Monitoring Drug Target Engagement in Cells and Tissues Using the Cellular Thermal Shift Assay.

Monitoring drug target engagement in cells and tissues using the cellular thermal shift assay.

Science. 2013 Jul 5; 341(6141): 84-7
Molina DM, Jafari R, Ignatushchenko M, Seki T, Larsson EA, Dan C, Sreekumar L, Cao Y, Nordlund P

The efficacy of therapeutics is dependent on a drug binding to its cognate target. Optimization of target engagement by drugs in cells is often challenging, because drug binding cannot be monitored inside cells. We have developed a method for evaluating drug binding to target proteins in cells and tissue samples. This cellular thermal shift assay (CETSA) is based on the biophysical principle of ligand-induced thermal stabilization of target proteins. Using this assay, we validated drug binding for a set of important clinical targets and monitored processes of drug transport and activation, off-target effects and drug resistance in cancer cell lines, as well as drug distribution in tissues. CETSA is likely to become a valuable tool for the validation and optimization of drug target engagement. HubMed – drug


The Impact of Combined Antiretroviral Therapy on Biologic False Positive Rapid Plasma Reagin (RPR) Serologies in a Longitudinal Cohort of HIV-infected Persons.

Clin Infect Dis. 2013 Jul 3;
Oboho IK, Gebo KA, Moore RD, Ghanem KG

Background.?To determine the impact of combination antiretroviral therapy (cART) and the degree of immunosuppression on biologic false-positive (BFP) rapid plasma reagin (RPR) tests among HIV-infected persons. Methods.?Nested retrospective study of HIV-infected patients enrolled in the Johns Hopkins HIV Clinical Cohort. BFP RPR was defined as a reactive RPR and a non-reactive fluorescent treponemal antibody-absorption (FTA-ABS) test. Patients with BFP tests were compared to two control groups: HIV-infected patients (1) with active syphilis (reactive RPR and FTA-ABS) and (2) without current syphilis (non-reactive RPR). A persistent BFP test was defined by having at least two visits with consistent BFP at all visits. Results.?Of 711 patients with HIV, 96 (13.5%) had BFP tests and 342 (48.1%) had syphilis. Twenty-two of 96 (23%) had persistent BFP tests. cART use was associated with decreased odds of BFP tests compared to persons with syphilis [adjusted odds ratio (aOR) 0.31, 95% CI: 0.15-0.63] and those with a non-reactive RPR [aOR 0.42 (0.22-0.81)]. cART use was also associated with decreased odds of BFP persistence [aOR 0.07 (0.01-0.33)]. Neither CD4 count nor HIV RNA was significantly associated with BFP test results. Lower RPR titers, younger age, and injection drug use were associated with increased odds of BFP. Conclusions.?The use of cART appears to decrease the odds of BFP RPR tests. This finding suggests that nontreponemal titer fluctuations in persons with HIV may reflect the influence of factors unrelated to syphilis disease activity. HubMed – drug


Multifunctional nanomicellar systems for delivering anticancer drugs.

J Biomed Mater Res A. 2013 Jun 19;
Chen YC, Lo CL, Hsiue GH

Most anticancer drugs cause severe side effect due to the lack of selectivity for cancer cells. In recent years, new strategies of micellar systems, which design for specifically target anticancer drugs to tumors, are developed at the forefront of polymeric science. To improve efficiency of delivery and cancer specificity, considerable emphasis has been placed on the development of micellar systems with passive and active targeting. In this review article, we summarized various strategies of designing multifunctional micellar systems in the purpose of improving delivery efficiency. Micellar systems compose of a multifunctional copolymer or a mixture of two or more copolymers with different properties is a plausible approach to tuning the resulting properties and satisfied various requirements for anticancer drug delivery. It appears that multifunctional micellar systems hold great potential in cancer therapy. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013. HubMed – drug


Poly(L-aspartamide)-Based Reduction-Sensitive Micelles as Nanocarriers to Improve Doxorubicin Content in Cell Nuclei and to Enhance Antitumor Activity.

Macromol Biosci. 2013 Jul 5;
Cui C, Xue YN, Wu M, Zhang Y, Yu P, Liu L, Zhuo RX, Huang SW

A reduction-sensitive graft polymer PHEA-S-S-C16 with poly{?,?-[N-(2-hydroxyethyl)-L-aspartamide]} (PHEA) as a backbone and a disulfide-containing alkyl as a side chain (HOOC-S-S-C16 ) is synthesized and evaluated for intracellular DOX delivery. PHEA-S-S-C16 can self-assemble into micelles in aqueous media and load DOX at a total content of 7.3%. In vitro release studies reveal that the release rate of DOX from PHEA-S-S-C16 micelles is accelerated in the presence of DTT. The results of cell experiments indicate that DOX-loaded mPEG-S-S-C16 micelles can achieve rapid DOX release in HeLa cells, as compared with their reduction-insensitive counterparts. Endocytosis inhibition analysis indicates that PHEA-S-S-C16 micelles entered cells mainly via clathrin-mediated endocytosis. HubMed – drug


Towards building a disease-phenotype knowledge base: extracting disease-manifestation relationship from literature.

Bioinformatics. 2013 Jul 4;
Xu R, Li L, Wang Q

Systems approaches to studying phenotypic relationships among diseases are emerging as an active area of research for both novel disease gene discovery and drug repurposing. Currently, systematic study of disease phenotypic relationships on a phenome-wide scale is limited because large-scale machine understandable disease phenotype relationship knowledge bases are often unavailable. Here, we present an automatic approach to extract disease-manifestation pairs (one specific type of disease-phenotype relationship) from the wide body of published biomedical literature.Data and METHODS: Our method leverages external knowledge and limits the amount of human effort required. For the text corpus, we used 119,085,682 MEDLINE sentences (21,354,075 citations). First, we used disease-manifestation pairs from existing biomedical ontologies as prior knowledge to automatically discover disease-manifestation-specific syntactic patterns. We then extracted additional pairs from MEDLINE using the learned patterns. Finally, we analyzed correlations between disease manifestations and disease-associated genes and drugs to demonstrate the potential of this newly created knowledge base in disease gene discovery and drug repurposing.In total, we extracted 121,359 unique disease-manifestation pairs with a high precision of 0.924. Among the extracted pairs, 120,419 (99.2%) have not been captured in existing structured knowledge sources. We have shown that disease manifestations correlate positively with both disease-associated genes and drug treatments.Conclusions: The main contribution of our study is the creation of a large-scale and accurate disease-manifestation phenotype relationship knowledge base. This unique knowledge base, when combined with existing phenotypic, genetic and proteomic datasets, can have profound implications in our deeper understanding of disease etiology and in rapid drug repurposing. CONTACT: HubMed – drug