bluuebunny/crossref_metadata_2025 huggingface dataset:
Weathering in the Parkinson Pit and its implications for exploration in the Mt Magnet Mining District, Western Australia
Authors: Scott K. M.
Published: July 2011

In the Parkinson Pit area at Mt Magnet, 560 km NNE of Perth, mafic and felsic rocks occur within a weathering profile that has been stripped to the saprolite. Irrespective of rock type within the pit area, the weathered profile consists of fresh rock, saprock, mottled saprolite and leached saprolite below a thin transported soil cover. The depth of weathering extends to 80 m adjacent to mineralization, although weathering depths appear to be less in mafic volcanic rocks outside the pit.

Weathering has led to separation of Ag from the primary Ag-bearing gold and the redistribution of other potential pathfinders elements (As, Co, Cu, Ni, Sb and Zn ) from the original sulphides (mainly pyrite) into Fe and Mn oxides. Gold grades have not been significantly affected by weathering.

Both mafic and felsic rocks in the Parkinson Pit area, have been metamorphosed to quartz+chlorite±mica+albite assemblages. However, hydrothermal alteration has destroyed albite and formed additional mica, so that the change: minor muscovite→paragonite±muscovite→muscovite, reflects an approach to mineralization. Because micas are retained when the rocks weather, this characteristic feature is maintained in the regolith, although changes in mica compositions and abundance are more obvious in mafic than in felsic rocks because of the greater initial mica content in the latter. Thus, proximity to mineralization, reflected by mica composition and abundance in mafic volcanic rocks, could be determined by PIMA and radiometric analysis of K content, even from weathered drill cuttings.
Type II iodothyronine deiodinase provides intracellular 3,5,3′-triiodothyronine to normal and regenerating mouse skeletal muscle
Authors: Marsili Alessandro , Tang Dan , Harney John W. , Singh Prabhat , Zavacki Ann Marie , Dentice Monica , Salvatore Domenico , Larsen P. Reed
Published: July 2011

The FoxO3-dependent increase in type II deiodinase (D2), which converts the prohormone thyroxine (T4) to 3,5,3′-triiodothyronine (T3), is required for normal mouse skeletal muscle differentiation and regeneration. This implies a requirement for an increase in D2-generated intracellular T3 under these conditions, which has not been directly demonstrated despite the presence of D2 activity in skeletal muscle. We directly show that D2-mediated T4-to-T3 conversion increases during differentiation in C2C12 myoblast and primary cultures of mouse neonatal skeletal muscle precursor cells, and that blockade of D2 eliminates this. In adult mice given 125I-T4 and 131I-T3, the intracellular 125I-T3/131I-T3 ratio is significantly higher than in serum in both the D2-expressing cerebral cortex and the skeletal muscle of wild-type, but not D2KO, mice. In D1-expressing liver and kidney, the 125I-T3/131I-T3 ratio does not differ from that in serum. Hypothyroidism increases D2 activity, and in agreement with this, the difference in 125I-T3/131I-T3 ratio is increased further in hypothyroid wild-type mice but not altered in the D2KO. Notably, in wild-type but not in D2KO mice, the muscle production of 125I-T3 is doubled after skeletal muscle injury. Thus, D2-mediated T4-to-T3 conversion generates significant intracellular T3 in normal mouse skeletal muscle, with the increased T3 required for muscle regeneration being provided by increased D2 synthesis, not by T3 from the circulation.
Mybl2, downregulated during colon epithelial cell maturation, is suppressed by miR-365
Authors: Papetti Michael , Augenlicht Leonard H.
Published: July 2011

Altered profiles of gene expression reflect the reprogramming of intestinal epithelial cells during their maturation along the crypt-luminal axis. To focus on genes important in this process, and how they in turn are regulated, we identified 14 transcripts commonly downregulated in expression during lineage-specific maturation of the immortalized cell lines Caco-2 (absorptive), HT29Cl16E (goblet), and HT29Cl19A (secretory) induced by contact inhibition of growth or the short-chain fatty acid butyrate. One such gene, Mybl2 (Myb-related protein B), has been linked to the stem cell phenotype, and we report is also markedly suppressed in maturing cells along the crypt-luminal axis in vivo. Mybl2 is not significantly downregulated transcriptionally during colon cell maturation, but we identified a potential micro-RNA (miRNA)-binding sequence in the Mybl2 3′-untranslated region that mediates reporter gene suppression in differentiating colon cells. Accordingly, miRNAs predicted to bind this functional target are upregulated in differentiating colon epithelial cells in vitro and in vivo; expression of one of these, hsa-miR-365 (but not hsa-324–5p), suppresses Mybl2 protein expression in proliferating Caco-2 cells. These data demonstrate that miRNA silencing plays an important role in regulating gene expression in maturing colon epithelial cells, and that utilizing a target-centered approach, rather than profiling global miRNA expression, can identify physiologically relevant, functional miRNAs.
Constitutive activation of the MEK/ERK pathway inhibits intestinal epithelial cell differentiation
Authors: Lemieux Etienne , Boucher Marie-Josée , Mongrain Sébastien , Boudreau François , Asselin Claude , Rivard Nathalie
Published: July 2011

The Ras/Raf/MEK/ERK cascade regulates intestinal epithelial cell proliferation. Indeed, while barely detectable in differentiated cells of the villi, ERK1/2-activated forms are detected in the nucleus of undifferentiated human intestinal crypt cells. In addition, we and others have reported that ERKs are selectively inactivated during enterocyte differentiation. However, whether inactivation of the ERK pathway is necessary for inhibition of both proliferation and induction of differentiation of intestinal epithelial cells is unknown. Human Caco-2/15 cells, undifferentiated crypt IEC-6 cells, and differentiating Cdx3-expressing IEC-6 cells were infected with retroviruses encoding either a hemagglutinin (HA)-tagged MEK1 wild type (wtMEK) or a constitutively active S218D/S222D MEK1 mutant (caMEK). Protein and gene expression was assessed by Western blotting, semiquantitative RT-PCR, and real-time PCR. Morphology was analyzed by transmission electron microscopy. We found that 1) IEC-6/Cdx3 cells formed multicellular layers after confluence and differentiated after 30 days in culture, as assessed by increased polarization, microvilli formation, expression of differentiation markers, and ERK1/2 inhibition; 2) while activated MEK prevented neither the inhibition of ERK1/2 activities nor the differentiation process in postconfluent Caco-2/15 cells, caMEK expression prevented ERK inhibition in postconfluent IEC-6/Cdx3 cells, thus leading to maintenance of elevated ERK1/2 activities; 3) caMEK-expressing IEC-6/Cdx3 cells exhibited altered multicellular structure organization, poorly defined tight junctions, reduced number of microvilli on the apical surface, and decreased expression of the hepatocyte nuclear factor 1α transcription factor and differentiation markers, namely apolipoprotein A-4, fatty acid-binding protein, calbindin-3, mucin 2, alkaline phosphatase, and sucrase-isomaltase; and 4) increased Cdx3 phosphorylation on serine-60 (S60) in IEC-6/Cdx3 cells expressing caMEK led to decreased Cdx2 transactivation potential. These results indicate that inactivation of the ERK pathway is required to ensure the full Cdx2/3 transcriptional activity necessary for intestinal epithelial cell terminal differentiation.
Effects of the menstrual cycle on muscle recruitment and oxidative fuel selection during cold exposure
Authors: Blondin Denis P. , Maneshi Anali , Imbeault Marie-Andrée , Haman François
Published: July 2011

Differences in core temperature and body heat content, generally observed between the luteal and follicular phase of the menstrual cycle, have been reported to modulate the thermogenic activity of cold-exposed women. However, it is unclear how this change in whole body shivering activity will influence fuel selection. The goal of this study was to quantify the effects of the menstrual cycle on muscle recruitment and oxidative fuel selection during low-intensity shivering. Electromyographic activity of eight large muscles was monitored while carbohydrate, lipid, and protein utilization was simultaneously quantified in the follicular and luteal phases of the menstrual cycle in nonacclimatized women shivering at a low intensity. The onset (∼25 min), intensity (∼15% of maximal voluntary contraction), and pattern (∼6 shivering bursts/min) of the shivering response did not differ between menstrual cycle phases, regardless of differences in core temperature and hormone levels. This resulted in lipids remaining the predominant substrate, contributing 75% of total heat production, independent of menstrual phase. We conclude that hormone fluctuations inherent in the menstrual cycle do not affect mechanisms of substrate utilization in the cold. Whether the large contribution of lipids to total heat production in fuel selection confers a survival advantage remains to be established.
Identifying functional single nucleotide polymorphisms in the human CArGome
Authors: Benson Craig C. , Zhou Qian , Long Xiaochun , Miano Joseph M.
Published: July 2011

Regulatory SNPs (rSNPs) reside primarily within the nonprotein coding genome and are thought to disturb normal patterns of gene expression by altering DNA binding of transcription factors. Nevertheless, despite the explosive rise in SNP association studies, there is little information as to the function of rSNPs in human disease. Serum response factor (SRF) is a widely expressed DNA-binding transcription factor that has variable affinity to at least 1,216 permutations of a 10 bp transcription factor binding site (TFBS) known as the CArG box. We developed a robust in silico bioinformatics screening method to evaluate sequences around RefSeq genes for conserved CArG boxes. Utilizing a predetermined phastCons threshold score, we identified 8,252 strand-specific CArGs within an 8 kb window around the transcription start site of 5,213 genes, including all previously defined SRF target genes. We then interrogated this CArG dataset for the presence of previously annotated common polymorphisms. We found a total of 118 unique CArG boxes harboring a SNP within the 10 bp CArG sequence and 1,130 CArG boxes with SNPs located just outside the CArG element. Gel shift and luciferase reporter assays validated SRF binding and functional activity of several new CArG boxes. Importantly, SNPs within or just outside the CArG box often resulted in altered SRF binding and activity. Collectively, these findings demonstrate a powerful approach to computationally define rSNPs in the human CArGome and provide a foundation for similar analyses of other TFBS. Such information may find utility in genetic association studies of human disease where little insight is known regarding the functionality of rSNPs.
Factor XIII: A Coagulation Factor With Multiple Plasmatic and Cellular Functions
Authors: Muszbek László , Bereczky Zsuzsanna , Bagoly Zsuzsa , Komáromi István , Katona Éva
Published: July 2011

Factor XIII (FXIII) is unique among clotting factors for a number of reasons: 1) it is a protransglutaminase, which becomes activated in the last stage of coagulation; 2) it works on an insoluble substrate; 3) its potentially active subunit is also present in the cytoplasm of platelets, monocytes, monocyte-derived macrophages, dendritic cells, chondrocytes, osteoblasts, and osteocytes; and 4) in addition to its contribution to hemostasis, it has multiple extra- and intracellular functions. This review gives a general overview on the structure and activation of FXIII as well as on the biochemical function and downregulation of activated FXIII with emphasis on new developments in the last decade. New aspects of the traditional functions of FXIII, stabilization of fibrin clot, and protection of fibrin against fibrinolysis are summarized. The role of FXIII in maintaining pregnancy, its contribution to the wound healing process, and its proangiogenic function are reviewed in details. Special attention is given to new, less explored, but promising fields of FXIII research that include inhibition of vascular permeability, cardioprotection, and its role in cartilage and bone development. FXIII is also considered as an intracellular enzyme; a separate section is devoted to its intracellular activation, intracellular action, and involvement in platelet, monocyte/macrophage, and dendritic cell functions.
Normalization of the Vasculature for Treatment of Cancer and Other Diseases
Authors: Goel Shom , Duda Dan G. , Xu Lei , Munn Lance L. , Boucher Yves , Fukumura Dai , Jain Rakesh K.
Published: July 2011

New vessel formation (angiogenesis) is an essential physiological process for embryologic development, normal growth, and tissue repair. Angiogenesis is tightly regulated at the molecular level. Dysregulation of angiogenesis occurs in various pathologies and is one of the hallmarks of cancer. The imbalance of pro- and anti-angiogenic signaling within tumors creates an abnormal vascular network that is characterized by dilated, tortuous, and hyperpermeable vessels. The physiological consequences of these vascular abnormalities include temporal and spatial heterogeneity in tumor blood flow and oxygenation and increased tumor interstitial fluid pressure. These abnormalities and the resultant microenvironment fuel tumor progression, and also lead to a reduction in the efficacy of chemotherapy, radiotherapy, and immunotherapy. With the discovery of vascular endothelial growth factor (VEGF) as a major driver of tumor angiogenesis, efforts have focused on novel therapeutics aimed at inhibiting VEGF activity, with the goal of regressing tumors by starvation. Unfortunately, clinical trials of anti-VEGF monotherapy in patients with solid tumors have been largely negative. Intriguingly, the combination of anti-VEGF therapy with conventional chemotherapy has improved survival in cancer patients compared with chemotherapy alone. These seemingly paradoxical results could be explained by a “normalization” of the tumor vasculature by anti-VEGF therapy. Preclinical studies have shown that anti-VEGF therapy changes tumor vasculature towards a more “mature” or “normal” phenotype. This “vascular normalization” is characterized by attenuation of hyperpermeability, increased vascular pericyte coverage, a more normal basement membrane, and a resultant reduction in tumor hypoxia and interstitial fluid pressure. These in turn can lead to an improvement in the metabolic profile of the tumor microenvironment, the delivery and efficacy of exogenously administered therapeutics, the efficacy of radiotherapy and of effector immune cells, and a reduction in number of metastatic cells shed by tumors into circulation in mice. These findings are consistent with data from clinical trials of anti-VEGF agents in patients with various solid tumors. More recently, genetic and pharmacological approaches have begun to unravel some other key regulators of vascular normalization such as proteins that regulate tissue oxygen sensing (PHD2) and vessel maturation (PDGFRβ, RGS5, Ang1/2, TGF-β). Here, we review the pathophysiology of tumor angiogenesis, the molecular underpinnings and functional consequences of vascular normalization, and the implications for treatment of cancer and nonmalignant diseases.
Maturation of the GABAergic Transmission in Normal and Pathologic Motoneurons
Authors: Allain Anne-Emilie , Le Corronc Hervé , Delpy Alain , Cazenave William , Meyrand Pierre , Legendre Pascal , Branchereau Pascal
Published: July 2011

γ-aminobutyric acid (GABA) acting on Cl−-permeable ionotropic type A (GABAA) receptors (GABAAR) is the major inhibitory neurotransmitter in the adult central nervous system of vertebrates. In immature brain structures, GABA exerts depolarizing effects mostly contributing to the expression of spontaneous activities that are instructive for the construction of neural networks but GABA also acts as a potent trophic factor. In the present paper, we concentrate on brainstem and spinal motoneurons that are largely targeted by GABAergic interneurons, and we bring together data on the switch from excitatory to inhibitory effects of GABA, on the maturation of the GABAergic system and GABAAR subunits. We finally discuss the role of GABA and its GABAAR in immature hypoglossal motoneurons of the spastic (SPA) mouse, a model of human hyperekplexic syndrome.
PTEN Positively Regulates UVB-Induced DNA Damage Repair
Authors: Ming Mei , Feng Li , Shea Christopher R. , Soltani Keyoumars , Zhao Baozhong , Han Weinong , Smart Robert C. , Trempus Carol S. , He Yu-Ying
Published: July 2011

Nonmelanoma skin cancer is the most common cancer in the United States, where DNA-damaging ultraviolet B (UVB) radiation from the sun remains the major environmental risk factor. However, the critical genetic targets of UVB radiation are undefined. Here we show that attenuating PTEN in epidermal keratinocytes is a predisposing factor for UVB-induced skin carcinogenesis in mice. In skin papilloma and squamous cell carcinoma (SCC), levels of PTEN were reduced compared with skin lacking these lesions. Likewise, there was a reduction in PTEN levels in human premalignant actinic keratosis and malignant SCCs, supporting a key role for PTEN in human skin cancer formation and progression. PTEN downregulation impaired the capacity of global genomic nucleotide excision repair (GG-NER), a critical mechanism for removing UVB-induced mutagenic DNA lesions. In contrast to the response to ionizing radiation, PTEN downregulation prolonged UVB-induced growth arrest and increased the activation of the Chk1 DNA damage pathway in an AKT-independent manner, likely due to reduced DNA repair. PTEN loss also suppressed expression of the key GG-NER protein xeroderma pigmentosum C (XPC) through the AKT/p38 signaling axis. Reconstitution of XPC levels in PTEN-inhibited cells restored GG-NER capacity. Taken together, our findings define PTEN as an essential genomic gatekeeper in the skin through its ability to positively regulate XPC-dependent GG-NER following DNA damage. Cancer Res; 71(15); 5287–95. ©2011 AACR.
Clusterin Inhibition Using OGX-011 Synergistically Enhances Hsp90 Inhibitor Activity by Suppressing the Heat Shock Response in Castrate-Resistant Prostate Cancer
Authors: Lamoureux Francois , Thomas Christian , Yin Min-Jean , Kuruma Hidetoshi , Beraldi Eliana , Fazli Ladan , Zoubeidi Amina , Gleave Martin E.
Published: July 2011

Small-molecule inhibitors of Hsp90 show promise in the treatment of castrate-resistant prostate cancer (CRPC); however, these inhibitors trigger a heat shock response that attenuates drug effectiveness. Attenuation is associated with increased expression of Hsp90, Hsp70, Hsp27, and clusterin (CLU) that mediate tumor cell survival and treatment resistance. We hypothesized that preventing CLU induction in this response would enhance Hsp90 inhibitor–induced CRPC cell death in vitro and in vivo. To test this hypothesis, we treated CRPC with the Hsp90 inhibitor PF-04929113 or 17-AAG in the absence or presence of OGX-011, an antisense drug that targets CLU. Treatment with either Hsp90 inhibitor alone increased nuclear translocation and transcriptional activity of the heat shock factor HSF-1, which stimulated dose- and time-dependent increases in HSP expression, especially CLU expression. Treatment-induced increases in CLU were blocked by OGX-011, which synergistically enhanced the activity of Hsp90 inhibition on CRPC cell growth and apoptosis. Accompanying these effects was a decrease in HSF-1 transcriptional activity as well as expression of HSPs, Akt, prostate-specific antigen, and androgen receptor. In vivo evaluation of the Hsp90 inhibitors with OGX-011 in xenograft models of human CRPC showed that OGX-011 markedly potentiated antitumor efficacy, leading to an 80% inhibition of tumor growth with prolonged survival compared with Hsp90 inhibitor monotherapy. Together, our findings indicate that Hsp90 inhibitor–induced activation of the heat shock response and CLU is attenuated by OGX-011, with synergistic effects on delaying CRPC progression. Cancer Res; 71(17); 5838–49. ©2011 AACR.
Clonal Relationship of Classical Hodgkin Lymphoma and Its Recurrences
Authors: Obermann Ellen C. , Mueller Nadine , Rufle Alexander , Menter Thomas , Mueller-Garamvoelgyi Esther , Cathomas Gieri , Dirnhofer Stephan , Tzankov Alexandar
Published: July 2011

Purpose: We investigated whether the first and all subsequent manifestations of Hodgkin lymphoma (HL) in a patient are clonally related.

Experimental Design: We identified a collective of 20 patients with sometimes multiple HL recurrences. Relapses were classified as early, that is, within twelve months (eight events in seven patients) or as late, that is, later than one year after the previous neoplasm (24 events in 17 patients). Hodgkin and Reed–Sternberg cells were microdissected after CD30 staining using laser capture technique. Immunoglobulin heavy chain (IgH) gene fragment lengths were analyzed after DNA preamplification, applying consensus FR3 and J primers by ABI 310 Genetic Analyzer. Sequencing of the amplified IgH products was carried out by ABI 3130 and 3730XL Genetic Analyzer. Epstein-Barr virus (EBV) association was assessed by EBV early RNA and LMP1.

Results: Three cases with early relapses after a first HL diagnosis were clonally related to the initial tumor, whereas three of four patients with early relapses after a first or second relapse were not, which was accompanied by change of EBV association in one case. Six patients presenting with late relapses were clonally unrelated, which was accompanied by change of phenotype in two cases and change of EBV association in one case. Two samples from recurrent tumors of the same patient could be successfully sequenced. These two late relapses were clonally unrelated by IgH fragment length and sequencing analysis.

Conclusions: Recurrent HL, especially those accompanied by an EBV-association switch or after a relapse, can represent an unrelated novel neoplasm. Our finding might play a role in clinical decision making. Clin Cancer Res; 17(16); 5268–74. ©2011 AACR.
XPF Expression Correlates with Clinical Outcome in Squamous Cell Carcinoma of the Head and Neck
Authors: Vaezi Alec , Wang XiaoZhe , Buch Shama , Gooding William , Wang Lin , Seethala Raja R. , Weaver David T. , D'Andrea Alan D. , Argiris Athanassios , Romkes Marjorie , Niedernhofer Laura J. , Grandis Jennifer R.
Published: July 2011

Purpose: Tumor-specific biomarkers that predict resistance to DNA damaging agents may improve therapeutic outcomes by guiding the selection of effective therapies and limiting morbidity related to ineffective approaches. XPF (ERCC4) is an essential component of several DNA repair pathways and XPF-deficient cells are exquisitely sensitive to DNA damaging agents. The purpose of this study was to determine whether XPF expression levels predict clinical response to DNA damaging agents in head and neck squamous cell carcinoma (HNSCC).

Experimental Design: Quantitative immunohistochemistry was used to measure XPF expression in tumors from a cohort of 80 patients with newly diagnosed HNSCC treated with radiation therapy with or without platinum-based chemotherapy; samples were collected prospectively. Genomic DNA isolated from blood samples was analyzed for nine single nucleotide polymorphisms (SNP) in the XPF gene by using a custom array. The primary endpoint was progression-free survival (PFS).

Results: XPF expression was higher in tumors from the oral cavity than from the other sites (P < 0.01). High XPF expression correlated with early time to progression both by univariate (HR = 1.87, P = 0.03) and multivariate analysis (HR = 1.83, P = 0.05). The one year PFS for high expressers was 47% (95% CI = 31–62) compared with 72% (95% CI = 55–83) for low expressers. In addition, we identified four XPF SNPs that showed marginal association with treatment failure.

Conclusions: Expression level of XPF in HNSCC tumors correlates with clinical response to DNA damaging agents. XPF has potential to guide next generation personalized cancer therapy. Clin Cancer Res; 17(16); 5513–22. ©2011 AACR.
Determinants of Successful CD8+ T-Cell Adoptive Immunotherapy for Large Established Tumors in Mice
Authors: Klebanoff Christopher A. , Gattinoni Luca , Palmer Douglas C. , Muranski Pawel , Ji Yun , Hinrichs Christian S. , Borman Zachary A. , Kerkar Sid P. , Scott Christopher D. , Finkelstein Steven E. , Rosenberg Steven A. , Restifo Nicholas P.
Published: July 2011

Purpose: Adoptive cell transfer (ACT) of tumor infiltrating or genetically engineered T cells can cause durable responses in patients with metastatic cancer. Multiple clinically modifiable parameters can comprise this therapy, including cell dose and phenotype, in vivo antigen restimulation, and common gamma-chain (γc) cytokine support. However, the relative contributions of each these individual components to the magnitude of the antitumor response have yet to be quantified.

Experimental Design: To systematically and quantitatively appraise each of these variables, we employed the Pmel-1 mouse model treating large, established B16 melanoma tumors. In addition to cell dose and magnitude of in vivo antigen restimulation, we also evaluated the relative efficacy of central memory (TCM), effector memory (TEM), and stem cell memory (TSCM) subsets on the strength of tumor regression as well as the dose and type of clinically available γc cytokines, including IL-2, IL-7, IL-15, and IL-21.

Results: We found that cell dose, T-cell differentiation status, and viral vaccine titer each were correlated strongly and significantly with the magnitude of tumor regression. Surprisingly, although the total number of IL-2 doses was correlated with tumor regression, no significant benefit to prolonged (≥6 doses) administration was observed. Moreover, the specific type and dose of γc cytokine only moderately correlated with response.

Conclusion: Collectively, these findings elucidate some of the key determinants of successful ACT immunotherapy for the treatment of cancer in mice and further show that γc cytokines offer a similar ability to effectively drive antitumor T-cell function in vivo. Clin Cancer Res; 17(16); 5343–52. ©2011 AACR.
The Novel HSP90 Inhibitor, IPI-493, Is Highly Effective in Human Gastrostrointestinal Stromal Tumor Xenografts Carrying Heterogeneous KIT Mutations
Authors: Floris Giuseppe , Sciot Raf , Wozniak Agnieszka , Van Looy Thomas , Wellens Jasmien , Faa Gavino , Normant Emmanuel , Debiec-Rychter Maria , Schöffski Patrick
Published: July 2011

Purpose: KIT activity is crucial for gastrointestinal stromal tumors (GIST). Imatinib (IMA) and sunitinib (SUN) are very effective KIT-inhibitors in patients with advanced GIST but have no curative potential. We evaluated the efficacy of the novel HSP90 inhibitor IPI-493 alone, or in combination with IMA or SUN in GIST xenografts with KIT mutations.

Experimental Design: Nude mice (n = 98) were grafted bilaterally with human GIST carrying KIT exon 11 (GIST-PSW), KIT exon 9 (GIST-BOE), or double, KIT imatinib-sensitive exon 11 and imatinib-resistant exon 17 mutations (GIST-48). Mice were divided into six treatment groups and dosed orally for 15 days as follows: (i) control group, sterile water; (ii) IMA alone; (iii) SUN alone; (iv) IPI-493 alone; (v) IPI-493+IMA; and (vi) IPI-493+SUN.

Results: Treatment with IPI-493 resulted in tumor growth stabilization, variable proliferation arrest, induction of apoptosis and necrosis, and downregulation of KIT and its signaling cascade, especially in the GIST-BOE model. Significant reduction of vessel density was observed with IPI-493 treatment, and was equal to SUN treatment in GIST-PSW and GIST-BOE xenografts. IPI-493 treatment effects were enhanced in combination with TKIs, especially with IPI-493+SUN. In our hands, IPI-493 showed dose-dependent liver damages.

Conclusions: When administered as a single agent in a xenograft model, the HSP90 inhibitor IPI-493 has consistent antitumor activity and induces KIT downregulation in GISTs with heterogeneous KIT mutations. IPI-493 synergizes with TKIs that are commonly used for the treatment of advanced or IMA-resistant GIST. The antitumor response of IPI-493 is particularly enhanced in combination with SUN. Clin Cancer Res; 17(17); 5604–14. ©2011 AACR.
Anti-VEGF Treatment–Resistant Pancreatic Cancers Secrete Proinflammatory Factors That Contribute to Malignant Progression by Inducing an EMT Cell Phenotype
Authors: Carbone Carmine , Moccia Tania , Zhu Cihui , Paradiso Genni , Budillon Alfredo , Chiao Paul J. , Abbruzzese James L. , Melisi Davide
Published: July 2011

Purpose: The resistance of tumors to antiangiogenic therapies is becoming increasingly relevant. There are currently no validated predictive biomarkers for selecting which cancer patients will benefit from antiangiogenic therapy. Also lacking are resistance biomarkers that can identify which escape pathways should be targeted after tumors develop resistance to VEGF treatment. Recent studies showed that anti-VEGF treatment can make tumor cells more aggressive and metastatic. However, the mechanisms and mediators of this are unidentified. Therefore, we aimed this study at directly identifying the tumor cell–initiated mechanisms responsible for the resistance of pancreatic cancer to anti-VEGF treatment.

Experimental Design: We established and validated two murine models of human pancreatic cancer resistant to the VEGF-specific antibody bevacizumab in vivo. We used a genome-wide analysis to directly identify which tumor-secreted factors were overexpressed by pancreatic cancer cells that were resistant to anti-VEGF treatment.

Results: Rather than direct proangiogenic factors, we identified several proinflammatory factors that were expressed at higher levels in cells resistant to anti-VEGF treatment than in treatment-sensitive control cells. These proinflammatory factors acted in a paracrine manner to stimulate the recruitment of CD11b+ proangiogenic myeloid cells. Also, we found that secreted factors overexpressed by anti-VEGF treatment-resistant pancreatic cancer cells acted in an autocrine manner to induce epithelial-to-mesenchymal transition (EMT) and were thus responsible for increased aggressiveness of bevacizumab-resistant pancreatic tumors.

Conclusions: Our results identified proinflammatory factors and EMT markers as potential biomarkers for selecting patients with pancreatic cancer for antiangiogenic therapy. Clin Cancer Res; 17(17); 5822–32. ©2011 AACR.
Treatment of Hepatitis C-Mediated Glomerular Disease
Authors: Sandri Ana Maria , Elewa Usama , Poterucha John J. , Fervenza Fernando C.
Published: July 2011

Chronic kidney disease (CKD) is becoming a major public health issue worldwide, mainly due to the increasing prevalence of hypertension, diabetes and aging population. Chronic hepatitis C virus (HCV) infection commonly involves the kidneys, can be a cause of CKD, and significantly impacts morbidity and mortality in these patients. Prompt recognition and knowledge of how to best manage these patients are essential in order to have a successful renal outcome. Patients with HCV and kidney involvement can often be managed with a specific combination of antiviral drugs, immunosuppressants, plasmapheresis, and newer monoclonal antibodies. However, no large randomized controlled trials have been conducted in this patient population, optimal management of HCV-mediated kidney diseases is not well defined, and treatment itself can be associated with significant toxicity in patients with CKD. This article reviews the recent literature, discusses the limitations of current therapies, as well as toxicity associated with treatment, and suggests future areas for research.
Post-Parathyroidectomy Parathyroid Hormone Levels: The Impact on Patient Survival – A Single-Centre Study in a Stage 5 Chronic Kidney Disease Population
Authors: Fotheringham James , Balasubramanian Saba P. , Harrison Barney , Wilkie Martin
Published: July 2011

Background/Aims: Both severe, uncontrolled and low parathyroid hormone (iPTH) levels are associated with adverse outcomes in stage 5 chronic kidney disease (CKD) patients; however, the impact of iPTH levels following parathyroidectomy (PTX) is unexplored. Methods: A total of 235 stage 5 CKD patients who underwent PTX between 1990 and 2007 were identified, and iPTH levels following surgery were used to divide patients according to the quartile of maximum iPTH recovery during the 5 years following PTX. Survival, biochemistry and pharmacotherapy were analysed. Results: The maximum iPTH level in each quartile during the follow-up period was <46, 47–139, 140–420 and >420 pg/ml. The overall 5-year survival for the group was 81%. Adjusting for age, time on renal replacement therapy and the presence of diabetes identified an increased hazard for mortality of 2.459 in the quartile of lowest iPTH recovery (p = 0.035). The median 1-alfacalcidol dose during the follow-up period was higher (0.5 µg/day) in the lower iPTH group compared to the 3 quartiles of higher iPTH recovery (0.25 µg/day). Conclusion: An association between the lowest quartile of iPTH recovery in the 5 years following PTX and poorer patient survival was found. This finding should be tested in larger datasets.
Interaction on an Additive Scale
Authors: de Mutsert Renée , de Jager Dinanda J. , Jager Kitty J. , Zoccali Carmine , Dekker Friedo W.
Published: July 2011

Many clinical epidemiological studies investigate whether a certain exposure, or risk factor, is associated with the incidence of disease or mortality. It may be of interest to study whether this association is different in different types of patients, or to study joint effects. To investigate whether the effect of one risk factor differs across the strata of another risk factor, the presence of interaction among two risk factors can be examined. In statistics, interaction refers to the inclusion of a product term of two risk factors in a statistical model. Statistical interaction thereby evaluates whether the association deviates from either additivity or multiplicativity, depending on the scale of the model. From a public health perspective, the assessment of interaction on an additive scale may be most relevant. For a transparent presentation of interaction effects, it is recommended to report the separate effect of each exposure as well as the joint effect compared to the unexposed group as a joint reference category to permit evaluation of interaction on both an additive and multiplicative scale.
Reporting of Interaction
Authors: de Jager Dinanda J. , de Mutsert Renée , Jager Kitty J. , Zoccali Carmine , Dekker Friedo W.
Published: July 2011

Interaction is the situation whereby the association of one risk factor with a certain outcome variable differs across strata of another risk factor. From a public health perspective, the assessment of interaction on an additive scale may be most relevant. Although additive models exist, logistic and Cox regression models are the most commonly used models in epidemiology. The resulting relative risks can be translated to an additive scale. The present paper presents surrogate measures to evaluate the presence of additive interaction when dealing with data on a multiplicative scale (relative risks). For a transparent presentation of interaction effects it is recommended to report the separate effect of each exposure as well as their joint effect compared to the unexposed group as joint reference category to permit evaluation of interaction on both an additive and multiplicative scale.
Brain Natriuretic Peptide between Traditional and Nontraditional Risk Factors in Hemodialysis Patients: Analysis of Cardiovascular Mortality in a Two-Year Follow-Up
Authors: Selim G. , Stojceva-Taneva O. , Spasovski G. , Georgievska-Ismail L. , Zafirovska-Ivanovska B. , Gelev S. , Dzekova P. , Trajcevska L. , Trojacanec-Piponska S. , Sikole A.
Published: July 2011

Background: The ability of brain natriuretic peptide (BNP) together with other traditional and nontraditional risk factors to predict cardiovascular (CV) mortality in hemodialysis (HD) patients has not been well established. The aim of this prospective study was to determine the predictive cutoff values of baseline measurement of BNP along with the known CV disease risk factors to predict all-cause and CV mortality in HD patients. Methods: BNP concentration before HD was measured in 125 prevalent HD patients (age 53.0 ± 13.5 years, HD vintage 75.2 ± 61.0 months). In addition, several traditional CV risk factors (blood pressure, dyslipidemia, diabetes mellitus, body mass index, left ventricular hypertrophy) and uremia/dialysis-related CV risk factors (anemia, calcium and phosphate impairment, malnutrition, inflammation, ultrafiltration, HD duration, Kt/V) were examined. Results: During the 2-year follow-up, we lost 28 out of 125 patients (22.5%), with CV disease (65.7%) being the main cause of mortality. The cutoff point for BNP, as predictor of the clinical outcome, according to the ROC curve was 1,194 pg/ml for CV mortality with sensitivity and specificity of 63 and 65%, respectively (AUC 0.61 and confidence interval (CI) 95% 0.47–0.75). Kaplan-Meier analysis showed that all-cause (log-rank, p = 0.002) and CV mortality (log-rank, p = 0.001) were the cause of a significantly lower survival in patients with a mean BNP >1,200 pg/ml. The univariate Cox regression analysis found the following factors to be predictors of all-cause mortality: hemoglobin (<110 g/l), phosphorus (>1.78 mmol/l), albumin (<40 g/l), C-reactive protein (CRP ≧10 mg/l), BNP (>1,200 pg/ml) and cardiac ejection fraction (≤55%). The multivariate Cox regression analyses demonstrated that only CRP ≧10 mg/l with a hazard ratio (HR) 6.82 (CI 95% 1.86–24.9, p = 0.004) and BNP >1,200 pg/ml with HR 5.79 (CI 95% 1.58–21.3, p = 0.004) were predictors of all-cause mortality. BNP >1,200 pg/ml with HR 13.52 (CI 95% 1.68–108.9, p = 0.014) was found to be an even stronger predictor of CV mortality than CRP ≧10 mg/l with HR 6.53 (CI 95% 1.35–31.6, p = 0.020). Conclusions: Our study pointed out that BNP >1,200 pg/ml as a marker of cardiac dysfunction and CRP ≧10 mg/l as a marker of inflammation identify HD patients at increased risk of CV mortality.
Capnographic Monitoring during Endoscopic Submucosal Dissection with Patients under Deep Sedation: A Prospective, Crossover Trial of Air and Carbon Dioxide Insufflations
Authors: Takano Akihito , Kobayashi Masaaki , Takeuchi Manabu , Hashimoto Satoru , Mizuno Ken-ichi , Narisawa Rintaro , Aoyagi Yutaka
Published: July 2011

Background and Aims: The safety of carbon dioxide (CO2) insufflation has not been fully established for esophageal and gastric endoscopic submucosal dissection (ESD) under deep sedation, because CO2 retention is not only caused by CO2 insufflation but also by the sedation level and the patient’s respiratory status. To clarify the clinical safety of CO2 insufflation, we conducted a crossover trial of air and CO2 insufflations. Methods: A total of 60 patients with early esophageal or gastric cancers underwent ESD during which insufflation was switched from CO2 to air or from air to CO2; transcutaneous partial pressure CO2 (PtcCO2) was monitored in all patients. We also assessed respiratory function, arterial blood gas analysis, and smoking history. Results: Although significant increases in PtcCO2 from baseline were observed, there were no significant differences in PtcCO2 levels during CO2 insufflation compared with levels during air insufflation in groups that received CO2 preceding air or air preceding CO2. All patients underwent ESD safely without adverse events, including 20 patients with subclinical respiratory dysfunction. The sedation protocol was the only significant predictor of CO2 retention, independent of CO2 insufflation. Conclusions: CO2 insufflation can be used as safely as air insufflation during ESD under deep sedation.
Bee Venom-Associated Th1/Th2 Immunoglobulin Class Switching Results in Immune Tolerance of NZB/W F1 Murine Lupus Nephritis
Authors: Lee Hyojung , Lee Eui-joon , Kim Hyunseong , Lee Gihyun , Um Eun-Jin , Kim Youngchul , Lee Boo-Yong , Bae Hyunsu
Published: July 2011

Background/Aims: Bee venom (BV) therapy has been used to treat inflammatory diseases including rheumatoid arthritis in humans and in experimental animals. This study was conducted to examine the therapeutic effect of BV on established lupus nephritis in New Zealand Black/White (NZB/W) F1 female mice. Methods: Beginning at 18 weeks of age, mice were given a subcutaneous injection of either BV (3 mg/kg BW) or an equal volume of saline once a week until the end of the study. To examine the effect of BV on CD4+CD25+Foxp3+ regulatory T cells, splenocytes from NZB/W mice (23 weeks of age) were treated with BV (1 µg/ml) or PBS in the presence of anti-CD3Ε (1 µg/ml) and anti-CD28 antibodies (4 µg/ml) for 48 h. Results: BV administration delayed the development of proteinuria to a significant extent, prevented renal inflammation, reduced tubular damage, and reduced immune deposits in the glomeruli. Interestingly, CD4+CD25+ regulatory T cells were significantly increased in vitro and in vivo after BV treatment. Conclusion: Collectively, the administration of BV that has immune modulating effects represents an applicable treatment of lupus nephritis in NZB/W F1 mice.
Lytic Resistance of Fibrin Containing Red Blood Cells
Authors: Wohner Nikolett , Sótonyi Péter , Machovich Raymund , Szabó László , Tenekedjiev Kiril , Silva Marta M.C.G. , Longstaff Colin , Kolev Krasimir
Published: July 2011

Objective—

Arterial thrombi contain variable amounts of red blood cells (RBCs), which interact with fibrinogen through an eptifibatide-sensitive receptor and modify the structure of fibrin. In this study, we evaluated the modulator role of RBCs in the lytic susceptibility of fibrin.

Methods and Results—

If fibrin is formed at increasing RBC counts, scanning electron microscopy evidenced a decrease in fiber diameter from 150 to 96 nm at 40% (v/v) RBCs, an effect susceptible to eptifibatide inhibition (restoring 140 nm diameter). RBCs prolonged the lysis time in a homogeneous-phase fibrinolytic assay with tissue plasminogen activator (tPA) by up to 22.7±1.6%, but not in the presence of eptifibatide. Confocal laser microscopy using green fluorescent protein–labeled tPA and orange fluorescent fibrin showed that 20% to 40% (v/v) RBCs significantly slowed down the dissolution of the clots. The fluorescent tPA variant did not accumulate on the surface of fibrin containing RBCs at any cell count above 10%. The presence of RBCs in the clot suppressed the tPA-induced plasminogen activation, resulting in 45% less plasmin generated after 30 minutes of activation at 40% (v/v) RBCs.

Conclusion—

RBCs confer lytic resistance to fibrin resulting from modified fibrin structure and impaired plasminogen activation through a mechanism that involves eptifibatide-sensitive fibrinogen-RBC interactions.
Bone Morphogenetic Protein Endothelial Cell Precursor–Derived Regulator Regulates Retinal Angiogenesis In Vivo in a Mouse Model of Oxygen-Induced Retinopathy
Authors: Moreno-Miralles Isabel , Ren Rongqin , Moser Martin , Hartnett Mary Elizabeth , Patterson Cam
Published: July 2011

Objective—

Bone morphogenetic proteins (BMPs) are potently proangiogenic; however, the mechanisms underlying the regulation of vessel development by BMPs are not fully understood. To assess the significance of BMP endothelial cell precursor-derived regulator (BMPER) in blood vessel formation in vivo, we investigated its role in retinal angiogenesis.

Methods and Results—

In a model of oxygen-induced retinopathy,
Bmper
mRNA expression and protein levels are downregulated, correlating with the initiation of Sma and Mad related protein phosphorylation in endothelial cells. Moreover,
Bmper
haploinsufficiency results in an increased rate of retinal revascularization, with retinas from
Bmper
+/− mice displaying increased numbers of branching points and angiogenic sprouts at the leading edge of the newly formed vasculature. Furthermore, although
Bmper
haploinsufficiency does not alter
Bmp
expression, it does lead to an increase in BMP signaling, as evidenced by increased phosphorylated Sma and Mad related protein levels in endothelial cells and increased expression of known BMP target genes.

Conclusion—

These observations provide compelling evidence that BMPER is important in the regulation of BMP signaling and revascularization in the hypoxic retina. These bring forth the possibility of novel therapeutic approaches for pathological angiogenesis based on manipulation of BMP signaling.
Pericyte-Derived MFG-E8 Regulates Pathologic Angiogenesis
Authors: Motegi Sei-ichiro , Leitner Wolfgang W. , Lu Michael , Tada Yayoi , Sárdy Miklós , Wu Chuanjin , Chavakis Triantafyllos , Udey Mark C.
Published: July 2011

Objective—

MFG-E8 (also called lactadherin and SED1) is a secreted glycoprotein that has been previously implicated in enhancement of vascular endothelial growth factor–dependent angiogenesis. Major sources of MFG-E8 in vivo and precise mechanisms of MFG-E8 action remain undetermined. The objective of this study was to identify important sources of MFG-E8 in vivo and further elucidate the role(s) of MFG-E8 in the regulation of angiogenesis.

Methods and Results—

We used knockout mice and anti-MFG-E8 antibodies to study MFG-E8 function in vivo. In melanomas and in retinas of mice with oxygen-induced retinopathy, MFG-E8 colocalized with pericytes rather than endothelial cells, and platelet-derived growth factor receptor β+ pericytes/pericyte precursors purified from tumors contained large amounts of MFG-E8 mRNA. Tumor- and retinopathy-associated angiogenesis was diminished in MFG-E8 knockout mice, and pericyte coverage of neovessels was reduced. Inhibition of MFG-E8 production by 10T1/2 cells (surrogate pericyte/pericyte precursors) using small interfering RNAs and short hairpin RNAs, or inhibition of MFG-E8 action with some anti-MFG-E8 antibodies, selectively attenuated migration in vitro. Significantly, the anti-MFG-E8 antibodies that inhibited 10T1/2 cell migration in vitro also inhibited pathological angiogenesis in vivo.

Conclusion—

These studies strongly implicate MFG-E8 in pericyte/pericyte precursor function and indicate that MFG-E8-directed therapeutics may merit further development.
Induction of Smooth Muscle Cell Migration During Arteriogenesis Is Mediated by Rap2
Authors: Pöling Jochen , Szibor Marten , Schimanski Silvia , Ingelmann Marie-Elisabeth , Rees Wolfgang , Gajawada Praveen , Kochfar Zaber , Lörchner Holger , Salwig Isabelle , Shin Jae-Young , Wiebe Karsten , Kubin Thomas , Warnecke Henning , Braun Thomas
Published: July 2011

Objective—

Collateral artery growth or arteriogenesis is the primary means of the circulatory system to maintain blood flow in the face of major arterial occlusions. Arteriogenesis depends on activation of fibroblast growth factor (FGF) receptors, but relatively little is known about downstream mediators of FGF signaling.

Methods and Results—

We screened for signaling components that are activated in response to administration of FGF-2 to cultured vascular smooth muscle cells (VSMCs) and detected a significant increase of Rap2 but not of other Ras family members, which corresponded to a strong upregulation of Rap2 and C-Raf in growing collaterals from rabbits with femoral artery occlusion. Small interfering RNAs directed against Rap2 did not affect FGF-2 induced proliferation of VSMC but strongly inhibited their migration. Inhibition of FGF receptor-1 (FGFR1) signaling by infusion of a sulfonic acid polymer or infection with a dominant-negative FGFR1 adenovirus inhibited Rap2 upregulation and collateral vessel growth. Similarly, expression of dominant-negative Rap2 blocked arteriogenesis, whereas constitutive active Rap2 enhanced collateral vessel growth.

Conclusion—

Rap2 is part of the arteriogenic program and acts downstream of the FGFR1 to stimulate VSMC migration. Specific modulation of Rap2 might be an attractive target to manipulate VSMC migration, which plays a role in numerous pathological processes.