bluuebunny/crossref_metadata_2025 huggingface dataset:
Syn-extensional granitoids in the Menderes core complex and the late Cenozoic extensional tectonics of the Aegean province
Authors: Dilek Yildirim , Altunkaynak Şafak , Öner Zeynep
Published: October 2009

The Miocene granitoid plutons exposed in the footwalls of major detachment faults in the Menderes core complex in western Anatolia represent syn-extensional intrusions, providing important geochronological and geochemical constraints on the nature of the late Cenozoic magmatism associated with crustal extension in the Aegean province. Ranging in composition from granite, granodiorite to monzonite, these plutons crosscut the extensional deformation fabrics in their metamorphic host rocks but are foliated, mylonitized and cataclastically deformed in shear zones along the detachment faults structurally upward near the surface. Crystallization and cooling ages of the granitoid rocks are nearly coeval with the documented ages of metamorphism and deformation dating back to the latest Oligocene–early Miocene that record tectonic extension and exhumation in the Menderes massif. The Menderes granitoids (MEG) are represented by mainly metaluminous-slightly peraluminous, high-K calc-alkaline and partly shoshonitic rocks with their silica contents ranging from 62.5 to 78.2 wt%. They display similar major and trace element characteristics and overlapping inter-element ratios (Zr/Nb, La/Nb, Rb/Nb, Ce/Y) suggesting common melt sources. Their enrichment in LILE, strong negative anomalies in Ba, Ta, Nb, Sr and Ti and high incompatible element abundances are consistent with derivation of their magmas from a subduction-metasomatized, heterogeneous sub-continental lithospheric mantle source. Fractional crystalization processes and lower to middle crustal contamination also affected the evolution of the MEG magmas. These geochemical characteristics of the MEG are similar to those of the granitoids in the Cyclades to the west and the Rhodope massif to the north. Partial melting of the subduction-metasomatized lithospheric mantle and the overlying lower-middle crust produced the MEG magmas starting in the late Oligocene–early Miocene. The heat and the basaltic material to induce this partial melting were provided by asthenospheric upwelling caused by lithospheric delamination. Rapid slab rollback of the post-Eocene Hellenic subduction zone may have peeled off the base of the subcontinental lithosphere, triggering the inferred lithospheric delamination. Both slab retreat-generated upper plate deformation and magmatically induced crustal weakening led to the onset of the Aegean extension, which has migrated southward through time.
The frictional strength of granular fault gouge: application of theory to the mechanics of low-angle normal faults
Authors: Boulton Carolyn , Davies Tim , McSaveney Mauri
Published: October 2009

There is a persistent body of literature that suggests low-angle normal faults (LANF) form and slip seismically; if true, the effective friction coefficient is much lower (<0.3) than that found in laboratory tests of rock friction (c.0.8) and in low-displacement faults that lack well-developed fault cores. This paper summarizes and discusses the mechanisms proposed to explain the low apparent friction of crustal-scale faults with low resolved shear stresses. Emphasis is placed on differentiating static weakening mechanisms, operating at strain ratesc.10−12s−1–10−15s−1, from dynamic weakening mechanisms, operating at strain rates >10−1s−1. Previous published explanations for low fault friction do not appear to meet the key requirements of (i) reducing both static and dynamic frictional strength of LANF and (ii) operating only along crustal-scale faults. Fault rock assemblages in quartzo-feldspathic continental crust reveal that grain size reduction, or comminution, plays a fundamental role in fault zone development. As a fault accrues displacement, a fault core forms that contains granular material. We postulate that dynamic rock fragmentation occurs during the shearing of confined granular material; dynamic fragmentation is a volume-dependent mechanism responsible for reducing the static and dynamic frictional strengths of faults.
Reconciling short- and long-term measures of extension in continental back arcs: heat flux, crustal structure and rotations within central North Island, New Zealand
Authors: Stern T. A.
Published: October 2009

Geodetic, palaeomagnetic and andesite-age data all point to a fan-like opening of central North Island, New Zealand, in the past 5 Ma. Palaeomagnetic rotation rates for the eastern North Island are
c.
6° Ma
−1
and this is accompanied by back-arc extension of up to 19 mm a
−1
at the Bay of Plenty coast and lesser values further south. Although the geodetic observations only span a decade, they show a remarkable consistency with the palaeomagnetic and volcanic arc migration data that span 5 Ma. A fan-like pattern of extension in central North Island is implied, similar to that seen in other continental back-arcs. When rapid fan-like openings do occur, they are likely to be accompanied by extreme thermal events. Heat flux from the central North Island occurs at one of the highest continental rates recorded:
c.
26 MW per km of strike of volcanic zone, or 4.3 GW in total. Prior to the Pliocene extension and rotation, central North Island had a
c.
20 Ma history of compression and overthrusting. It is proposed that thickening, then subsequent detachment of mantle lithosphere during this phase had a role to play in the Pliocene back-arc opening and the consequent extreme heat flux.
Timing and nature of formation of the Ios metamorphic core complex, southern Cyclades, Greece
Authors: Thomson Stuart N. , Ring Uwe , Brichau Stephanie , Glodny Johannes , Will Thomas M.
Published: October 2009

We apply low-temperature thermochronology, Rb/Sr geochronology, petrological data, and structural mapping to constrain the timing and kinematics of the Ios metamorphic core complex. Top-to-north extension in the lower plate Headland Shear Zone was active at 18–19 Ma under metamorphic conditions of 475–610 °C and 0.65–1.1 GPa. The South Cyclades Shear Zone/Ios Detachment Fault (SCSZ/IDF) system shows top-to-south extensional shear active at
c.
19 Ma at 380–550 °C, with local top-to-north bands. Extensional shear above the SCSZ/IDF is dominantly top-to-south to top-to-SW.
PT
estimates from an eclogite boudin constrain Eocene high-pressure metamorphism to 430–560 °C and 1.21±0.42 GPa to 0.66±0.37 GPa. Similar low-temperature thermochronometric ages across Ios demonstrate that ductile extensional movement ceased by
c.
15 Ma. Exhumation to shallow crustal levels took place between
c.
15 and 9 Ma at cooling rates of up to 120 °C Ma
−1
with a slow down to <20 °C Ma
−1
between 12 and 9 Ma, most likely accommodated by extensional slip at rates of
c.
3 km Ma
−1
along the top-to-SW Coastal Fault System. We propose a model of bivergent extension for exhumation of the Ios core complex between 19 and 9 Ma, with Ios forming a secondary antithetic top-to-south to top-to-SW extensional fault system to a more dominant top-to-north Naxos/Paros detachment system.
Cenozoic tectonic evolution of Naxos Island through a multi-faceted approach of fission-track analysis
Authors: Seward Diane , Vanderhaeghe Olivier , Siebenaller Luc , Thomson Stuart , Hibsch Christian , Zingg Anatol , Holzner Patrick , Ring Uwe , Duchêne Stephanie
Published: October 2009

New zircon and apatite fission-track ages obtained on samples from all lithotectonic units exposed on Naxos Island are presented. Zircon ages of the exhumed metamorphic rocks range from 25.2 to 9.3 Ma and from 13.0 to 6.4 Ma for apatite. Zircon track-length analysis distinguishes partial overprinting of an earlier event (M
1
) in the south. Northwards no overprint is seen and the ages there represent rapid exhumation since
c.
12 Ma. Both zircon and apatite ages are slightly older toward the north of the island probably due to variation of the geotherm in the proximity of the fault.

Zircon fission-track ages of the granodiorite range from 13.7 to 12.2 Ma are statistically identical to previously determined U–Pb ages. Apatite fission-track ages however, yield a younging trend from south to north from 12.9 to 9.0 Ma. This could be due to differential depth of emplacement and/or to differential exhumation during tectonic unroofing by a top-to-the north detachment.

Fission-track ages on detrital grains in Lower Miocene sediments indicate a source not identified within the present outcropping rocks of Naxos. Ages on boulders and grains in the Middle to Upper Miocene sediments point to rapid erosion until about 8.5–7 Ma.
Chloride Channels: Often Enigmatic, Rarely Predictable
Authors: Duran Charity , Thompson Christopher H. , Xiao Qinghuan , Hartzell H. Criss
Published: October 2009

Until recently, anion (Cl−) channels have received considerably less attention than cation channels. One reason for this may be that many Cl−channels perform functions that might be considered cell-biological, like fluid secretion and cell volume regulation, whereas cation channels have historically been associated with cellular excitability, which typically happens more rapidly. In this review, we discuss the recent explosion of interest in Cl−channels, with special emphasis on new and often surprising developments over the past five years. This is exemplified by the findings that more than half of the ClC family members are antiporters, and not channels, as was previously thought, and that bestrophins, previously prime candidates for Ca2+-activated Cl−channels, have been supplanted by the newly discovered anoctamins and now hold a tenuous position in the Cl−channel world.
A Conversation with Rita Levi-Montalcini
Authors: Chao Moses V.
Published: October 2009

There are very few proven theories that exist in biology. One that has stood the test of time is the neurotrophic theory. It explains why only half of the neurons produced early in development are needed to form a functional nervous system. The explanation came from the discovery of nerve growth factors (NGFs), which help nourish neurons, guide their axons to their proper connections, and prevent cell death. Rita Levi-Montalcini, who formulated this idea, celebrated her 100th birthday on April 22, 2009 in Rome. I had the opportunity to interview her at the European Brain Research Institute (EBRI) in September 2008, which forms the basis of this article. Shortly after the interview, Rita attended the International NGF meeting, held in the Upper Galilee region of Israel (Kfar Blum, Israel). Despite her age, she traveled to the meeting by flying to Tel Aviv and taking a 4-h car ride to the conference site. Remarkably, she participated in the meeting by giving a 30-min talk and sponsoring a poster (see Figure 1 ).
Role of the AMPKγ3 isoform in hypoxia-stimulated glucose transport in glycolytic skeletal muscle
Authors: Deshmukh Atul S. , Glund Stephan , Tom Robby Z. , Zierath Juleen R.
Published: October 2009

Skeletal muscle glucose transport is regulated via the canonical insulin-signaling cascade as well as by energy-sensing signals. 5′-AMP-activated protein kinase (AMPK) has been implicated in the energy status regulation of glucose transport. We determined the role of the AMPKγ3 isoform in hypoxia-mediated energy status signaling and glucose transport in fast-twitch glycolytic extensor digitorum longus (EDL) muscle from AMPKγ3-knockout (KO) mice and wild-type mice. Although hypoxia increased glucose transport ( P < 0.001) in wild-type mice, this effect was attenuated in AMPKγ3-KO mice (45% reduction, P < 0.01). The role of Ca2+-mediated signaling was tested using the Ca2+/calmodulin competitive inhibitor KN-93. KN-93 exposure reduced hypoxia-mediated glucose transport in AMPKγ3-KO and wild-type mice ( P < 0.05). To further explore the underlying signaling mechanisms, phosphorylation of CaMKII, AMPK, ACC, and TBC1D1/D4 as well as isoform-specific AMPK activity was determined. Basal and hypoxia-mediated phosphorylation of CaMKII, AMPK, and ACC as well as α1- and α2-associated AMPK activity was comparable between AMPKγ3-KO and wild-type mice. KN-93 reduced hypoxia-mediated CaMKII phosphorylation in AMPKγ3-KO and wild-type mice ( P < 0.05), whereas phosphorylation of AMPK and ACC as well as α1- and α2-associated AMPK activity was unaltered. Hypoxia increased TBC1D1/D4 phosphorylation in AMPKγ3-KO and wild-type mice ( P < 0.001). KN-93 exposure prevented this effect in AMPKγ3-KO, but not in wild-type mice. Taken together, we provide direct evidence for a role of the AMPKγ3 isoform in hypoxia-mediated glucose transport in glycolytic muscle. Moreover, hypoxia-mediated TBC1D1/D4 phosphorylation was uncoupled from glucose transport in AMPKγ3-KO mice, indicating that TBC1D1/D4-independent mechanisms contribute to glucose transport in skeletal muscle.
Long-term Fenretinide treatment prevents high-fat diet-induced obesity, insulin resistance, and hepatic steatosis
Authors: Preitner Frederic , Mody Nimesh , Graham Timothy E. , Peroni Odile D. , Kahn Barbara B.
Published: October 2009

The synthetic retinoid Fenretinide (FEN) increases insulin sensitivity in obese rodents and is in early clinical trials for treatment of insulin resistance in obese humans with hepatic steatosis (46). We aimed to determine the physiological mechanisms for the insulin-sensitizing effects of FEN. Wild-type mice were fed a high-fat diet (HFD) with or without FEN from 4–5 wk to 36–37 wk of age (preventive study) or following 22 wk of HF diet-induced obesity (12 wk intervention study). Retinol-binding protein-4 (RBP4) knockout mice were also fed the HFD with or without FEN in a preventive study. FEN had minimal effects on HFD-induced body weight gain but markedly reduced HFD-induced adiposity and hyperleptinemia in both studies. FEN-HFD mice gained epididymal fat but not subcutaneous or visceral fat mass in contrast to HFD mice without FEN. FEN did not have a measurable effect on energy expenditure, food intake, physical activity, or stool lipid content. Glucose infusion rate during hyperinsulinemic-euglycemic clamp was reduced 86% in HFD mice compared with controls and was improved 3.6-fold in FEN-HFD compared with HFD mice. FEN improved insulin action on glucose uptake and glycogen levels in muscle, insulin-stimulated suppression of hepatic glucose production, and suppression of serum FFA levels in HFD mice. Remarkably, FEN also reduced hepatic steatosis. In RBP4 knockout mice, FEN reduced the HFD-induced increase in adiposity and hyperleptinemia. In conclusion, long-term therapy with FEN partially prevents or reverses obesity, insulin resistance, and hepatic steatosis in mice on HFD. The anti-adiposity effects are independent of the RBP4 lowering effect.
Changed mitochondrial function by pre- and/or postpartum diet alterations in sheep
Authors: Jørgensen Wenche , Gam Christiane , Andersen Jesper Løvind , Schjerling Peter , Scheibye-Knudsen Morten , Mortensen Ole Hartvig , Grunnet Niels , Nielsen Mette Olaf , Quistorff Bjørn
Published: October 2009

In a sheep model, we investigated diet effects on skeletal muscle mitochondria to look for fetal programming. During pregnancy, ewes were fed normally (N) or were 50% food restricted (L) during the last trimester, and lambs born to these ewes received a normal (N) or a high-fat diet (H) for the first 6 mo of life. We examined mitochondrial function in permeabilized muscle fibers from the lambs at 6 mo of age (adolescence) and after 24 mo of age (adulthood). The postpartum H diet for the lambs induced an ∼30% increase ( P < 0.05) of mitochondrial V̇o2maxand an ∼50% increase ( P < 0.05) of the respiratory coupling ratio (RCR) combined with lower levels of UCP3 and PGC-1α mRNA levels ( P < 0.05). These effects proved to be reversible by a normal diet from 6 to 24 mo of age. However, at 24 mo, a long-term effect of the maternal gestational diet restriction (fetal programming) became evident as a lower V̇o2max(∼40%, P < 0.05), a lower state 4 respiration (∼40%, P < 0.05), and lower RCR (∼15%, P < 0.05). Both PGC-1α and UCP3 mRNA levels were increased ( P < 0.05). Two analyzed muscles were affected differently, and muscle rich in type I fibers was more susceptible to fetal programming. We conclude that fetal programming, seen as a reduced V̇o2maxin adulthood, results from gestational undernutrition. Postnatal high-fat diet results in a pronounced RCR and V̇o2maxincrease in adolescence. However, these effects are reversible by diet correction and are not maintained in adulthood.
Novel Lipogenic Enzyme ELOVL7 Is Involved in Prostate Cancer Growth through Saturated Long-Chain Fatty Acid Metabolism
Authors: Tamura Kenji , Makino Asami , Hullin-Matsuda Françoise , Kobayashi Toshihide , Furihata Mutsuo , Chung Suyoun , Ashida Shingo , Miki Tsuneharu , Fujioka Tomoaki , Shuin Taro , Nakamura Yusuke , Nakagawa Hidewaki
Published: October 2009

A number of epidemiologic studies have indicated a strong association between dietary fat intake and prostate cancer development, suggesting that lipid metabolism plays some important roles in prostate carcinogenesis and its progression. In this study, through our genome-wide gene expression analysis of clinical prostate cancer cells, we identified a novel lipogenic gene, ELOVL7, coding a possible long-chain fatty acid elongase, as overexpressed in prostate cancer cells. ELOVL7 expression is regulated by the androgen pathway through SREBP1, as well as other lipogenic enzymes. Knockdown of ELOVL7 resulted in drastic attenuation of prostate cancer cell growth, and it is notable that high-fat diet promoted the growth of in vivo tumors of ELOVL7-expressed prostate cancer. In vitro fatty acid elongation assay and fatty acid composition analysis indicated that ELOVL7 was preferentially involved in fatty acid elongation of saturated very-long-chain fatty acids (SVLFA, C20:0∼). Lipid profiles showed that knockdown of ELOVL7 in prostate cancer cells affected SVLFAs in the phospholipids and the neutral lipids, such as cholesterol ester. Focusing on cholesterol ester as a source of de novo steroid synthesis, we show that ELOVL7 affected de novo androgen synthesis in prostate cancer cells. These findings suggest that EVOLV7 could be involved in prostate cancer growth and survival through the metabolism of SVLFAs and their derivatives, could be a key molecule to elucidate the association between fat dietary intake and prostate carcinogenesis, and could also be a promising molecular target for development of new therapeutic or preventive strategies for prostate cancers. [Cancer Res 2009;69(20):8133–40]
Immunoselection of Breast and Ovarian Cancer Cells with Trastuzumab and Natural Killer Cells: Selective Escape of CD44high/CD24low/HER2low Breast Cancer Stem Cells
Authors: Reim Florian , Dombrowski Yvonne , Ritter Cathrin , Buttmann Mathias , Häusler Sebastian , Ossadnik Monika , Krockenberger Mathias , Beier Dagmar , Beier Christoph P. , Dietl Johannes , Becker Jürgen C. , Hönig Arnd , Wischhusen Jörg
Published: October 2009

Although trastuzumab (Herceptin) has substantially improved the overall survival of patients with mammary carcinomas, even initially well-responding tumors often become resistant. Because natural killer (NK) cell–mediated antibody-dependent cell-mediated cytotoxicity (ADCC) is thought to contribute to the therapeutic effects of trastuzumab, we have established a cell culture system to select for ADCC-resistant SK-OV-3 ovarian cancer and MCF7 mammary carcinoma cells. Ovarian cancer cells down-regulated HER2 expression, resulting in a more resistant phenotype. MCF7 breast cancer cells, however, failed to develop resistance in vitro. Instead, treatment with trastuzumab and polyclonal NK cells resulted in the preferential survival of individual sphere-forming cells that displayed a CD44highCD24low “cancer stem cell–like” phenotype and expressed significantly less HER2 compared with non–stem cells. Likewise, the CD44highCD24low population was also found to be more immunoresistant in SK-BR3, MDA-MB231, and BT474 breast cancer cell lines. When immunoselected MCF7 cells were then re-expanded, they mostly lost the observed phenotype to regenerate a tumor cell culture that displayed the initial HER2 surface expression and ADCC-susceptibility, but was enriched in CD44highCD24low cancer stem cells. This translated into increased clonogenicity in vitro and tumorigenicity in vivo. Thus, we provide evidence that the induction of ADCC by trastuzumab and NK cells may spare the actual tumor-initiating cells, which could explain clinical relapse and progress. Moreover, our observation that the “relapsed” in vitro cultures show practically identical HER2 surface expression and susceptibility toward ADCC suggests that the administration of trastuzumab beyond relapse might be considered, especially when combined with an immune-stimulatory treatment that targets the escape variants. [Cancer Res 2009;69(20):8058–66]
Altered Runx1 Subnuclear Targeting Enhances Myeloid Cell Proliferation and Blocks Differentiation by Activating a miR-24/MKP-7/MAPK Network
Authors: Zaidi Sayyed K. , Dowdy Christopher R. , van Wijnen Andre J. , Lian Jane B. , Raza Azra , Stein Janet L. , Croce Carlo M. , Stein Gary S.
Published: October 2009

Disruption of Runx1/AML1 subnuclear localization, either by a single amino acid substitution or by a chromosomal translocation [e.g., t(8;21)], is linked to the etiology of acute myeloid leukemia (AML). Here, we show that this defect induces a select set of micro-RNAs (miR) in myeloid progenitor cells and AML patients with t(8;21). Both Runx1 and the t(8;21)-encoded AML1-ETO occupy the miR-24-23-27 locus and reciprocally control miR-24 transcription. miR-24 directly downregulates mitogen-activated protein kinase (MAPK) phosphatase-7 and enhances phosphorylation of both c-jun-NH2-kinase and p38 kinases. Expression of miR-24 stimulates myeloid cell growth, renders proliferation independent of interleukin-3, and blocks granulocytic differentiation. Thus, compromised Runx1 function induces a miR-dependent mechanism that, through MAPK signaling, enhances myeloid proliferation but blocks differentiation—key steps that contribute to leukemia. [Cancer Res 2009;69(21):8249–55]
microRNA-21 Negatively Regulates Cdc25A and Cell Cycle Progression in Colon Cancer Cells
Authors: Wang Peng , Zou Fangdong , Zhang Xiaodong , Li Hua , Dulak Austin , Tomko Robert J. , Lazo John S. , Wang Zhenghe , Zhang Lin , Yu Jian
Published: October 2009

microRNAs (miRNA) are small noncoding RNAs that participate in diverse biological processes by suppressing target gene expression. Altered expression of miR-21 has been reported in cancer. To gain insights into its potential role in tumorigenesis, we generated miR-21 knockout colon cancer cells through gene targeting. Unbiased microarray analysis combined with bioinformatics identified cell cycle regulator Cdc25A as a miR-21 target. miR-21 suppressed Cdc25A expression through a defined sequence in its 3′-untranslated region. We found that miR-21 is induced by serum starvation and DNA damage, negatively regulates G1-S transition, and participates in DNA damage–induced G2-M checkpoint through down-regulation of Cdc25A. In contrast, miR-21 deficiency did not affect apoptosis induced by a variety of commonly used anticancer agents or cell proliferation under normal cell culture conditions. Furthermore, miR-21 was found to be underexpressed in a subset of Cdc25A-overexpressing colon cancers. Our data show a role of miR-21 in modulating cell cycle progression following stress, providing a novel mechanism of Cdc25A regulation and a potential explanation of miR-21 in tumorigenesis. [Cancer Res 2009;69(20):8157–65]
Glioblastoma Cells Require Glutamate Dehydrogenase to Survive Impairments of Glucose Metabolism or Akt Signaling
Authors: Yang Chendong , Sudderth Jessica , Dang Tuyen , Bachoo Robert G. , McDonald Jeffrey G. , DeBerardinis Ralph J.
Published: October 2009

Oncogenes influence nutrient metabolism and nutrient dependence. The oncogene c-Myc stimulates glutamine metabolism and renders cells dependent on glutamine to sustain viability (“glutamine addiction”), suggesting that treatments targeting glutamine metabolism might selectively kill c-Myc–transformed tumor cells. However, many current or proposed cancer therapies interfere with the metabolism of glucose, not glutamine. Here, we studied how c-Myc–transformed cells maintained viability when glucose metabolism was impaired. In SF188 glioblastoma cells, glucose deprivation did not affect net glutamine utilization but elicited a switch in the pathways used to deliver glutamine carbon to the tricarboxylic acid cycle, with a large increase in the activity of glutamate dehydrogenase (GDH). The effect on GDH resulted from the loss of glycolysis because it could be mimicked with the glycolytic inhibitor 2-deoxyglucose and reversed with a pyruvate analogue. Furthermore, inhibition of Akt signaling, which facilitates glycolysis, increased GDH activity whereas overexpression of Akt suppressed it, suggesting that Akt indirectly regulates GDH through its effects on glucose metabolism. Suppression of GDH activity with RNA interference or an inhibitor showed that the enzyme is dispensable in cells able to metabolize glucose but is required for cells to survive impairments of glycolysis brought about by glucose deprivation, 2-deoxyglucose, or Akt inhibition. Thus, inhibition of GDH converted these glutamine-addicted cells to glucose-addicted cells. The findings emphasize the integration of glucose metabolism, glutamine metabolism, and oncogenic signaling in glioblastoma cells and suggest that exploiting compensatory pathways of glutamine metabolism can improve the efficacy of cancer treatments that impair glucose utilization. [Cancer Res 2009;69(20):7986–93]
Lung Adenocarcinoma with EGFR Amplification Has Distinct Clinicopathologic and Molecular Features in Never-Smokers
Authors: Sholl Lynette M. , Yeap Beow Y. , Iafrate A. John , Holmes-Tisch Alison J. , Chou Yi-Ping , Wu Ming-Tsang , Goan Yih-Gang , Su Li , Benedettini Elisa , Yu Jian , Loda Massimo , Jänne Pasi A. , Christiani David C. , Chirieac Lucian R.
Published: October 2009

In a subset of lung adenocarcinomas, the epidermal growth factor receptor (EGFR) is activated by kinase domain mutations and/or gene amplification, but the interaction between the two types of abnormalities is complex and unclear. For this study, we selected 99 consecutive never-smoking women of East Asian origin with lung adenocarcinomas that were characterized by histologic subtype. We analyzed EGFR mutations by PCR-capillary sequencing, EGFR copy number abnormalities by fluorescence and chromogenic in situ hybridization and quantitative PCR, and EGFR expression by immunohistochemistry with both specific antibodies against exon 19 deletion–mutated EGFR and total EGFR. We compared molecular and clinicopathologic features with disease-free survival. Lung adenocarcinomas with EGFR amplification had significantly more EGFR exon 19 deletion mutations than adenocarcinomas with disomy, and low and high polysomy (100% versus 54%, P = 0.009). EGFR amplification occurred invariably on the mutated and not the wild-type allele (median mutated/wild-type ratios 14.0 versus 0.33, P = 0.003), was associated with solid histology (P = 0.008), and advanced clinical stage (P = 0.009). EGFR amplification was focally distributed in lung cancer specimens, mostly in regions with solid histology. Patients with EGFR amplification had a significantly worse outcome in univariate analysis (median disease-free survival, 16 versus 31 months, P = 0.01) and when adjusted for stage (P = 0.027). Lung adenocarcinomas with EGFR amplification have a unique association with exon 19 deletion mutations and show distinct clinicopathologic features associated with a significantly worsened prognosis. In these cases, EGFR amplification is heterogeneously distributed, mostly in areas with a solid histology. [Cancer Res 2009;69(21):8341–8]
Phase I Biodistribution and Pharmacokinetic Study of Lewis Y–Targeting Immunoconjugate CMD-193 in Patients with Advanced Epithelial Cancers
Authors: Herbertson Rebecca A. , Tebbutt Niall C. , Lee Fook-Thean , MacFarlane David J. , Chappell Bridget , Micallef Noel , Lee Sze-Ting , Saunder Timothy , Hopkins Wendie , Smyth Fiona E. , Wyld David K. , Bellen John , Sonnichsen Daryl S. , Brechbiel Martin W. , Murone Carmel , Scott Andrew M.
Published: October 2009

Purpose: This phase I study explored the biodistribution and pharmacokinetics of the immunoconjugate CMD-193 [a humanized anti–Lewis Y (Ley) antibody conjugated with calicheamicin in patients with advanced cancers expressing the Ley antigen.

Experimental Design: The primary objectives were to determine biodistribution and pharmacokinetics of CMD-193. Secondary objectives included response rates and change in tumor metabolism. Patients with progressive, measurable, and Ley positive malignancies were eligible for enrollment in one of two dose cohorts, 1.0 and 2.6 mg/m2. The first cycle was trace labeled with 111In for biodistribution assessment using γ camera imaging. Subsequent cycles were administered every 3 weeks up to a maximum of six cycles, depending on toxicity and response. Pharmacokinetic analysis was based on radioassay and ELISA.

Results: Nine patients were enrolled in the study. Biodistribution images showed initial blood pool activity, followed by markedly increased hepatic uptake by day 2, and fast blood clearance in all patients. There was low uptake in tumor in all patients. The overall T½β of 111In-CMD-193 was 102.88 ± 35.67 hours, with no statistically significant difference between the two dose levels. One patient had a partial metabolic response on 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG PET) after four cycles, but no radiological responses were observed. Myelosuppression and effects on liver function were the most significant adverse effects.

Conclusions: CMD-193 shows rapid blood clearance and increased hepatic uptake compared with prior studies of the parental antibody hu3S193. These results highlight the importance of biodistribution and pharmacodynamic assessment in early phase studies of new biologics to assist in clinical development. (Clin Cancer Res 2009;15(21):6709–15)
Interferon-γ–Dependent Infiltration of Human T Cells into Neuroblastoma TumorsIn vivo
Authors: Reid Gregor S.D. , Shan Xiaochuan , Coughlin Christina M. , Lassoued Wiem , Pawel Bruce R. , Wexler Leonard H. , Thiele Carol J. , Tsokos Maria , Pinkus Jack L. , Pinkus Geraldine S. , Grupp Stephan A. , Vonderheide Robert H.
Published: October 2009

Purpose: To investigate the impact of interferon-γ–mediated upregulation of major histocompatibility complex class I expression on tumor-specific T-cell cytotoxicity and T-cell trafficking into neuroblastoma tumors in vivo.

Experimental Design: Restoration of major histocompatibility complex class I expression by interferon-γ treatment enhances killing of neuroblastoma cells. To understand the potential of this approach in vivo, we developed a novel model of neuroblastoma in which NOD/scid/IL2Rγnull immunodeficient mice are engrafted with both human T cells and tumor cells.

Results: Here, we show enhanced killing of neuroblastoma cells by patient-derived, tumor-specific T cells in vitro. In addition, interferon-γ treatment in vivo induces efficient upregulation of major histocompatibility complex class I expression on neuroblastoma tumor cells, and this is accompanied by significantly enhanced infiltration of T cells into the tumor. In a pilot clinical trial in patients with high-risk neuroblastoma, we similarly observed augmented T-cell trafficking into neuroblastoma nests in tumor biopsy specimens obtained from patients after 5 days of systemic interferon-γ therapy.

Conclusions: Interferon-γ overcomes critical obstacles to the killing of human neuroblastoma cells by specific T cells. Together, these findings provide a rationale for the further testing of interferon-γ as an approach for improving the efficacy of T cell–based therapies for neuroblastoma and other major histocompatibility complex class I–deficient malignancies. In addition, we describe a model that may expedite the preclinical screening of approaches aimed at augmenting T-cell trafficking into human tumors. (Clin Cancer Res 2009;15(21):6602–8)
The Novel Expanded Porphyrin, Motexafin Gadolinium, Combined with [90Y]Ibritumomab Tiuxetan for Relapsed/Refractory Non-Hodgkin's Lymphoma: Preclinical Findings and Results of a Phase I Trial
Authors: Evens Andrew M. , Spies William G. , Helenowski Irene B. , Patton David , Spies Stewart , Jovanovic Borko D. , Miyata Sarah , Hamilton Elizabeth , Variakojis Daina , Chen Jun , Naumovski Louie , Rosen Steven T. , Winter Jane N. , Miller Richard A. , Gordon Leo I.
Published: October 2009

Purpose: Therapeutic strategies to enhance the efficacy of radioimmunotherapy have not been explored. Motexafin gadolinium is a novel anticancer agent that targets redox-dependent pathways and enhances sensitivity of tumor cells to ionizing radiation.

Experimental Design: We did preclinical studies examining motexafin gadolinium combined with rituximab and/or radiation in lymphoma cells. We subsequently completed a phase I clinical trial combining escalating doses of motexafin gadolinium concurrently with standard [90Y]ibritumomab tiuxetan for patients with relapsed/refractory non-Hodgkin's lymphoma.

Results: In HF1 lymphoma cells, motexafin gadolinium and rituximab resulted in synergistic cytotoxicity (combination index, 0.757) through a mitochondrial-mediated caspase-dependent pathway, whereas cell death in Ramos and SUDHL4 cells was additive. Motexafin gadolinium/rituximab combined with radiation (1-3 Gy) resulted in additive apoptosis. Twenty-eight of 30 patients were evaluable on the phase I clinical trial. Median age was 65 years (47-87 years), and histologies were marginal-zone (n = 1), mantle-cell (n = 3), diffuse large cell (n = 6), and follicular lymphoma (n = 18). Of all patients, 86% were rituximab refractory. Therapy was well tolerated, and no dose-limiting toxicity was seen. Overall response rate was 57% [complete remission (CR), 43%], with median time–to–treatment failure of 10 months (1-48+ months) and median duration-of-response of 17 months. Of note, all responses were documented at 4 weeks. Furthermore, in rituximab-refractory follicular lymphoma (n = 14), overall response rate was 86% (CR, 64%), with a median time–to–treatment failure of 14 months (2-48+ months).

Conclusions: This represents the first report of a novel agent to be combined safely concurrently with radioimmunotherapy. Furthermore, tumor responses with [90Y]ibritumomab tiuxetan/motexafin gadolinium were prompt with a high rate of CRs, especially in rituximab-refractory follicular lymphoma. (Clin Cancer Res 2009;15(20):6462–71)
Comparative Impact of Trastuzumab and Cyclophosphamide on HER-2–Positive Human Breast Cancer Xenografts
Authors: Francia Giulio , Man Shan , Lee Chyan-Jang , Lee Christina R. , Xu Ping , Mossoba Miriam E. , Emmenegger Urban , Medin Jeffrey A. , Kerbel Robert S.
Published: October 2009

Purpose: Metronomic chemotherapy is a minimally toxic and frequently effective new treatment strategy that is beginning to show promising phase II clinical trial results, particularly for metastatic breast cancer when combined with various molecularly targeted antitumor agents. Here, we assessed a treatment strategy that uses trastuzumab plus daily oral metronomic cyclophosphamide on metastatic Her-2–positive human breast cancer models.

Experimental Design: Treatments were initiated on orthotopic transplanted primary tumors as well as established visceral metastatic disease of two independent Her-2–positive breast cancer models, both independently derived from the human MDA-MB-231 breast cancer cell line. Outcome was assessed by noninvasive measurements of tumor cell–secreted human choriogonadotropin in the urine as a surrogate marker of relative tumor burden, or by whole body bioluminescent imaging, in addition to prolongation of survival.

Results: Orthotopic primary tumors responded to trastuzumab monotherapy with significant growth delays, whereas minimal antitumor effect was observed when mice with metastatic disease were treated. Nevertheless, trastuzumab showed a benefit in this latter setting when combined with metronomic low-dose cyclophosphamide as assessed by prolongation of survival. This benefit was similar to trastuzumab plus maximum tolerated dose cyclophosphamide, but was associated with lesser toxicity.

Conclusions: Trastuzumab combined with metronomic cyclophosphamide may be an effective long-term maintenance strategy for the treatment of Her-2–positive metastatic breast cancer. (Clin Cancer Res 2009;15(20):6358–66)
Increased Ectonucleotidase Expression and Activity in Regulatory T Cells of Patients with Head and Neck Cancer
Authors: Mandapathil Magis , Szczepanski Miroslaw J. , Szajnik Marta , Ren Jin , Lenzner Diana E. , Jackson Edwin K. , Gorelik Elieser , Lang Stephan , Johnson Jonas T. , Whiteside Theresa L.
Published: October 2009

Purpose: Regulatory T cell (Treg) frequency and activity are increased in cancer patients and play a major role in tumor escape. Although disease progression is favored by the presence of Treg, mechanisms used by Treg to suppress antitumor immunity are unknown. The ectonucleotidases CD39 and CD73 are expressed in Treg and convert ATP into immunosuppressive adenosine. In this study, the involvement of the adenosinergic pathway in Treg-mediated suppression in head and neck squamous cell carcinoma (HNSCC) patients was evaluated.

Experimental Design: HNSCC patients with an active disease (n = 19) and patients with no evident disease after therapy (n = 14) were studied. Ectonucleotidase expression on CD4+ T cells and CD4+CD25high Treg was evaluated by flow cytometry and compared with normal controls. Ectonucleotidase activity was also compared within these three groups. The data were analyzed for associations of ectonucleotidase expression/function with disease stage.

Results: The percentages and expression levels of CD39 and CD73 in CD4+ T cells and Treg were greater in HNSCC than in normal controls and highest in patients with no evident disease. Patients' Treg hydrolyzed ATP at higher rates and produced higher levels of adenosine than normal controls' Treg. The increased frequency and enzymatic activity of CD4+CD39+ cells corresponded to increased adenosine-mediated suppression of effector T cells, which was partly inhibited by ARL67156, an ectonucleotidase inhibitor, and by ZM241385, a selective A2a/A2b receptor antagonist.

Conclusions: CD39+ Treg frequency and adenosine-mediated suppression are significantly increased in HNSCC patients. The adenosinergic pathway is involved in Treg-mediated immunosuppression in cancer and its attenuation could be a promising immunotherapeutic strategy for patients with HNSCC. (Clin Cancer Res 2009;15(20):6348–57)
Overexpression of Prostate-Specific TMPRSS2(exon 0)-ERG Fusion Transcripts Corresponds with Favorable Prognosis of Prostate Cancer
Authors: Hermans Karin G. , Boormans Joost L. , Gasi Delila , van Leenders Geert J.H.L. , Jenster Guido , Verhagen Paul C.M.S. , Trapman Jan
Published: October 2009

Purpose: To gain insight in the mechanism and clinical relevance of TMPRSS2-ERG expression in prostate cancer, we determined the specific characteristics of fusion transcripts starting at TMPRSS2 exon 1 and at a more upstream and less characterized exon 0.

Experimental Design: We used quantitative PCR analysis to investigate expression of wild-type TMPRSS2(exon 0) and TMPRSS2(exon 1) and of ERG fusion transcripts. Expression was tested in normal tissue samples, in prostate cancer cell lines and xenografts, and in fresh-frozen clinical prostate cancer samples (primary tumors and recurrences). Expression in clinical samples was correlated with disease progression.

Results: TMPRSS2(exon 0) and TMPRSS2(exon 1) transcripts were similarly androgen regulated in prostate cancer cell lines, but the expression levels of TMPRSS2(exon 1) were much higher. Comparison of expression in different tissues showed TMPRSS2(exon 0) expression to be much more prostate specific. In androgen receptor–positive prostate cancer xenografts, TMPRSS2(exon 1) transcripts were expressed at similar levels, but TMPRSS2(exon 0) transcripts were expressed at very variable levels. The same phenomenon was observed for TMPRSS2-ERG fusion transcripts. In clinical prostate cancers, the expression of TMPRSS2(exon 0)-ERG was even more variable. Expression of TMPRSS2(exon 0)-ERG transcripts was detected in 55% (24 of 44) of gene fusion–positive primary tumors but only in 15% (4 of 27) of gene fusion–positive recurrences and at much lower levels. Furthermore, in primary tumors, expression of TMPRSS2(exon 0)-ERG transcripts was an independent predictor of biochemical progression-free survival.

Conclusion: The expression of TMPRSS2(exon 0)-ERG fusion transcripts in prostate cancer is associated with a less-aggressive biological behavior. (Clin Cancer Res 2009;15(20):6398–403)
A Phase I Dose-Escalation Study of Danusertib (PHA-739358) Administered as a 24-Hour Infusion with and without Granulocyte Colony-Stimulating Factor in a 14-Day Cycle in Patients with Advanced Solid Tumors
Authors: Cohen Roger B. , Jones Suzanne F. , Aggarwal Charu , von Mehren Margaret , Cheng Jonathan , Spigel David R. , Greco F. Anthony , Mariani Mariangela , Rocchetti Maurizio , Ceruti Roberta , Comis Silvia , Laffranchi Bernard , Moll Jurgen , Burris Howard A.
Published: October 2009

Purpose: This study was conducted to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of the i.v. pan-aurora kinase inhibitor PHA-739358, danusertib, in patients with advanced solid tumors.

Experimental Design: In part 1, patients received escalating doses of danusertib (24-hour infusion every 14 days) without filgrastim (granulocyte colony-stimulating factor, G-CSF). Febrile neutropenia was the dose-limiting toxicity without G-CSF. Further dose escalation was done in part 2 with G-CSF. Blood samples were collected for danusertib pharmacokinetics and pharmacodynamics. Skin biopsies were collected to assess histone H3 phosphorylation (pH3).

Results: Fifty-six patients were treated, 40 in part 1 and 16 in part 2. Febrile neutropenia was the dose-limiting toxicity in part 1 without G-CSF. Most other adverse events were grade 1 to 2, occurring at doses ≥360 mg/m2 with similar incidence in parts 1 and 2. The maximum tolerated dose without G-CSF is 500 mg/m2. The recommended phase 2 dose in part 2 with G-CSF is 750 mg/m2. Danusertib showed dose-proportional pharmacokinetics in parts 1 and 2 with a median half-life of 18 to 26 hours. pH3 modulation in skin biopsies was observed at ≥500 mg/m2. One patient with refractory small cell lung cancer (1,000 mg/m2 with G-CSF) had an objective response lasting 23 weeks. One patient with refractory ovarian cancer had 27% tumor regression and 30% CA125 decline.

Conclusions: Danusertib was well tolerated with target inhibition in skin at ≥500 mg/m2. Preliminary evidence of antitumor activity, including a partial response and several occurrences of prolonged stable disease, was seen across a variety of advanced refractory cancers. Phase II studies are ongoing. (Clin Cancer Res 2009;15(21):6694–701)
DNA Ploidy Cytometry Testing for Cervical Cancer Screening in China (DNACIC Trial): a Prospective Randomized, Controlled Trial
Authors: Tong Hua , Shen Rong , Wang ZhuMing , Kan YanJing , Wang YiQuan , Li FengShan , Wang FuZhou , Yang Jie , Guo XiRong ,   for the Mass Cervical Cancer Screening Regimen Group (MACREG)
Published: October 2009

Purpose: This randomized, controlled trial was designed to determine whether the DNA cytometry testing is superior to the conventional cytologic testing for mass cervical cancer screening.

Experimental Design: After approval by the institutional ethics review boards from three separate screening centers, a total of 23,993 Chinese women ages 20 to 65 years were randomly assigned into one of the two groups: a DNA cytometry testing group (11,999 women) and a cytologic testing group (11,994 women). Each woman underwent the other testing after first attending the assigned screening test. Women with positive results after assigned testing additionally underwent colposcopy and human papillomaviruses detections, and those with cervical precancerous or cancerous lesions received appropriate treatment. Sensitivity and specificity estimates were adjusted for verification bias. Analyses were by intention to treat and per protocol ways.

Results: In the cytometric DNA testing group, cervical cancer was diagnosed in 40 subjects, compared with 24 subjects in the cytologic testing group [hazard ratio for the detection of advanced cancer in the DNA cytometry testing group, 0.42; 95% confidence interval (CI), 0.27-0.60]. The sensitivity of the DNA cytometry testing for cervical cancer was 91.7% (95% CI, 64.3-95.8), whereas the sensitivity of cytologic testing was 44.5% (95% CI, 25.2-61.3; P = 0.008). The specificity was 54.1% (95% CI, 31.6-69.0) for DNA cytometry testing and 70.6% (95% CI, 46.8-82.5; P = 0.003) for cytologic testing. The sensitivity of both tests used together was 100%, and the specificity was 91.8%. A total of 187 subjects reported mild to severe adverse events after treatment with positive results in 319 women.

Conclusions: Our results highlight the benefit of the DNA cytometry testing strategy in mass cervical cancer screening with greater sensitivity and positive predicted value than the conventional cytologic testing in developing settings. (Clin Cancer Res 2009;15(20):6438–45)
Reconstitution of Amphiregulin–Epidermal Growth Factor Receptor Signaling in Lung Squamous Cell Carcinomas Activates PTHrP Gene Expression and Contributes to Cancer-Mediated Diseases of the Bone
Authors: Gilmore Jennifer L. , Gonterman Ryan M. , Menon Keshav , Lorch Gwendolen , Riese David J. , Robling Alex , Foley John
Published: October 2009

Parathyroid hormone–related protein (PTHrP) is the causative factor of the paraneoplastic syndrome humoral hypercalcemia of malignancy (HHM) and it also contributes to osteolytic metastases, both of which are common complications of squamous carcinomas of the lung. Inhibition of autocrine epidermal growth factor receptor (EGFR) signaling has been shown to reduce plasma calcium and PTHrP concentrations in two lung squamous cell carcinoma xenograft models of HHM. The purpose of this study was to investigate the mechanism by which EGFR is activated and stimulates PTHrP gene expression in lung squamous carcinoma cell lines. Amphiregulin (AREG) was the only EGFR ligand that could be consistently detected in conditioned media from the SCC lines, and reduction of its expression either by siRNA or by precipitating antibody reduced PTHrP mRNA expression as effectively as EGFR-targeted inhibition. Using siRNA knockdown or inhibitors to upstream regulators of AREG shedding including TACE, Src/Lck, and Gi/o, also reduced PTHrP mRNA expression. We determined that blockade of autocrine AREG-EGFR signaling does not affect PTHrP mRNA stability. Of the three PTHrP promoters (P1, P2, and P3), P1 mRNA could be reduced by nearly 100% with an EGFR inhibitor, and both epidermal growth factor and AREG stimulated P1 mRNA by ∼5-fold. Finally, ectopic expression of EGFR in a receptor-low but AREG-expressing cell line increased PTHrP mRNA levels in vitro, and induced the capability to cause HHM and rapid osteolytic growth in vivo. Taken together, we provide evidence that AREG stimulation of EGFR results in high levels of PTHrP gene expression, contributing to cancer-associated bone pathology. (Mol Cancer Res 2009;7(10):1714–28)