Discovery of [11C]MK-6884: a positron emission tomography (PET) imaging agent for the study of M4 muscarinic receptor positive allosteric modulators (PAMs) in neurodegenerative diseases

The measurement of receptor occupancy (RO) using positron emission tomography (PET) has been instrumental in guiding discovery and development of CNS directed therapeutics. We and others have investigated muscarinic acetylcholine receptor 4 (M4) positive allosteric modulators (PAMs) for the treatment of symptoms associated with neuropsychiatric disorders. In this article, we describe the synthesis, in vitro, and in vivo characterization of a series of central pyridine-related M4 PAMs that can be conveniently radiolabeled with carbon-11 as PET tracers for the in vivo imaging of an allosteric binding site of the M4 receptor. We first demonstrated its feasibility by mapping the receptor distribution in mouse brain and confirming that a lead molecule 1 binds selectively to the receptor only in the presence of the orthosteric agonist carbachol. Through a competitive binding affinity assay and a number of physiochemical properties filters, several related compounds were identified as candidates for in vivo evaluation. These candidates were then radiolabeled with 11C and studied in vivo in rhesus monkeys. This research eventually led to the discovery of the clinical radiotracer candidate [11C]MK-6884

Preclinical Evaluation of Genomic-Based Therapies in Pancreatic Cancer and Glioblastoma

INTRODUCTION: The focus of this study is the testing of biomarker-driven analytical methods to identify targeted therapies in pancreatic cancer and glioblastoma, which are highly invasive and metastatic cancers with poor outcomes and few treatment options. The objective was to make treatment predictions based on the molecular signatures of pancreatic cancer and glioblastoma samples, then to evaluate the efficacy of these therapies using preclinical models. METHODS AND MATERIALS: XenoBase Bio-Integration Suite (XB-BIS) in an informatics platform for the analysis of molecular data using Personalized Medicine (PMED) algorithms. PMED applies four independent methods (Drug Target Expression, Connectivity Map, Parametric Gene Set Enrichment, and GeneGo Network Topological Enrichment Analysis) to a genomic dataset to identify targeted therapies. Affymetrix data was collected from panels of pancreatic cancer cell lines and human glioblastoma specimens and analyzed in XB-BIS to predict therapies, which were evaluated in vivo. RESULTS: Treatment of mice with subcutaneous pancreatic tumors with Chlorpromazine, predicted by CMAP, resulted in a decrease in tumor volume and extended survival compared to control animals. Predictive algorithms identified BCNU, Doxorubicin, and Marimastat as potential treatments for glioblastoma. Combination treatment of mice implanted intracranially with U251 glioblastoma cells showed extended survival compared to control mice and similar survival to standard-of-care treatment, Temozolomide. CONCLUSIONS: We have demonstrated efficacy of therapies identified by the PMED approach in relevant models of pancreatic cancer and glioblastoma. While further investigation is needed, these therapies could prove to be a great resource against two devastating human diseases

Complete genome of Staphylococcus aureus Tager 104 provides evidence of its relation to modern systemic hospital-acquired strains

Background: Staphylococcus aureus (S. aureus) infections range in severity due to expression of certain virulence factors encoded on mobile genetic elements (MGE). As such, characterization of these MGE, as well as single nucleotide polymorphisms, is of high clinical and microbiological importance. To understand the evolution of these dangerous pathogens, it is paramount to define reference strains that may predate MGE acquisition. One such candidate is S. aureus Tager 104, a previously uncharacterized strain isolated from a patient with impetigo in 1947. Results: We show here that S. aureus Tager 104 can survive in the bloodstream and infect naïve organs. We also demonstrate a procedure to construct and validate the assembly of S. aureus genomes, using Tager 104 as a proof-of-concept. In so doing, we bridged confounding gap regions that limited our initial attempts to close this 2.82 Mb genome, through integration of data from Illumina Nextera paired-end, PacBio RS, and Lucigen NxSeq mate-pair libraries. Furthermore, we provide independent confirmation of our segmental arrangement of the Tager 104 genome by the sole use of Lucigen NxSeq libraries filled by paired-end MiSeq reads and alignment with SPAdes software. Genomic analysis of Tager 104 revealed limited MGE, and a νSaβ island configuration that is reminiscent of other hospital acquired S. aureus genomes. Conclusions: Tager 104 represents an early-branching ancestor of certain hospital-acquired strains. Combined with its earlier isolation date and limited content of MGE, Tager 104 can serve as a viable reference for future comparative genome studies. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2433-8) contains supplementary material, which is available to authorized users

Precision Medicine in Rhabdomyosarcoma: Using Patient Derived Xenografts as models of drug efficacy and acquired resistance

Background. Precision (Personalized) medicine has the potential to revolutionize patient health care and whilst there have been huge advances for a few cancers of known etiology, for many cancers, the fundamental causes of the disease process remain either elusive or have no available therapy. Here we outline a study in alveolar rhabdomyosarcoma, in which we use gene expression profiling and a series of drug prediction algorithms combined with a matched patient derived xenograft model (PDX) to test predicted therapies. Procedure. A PDX model was developed from a patient biopsy and a number of drugs identified using gene expression analysis in combination with drug prediction algorithms. Drugs chosen from each of the predictive methodologies, along with the patient’s standard-of-care (ICE-T), were tested in vivo in the PDX tumor. A second study was initiated using the tumors that re-grew following the ICE-T treatment. Further expression analysis identified additional therapies with potential anti-tumor efficacy. Results. A number of the predicted therapies were found to be active against the tumors in particular BGJ398 (FGFR2) and ICE-T. Re-transplantation of the ICE-T treated tumorgrafts demonstrated a decrease in response to ICE-T recapitulating the patient’s refractory disease. Gene expression profiling of the ICE-T treated tumorgrafts identified cytarabine (SLC29A1) as a potential therapy, which was shown, along with BGJ398, to be highly active in vivo. Conclusions. This study illustrates that tumorgrafts are ideal surrogates for testing potential therapeutic strategies based on gene expression analysis, modeling clinical drug resistance and hold the potential to assist in guiding prospective patient care

Comparison of RAST annotations of <i>Thermus</i> chromosomes.

<p>Abbreviations: Taq, <i>T</i>. <i>aquaticus</i> Y51MC23; Tsc, <i>T</i>. <i>scotoductus</i> SA-01; Tth HB8, <i>T</i>. <i>thermophilus</i> HB8; Tth HB27, <i>T</i>. <i>thermophilus</i> HB27.</p><p>Comparison of RAST annotations of <i>Thermus</i> chromosomes.</p

Molecular phylogenetic analysis of <i>Thermus</i> species by maximum likelihood method using 16S rRNA gene sequences.

<p>The tree with the highest log likelihood (-3496.7463) is shown. The percentage of trees in which the associated taxa clustered together is shown next to the branches.</p