The Value of Phenotypic Precision Medicine in Prostate Cancer.

Prostate cancer is the most common cancer among men and the second leading cause of cancer-related death. For patients who develop metastatic disease, tissue-based and circulating-tumor-based molecular and genomic biomarkers have emerged as a means of improving outcomes through the application of precision medicine. However, the benefit is limited to a minority of patients. An additional approach to further characterize the biology of advanced prostate cancer is through the use of phenotypic precision medicine, or the identification and targeting of phenotypic features of an individual patient's cancer. In this review article, we will discuss the background, potential clinical benefits, and limitations of genomic and phenotypic precision medicine in prostate cancer. We will also highlight how the emergence of image-based phenotypic medicine may lead to greater characterization of advanced prostate cancer disease burden and more individualized treatment approaches in patients.

Prostate-specific membrane antigen-targeted theranostics: past, present, and future approaches.

Although prostate cancer is the type of cancer most commonly survived by men in the United States, it remains the second most common cause of death from cancer, largely owing to metastatic disease. Patients with metastatic castration-resistant prostate cancer (mCRPC) whose disease has progressed on standard-of-care therapies have few options and a poor prognosis. Prostate-specific membrane antigen (PSMA) is a type II integral membrane protein that is commonly expressed in prostate cancer. Expression is limited on extra-prostatic tissues other than the salivary glands, lacrimal glands, duodenal epithelium, Kupffer cells, and renal tubules. PSMA-directed theranostics has emerged to exploit the specificity of PSMA for prostate cancer cells and has demonstrated promising results in the clinic. Radionuclides linked to PSMA inhibitors/binders have resulted in US Food and Drug Administration (FDA) approval of 2 radiodiagnostics for PSMA-directed positron emission tomography/computed tomography. In addition, these radionuclides have led to the development of lutetium Lu 177PSMA-617 therapy, which is currently under priority FDA review. Multiple novel PSMA-targeted modalities have been developed and are currently under clinical investigation, including ligand-drug and cellular immune therapies. In this review, we discuss the development of PSMA-directed theranostics, along with its clinical implications, limitations, and future directions.

A synthetic lethal screen for Snail-induced enzalutamide resistance identifies JAK/STAT signaling as a therapeutic vulnerability in prostate cancer.

Despite substantial improvements in the treatment landscape of prostate cancer, the evolution of hormone therapy-resistant and metastatic prostate cancer remains a major cause of cancer-related death globally. The mainstay of treatment for advanced prostate cancer is targeting of androgen receptor signaling, including androgen deprivation therapy plus second-generation androgen receptor blockade (e.g., enzalutamide, apalutamide, darolutamide), and/or androgen synthesis inhibition (abiraterone). While these agents have significantly prolonged the lives of patients with advanced prostate cancer, is nearly universal. This therapy resistance is mediated by diverse mechanisms, including both androgen receptor-dependent mechanisms, such as androgen receptor mutations, amplifications, alternative splicing, and amplification, as well as non-androgen receptor-mediated mechanisms, such as lineage plasticity toward neuroendocrine-like or epithelial-mesenchymal transition (EMT)-like lineages. Our prior work identified the EMT transcriptional regulator Snail as critical to hormonal therapy resistance and is commonly detected in human metastatic prostate cancer. In the current study, we sought to interrogate the actionable landscape of EMT-mediated hormone therapy resistant prostate cancer to identify synthetic lethality and collateral sensitivity approaches to treating this aggressive, therapy-resistant disease state. Using a combination of high-throughput drug screens and multi-parameter phenotyping by confluence imaging, ATP production, and phenotypic plasticity reporters of EMT, we identified candidate synthetic lethalities to Snail-mediated EMT in prostate cancer. These analyses identified multiple actionable targets, such as XPO1, PI3K/mTOR, aurora kinases, c-MET, polo-like kinases, and JAK/STAT as synthetic lethalities in Snail+ prostate cancer. We validated these targets in a subsequent validation screen in an LNCaP-derived model of resistance to sequential androgen deprivation and enzalutamide. This follow-up screen provided validation of inhibitors of JAK/STAT and PI3K/mTOR as therapeutic vulnerabilities for both Snail+ and enzalutamide-resistant prostate cancer.

Loss of ATRX promotes aggressive features of osteosarcoma with increased NF-κB signaling and integrin binding.

Osteosarcoma (OS) is a lethal disease with few known targeted therapies. Here, we show that decreased ATRX expression is associated with more aggressive tumor cell phenotypes, including increased growth, migration, invasion, and metastasis. These phenotypic changes correspond with activation of NF-κB signaling, extracellular matrix remodeling, increased integrin αvß3 expression, and ETS family transcription factor binding. Here, we characterize these changes in vitro, in vivo, and in a data set of human OS patients. This increased aggression substantially sensitizes ATRX-deficient OS cells to integrin signaling inhibition. Thus, ATRX plays an important tumor-suppression role in OS, and loss of function of this gene may underlie new therapeutic vulnerabilities. The relationship between ATRX expression and integrin binding, NF-κB activation, and ETS family transcription factor binding has not been described in previous studies and may impact the pathophysiology of other diseases with ATRX loss, including other cancers and the ATR-X α thalassemia intellectual disability syndrome.

Liquid Biopsy: It's the Bloody Truth!

Liquid biopsy is a promising clinical tool that can provide critical information for prognostication and which may inform treatment decisions in men with metastatic castration-resistant prostate cancer. Here we discuss the Foundation Medicine plasma cell-free circulating tumor DNA assay, its pros and cons, and potential clinical utility.See related article by Tukachinsky et al., p. 3094.

A Zebrafish Model of Metastatic Colonization Pinpoints Cellular Mechanisms of Circulating Tumor Cell Extravasation.

Metastasis is a multistep process in which cells must detach, migrate/invade local structures, intravasate, circulate, extravasate, and colonize. A full understanding of the complexity of this process has been limited by the lack of ability to study these steps in isolation with detailed molecular analyses. Leveraging a comparative oncology approach, we injected canine osteosarcoma cells into the circulation of transgenic zebrafish with fluorescent blood vessels in a biologically dynamic metastasis extravasation model. Circulating tumor cell clusters that successfully extravasated the vasculature as multicellular units were isolated under intravital imaging (n = 6). These extravasation-positive tumor cell clusters sublines were then molecularly profiled by RNA-Seq. Using a systems-level analysis, we pinpointed the downregulation of KRAS signaling, immune pathways, and extracellular matrix (ECM) organization as enriched in extravasated cells (p < 0.05). Within the extracellular matrix remodeling pathway, we identified versican (VCAN) as consistently upregulated and central to the ECM gene regulatory network (p < 0.05). Versican expression is prognostic for a poorer metastasis-free and overall survival in patients with osteosarcoma. Together, our results provide a novel experimental framework to study discrete steps in the metastatic process. Using this system, we identify the versican/ECM network dysregulation as a potential contributor to osteosarcoma circulating tumor cell metastasis.

The Effects of Glaucoma Drainage Devices on Oxygen Tension, Glycolytic Metabolites, and Metabolomics Profile of Aqueous Humor in the Rabbit.

PURPOSE: Glaucoma drainage device (GDD) implantation can lead to corneal decompensation. We evaluated changes over time in oxygen tension and in the metabolic environment of the aqueous humor after GDD implantation in the rabbit eye. METHODS: Ahmed Glaucoma Valves were implanted in the left eyes of eight male New Zealand white rabbits. Right eyes were used as a control. Oxygen tension was measured immediately before surgery and at 1 and 2 months postoperation. Aqueous humor was collected from the surgical and control eyes at 1, 2, and 5 months postoperation. Aqueous humor samples collected at 1 and 5 months postoperation were selected for broad-spectrum metabolomics analysis using ultra-performance liquid chromatography-time of flight-mass spectrometry (UPLC TOF-MS). Multivariate analysis methods were used to identify metabolite profiles that separated the surgical and control eye at 1 and 5 months. RESULTS: There was a significant decrease in oxygen tension in aqueous humor of the surgical eyes (9 mm Hg, 95% confidence interval [CI]: -14.7 to -3.5). Differences in the metabolic profiles between the surgical and control eye at 1 and 5 months were observed, as were differences for the surgical eye at 1 and 5 months. In addition, a metabolite profile was identified that differentiated the surgical eyes at 1 and 5 months. CONCLUSION: Changes in the oxygen tension and metabolic intermediates occur within the aqueous humor as early as 1 month after GDD implantation. TRANSLATIONAL RELEVANCE: Corneal decompensation following GDD implantation could be secondary to disruption of the normal aqueous circulation, resulting in hypoxia and an altered metabolic profile. Alterations to the GDD design might minimize aqueous disruption and prevent corneal decompensation.

The role of radiation therapy in the management of sialorrhea: A systematic review.

PURPOSE: Up to 80% of patients with Parkinson disease and 30% of patients with amyotrophic lateral sclerosis (ALS) suffer from sialorrhea. Patients who fail medical and surgical therapy should be considered for external beam radiation therapy (EBRT). In this study, we conduct a systematic review to determine the dose and techniques used that result in greatest efficacy and lowest toxicity for the administration of EBRT in patients with Parkinson disease or ALS-associated sialorrhea. METHODS AND MATERIALS: This review included 216 patients from four prospective and six retrospective studies published from 1998 to 2014, with ALS or Parkinson disease who were treated with electron or photon EBRT for sialorrhea. RESULTS: A total of 216 patients were treated with EBRT from 10 studies. The indication for EBRT was failure of alternative medical treatment in all ALS patients. For patients with Parkinson disease, EBRT was the primary mode of treatment in 68% of cases. Overall, 176 (81%) of 216 patients treated with EBRT for sialorrhea reported symptomatic improvement from baseline. The most common target was the inferior two-thirds of the bilateral parotid glands and the entire bilateral submandibular glands. The total number of patients who experienced short-term toxicity was 86 of 216 patients (40%). The total number of patients who experienced long-term toxicity was 24 of 207 (12%). CONCLUSIONS: EBRT is an effective treatment for sialorrhea in patients suffering from ALS or Parkinson disease. Treatment to the bilateral submandibular glands and caudal parotid glands is the most common field arrangement.

Sinonasal Tract Inflammation as a Precursor to Nasopharyngeal Carcinoma: A Systematic Review and Meta-Analysis.

OBJECTIVE: Chronic inflammation has been described as a precursor to the development of malignancy in several disease states. However, the relationship of sinonasal tract inflammation to nasopharyngeal carcinoma (NPC) remains poorly defined. DATA SOURCES: Systematic review of primary studies identified through PubMed, EMBASE, MEDLINE, and Cochrane. METHODS REVIEW: Systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. MEDLINE, EMBASE, and Cochrane databases were queried for English-language studies published between 1980 and 2015. Studies were excluded that did not provide quantitative data on sinonasal tract inflammation such as chronic rhinosinusitis (CRS), allergic rhinitis (AR), or human papillomavirus (HPV) status and NPC. An itemized assessment of the risk of bias was conducted for each included study. RESULTS: Of the 325 studies identified during systematic review, 5 met the criteria for analysis. The level of evidence of those studies was generally low. There was an increased risk of NPC in patients with a previous diagnosis of CRS or AR. Meta-analysis demonstrated an odds ratio (95% confidence interval [CI]) of 2.35 (2.00-2.76) for all studies. Subgroup analysis of patients with sinonasal inflammation had an odds ratio of 2.39 (95% CI, 2.20-2.60). Patients with AR had an odds ratio of 2.29 (95% CI, 2.06-2.54), while those with CRS had an odds ratio of 2.70 (95% CI, 1.98-3.70). CONCLUSIONS: This systematic review and meta-analysis suggests an association between previous sinonasal inflammatory disease and subsequent NPC. Prospective studies are needed to further examine this relationship.