Discovery Category Highlights

Immune Checkpoint Blockade as a Novel Immunotherapeutic Strategy for Renal Cell Carcinoma: A Review on Clinical Trials

Abstract: Renal cell carcinoma (RCC) is a common genitourinary malignancy, and, when metastatic, is almost uniformly fatal. Non-specific immunotherapy was for many years the mainstay of treatment for metastatic RCC, but led to only modest success and significant side-effects. More recently, seven targeted therapy drugs have been approved to impede RCC cell growth, proliferation, and angiogenesis and have had a significant impact on patient outcomes, but with infrequent long term responders. Thus, a renewed emphasis on immunotherapy has emerged over the last several years with the development and testing of a novel class of immunotherapeutic agents called checkpoint inhibitors. These drugs have targeted the programmed cell death 1 (PD-1) and cytotoxic leukocyte antigen 4 (CTLA-4) pathways on regulatory T cells, leading to immune response enhancement and immune-mediated anti-tumor effects in multiple malignancies, including RCC. A number of studies recently reported utilizing checkpoint inhibitors, either alone or in combination with other checkpoint inhibitors or vascular endothelial growth factor targeting agents, have shown significant and at times durable responses in RCC patients. This has led to the development of further phase I, II, and III trials and this review will discuss the history and currently available data for immune checkpoint blockade in RCC. ... Read more

Targeted Therapy for Hereditary Cancer Syndromes: Neurofibromatosis Type 1, Neurofibromatosis Type 2, and Gorlin Syndrome

Abstract: Hereditary cancer syndromes are well known in the oncology community, typically affecting children, adolescents, and young adults and thereby resulting in great cumulative morbidity and mortality. These syndromes often lag behind their de novo counterparts in the development of approved novel treatment options due to their rarity in the general population. Recent work has allowed the identification of molecular aberrations and associated targeted therapies that may effectively treat these conditions. In this review, we seek to characterize some of the involved aberrations and associated targeted therapies for several germline malignancies, including Neurofibromatosis types 1 and 2, and Gorlin syndrome. Though patients with hereditary cancer syndromes may be too rare to effectively include in large clinical trials, by understanding the pathophysiology of these diseases, clinicians can attain insights into the use of targeted therapies in their own practice when treating affected individuals. ... Read more

Enterovirus Persistence as a Mechanism in the Pathogenesis of Type 1 Diabetes

Abstract: Beyond acute clinical conditions, the role of enteroviruses (EVs) in chronic human diseases has been described. Although they are considered as highly cytolytic viruses, EVs can persist in various tissues. The persistence is believed to play a major role in the pathogenesis of EV related chronic diseases such as type 1 diabetes (T1D). T1D is characterized by an autoimmune destruction of pancreatic beta cells, and results from interplay between a genetic predisposition, the immune system, and environmental factors. EVs and especially group B coxsackieviruses (CVB) have been the most incriminated as exogenous agents involved in the development of T1D. Enteroviral persistence is the result of a virus-host coevolution combining a cell resistance to lysis through mutations or down-regulation of viral receptor, and a decrease of the viral replication by genomic modifications or the production of a stable double-stranded RNA form. CVB can persist in pancreatic cells and therefore could trigger, in genetically predisposed individuals, the autoimmune destruction of beta cells mainly through an activation of inflammation. The persistence of the virus in other tissues such as intestine, blood cells, and thymus has been described, and could also contribute to some extent to the enteroviral pathogenesis of T1D. The molecular and cellular mechanisms of CVB persistence and the link with the development of T1D should be investigated further. ... Read more

Challenges to Chimeric Antigen Receptor (CAR)-T Cell Therapy for Cancer

Abstract: Chimeric antigen receptor (CAR)-expressing T cells have demonstrated potent clinical efficacy in patients with B cell malignancies. However, the use of CAR-T cell therapy targeting other cancers has, in part, been limited by both the induction of antigen-specific toxicities targeting normal tissues expressing the target-antigen, and the extreme potency of CAR-T cell treatments resulting in life-threatening cytokine-release syndromes. Herein, we discuss toxicities associated with CAR-T cell therapy in the clinic. Further, we discuss potential clinical interventions to ameliorate these toxicities and the application of preclinical animal models to predict the clinical utility of CAR-T cell therapy. ... Read more

Mechanisms of Autoimmune Liver Disease

Abstract: The immune system of the liver is characterized by a predominant innate component. Several innate immune cell populations have been implicated in the pathogenesis of immune-mediated hepatic diseases, which are frequently associated with systemic symptoms or with co-morbidities affecting other organ systems. Thus, next to tissue-specific factors, general tolerance mechanisms are affected in devastating hepatic disorders like primary sclerosing cholangitis (PSC), autoimmune hepatitis (AIH), or primary biliary cirrhosis (PBC). The innate immune cell populations abundantly detected within the liver and endowed with potent immunomodulatory capacities include innate lymphoid cells (ILCs) and natural killer T (NKT) cells. While both ILCs and NKT cells can be activated by different cytokines and/or chemokines, NKT cells also respond to (glyco-) lipid antigens engaging their canonical, semi-invariant TCR. Once activated, ILCs and NKT cells release copious amounts of Th1, Th2, and/or Th17 cytokines that shape subsequent innate and adaptive immune responses. Those immunomodulatory features as well as the recently described antigen-presenting capacity of ILCs and/or the bi-directional functional role of NKT cells might not only underlie the pathogenic mechanisms in the respective disorders, but also provide promising targets for clinical intervention. We will discuss these novel aspects as well as the role of alarmin-like cytokines such as IL-33 in the context of ILC and NKT cell activation and the consequences for the induction and progress of hepatic tissue damage and fibrosis. ... Read more

New Drugs for the Treatment of Hyperkalemia in Patients Treated with Renin-Angiotensin-Aldosterone System Inhibitors -- Hype or Hope?

Abstract: Hyperkalemia (serum potassium >5.5 mmol/L) may result from increased potassium intake, impaired distribution between the intracellular and extracellular spaces, and/or reduced renal excretion. Renin-angiotensin-aldosterone system inhibitors (RAASIs) represent an important therapeutic strategy in patients with hypertension, heart failure, chronic kidney disease, and diabetes, but hyperkalemia is a key limitation to fully titrate RAASIs in these patients who are most likely to benefit from treatment. Thus, we need new drugs to control hyperkalemia in these patients while maintaining the use of RAASIs. We review two new polymer-based, non-systemic agents under clinical development, patiromer calcium and zirconium silicate, designed to increase potassium loss via the gastrointestinal tract for the management of hyperkalemia. ... Read more

MicroRNAs Regulate Immune System Via Multiple Targets

Abstract: MicroRNAs (miRNAs) represent the most abundant class of regulators of gene expression. Each miRNA may suppress multiple mRNA targets, while one mRNA can be targeted by many miRNAs for precise control of a wide range of cellular processes. The important role of miRNAs in the immune system is highlighted by the conditional Dicer knockout mouse, which exhibited profound aberrant development and function of immune cells. One particular miRNA, miR-155, is highly expressed and plays important role in lymphocytes. In this review we focused on the role of miRNA, especially miR-155, via their predicted and known mRNA targets in innate and adaptive immunity. Finally, we discussed the potential of miRNAs as novel targets for the diagnosis and therapy of immune system diseases. ... Read more

Entecavir Promotes CD34+ Stem Cell Proliferation in the Peripheral Blood and Liver of Chronic Hepatitis B and Liver Cirrhosis Patients

Abstract: Entecavir (ETV) has been used for more than 2 decades in treating hepatitis B virus (HBV) infections. It has shown significant anti-HBV effect and has led to histological improvement in the liver of chronic hepatitis B (CHB) patients. In patients treated with ETV for over two years, reversal of cirrhosis to normal tissue has also been observed. However, the mechanisms of these tissue repairing or recovery processes are not yet clear. In order to determine the roles that bone marrow and liver stem/progenitor cells play in these processes, we evaluated the CD34+ and CD133+ stem/progenitor cells in peripheral blood from 292 patients and liver tissues from 43 patients who had received therapies with and without ETV. A significant increase in both CD34+ and CD133+ cells was found in CHB and cirrhosis patients compared to the healthy controls. In patients treated with ETV, CD34+ cells increased 2 and 4 fold in peripheral blood and liver tissues, respectively, while their CD4+ and CD8+ cells remained the same. On the other hand, CD133+ cells did not change or even slightly decreased with ETV treatment. Results from immunohistochemistry staining, real time RT-PCR, and the enzyme-linked immunosorbent assay also revealed the same level of CD34+ cell increase and CD133+ cell decrease (or no change) in ETV treated patients, compared to patients without ETV therapies. Liver functions in patients with ETV treatment improved in general, but one liver cirrhosis patient with high expression of CD133 in liver tissue developed hepatocellular carcinoma (HCC). In summary, ETV may have differential effects on various stem cell subtypes. ETV-activated stem cells in bone marrow and liver tissues may contribute to the recovery from injuries caused by HBV infection. They also contribute to the regeneration of normal tissue and the recovery of normal liver function. Meanwhile, ETV does not activate stem cells that may participate in the initiation of HCC. ... Read more

Fibromyalgia, Autism, and Opioid Addiction as Natural and Induced Disorders of the Endogenous Opioid Hormonal System

Abstract: Introduction: Because of their circulation through the blood, the multiplicity of receptor sites, and the diversity of functions, opioids may most accurately be designated as a hormone. Opioids modulate the intensity of pain. In mammals, the opioid system has been modified to modulate social interactions as well (Panksepp and Watt, 2011). Methods: Over 10,000 patient encounters were observed on a neuropsychoanalytic addiction medicine service. Cold pressor times (CPT) were recorded before and after stimulation of the opioid system with low-dose naltrexone (LDN) for patients after opioid detoxification and for fibromyalgia patients. Results: Patients maintained on opioids relate autistically. The cold, unrelated nature of their human interactions was reversed by detoxification from opioids. Fibromyalgia patients have difficulty participating in human relationships, as if they lack an ability to respond interpersonally, as do post-detoxification patients. LDN improved pain tolerance as shown by a significant increase on CPT for post detoxification patients from 16 seconds to 55 seconds and in fibromyalgia patients from 21 seconds to 42 seconds, and improved relatedness. The correlation of opioid prescribing increasing over time and autism prevalence increasing over time is highly significant. Conclusions: 1. Opioid-maintained patients relate autistically. 2. Autism is a hyperopioidergic disorder. 3. Fibromylagia is a hypoopioidergic disorder. 4. Low opioid tone caused by opioid maintenance or fibromyalgia can usually be reversed with low-dose naltrexone. 5. The increase in the incidence of autism may have been caused by the increase in use of opioids for analgesia during childbirth. ... Read more

Recent Advances in the Treatment of Hepatitis C

Abstract: Hepatitis C virus (HCV) therapeutics is amidst a revolution. With the recent approval of sofosbuvir (Sovaldi) and simeprevir (Olysio), clinicians and patients started to recognize that for the first time in the history, hepatitis C can be cured in a majority of patients without interferon. These new regimens are safe, and have excellent efficacy and minimal adverse events. Sofosbuvir, a nucleotide analogue (NS5B polymerase inhibitor), is a potent drug with excellent tolerability and pan-genotypic activity with a high barrier to resistance. Simeprevir, a second-generation protease inhibitor which inhibits the initial cleavage of the HCV poly-protein by the NS3/4A protease. Simeprevir has been evaluated in clinical trials in combination with interferon and ribavirin based therapy and also in the COSMO trial in combination with sofosbuvir. More directly acting antiviral therapy drugs are in the pipeline with several drugs being expected to be approved by the FDA in late 2014. Although these drugs have excellent efficacy, they are more costly. The price of these drugs limits treatments of many patients in the world especially in countries with limited economic resources. However, with the availability of a variety of excellent directly acting antivirals (DAAs) in the near future, hopefully many patients would be able to afford the treatment. The future in HCV therapy will focus on special groups of patients who were excluded from initial HCV clinical trials such as post-liver transplant HCV recurrence, patients with HCV/HIV co-infection, and patients with advanced cirrhosis. ... Read more

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