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Health state utilities in non-small cell lung cancer: An international study.

Quality of life weights (utilities) are an important input in economic evaluation and evidence suggests that there can be important differences between countries. This study was designed to capture utilities for metastatic non-small cell lung cancer and common grade III/IV toxicities associated with treatment from local populations in the United Kingdom, Australia, France, China, Taiwan, and Korea. Toxicities included neutropenia, febrile neutropenia, fatigue, diarrhea, nausea and vomiting, rash, bleeding, hypertension, and hair loss.
Existing health state descriptions of non-small cell lung cancer were adapted to represent descriptions of patients on first-line treatment. Twenty-three states were translated and assessed in cognitive debrief content validation interviews with oncologists in each country. Seventy-five respondents per country completed a time trade-off interview to evaluate the states. Variation between countries for all states was explored with a Generalized Estimating Equations model.
The mean utility for &quot;stable disease and no side effects&quot; (base state) varied between 0.84 (United Kingdom) and 0.54 (Taiwan). The largest utility decrements were found for febrile neutropenia (0.47) and neutropenia (0.35) across all countries. Asian countries regarded bleeds as a severe toxicity whereas non-Asian countries did not and valued diarrhea and fatigue as more severe. Significant differences in utilities between countries emerged with the Taiwanese population in particular rating states as significantly worse than other countries.
This study improves our understanding of how utilities for the same states can vary across countries. The study shows the importance of capturing utilities that reflect the preferences of the local population.
© 2016 John Wiley &amp; Sons Australia, Ltd.

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Hepatitis B virus PreS2-mutant large surface antigen activates store-operated calcium entry and promotes chromosome instability.

Hepatitis B virus (HBV) is a driver of hepatocellular carcinoma, and two viral products, X and large surface antigen (LHBS), are viral oncoproteins. During chronic viral infection, immune-escape mutants on the preS2 region of LHBS (preS2-LHBS) are gain-of-function mutations that are linked to preneoplastic ground glass hepatocytes (GGHs) and early disease onset of hepatocellular carcinoma. Here, we show that preS2-LHBS provoked calcium release from the endoplasmic reticulum (ER) and triggered stored-operated calcium entry (SOCE). The activation of SOCE increased ER and plasma membrane (PM) connections, which was linked by ER- resident stromal interaction molecule-1 (STIM1) protein and PM-resident calcium release- activated calcium modulator 1 (Orai1). Persistent activation of SOCE induced centrosome overduplication, aberrant multipolar division, chromosome aneuploidy, anchorage-independent growth, and xenograft tumorigenesis in hepatocytes expressing preS2- LHBS. Chemical inhibitions of SOCE machinery and silencing of STIM1 significantly reduced centrosome numbers, multipolar division, and xenograft tumorigenesis induced by preS2-LHBS. These results provide the first mechanistic link between calcium homeostasis and chromosome instability in hepatocytes carrying preS2-LHBS. Therefore, persistent activation of SOCE represents a novel pathological mechanism in HBV-mediated hepatocarcinogenesis.

Mifepristone Improves Octreotide Efficacy in Resistant Ectopic Cushing’s Syndrome.

A 30-year-old Caucasian man presented with severe Cushing’s syndrome (CS) resulting from ectopic adrenocorticotropin syndrome (EAS) from a metastatic pancreatic neuroendocrine tumor. The patient remained hypercortisolemic despite treatment with steroidogenesis inhibitors, chemotherapy, and octreotide long-acting release (LAR) and was enrolled in a 24-week, phase 3 clinical trial of mifepristone for inoperable hypercortisolemia. After mifepristone was added to ongoing octreotide LAR treatment, EAS symptoms essentially resolved. Cortisol decreased dramatically, despite mifepristone’s competitive glucocorticoid receptor antagonist effects. The clinical and biochemical effects reversed upon mifepristone discontinuation despite the continued use of octreotide LAR therapy. Substantial improvement in octreotide LAR efficacy with mifepristone use was noted in this patient with ectopic CS, consistent with upregulation of somatostatin receptors previously downregulated by hypercortisolemia.

Crystal Structure of the Homing Endonuclease I-CvuI Provides a New Template for Genome Modification.

Homing endonucleases recognize and generate a DNA double-strand break, which has been used to promote gene targeting. These enzymes recognize long DNA stretches; they are highly sequence-specific enzymes and display a very low frequency of cleavage even in complete genomes. Although a large number of homing endonucleases have been identified, the landscape of possible target sequences is still very limited to cover the complexity of the whole eukaryotic genome. Therefore, the finding and molecular analysis of homing endonucleases identified but not yet characterized may widen the landscape of possible target sequences. The previous characterization of protein-DNA interaction before the engineering of new homing endonucleases is essential for further enzyme modification. Here we report the crystal structure of I-CvuI in complex with its target DNA and with the target DNA of I-CreI, a homologue enzyme widely used in genome engineering. To characterize the enzyme cleavage mechanism, we have solved the I-CvuI DNA structures in the presence of non-catalytic (Ca(2+)) and catalytic ions (Mg(2+)). We have also analyzed the metal dependence of DNA cleavage using Mg(2+) ions at different concentrations ranging from non-cleavable to cleavable concentrations obtained from in vitro cleavage experiments. The structure of I-CvuI homing endonuclease expands the current repertoire for engineering custom specificities, both by itself as a new scaffold alone and in hybrid constructs with other related homing endonucleases or other DNA-binding protein templates.
© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

p21-activated Kinases (PAKs) Mediate the Phosphorylation of PREX2 Protein to Initiate Feedback Inhibition of Rac1 GTPase.

Phosphatidylinositol 3,4,5-trisphosphate (PIP3)-dependent Rac exchanger 2 (PREX2) is a guanine nucleotide exchange factor (GEF) for the Ras-related C3 botulinum toxin substrate 1 (Rac1) GTPase, facilitating the exchange of GDP for GTP on Rac1. GTP-bound Rac1 then activates its downstream effectors, including p21-activated kinases (PAKs). PREX2 and Rac1 are frequently mutated in cancer and have key roles within the insulin-signaling pathway. Rac1 can be inactivated by multiple mechanisms; however, negative regulation by insulin is not well understood. Here, we show that in response to being activated after insulin stimulation, Rac1 initiates its own inactivation by decreasing PREX2 GEF activity. Following PREX2-mediated activation of Rac1 by the second messengers PIP3 or Gβγ, we found that PREX2 was phosphorylated through a PAK-dependent mechanism. PAK-mediated phosphorylation of PREX2 reduced GEF activity toward Rac1 by inhibiting PREX2 binding to PIP3 and Gβγ. Cell fractionation experiments also revealed that phosphorylation prevented PREX2 from localizing to the cellular membrane. Furthermore, the onset of insulin-induced phosphorylation of PREX2 was delayed compared with AKT. Altogether, we propose that second messengers activate the Rac1 signal, which sets in motion a cascade whereby PAKs phosphorylate and negatively regulate PREX2 to decrease Rac1 activation. This type of regulation would allow for transient activation of the PREX2-Rac1 signal and may be relevant in multiple physiological processes, including diseases such as diabetes and cancer when insulin signaling is chronically activated.
© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.