bluuebunny/crossref_metadata_2025 huggingface dataset:
Apelin is necessary for the maintenance of insulin sensitivity
Authors: Yue Patrick , Jin Hong , Aillaud Marissa , Deng Alicia C. , Azuma Junya , Asagami Tomoko , Kundu Ramendra K. , Reaven Gerald M. , Quertermous Thomas , Tsao Philip S.
Published: October 2009

The recently discovered peptide apelin is known to be involved in the maintenance of insulin sensitivity. However, questions persist regarding its precise role in the chronic setting. Fasting glucose, insulin, and adiponectin levels were determined on mice with generalized deficiency of apelin (APKO). Additionally, insulin (ITT) and glucose tolerance tests (GTT) were performed. To assess the impact of exogenously delivered apelin on insulin sensitivity, osmotic pumps containing pyroglutamated apelin-13 or saline were implanted in APKO mice for 4 wk. Following the infusion, ITT/GTTs were repeated and the animals euthanized. Soleus muscles were harvested and homogenized in lysis buffer, and insulin-induced Akt phosphorylation was determined by Western blotting. Apelin-13 infusion and ITTs/GTTs were also performed in obese diabetic db/db mice. To probe the underlying mechanism for apelin's effects, apelin-13 was also delivered to cultured C2C12myotubes. 2-[3H]deoxyglucose uptake and Akt phosphorylation were assessed in the presence of various inhibitors. APKO mice had diminished insulin sensitivity, were hyperinsulinemic, and had decreased adiponectin levels. Soleus lysates had decreased insulin-induced Akt phosphorylation. Administration of apelin to APKO and db/db mice resulted in improved insulin sensitivity. In C2C12myotubes, apelin increased glucose uptake and Akt phosphorylation. These events were fully abrogated by pertussis toxin, compound C, and siRNA knockdown of AMPKα1 but only partially diminished by LY-294002 and not at all by l-NAME. We conclude that apelin is necessary for the maintenance of insulin sensitivity in vivo. Apelin's effects on glucose uptake and Akt phosphorylation are in part mediated by a Giand AMPK-dependent pathway.
Laminar Diversity of Dynamic Sound Processing in Cat Primary Auditory Cortex
Authors: Atencio Craig A. , Schreiner Christoph E.
Published: October 2009

For primary auditory cortex (AI) laminae, there is little evidence of functional specificity despite clearly expressed cellular and connectional differences. Natural sounds are dominated by dynamic temporal and spectral modulations and we used these properties to evaluate local functional differences or constancies across laminae. To examine the layer-specific processing of acoustic modulation information, we simultaneously recorded from multiple AI laminae in the anesthetized cat. Neurons were challenged with dynamic moving ripple stimuli and we subsequently computed spectrotemporal receptive fields (STRFs). From the STRFs, temporal and spectral modulation transfer functions (tMTFs, sMTFs) were calculated and compared across layers. Temporal and spectral modulation properties often differed between layers. On average, layer II/III and VI neurons responded to lower temporal modulations than those in layer IV. tMTFs were mainly band-pass in granular layer IV and became more low-pass in infragranular layers. Compared with layer IV, spectral MTFs were broader and their upper cutoff frequencies higher in layers V and VI. In individual penetrations, temporal modulation preference was similar across layers for roughly 70% of the penetrations, suggesting a common, columnar functional characteristic. By contrast, only about 30% of penetrations showed consistent spectral modulation preferences across layers, indicative of functional laminar diversity or specialization. Since local laminar differences in stimulus preference do not always parallel the main flow of information in the columnar cortical microcircuit, this indicates the influence of additional horizontal or thalamocortical inputs. AI layers that express differing modulation properties may serve distinct roles in the extraction of dynamic sound information, with the differing information specific to the targeted stations of each layer.
Effect of Resistance Training on Hematological Blood Markers in Older Men and Women: A Pilot Study
Authors: Bobeuf Florian , Labonté Mélissa , Khalil Abdelouahed , Dionne Isabelle J.
Published: October 2009

The aim of this study was to examine the effects of resistance training on hematological blood markers in older individuals. Twenty-nine men and women participated to this study. Subjects were randomized in 2 groups: (1) control (n=13) and (2) resistance training (n=16). At baseline and after the intervention, subjects were submitted to a blood sample to determine their hematological profile (red blood cells, hemoglobin, hematocrit, platelets, leukocytes, neutrophils, lymphocytes, monocytes, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red cell distribution width). At baseline, no difference was observed between groups. Moreover, we found no significant difference after the intervention on any of these markers. A 6-month resistance program in healthy older individuals seems to have no beneficial nor deleterious effects on hematological blood parameters. However, resistance training was well tolerated and should be recommended for other health purposes. Further studies are needed to confirm these results in a large population.
Whole Genome Association Study in a Homogenous Population in Shandong Peninsula of China Reveals JARID2 as a Susceptibility Gene for Schizophrenia
Authors: Liu Yang , Chen Gang , Norton Nadine , Liu Wenmin , Zhu Haining , Zhou Peng , Luan Meng , Yang Shulin , Chen Xing , Carroll Liam , Williams Nigel M. , O′Donovan Michael C. , Kirov George , Owen Michael J.
Published: October 2009

DNA pooling can provide an economic and efficient way to detect susceptibility loci to complex diseases. We carried out a genome screen with 400 microsatellite markers spaced at approximately 10 cm in two DNA pools consisting of 119 schizophrenia (SZ) patients and 119 controls recruited from a homogenous population in the Chang Le area of the Shandong peninsula of China. Association of D6S289, a dinucleotide repeat polymorphism in the JARID2 gene with SZ, was found and confirmed by individual genotyping (X2 = 17.89; P = .047). In order to refine the signal, we genotyped 14 single nucleotide polymorphisms (SNPs) covering JARID2 and the neighboring gene, DNTBP1, in an extended sample of 309 cases and 309 controls from Shandong peninsula (including the samples from the pools). However, rs2235258 and rs9654600 in JARID2 showed association in allelic, genotypic and haplotypic tests with SZ patients from Chang Le area. This was not replicates in the extended sample, we conclude that JARID2 could be a susceptibility gene for SZ.
Arithmetic Identities Involving Genocchi and Stirling Numbers
Authors: Liu Guodong
Published: October 2009

An explicit formula, the generalized Genocchi numbers, was established and some identities and congruences involving the Genocchi numbers, the Bernoulli numbers, and the Stirling numbers were obtained.
Ileovesicostomy Update: Changes for the 21st Century
Authors: Zimmerman W. Britt , Santucci Richard A.
Published: October 2009

Objectives. To review the literature regarding ileovesicostomy and evaluate our patient population for clinical characteristics.Methods. Various surgical reconstructive techniques allow management of difficult clinical scenarios involving patients with neurogenic bladder, irretraceable lower urinary tract symptoms, lower urinary tract disaster, and urethrocutaneous fistulae. One such reconstructive technique employed is the ileovesicostomy. This procedure provides patients with a low-pressure urinary conduit utilizing the ileum and native bladder that empties without catheterization. We describe our patient population who underwent ileovesicostomy for 5 consecutive years ending 2007 at Detroit Receiving Hospital.Results. Most common diagnosis was neurogenic bladder secondary to spinal cord injury. Our population and clinical outcomes are similar to those previously reported in the literature.Conclusions. Based on our experience, we suggest that patients with severe lower urinary tract symptoms and who are unable to perform clean intermittent catheterization and/or refractory to medical therapy ileovesicostomy should be the procedure of choice.
The Synergistic Effect of ConditionalPtenLoss and OncogenicK-rasMutation on Endometrial Cancer Development Occurs via Decreased Progesterone Receptor Action
Authors: Kim Tae Hoon , Wang Jinrong , Lee Kevin Y. , Franco Heather L. , Broaddus Russell R. , Lydon John P. , Jeong Jae-Wook , DeMayo Francesco J.
Published: October 2009

Endometrial cancer is the most common gynecological cancer. Estrogen-dependent endometrioid carcinoma is the most common type of endometrial cancer, and alterations in the expression ofPTENandK-rashave been associated with this disease. To study the roles ofPtenandK-rasin endometrial cancer, we generatedPtenablation and oncogenicK-rasmutation in progesterone receptor positive cells(PRcre/+Ptenf/fK-rasG12D). Double mutant mice dramatically accelerated the development of endometrial cancer compared to a single mutation of either gene. Histological analysis showed that all of the 1-month old double mutant female mice developed endometrial cancer with myometrial invasion. The expression of PR was downregulated in double mutant mice compared to a single mutation of either gene which resulted in decreased suppression of estrogen signaling. Therefore, these results suggest a synergistic effect of dysregulation of thePtenandK-rassignaling pathways during endometrial tumorigenesis.
p73 and p63 Sustain Cellular Growth by Transcriptional Activation of Cell Cycle Progression Genes
Authors: Lefkimmiatis Konstantinos , Caratozzolo Mariano Francesco , Merlo Paola , D'Erchia Anna Maria , Navarro Beatriz , Levrero Massimo , Sbisa' Elisabetta , Tullo Apollonia
Published: October 2009

Despite extensive studies on the role of tumor suppressor p53 protein and its homologues, p73 and p63, following their overexpression or cellular stress, very little is known about the regulation of the three proteins in cells during physiologic cell cycle progression. We report a role for p73 and p63 in supporting cellular proliferation through the transcriptional activation of the genes involved in G1-S and G2-M progression. We found that in MCF-7 cells, p73 and p63, but not p53, are modulated during the cell cycle with a peak in S phase, and their silencing determines a significant suppression of proliferation compared with the control. Chromatin immunoprecipitation analysis shows that in cycling cells, p73 and p63 are bound to the p53-responsive elements (RE) present in the regulatory region of cell cycle progression genes. On the contrary, when the cells are arrested in G0-G1, p73 detaches from the REs and it is replaced by p53, which represses the expression of these genes. When the cells move in S phase, p73 is recruited again and p53 is displaced or is weakly bound to the REs. These data open new possibilities for understanding the involvement of p73 and p63 in cancer. The elevated concentrations of p73 and p63 found in many cancers could cause the aberrant activation of cell growth progression genes and therefore contribute to cancer initiation or progression under certain conditions. [Cancer Res 2009;69(22):8563–71]
Tumor Growth Instability and Its Implications for Chemotherapy
Authors: Castorina Paolo , Carcò Daniela , Guiot Caterina , Deisboeck Thomas S.
Published: October 2009

Optimal delivery of chemotherapy intensity is dependent on host- and tumor-specific characteristics. In this article, the chemotherapy late intensity schedule is revised to account for tumor growth instability, where a small tumor cell fraction emerges that exhibits a higher proliferation rate than the parent strain. Modeling this instability as simplified two-population dynamics, we find that: (a) if this instability precedes the onset of treatment, the slope of the linear increase of the drug concentration for the standard “Norton-Simon late intensity schedule” changes and the initial value of the dose strongly depends on the ratio of the two tumor cell populations and on their distinct growth rates; and (b) if the instability trails the initial treatment, the effective chemotherapeutic drug concentration changes as well. Both cases point toward testable potential refinements of the Norton-Simon late intensity schedule. [Cancer Res 2009;69(21):8507–15]
Noninvasive Multiparametric Imaging of Metastasis-Permissive Microenvironments in a Human Prostate Cancer Xenograft
Authors: Penet Marie-France , Pathak Arvind P. , Raman Venu , Ballesteros Paloma , Artemov Dmitri , Bhujwalla Zaver M.
Published: October 2009

Metastasis continues to be one of the major causes of mortality from prostate cancer. Because human malignant cell lines metastasize more readily from orthotopic sites than from heterotopic sites, to identify metastasis-permissive tumor microenvironments, we used noninvasive imaging to compare the in vivo vascular, metabolic, and physiologic characteristics of a human prostate cancer xenograft implanted orthotopically in the prostate or s.c. in the flank. Hypoxia was detected in these xenografts by placing an enhanced green fluorescence protein optical reporter under the control of a hypoxia response element. A multiparametric analysis of hypoxia, extracellular pH, vascularization, and metabolism provided a characterization of environments that are permissive for metastasis to occur. We found that orthotopic tumors, which metastasized more easily, were characterized by higher vascular volume, permeability, and total choline and a more acidic extracellular pH. Interestingly, metastatic deposits in the lymph nodes as well as cancer cells in ascites fluid were found to be hypoxic, explaining, in part, the refractory nature of metastatic disease. These results also provide the basis for clinically translatable noninvasive imaging markers for predicting metastatic risk in prostate cancer. [Cancer Res 2009;69(22):8822–9]
Fanconi Anemia Complementation Group FANCD2 Protein Serine 331 Phosphorylation Is Important for Fanconi Anemia Pathway Function and BRCA2 Interaction
Authors: Zhi Gang , Wilson James B. , Chen Xiaoyong , Krause Diane S. , Xiao Yuxuan , Jones Nigel J. , Kupfer Gary M.
Published: October 2009

Fanconi anemia is a cancer-prone inherited bone marrow failure and cancer susceptibility syndrome with at least 13 complementation groups (FANCA, FANCB, FANCC, FANCD1, FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ, FANCL, FANCM, and FANCN). Our laboratory has previously described several regulatory phosphorylation events for core complex member proteins FANCG and FANCA by phosphorylation. In this study, we report a novel phosphorylation site serine 331 (S331) of FANCD2, the pivotal downstream player of the Fanconi anemia pathway. Phosphorylation of S331 is important for its DNA damage–inducible monoubiquitylation, resistance to DNA cross-linkers, and in vivo interaction with FANCD1/BRCA2. A phosphomimetic mutation at S331 restores all of these phenotypes to wild-type. In vitro and in vivo experiments show that phosphorylation of S331 is mediated by CHK1, the S-phase checkpoint kinase implicated in the Fanconi anemia DNA repair pathway. [Cancer Res 2009;69(22):8775–83]
Prognostic Significance of Molecular Markers and Extent of Resection in Primary Glioblastoma Patients
Authors: Felsberg Jörg , Rapp Marion , Loeser Simon , Fimmers Rolf , Stummer Walter , Goeppert Matthias , Steiger Hans-Jacob , Friedensdorf Britta , Reifenberger Guido , Sabel Michael C.
Published: October 2009

Purpose: Despite multimodal aggressive treatment glioblastoma patients still face a rather poor prognosis. Recent data indicate that certain molecular markers, in particular MGMT promoter hypermethylation, are associated with response to alkylating chemotherapy and longer survival. The clinical significance of other glioblastoma-associated molecular aberrations and their relationship to MGMT promoter hypermethylation is still poorly understood.

Experimental Design: We conducted a translational study involving 67 newly diagnosed glioblastoma patients treated at our institution from 1998 to 2004. All patients were treated by open resection, followed by radiotherapy and adjuvant temozolomide chemotherapy. The tumors were investigated for MGMT promoter methylation, mRNA and protein expression, as well as presence of MGMT sequence polymorphisms. In addition, we screened for genetic aberrations of the EGFR, TP53, CDK4, MDM2, and PDGFRA genes as well as allelic losses on chromosomal arms 1p, 10q, and 19q.

Results: Correlation of molecular findings with clinical data revealed significantly longer time to progression after onset of chemotherapy and longer overall survival of patients with MGMT-hypermethylated tumors. In contrast, MGMT protein expression, MGMT polymorphisms, and aberrations in any of the other genes and chromosomes were not significantly linked to patient outcome. Multivariate analysis identified MGMT promoter hypermethylation and near-complete tumor resection as the most important parameters associated with better prognosis.

Conclusion: Our study provides novel insights into the significance of molecular and clinical markers in predicting the prognosis of glioblastoma patients, which may improve stratification of patients into distinct prognostic subgroups. (Clin Cancer Res 2009;15(20):6683–93)
Validation of TPX2 as a Potential Therapeutic Target in Pancreatic Cancer Cells
Authors: Warner Steven L. , Stephens Bret J. , Nwokenkwo Stanley , Hostetter Galen , Sugeng Anastasia , Hidalgo Manuel , Trent Jeffery M. , Han Haiyong , Von Hoff Daniel D.
Published: October 2009

Purpose: The targeting protein for Xklp2 (TPX2) has recently gained attention as a putative oncogene possibly amplified in several human malignancies, including pancreatic adenocarcinoma. In this work, we sought to evaluate the copy number and expression of TPX2 in pancreatic cancer cell lines and tumor tissues and to further explore the potential of TPX2 as a therapeutic target.

Experimental Design: The DNA copy number and expression of the TPX2 gene were surveyed in pancreatic cancer cell lines and tumor tissues and compared with those of immortalized normal pancreatic ductal cells and normal pancreatic tissues. The cellular effects of TPX2 knockdown using small interfering RNA oligonucleotides in pancreatic cancer cells, such as growth in tissue culture, in soft agar, and in nude mice; apoptosis; and sensitivity to paclitaxel, were also investigated using various assays.

Results: Low-copy-number TPX2 amplification was found in pancreatic cancer cell lines and low-passage pancreatic cancer tumor xenografts. TPX2 expression was upregulated in pancreatic cancer cell lines at both the mRNA and protein levels relative to the immortalized pancreatic ductal epithelial cell line HPDE6. Immunohistochemical staining of a tissue microarray showed that TPX2 expression was higher in pancreatic tumors compared with their normal counterparts. Treatment with TPX2 targeting small interfering RNAs effectively reduced pancreatic cancer cell growth in tissue culture, induced apoptosis, and inhibited growth in soft agar and in nude mice. Knockdown of TPX2 also sensitized pancreatic cancer cells to paclitaxel treatment.

Conclusions: Our results suggest that TPX2 might be an attractive target for pancreatic cancer therapy. (Clin Cancer Res 2009;15(21):6519–28)
Intratumoral Expression of Mature Human Neutrophil Peptide-1 Mediates Antitumor Immunity in Mice
Authors: Wang Yong-sheng , Li Dan , Shi Hua-shan , Wen Yan-jun , Yang Li , Xu Ning , Chen Xian-cheng , Chen Xiang , Chen Ping , Li Jiong , Deng Hong-xin , Wang Chun-ting , Xie Gang , Huang Shan , Mao Yong-qiu , Chen Li-juan , Zhao Xia , Wei Yu-quan
Published: October 2009

Purpose: Human neutrophil peptides (HNP1-3), small molecular antimicrobial peptides, are expressed within tumors and associated with tumor necrosis and inhibition of angiogenesis. Recent investigations have suggested that HNP1-3 are likely to be involved in the host immune responses to tumors.

Experimental Design: We used recombinant pSec-HNP1, which expresses a secretable form of HNP1, to obtain expression of HNP1 in the tumor milieu in immunocompetent mice to explore the possible roles of HNP1 in tumor immunity. The antitumor effects were investigated in established CT26 colon cancer and 4T1 breast cancer models.

Results: HNP1-mediated chemotactic and activating effects on immature dendritic cells were detected both in vitro and in vivo. Intratumoral expression of HNP1 resulted in not only significant tumor growth inhibition but also increased CTL infiltration within tumors. Adoptive transfer of splenocytes and a 51Cr release assay revealed specific cellular immune responses. Furthermore, increased antibodies were also found in sera from pSec-HNP1treated mice supporting specific humoral immune responses. Increased apoptosis and decreased angiogenesis were also shown in treated tumors.

Conclusions: These findings indicate that HNP1 can exert multiple antitumor effects through different mechanisms; more importantly, HNP1 mediates host immune responses to tumors in situ through the recruitment and subsequent activation of immature dendritic cells and thus shows promising potential in cancer therapy. (Clin Cancer Res 2009;15(22):690111)
Comprehensive Genomic Analysis Reveals Clinically Relevant Molecular Distinctions between Thymic Carcinomas and Thymomas
Authors: Girard Nicolas , Shen Ronglai , Guo Tianhua , Zakowski Maureen F. , Heguy Adriana , Riely Gregory J. , Huang James , Lau Christopher , Lash Alex E. , Ladanyi Marc , Viale Agnes , Antonescu Cristina R. , Travis William D. , Rusch Valerie W. , Kris Mark G. , Pao William
Published: October 2009

Purpose: Thymomas and thymic carcinomas are rare intrathoracic malignancies that can be invasive and refractory to conventional treatment. Because these tumors both originate from the thymus, they are often grouped together clinically. However, whether the underlying biology of these tumors warrants such clustering is unclear, and the optimum treatment of either entity is unknown.

Experimental Design: All thymic tumors were profiled for mutations in genes encoding components of the EGFR and KIT signaling pathways, assessed for EGFR and KIT expression by immunohistochemistry, and analyzed by array-based comparative genomic hybridization. Previously untreated tumors were subjected to global gene expression arrays.

Results: We analyzed 45 thymic tumors [thymoma, n = 38 (type A, n = 8; type B2, n = 22; type B3, n = 8); thymic carcinoma, n = 7]. One thymoma and one thymic carcinoma harbored KRAS mutations (G12A and G12V, respectively), and one thymoma had a G13V HRAS mutation. Three tumors displayed strong KIT staining. Two thymic carcinomas harbored somatic KIT mutations (V560del and H697Y). In cell viability assays, the V560del mutant was associated with similar sensitivities to imatinib and sunitinib, whereas the H697Y mutant displayed greater sensitivity to sunitinib. Genomic profiling revealed distinct differences between type A to B2 thymomas versus type B3 and thymic carcinomas. Moreover, array-based comparative genomic hybridization could readily distinguish squamous cell carcinomas of the thymus versus the lung, which can often present a diagnostic challenge.

Conclusions: Comprehensive genomic analysis suggests that thymic carcinomas are molecularly distinct from thymomas. These data have clinical, pathologic, and therapeutic implications for the treatment of thymic malignancies. (Clin Cancer Res 2009;15(22):67909)
Genomic and Expression Profiling of Glioblastoma Stem Cell–Like Spheroid Cultures Identifies Novel Tumor-Relevant Genes Associated with Survival
Authors: Ernst Aurélie , Hofmann Stefanie , Ahmadi Rezvan , Becker Natalia , Korshunov Andrey , Engel Felix , Hartmann Christian , Felsberg Jörg , Sabel Michael , Peterziel Heike , Durchdewald Moritz , Hess Jochen , Barbus Sebastian , Campos Benito , Starzinski-Powitz Anna , Unterberg Andreas , Reifenberger Guido , Lichter Peter , Herold-Mende Christel , Radlwimmer Bernhard
Published: October 2009

Purpose: Glioblastoma spheroid cultures are enriched in tumor stem-like cells and therefore may be more representative of the respective primary tumors than conventional monolayer cultures. We exploited the glioma spheroid culture model to find novel tumor-relevant genes.

Experimental Design: We carried out array-based comparative genomic hybridization of spheroid cultures derived from 20 glioblastomas. Microarray-based gene expression analysis was applied to determine genes with differential expression compared with normal brain tissue and to nonneoplastic brain spheroids in glioma spheroid cultures. The protein expression levels of three candidates were determined by immunohistochemistry on tissue microarrays and correlated with clinical outcome. Functional analysis of PDPN was done.

Results: Genomic changes in spheroid cultures closely resembled those detected in primary tumors of the corresponding patients. In contrast, genomic changes in serum-grown monolayer cultures established from the same patients did not match well with the respective primary tumors. Microarray-based gene expression analysis of glioblastoma spheroid cultures identified a set of novel candidate genes being upregulated or downregulated relative to normal brain. Quantitative real-time PCR analyses of 8 selected candidate genes in 20 clinical glioblastoma samples validated the microarray findings. Immunohistochemistry on tissue microarrays revealed that expression of AJAP1, EMP3, and PDPN was significantly associated with overall survival of astrocytic glioma patients. Invasive capacity and RhoA activity were decreased in PDPN-silenced spheroids.

Conclusion: We identified a set of novel candidate genes that likely play a role in glioblastoma pathogenesis and implicate AJAP1, EMP3, and PDPN as molecular markers associated with the clinical outcome of glioma patients. (Clin Cancer Res 2009;15(21):6541–50)
Quantifying Antivascular Effects of Monoclonal Antibodies to Vascular Endothelial Growth Factor: Insights from Imaging
Authors: O'Connor James P.B. , Carano Richard A.D. , Clamp Andrew R. , Ross Jed , Ho Calvin C.K. , Jackson Alan , Parker Geoff J.M. , Rose Chris J. , Peale Franklin V. , Friesenhahn Michel , Mitchell Claire L. , Watson Yvonne , Roberts Caleb , Hope Lynn , Cheung Sue , Reslan Hani Bou , Go Mary Ann T. , Pacheco Glenn J. , Wu Xiumin , Cao Tim C. , Ross Sarajane , Buonaccorsi Giovanni A. , Davies Karen , Hasan Jurjees , Thornton Paula , del Puerto Olivia , Ferrara Napoleone , van Bruggen Nicholas , Jayson Gordon C.
Published: October 2009

Purpose: Little is known concerning the onset, duration, and magnitude of direct therapeutic effects of anti–vascular endothelial growth factor (VEGF) therapies. Such knowledge would help guide the rational development of targeted therapeutics from bench to bedside and optimize use of imaging technologies that quantify tumor function in early-phase clinical trials.

Experimental Design: Preclinical studies were done using ex vivo microcomputed tomography and in vivo ultrasound imaging to characterize tumor vasculature in a human HM-7 colorectal xenograft model treated with the anti-VEGF antibody G6-31. Clinical evaluation was by quantitative magnetic resonance imaging in 10 patients with metastatic colorectal cancer treated with bevacizumab.

Results: Microcomputed tomography experiments showed reduction in perfused vessels within 24 to 48 h of G6-31 drug administration (P ≤ 0.005). Ultrasound imaging confirmed reduced tumor blood volume within the same time frame (P = 0.048). Consistent with the preclinical results, reductions in enhancing fraction and fractional plasma volume were detected in patient colorectal cancer metastases within 48 h after a single dose of bevacizumab that persisted throughout one cycle of therapy. These effects were followed by resolution of edema (P = 0.0023) and tumor shrinkage in 9 of 26 tumors at day 12.

Conclusion: These data suggest that VEGF-specific inhibition induces rapid structural and functional effects with downstream significant antitumor activity within one cycle of therapy. This finding has important implications for the design of early-phase clinical trials that incorporate physiologic imaging. The study shows how animal data help interpret clinical imaging data, an important step toward the validation of image biomarkers of tumor structure and function. (Clin Cancer Res 2009;15(21):6674–82)
Reciprocal Regulation of c-Src and STAT3 in Non-Small Cell Lung Cancer
Authors: Byers Lauren Averett , Sen Banibrata , Saigal Babita , Diao Lixia , Wang Jing , Nanjundan Meera , Cascone Tina , Mills Gordon B. , Heymach John V. , Johnson Faye M.
Published: October 2009

Purpose: Signal transducer and activator of transcription-3 (STAT3) is downstream of growth factor and cytokine receptors, and regulates key oncogenic pathways in nonsmall cell lung cancer (NSCLC). Activation of STAT3 by cellular Src (c-Src) promotes tumor progression. We hypothesized that c-Src inhibition could activate STAT3 by inducing a homeostatic feedback loop, contributing to c-Src inhibitor resistance.

Experimental Design: The effects of c-Src inhibition on total and phosphorylated STAT3 were measured in NSCLC cell lines and in murine xenograft models by Western blotting. c-Src and STAT3 activity as indicated by phosphorylation was determined in 46 human tumors and paired normal lung by reverse phase protein array. Modulation of dasatinib (c-Src inhibitor) cytotoxicity by STAT3 knockdown was measured by MTT, cell cycle, and apoptosis assays.

Results: Depletion of c-Src by small interfering RNA or sustained inhibition by dasatinib increased pSTAT3, which could be blocked by inhibition of JAK. Similarly, in vivo pSTAT3 levels initially decreased but were strongly induced after sustained dasatinib treatment. In human tumors, phosphorylation of the autoinhibitory site of c-Src (Y527) correlated with STAT3 phosphorylation (r = 0.64; P = 2.5 106). STAT3 knockdown enhanced the cytotoxicity of dasatinib.

Conclusions: c-Src inhibition leads to JAK-dependent STAT3 activation in vitro and in vivo. STAT3 knockdown enhances the cytotoxicity of dasatinib, suggesting a compensatory pathway that allows NSCLC survival. Data from human tumors showed a reciprocal regulation of c-Src and STAT3 activation, suggesting that this compensatory pathway functions in human NSCLC. These results provide a rationale for combining c-Src and STAT3 inhibition to improve clinical responses. (Clin Cancer Res 2009;15(22):685261)
Human Papillomavirus in Head and Neck Cancer: Its Role in Pathogenesis and Clinical Implications
Authors: Chung Christine H. , Gillison Maura L.
Published: October 2009

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer with an annual incidence of approximately 400,000 worldwide. Although the principal risk factors for head and neck cancer remain tobacco and alcohol use, human papillomavirus (HPV) has recently been found to be etiologically associated with 20 to 25 of HNSCC, mostly in the oropharynx. HPV causes human cancers by expressing two viral oncoproteins, E6 and E7. These oncoproteins degrade and destabilize two major tumor suppressor proteins, p53 and pRb, through ubiquitination. Additional studies have shown that E6 and E7 can directly bind to multiple host proteins other than p53 and pRb (e.g., Bak and p21Cip1), further contributing to genetic instability. However, expression of E6 and E7 alone is not sufficient for cellular transformation, and the additional genetic alterations necessary for malignant progression in the setting of virus-induced genomic instability are unknown. In addition to the etiological differences, HPV-positive cancers are clinically distinct when compared with HPV-negative cancers with regard to treatment response and survival outcome, with tumor HPV-positivity being a favorable prognostic biomarker. Further understanding of carcinogenesis and clinical behavior of HPV-positive cancers will improve disease prevention, patient care, and surveillance strategies for HNSCC patients. (Clin Cancer Res 2009;15(22):675862)
MYC-Induced Cancer Cell Energy Metabolism and Therapeutic Opportunities
Authors: Dang Chi V. , Le Anne , Gao Ping
Published: October 2009

Although cancers have altered glucose metabolism, termed the Warburg effect, which describes the increased uptake and conversion of glucose to lactate by cancer cells under adequate oxygen tension, changes in the metabolism of glutamine and fatty acid have also been documented. The MYC oncogene, which contributes to the genesis of many human cancers, encodes a transcription factor c-Myc, which links altered cellular metabolism to tumorigenesis. c-Myc regulates genes involved in the biogenesis of ribosomes and mitochondria, and regulation of glucose and glutamine metabolism. With E2F1, c-Myc induces genes involved in nucleotide metabolism and DNA replication, and microRNAs that homeostatically attenuate E2F1 expression. With the hypoxia inducible transcription factor HIF-1, ectopic c-Myc cooperatively induces a transcriptional program for hypoxic adaptation. Myc regulates gene expression either directly, such as glycolytic genes including lactate dehydrogenase A (LDHA), or indirectly, such as repression of microRNAs miR-23a/b to increase glutaminase (GLS) protein expression and glutamine metabolism. Ectopic MYC expression in cancers, therefore, could concurrently drive aerobic glycolysis and/or oxidative phosphorylation to provide sufficient energy and anabolic substrates for cell growth and proliferation in the context of the tumor microenvironment. Collectively, these studies indicate that Myc-mediated altered cancer cell energy metabolism could be translated for the development of new anticancer therapies. (Clin Cancer Res 2009;15(21):6479–83)
Synergistic Enhancement of CD8+ T Cell–Mediated Tumor Vaccine Efficacy by an Anti–Transforming Growth Factor-β Monoclonal Antibody
Authors: Terabe Masaki , Ambrosino Elena , Takaku Shun , O'Konek Jessica J. , Venzon David , Lonning Scott , McPherson John M. , Berzofsky Jay A.
Published: October 2009

Purpose: Transforming growth factor-β (TGF-β) is an immunosuppressive cytokine, having direct suppressive activity against conventional CD4+ and CD8+T cells and natural killer cells, thereby inhibiting tumor immunosurveillance. Here, we investigated possible synergy between anti–TGF-β (1D11) and a peptide vaccine on induction of antitumor immunity, and the mechanisms accounting for synergistic efficacy.

Experimental Design: The effect of combination treatment with a peptide vaccine and anti–TGF-β was examined in a subcutaneous TC1 tumor model, as well as the mechanisms of protection induced by this treatment.

Results: Anti–TGF-β significantly and synergistically improved vaccine efficacy as measured by reduction in primary tumor growth, although anti–TGF-β alone had no impact. The number of tumor antigen–specific CTL with high functional avidity as measured by IFN-γ production and lytic activity was significantly increased in vaccinated mice by TGF-β neutralization. Although TGF-β is known to play a critical role in CD4+Foxp3+ Treg cells, Treg depletion/suppression by an anti-CD25 monoclonal antibody (PC61) before tumor challenge did not enhance vaccine efficacy, and adding anti–TGF-β did not affect Treg numbers in lymph nodes or tumors or their function. Also, TGF-β neutralization had no effect on interleukin-17–producing T cells, which are induced by TGF-β and interleukin-6. Absence of type II NKT cells, which induce myeloid cells to produce TGF-β, was not sufficient to eliminate all sources of suppressive TGF-β. Finally, the synergistic protection induced by anti–TGF-β vaccine augmentation was mediated by CD8+ T cells since anti-CD8 treatment completely abrogated the effect.

Conclusions: These results suggest that TGF-β blockade may be useful for enhancing cancer vaccine efficacy. (Clin Cancer Res 2009;15(21):6560–9)
Systemic Inhibition of Transforming Growth Factor-β in Glioma-Bearing Mice Improves the Therapeutic Efficacy of Glioma-Associated Antigen Peptide Vaccines
Authors: Ueda Ryo , Fujita Mitsugu , Zhu Xinmei , Sasaki Kotaro , Kastenhuber Edward R. , Kohanbash Gary , McDonald Heather A. , Harper Jay , Lonning Scott , Okada Hideho
Published: October 2009

Purpose: A variety of cancers, including malignant gliomas, overexpress transforming growth factor-β (TGF-β), which helps tumors evade effective immune surveillance through a variety of mechanisms, including inhibition of CD8+ CTLs and enhancing the generation of regulatory T (Treg) cells. We hypothesized that inhibition of TGF-β would improve the efficacy of vaccines targeting glioma-associated antigen (GAA)–derived CTL epitopes by reversal of immunosuppression.

Experimental Design: Mice bearing orthotopic GL261 gliomas were treated systemically with a TGF-β–neutralizing monoclonal antibody, 1D11, with or without s.c. vaccinations of synthetic peptides for GAA-derived CTL epitopes, GARC-1 (77-85) and EphA2 (671-679), emulsified in incomplete Freund's adjuvant.

Results: Mice receiving the combination regimen exhibited significantly prolonged survival compared with mice receiving either 1D11 alone, GAA vaccines alone, or mock treatments alone. TGF-β neutralization enhanced the systemic induction of antigen-specific CTLs in glioma-bearing mice. Flow cytometric analyses of brain-infiltrating lymphocytes revealed that 1D11 treatment suppressed phosphorylation of Smad2, increased GAA-reactive/IFN-γ–producing CD8+ T cells, and reduced CD4+/FoxP3+ Treg cells in the glioma microenvironment. Neutralization of TGF-β also upregulated plasma levels of interleukin-12, macrophage inflammatory protein-1α, and IFN-inducible protein-10, suggesting a systemic promotion of type-1 cytokine/chemokine production. Furthermore, 1D11 treatment upregulated plasma interleukin-15 levels and promoted the persistence of GAA-reactive CD8+ T cells in glioma-bearing mice.

Conclusions: These data suggest that systemic inhibition of TGF-β by 1D11 can reverse the suppressive immunologic environment of orthotopic tumor-bearing mice both systemically and locally, thereby enhancing the therapeutic efficacy of GAA vaccines. (Clin Cancer Res 2009;15(21):6551–9)
A Genomic Approach to Improve Prognosis and Predict Therapeutic Response in Chronic Lymphocytic Leukemia
Authors: Friedman Daphne R. , Weinberg J. Brice , Barry William T. , Goodman Barbara K. , Volkheimer Alicia D. , Bond Karen M. , Chen Youwei , Jiang Ning , Moore Joseph O. , Gockerman Jon P. , Diehl Louis F. , Decastro Carlos M. , Potti Anil , Nevins Joseph R.
Published: October 2009

Purpose: Chronic lymphocytic leukemia (CLL) is a B-cell malignancy characterized by a variable clinical course. Several parameters have prognostic capabilities but are associated with altered response to therapy in only a small subset of patients.

Experimental Design: We used gene expression profiling methods to generate predictors of therapy response and prognosis. Genomic signatures that reflect progressive disease and responses to chemotherapy or chemoimmunotherapy were created using cancer cell lines and patient leukemia cell samples. We validated and applied these three signatures to independent clinical data from four cohorts, representing a total of 301 CLL patients.

Results: A genomic signature of prognosis created from patient leukemic cell gene expression data coupled with clinical parameters significantly differentiated patients with stable disease from those with progressive disease in the training data set. The progression signature was validated in two independent data sets, showing a capacity to accurately identify patients at risk for progressive disease. In addition, genomic signatures that predict response to chlorambucil or pentostatin, cyclophosphamide, and rituximab were generated and could accurately distinguish responding and nonresponding CLL patients.

Conclusions: Thus, microarray analysis of CLL lymphocytes can be used to refine prognosis and predict response to different therapies. These results have implications for standard and investigational therapeutics in CLL patients. (Clin Cancer Res 2009;15(22):694755)
The p53 Family Protein p73 Provides New Insights into Cancer Chemosensitivity and Targeting
Authors: Lunghi Paolo , Costanzo Antonio , Mazzera Laura , Rizzoli Vittorio , Levrero Massimo , Bonati Antonio
Published: October 2009

The p53 tumor suppressor is part of a small family of related proteins that includes two other members, p73 and p63. Interest in the p53 family members, their functions and their complex interactions and regulation, has steadily grown over recent years and does not show signs of waning. p73 is a major determinant of chemosensitivity in humans, and mutant p53 proteins carrying specific polymorphisms can induce drug resistance by inhibiting TAp73. Cooperation between TA (transactivating, proapoptotic, antiproliferative) and ΔN (truncated, antiapoptotic, pro-proliferative) p73 isoforms and among the three family members guarantees equilibrium between proliferation, differentiation, and cell death, thus creating a harmony that is lost in several human cancers. In this article, we review our current knowledge of the role of p73 in cancer chemosensitivity and the real prospect of therapy targeting this molecule. We also draw attention to the crucial role of specific phosphorylation and acetylation events for p73-induced apoptosis and drug chemosensitivity. (Clin Cancer Res 2009;15(21):6495–502)
Mechanisms of Sunitinib Resistance in Gastrointestinal Stromal Tumors Harboring KITAY502-3ins Mutation: An In vitro Mutagenesis Screen for Drug Resistance
Authors: Guo Tianhua , Hajdu Mihai , Agaram Narasimhan P. , Shinoda Hiroko , Veach Darren , Clarkson Bayard D. , Maki Robert G. , Singer Samuel , DeMatteo Ronald P. , Besmer Peter , Antonescu Cristina R.
Published: October 2009

Purpose: Although tyrosine kinase inhibitors have improved survival in advanced gastrointestinal stromal tumor (GIST), complete response is rare and most patients eventually fail the first-line treatment with imatinib. Sunitinib malate is the only approved second-line therapy for patients with imatinib-resistant or imatinib-intolerant GIST. The clinical benefit of sunitinib is genotype-dependent in regards to both primary and secondary mutations, with GIST patients harboring the KITAY502-3ins exon 9 mutation being the most sensitive.

Experimental Design: As sunitinib resistance is now emerging, our goal was to investigate mechanisms of progression and to test the efficacy of novel tyrosine kinase inhibitor on these resistant mutants in vitro. N-ethyl-N-nitrosourea mutagenesis of Ba/F3 cells expressing the KITAY502-3ins mutant was used to investigate novel patterns of resistant mutations evolving in the presence of sunitinib.

Results: Tumors from patients who developed sunitinib resistance after at least 1 year of radiographic response were analyzed, showing similar findings of a primary KITAY502-3ins mutation and a secondary mutation in the KIT activation loop. Ba/F3 cells expressing these sunitinib-resistant double mutants showed sensitivity to both dasatinib and nilotinib.

Conclusions: Sunitinib resistance in GIST shares similar pathogenetic mechanisms identified in imatinib failure, with acquisition of secondary mutations in the activation domain after an extended initial response to the drug. Moreover, in vitro mutagenesis with or without N-ethyl-N-nitrosourea of Ba/F3 cells expressing KITAY502-3ins showed acquisition of secondary mutations restricted to the second kinase domain of KIT. In contrast, in vitro resistance to imatinib produces a broader spectrum of secondary mutations including mutations in both KIT kinase domains. (Clin Cancer Res 2009;15(22):686270)
The Neuropharmacokinetics of Temozolomide in Patients with Resectable Brain Tumors: Potential Implications for the Current Approach to Chemoradiation
Authors: Portnow Jana , Badie Behnam , Chen Mike , Liu An , Blanchard Suzette , Synold Timothy W.
Published: October 2009

Purpose: Intracerebral microdialysis (ICMD) is an accepted method for monitoring changes in neurochemistry from acute brain injury. The goal of this pilot study was to determine the feasibility of using ICMD to examine the neuropharmacokinetics of temozolomide in brain interstitium following oral administration.

Experimental Design: Patients with primary or metastatic brain tumors had a microdialysis catheter placed in peritumoral brain tissue at the time of surgical debulking. Computerized tomography scan confirmed the catheter location. Patients received a single oral dose of temozolomide (150 mg/m2) on the first postoperative day, serial plasma and ICMD samples were collected over 24 hours, and temozolomide concentrations were determined by tandem mass spectrometry.

Results: Nine patients were enrolled. Dialysate and plasma samples were successfully collected from seven of the nine patients. The mean temozolomide areas under the concentration-time curve (AUC) in plasma and brain interstitium were 17.1 and 2.7 g/mL hour, with an average brain interstitium/plasma AUC ratio of 17.8. The mean peak temozolomide concentration in the brain was 0.6 0.3 g/mL, and the mean time to reach peak level in brain was 2.0 0.8 hours.

Conclusions: The use of ICMD to measure the neuropharmacokinetics of systemically administered chemotherapy is safe and feasible. Concentrations of temozolomide in brain interstitium obtained by ICMD are consistent with published data obtained in a preclinical ICMD model, as well as from clinical studies of cerebrospinal fluid. However, the delayed time required to achieve maximum temozolomide concentrations in brain suggests that current chemoradiation regimens may be improved by administering temozolomide 2 to 3 hours before radiation. (Clin Cancer Res 2009;15(22):70928)
Effects of Src kinase inhibition induced by dasatinib in non–small cell lung cancer cell lines treated with cisplatin
Authors: Ceppi Paolo , Papotti Mauro , Monica Valentina , Iacono Marco Lo , Saviozzi Silvia , Pautasso Marisa , Novello Silvia , Mussino Stefano , Bracco Enrico , Volante Marco , Scagliotti Giorgio V.
Published: October 2009

c-Src is a tyrosine kinase involved in tumor proliferation, migration, and angiogenesis and has been shown to modulate the cytotoxicity following cisplatin-induced DNA damages. c-Src is frequently activated in non–small cell lung cancer (NSCLC) tissues and cell lines, but no preclinical data regarding the effects of the novel potent Src inhibitor, dasatinib (BMS-354825), in the modulation of cisplatin resistance are currently available. The present study reports that treatment with dasatinib completely abrogated Src phosphorylation in the majority of the NSCLC cell lines tested (n = 7), with modest effects on cell proliferation and survival. In five cell lines, a higher cytotoxicity was observed delivering cisplatin in combination with dasatinib: the most evident effects were found in the squamous H520 cells due to the effective block of cisplatin-induced Src phosphorylation. Moreover, dasatinib treatment significantly blocked cisplatin-induced transcription of a panel of DNA repair and synthesis genes. In addition, a real-time PCR analysis done on tumor and matched normal lung specimens from 44 surgically resected NSCLC patients showed that Src transcripts are significantly upregulated in 23% of cases. In conclusion, Src-directed therapeutic strategies could interfere with cisplatin resistance, possibly allowing to reduce cisplatin doses, thus improving its efficacy. The data of this study support further clinical studies aimed to evaluate the efficacy of Src-inhibiting agents in combination with cisplatin in the treatment of NSCLC. [Mol Cancer Ther 2009;8(11):3066–74]