from the National Institutes of Health (NIH) and federal RePORTER databases in December 2019. We identified currently active awards in fcLUT, NUBC, and malignant urologic conditions and the associated demographic features of awardees. The authors also examined temporal funding trends for such awards. RESULTS: These database searches revealed that there are consistently fewer awards and funding dollars for the study of fcLUT compared to other benign conditions with similar prevalences. While most research topics have received increased funding in awards and overall funding dollars over time, fcLUT funding has remained relatively flat. Urologists are also underrepresented; only 11 of the 86 recipients of NIH R01 awards to study fcLUT have clinical training in urology. CONCLUSIONS: Even when compared to NUBC, funding for the study of fcLUT remains low and has stagnated over time. Further, investigators who are clinicians in the field of urology are in the minority of those doing this study. Given the need for clinical perspectives in fcLUT research, the lack of urologist representation will inhibit discovery and translational advances.

Optimal Endocrine Evaluation and Treatment of Male Infertility.

This article aims to define the optimal endocrine workup of male factor infertility, including evaluation and treatment of men who have previously been on exogenous testosterone or anabolic steroids. Future directions include the expansion of genetic testing for infertility to include endocrine gene products.

Syngeneic murine model for prostate cancer using RM1 cells transfected with gp100.

BACKGROUND: Prostate cancer (PC) is the most commonly diagnosed solid tumor in men. A major challenge in PC immunotherapy is the lack of an animal model that resembles human adenocarcinoma and allows for manipulation or monitoring of the immune response. Mouse models are needed for preclinical testing of new immunotherapies, whether used alone or in combination with established drugs, and to develop companion biomarkers that can be validated in clinical trials. METHODS: To develop a syngeneic prostate adenocarcinoma model with a well-defined tumor antigen, murine RM1 PC cells were transfected with the endogenous mouse melanoma protein, gp100 (RM1-gp100). Gp100 was attractive because it is a self-protein and it instantly allowed us to use the large trove of immune research tools developed for melanoma research. A dendritic cell (DC) vaccine was used as model immunotherapy to demonstrate that adoptive immunotherapy against gp100 decreases the growth of RM1-gp100 but not RM1. RESULTS: Expressing gp100 did not change the growth of RM1 cell in vitro or in vivo. The DCs pulsed with RM1-gp100 could be used to stimulate Pmel-1 lymphocyte proliferation and activation. Pmel-1 lymphocytes could be adoptively transferred into C57Bl/6 mice that were treated with DCs pulsed with RM1-gp100. The resulting Pmel-1 lymphocytes were monitored to assess the primary cellular immune response and memory response. CONCLUSION: We describe a murine model for prostate adenocarcinoma with a well-characterized antigen that can be used in an immunologically intact mice to monitor the temporal CD8+ lymphocyte-mediated antitumor immunity.

Urologic conditions associated with malignancy.

INTRODUCTION: Recent advances in cancer research have highlighted the role of genetics in malignancy. Genetic dysregulation of core cellular functions similarly influences benign conditions. These common genetic factors have led researchers to identify an association between certain urologic conditions and malignancy. The objective of this review is to evaluate the literature linking benign urologic conditions including male infertility, Peyronie's disease, cryptorchidism, and hypospadias, to malignancy. METHODS: A search of PubMed was performed using the following search terms and their combinations: male infertility, female infertility, cancer, malignancy, mortality, male urologic conditions, azoospermia, Peyronie's disease, cryptorchidism, hypospadias, and genetics. Studies were assessed for quality and included or excluded based on study design and relevance to the topic of urologic conditions and malignancy. RESULTS: A total of 52 studies were evaluated, of which 38 were included. Associations between male infertility and testicular cancer, prostate cancer, and other cancers including melanoma, bladder cancer, and thyroid cancer were examined. Several genetic alterations were found to be common in the pathogenesis of both male infertility and carcinogenesis. Associations between female infertility and breast, ovarian, and endometrial cancer are also assessed, as are the relationships between Peyronie's disease, cryptorchidism, and hypospadias and malignancy. CONCLUSIONS: Recent work has identified associations between a number of malignancies and benign urologic conditions including male infertility, Peyronie's disease, cryptorchidism, and hypospadias. Molecular and genetic mechanisms have been proposed, but no definitive causal relationships have been identified to date. Future work will continue to better define the links between malignancy and benign urologic conditions and ultimately facilitate risk stratification, screening, and treatment of affected men.

Povidone-iodine results in rapid killing of thymic epithelial tumour cells through cellular fixation†.

OBJECTIVES: Hyperthermic pleural lavage with povidone-iodine (PVP-I) is utilized to control micrometastatic disease following cytoreductive surgery for thymic epithelial tumours (TETs). Our objective was to investigate whether PVP-I demonstrates direct cytotoxicity against human TET cells. METHODS: Human Met-5A (immortalized mesothelial cell), IU-TAB-1 (thymoma) and Ty-82 (thymic carcinoma) cell lines were treated with serial dilutions of PVP-I (0.01-10%) for 5, 30 and 60 min at 37°C and 42°C. MTT assays and flow cytometry were used to evaluate cell death and apoptosis. Membrane permeability was assayed by intracellular staining of cleaved poly-ADP-ribose polymerase. Cellular fixation was evaluated by membrane disruption of dead cells by dimethylsulphoxide and by comparing cleaved poly-ADP-ribose polymerase staining following PVP-I with known fixatives. RESULTS: MTT assays demonstrated that PVP-I concentrations greater than 0.5% led to rapid cell death in both TET cell lines regardless of temperature. IC50 values following 5 min of exposure to PVP-I were 8.4 mM (0.3%) and 13.3 mM (0.48%) for IU-TAB-1 and Ty-82, respectively and 8.9 mM (0.32%) for MeT-5A. Flow cytometry demonstrated that 5-min exposure of either cell line to 1% PVP-I resulted in profound cell death: 74% and 58% at 5 min and 97% and 95% at 30 min, for IU-TAB-1 and Ty-82 cells, respectively. Resistance of PVP-I-treated cells to dimethylsulphoxide lysis and similar cleaved poly-ADP-ribose polymerase expression following PVP-I and known fixatives revealed cellular fixation as the mechanism of death following PVP-I exposure. CONCLUSIONS: PVP-I results in rapid death of human TET cells and normal mesothelial cells through a cellular fixation mechanism and may, therefore, favourably impact the control of micrometastatic disease following resection of TETs with pleural dissemination.

Penile prosthesis biofilm formation and emerging therapies against them.

Infections are among the most feared and devastating complications of penile prosthesis infections, often requiring surgical exploration and explantation are prosthesis infections. While the rate of infections have decreased due to antibiotic prophylaxis, antiseptic device preparation, increased sterility in implantation techniques and device modifications, infections still occur at a rate of 1-3%. This article reviews the formation of biofilms on penile prostheses and novel, experimental methods to prevent and eradicate them.

Alternatives to Testosterone Therapy: A Review.

INTRODUCTION: Although testosterone therapy (TTh) is an effective treatment for hypogonadism, recent concerns regarding its safety have been raised. In 2015, the US Food and Drug Administration issued a warning about potential cardiovascular risks resulting from TTh. Fertility preservation is another reason to search for viable alternative therapies to conventional TTh, and in this review we evaluate the literature examining these alternatives. AIMS: To review the role and limitations of non-testosterone treatments for hypogonadism. METHODS: A literature search was conducted using PubMed to identify relevant studies examining medical and non-medical alternatives to TTh. Search terms included hypogonadism, testosterone replacement therapy, testosterone therapy, testosterone replacement alternatives, diet and exercise and testosterone, varicocele repair and testosterone, stress reduction and testosterone, and sleep apnea and testosterone. MAIN OUTCOME MEASURES: Review of peer-reviewed literature. RESULTS: Medical therapies examined include human chorionic gonadotropins, aromatase inhibitors, and selective estrogen receptor modulators. Non-drug therapies that are reviewed include lifestyle modifications including diet and exercise, improvements in sleep, decreasing stress, and varicocele repair. The high prevalence of obesity and metabolic syndrome in the United States suggests that disease modification could represent a viable treatment approach for affected men with hypogonadism. CONCLUSIONS: These alternatives to TTh can increase testosterone levels and should be considered before TTh. Lo EM, Rodriguez KM, Pastuszak AW, Khera M. Alternatives to Testosterone Therapy: A Review. Sex Med Rev 2018;6:106-113.

Connexin 36 and rod bipolar cell independent rod pathways drive retinal ganglion cells and optokinetic reflexes.

Rod pathways are a parallel set of synaptic connections which enable night vision by relaying and processing rod photoreceptor light responses. We use dim light stimuli to isolate rod pathway contributions to downstream light responses then characterize these contributions in knockout mice lacking rod transducin-α (Trα), or certain pathway components associated with subsets of rod pathways. These comparisons reveal that rod pathway driven light sensitivity in retinal ganglion cells (RGCs) is entirely dependent on Trα, but partially independent of connexin 36 (Cx36) and rod bipolar cells. Pharmacological experiments show that rod pathway-driven and Cx36-independent RGC ON responses are also metabotropic glutamate receptor 6-dependent. To validate the RGC findings in awake, behaving animals we measured optokinetic reflexes (OKRs), which are sensitive to changes in ON pathways. Scotopic OKR contrast sensitivity was lost in Trα(-/-) mice, but indistinguishable from controls in Cx36(-/-) and rod bipolar cell knockout mice. Mesopic OKRs were also altered in mutant mice: Trα(-/-) mice had decreased spatial acuity, rod BC knockouts had decreased sensitivity, and Cx36(-/-) mice had increased sensitivity. These results provide compelling evidence against the complete Cx36 or rod BC dependence of night vision's ON component. Further, the findings suggest the parallel nature of rod pathways provides considerable redundancy to scotopic light sensitivity but distinct contributions to mesopic responses through complicated interactions with cone pathways.