MEK Inhibition Sensitizes Pancreatic Cancer to STING Agonism by Tumor Cell-intrinsic Amplification of Type I IFN Signaling.

PURPOSE: Stimulator of interferon genes (STING) agonists are currently in development for treatment of solid tumors, including pancreatic ductal adenocarcinoma (PDAC). Response rates to STING agonists alone have been promising yet modest, and combination therapies will likely be required to elicit their full potency. We sought to identify combination therapies and mechanisms that augment the tumor cell-intrinsic effect of therapeutically relevant STING agonists apart from their known effects on tumor immunity. EXPERIMENTAL DESIGN: We screened 430 kinase inhibitors to identify synergistic effectors of tumor cell death with diABZI, an intravenously administered and systemically available STING agonist. We deciphered the mechanisms of synergy with STING agonism that cause tumor cell death in vitro and tumor regression in vivo. RESULTS: We found that MEK inhibitors caused the greatest synergy with diABZI and that this effect was most pronounced in cells with high STING expression. MEK inhibition enhanced the ability of STING agonism to induce type I IFN-dependent cell death in vitro and tumor regression in vivo. We parsed NFκB-dependent and NFκB-independent mechanisms that mediate STING-driven type I IFN production and show that MEK signaling inhibits this effect by suppressing NFκB activation. CONCLUSIONS: Our results highlight the cytotoxic effects of STING agonism on PDAC cells that are independent of tumor immunity and that these therapeutic benefits of STING agonism can be synergistically enhanced by MEK inhibition.

Antibiotic Resistance among Urinary Isolates from Female Outpatients in the United States in 2003 and 2012.

A retrospective analysis was performed using The Surveillance Network, USA, to examine the prevalence of antibiotic resistance among urine isolates from U.S. female outpatients in 2012 and assessed trends in antibiotic resistance comparing data from 2003 and 2012. The most common pathogen identified in 2012 (n = 285,325) was Escherichia coli (64.9% of isolates). In 2012, E. coli resistance to nitrofurantoin was low (<3%) across all age groups. E. coli resistance to ciprofloxacin was high among adults (11.8%) and elderly outpatients (29.1%). When comparing the 2003 and 2012 data from isolates from adults, E. coli resistance to nitrofurantoin changed only slightly (from 0.7% to 0.9%), whereas increases in resistance to ciprofloxacin (3.6% to 11.8%) and trimethoprim-sulfamethoxazole (17.2% to 22.2%) changed substantially. In the United States, E. coli has become increasingly resistant to ciprofloxacin and trimethoprim-sulfamethoxazole (TMP-SMX) in adult female outpatients. Nitrofurantoin retains high levels of antibiotic activity against urinary E. coli.

Performance of a new rapid test for the detection of hepatitis B surface antigen in various patient populations.

BACKGROUND: Rapid diagnostic tests (RDT) have been developed for the detection of hepatitis B surface antigen (HBsAg). They represent a promising alternative to enzyme immunoassays and a powerful tool for large-scale screening and diagnosis of HBV infection, especially in regions without easy access to serological and molecular testing. OBJECTIVES: The aims of the present study were to evaluate the characteristics and clinical performance of a new CE-marked HBsAg RDT, DRW-HBsAg v2.0 assay (Diagnostics for the Real World™, Ltd., USA), in various patient populations, including those chronically infected with HBV, patients with severe acute hepatitis of unknown origin and pregnant women with unknown HBV serological status at delivery. RESULTS: The lower limit of detection of the assay, evaluated in 21 clinical samples, ranged from 0.30 ± 0.07 to 0.97 ± 0.26 international units/mL (using Abbott Architect as a reference), depending on the HBV genotype. The assay tested positive in 100% of patients with chronic hepatitis B, 96.3% of HBsAg-positive acute hepatitis patients, and 95.2% of HBsAg-positive pregnant women. Its specificity was 98.8% in HBsAg-negative patients, 98.7% in HBsAg-negative patients with acute hepatitis of unknown origin and 97.8% in HBsAg-negative pregnant women. Amino acid substitutions in the HBsAg major hydrophilic region did not affect HBsAg detection by DRW-HBsAg v2.0. CONCLUSIONS: The new DRW-HBsAg v2.0 assay is a simple, rapid, easy-to-run and highly sensitive assay that can be used in both high- and low-risk populations for the diagnosis of HBsAg carriage. It appears to be a promising new tool for large-scale screening and diagnosis of HBV infection.

Cyclophilin-40 has a cellular role in the aryl hydrocarbon receptor signaling.

Cyclophilin-40 (CyP40) promotes the formation of the gel shift complex that contains the aryl hydrocarbon receptor (AhR), AhR nuclear translocator (Arnt) and dioxin response element (DRE) using baculovirus expressed proteins. Here we reported that CyP40 plays a role in the AhR signaling. When the CyP40 content in MCF-7 cells is reduced, up-regulation of cyp1a1 and cyp1b1 by 3-methylchloranthrene (3MC) is also reduced, suggesting that CyP40 is essential for maximal AhR function. The CyP40 region containing amino acids 186-215, but not the peptidyl-prolyl cis-trans isomerase and tetratricopeptide repeat domains, is essential for forming the AhR/Arnt/DRE complex. CyP40 is found in the cell nucleus after 3MC treatment and appears to promote the DRE binding form of the AhR/Arnt heterodimer.

A truncated Ah receptor blocks the hypoxia and estrogen receptor signaling pathways: a viable approach for breast cancer treatment.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor which requires heterodimerization with the Ah receptor nuclear translocator (Arnt) for function. Arnt is also a dimerization partner of the hypoxia inducible factor 1alpha (HIF-1alpha) for the hypoxia signaling. Additionally, Arnt is found to be a potent coactivator of the estrogen receptor (ER) signaling. Thus we examined whether the presence of an increased amount of AhR may suppress both the HIF-1alpha and ER signaling pathways by sequestering Arnt. We tested our hypothesis using a human AhR construct C Delta553 which is capable of heterodimerizing with Arnt in the absence of a ligand. Transient transfection studies using a corresponding luciferase reporter plasmid in MCF-7 cells showed that C Delta553 effectively suppressed the AhR, HIF-1alpha, and ER signaling pathways. Reverse transcription/real-time QPCR data showed that C Delta553 blocked the up-regulation of the target genes controlled by AhR (CYP1A1), HIF-1alpha (VEGF, aldolase C, and LDH-A), and ER (GREB1, pS2, and c-myc) in MCF-7 cells. Since both HIF-1alpha and ER are highly active in the ER-positive breast cancer, C Delta553 has the potential to be developed as a protein drug to treat breast cancer by blocking these two signaling pathways.

A novel Arnt-interacting protein Ainp2 enhances the aryl hydrocarbon receptor signalling.

In an effort to better understand the Ah receptor nuclear translocator (Arnt)-dependent signaling mechanisms, we employed a phage display system to identify Arnt-interacting peptides. Human liver cDNA library was utilized to screen for Arnt-interacting peptides using an Arnt construct fused to thioredoxin (TH-ArntCDelta418). Two clones, namely Ainp1 and Ainp2 (Arnt-interacting peptide), were identified and subsequently Ainp2 was further characterized. Ainp2 interacts with TH-ArntCDelta418 in the GST pull-down and mammalian two-hybrid assays. Northern blot results revealed that Ainp2 is predominantly expressed in human liver. The putative full-length Ainp2 cDNA sequence was subsequently cloned using RACE PCR. Endogenous expression of Ainp2 was found in Jurkat cells at the mRNA and protein levels. Results from the transient transfection studies using a DRE-driven reporter plasmid and the real-time QPCR experiments examining the endogenous CYP1A1 expression showed that Ainp2 enhances the 3-methylchloranthrene-induced activity in HepG2 cells, suggesting that Ainp2 plays a role in the Arnt-dependent function

Discovery of 5-[5-fluoro-2-oxo-1,2- dihydroindol-(3Z)-ylidenemethyl]-2,4- dimethyl-1H-pyrrole-3-carboxylic acid (2-diethylaminoethyl)amide, a novel tyrosine kinase inhibitor targeting vascular endothelial and platelet-derived growth factor receptor tyrosine kinase.

To improve the antitumor properties and optimize the pharmaceutical properties including solubility and protein binding of indolin-2-ones, a number of different basic and weakly basic analogues were designed and synthesized. 5-[5-Fluoro-2-oxo-1,2-dihydroindol-(3Z)-ylidenemethyl]-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (2-diethylaminoethyl)amide (12b or SU11248) has been found to show the best overall profile in terms of potency for the VEGF-R2 and PDGF-Rbeta tyrosine kinase at biochemical and cellular levels, solubility, protein binding, and bioavailability. 12b is currently in phase I clinical trials for the treatment of cancers.