bluuebunny/crossref_metadata_2025 huggingface dataset:
Connective Tissue Growth Factor Confers Drug Resistance in Breast Cancer through Concomitant Up-regulation of Bcl-xL and cIAP1
Authors: Wang Ming-Yang , Chen Pai-Sheng , Prakash Ekambaranellore , Hsu Hsing-Chih , Huang Hsin-Yi , Lin Ming-Tsan , Chang King-Jen , Kuo Min-Liang
Published: April 2009

Connective tissue growth factor (CTGF) expression is elevated in advanced breast cancer and promotes metastasis. Chemotherapy response is only transient in most metastatic diseases. In the present study, we examined whether CTGF expression could confer drug resistance in human breast cancer. In breast cancer patients who received neoadjuvant chemotherapy, CTGF expression was inversely associated with chemotherapy response. Overexpression of CTGF in MCF7 cells (MCF7/CTGF) enhanced clonogenic ability, cell viability, and resistance to apoptosis on exposure to doxorubicin and paclitaxel. Reducing the CTGF level in MDA-MB-231 (MDA231) cells by antisense CTGF cDNA (MDA231/AS cells) mitigated this drug resistance capacity. CTGF overexpression resulted in resistance to doxorubicin- and paclitaxel-induced apoptosis by up-regulation of Bcl-xL and cellular inhibitor of apoptosis protein 1 (cIAP1). Knockdown of Bcl-xL or cIAP1 with specific small interfering RNAs abolished the CTGF-mediated resistance to apoptosis induced by the chemotherapeutic agents in MCF7/CTGF cells. Inhibition of extracellular signal–regulated kinase (ERK)-1/2 effectively reversed the resistance to apoptosis as well as the up-regulation of Bcl-xL and cIAP1 in MCF7/CTGF cells. A neutralizing antibody against integrin αvβ3 significantly attenuated CTGF-mediated ERK1/2 activation and up-regulation of Bcl-xL and cIAP1, indicating that the integrin αvβ3/ERK1/2 signaling pathway is essential for CTGF functions. The Bcl-xL level also correlated with the CTGF level in breast cancer patients. We also found that a COOH-terminal domain peptide from CTGF could exert activities similar to full-length CTGF, in activation of ERK1/2, up-regulation of Bcl-xL/cIAP1, and resistance to apoptosis. We conclude that CTGF expression could confer resistance to chemotherapeutic agents through augmenting a survival pathway through ERK1/2-dependent Bcl-xL/cIAP1 up-regulation. [Cancer Res 2009;69(8):3482–91]
Histone Deacetylase Inhibitor Sodium Butyrate Enhances the Cell Killing Effect of Psoralen plus UVA by Attenuating Nucleotide Excision Repair
Authors: Toyooka Tatsushi , Ibuki Yuko
Published: April 2009

The use of histone deacetylase inhibitors (HDACI), a promising new class of antineoplastic agents, in combination with cytotoxic agents, such as ionizing radiation and anticancer drugs, has been attracting attention. In this study, we found that sodium butyrate (SB), a widely studied HDACI, remarkably enhanced the cell killing effect of psoralen plus UVA (PUVA) in several cancer cell lines, including skin melanoma. Although a single treatment with PUVA or SB did not greatly affect cell survival, combined treatment with SB and PUVA induced marked apoptosis within 24 hours. The SB-induced augmentation of the cell killing effect was more dramatic in combination with PUVA than with anticancer drugs. The number of double-strand breaks that formed during the repair of PUVA-induced interstrand cross-links (ICL) in chromosomal DNA was significantly reduced in SB-pretreated cells, suggesting that the ability to repair ICL was attenuated by SB. In addition, the incorporation of bromodeoxyuridine and the formation of repair foci of proliferating cell nuclear antigen after PUVA treatment, associated with nucleotide excision repair (NER) in the removal of ICL, were not observed in SB-pretreated cells. Furthermore, the repair kinetics of UV-induced cyclobutane pyrimidine dimers (well-known photolesions repaired by NER) were much slower in SB-pretreated cells than in untreated cells. These results indicated that the enhanced cell killing effect of PUVA by SB was attributable to an attenuated ability to repair DNA and, especially, dysfunctional NER. [Cancer Res 2009;69(8):3492–500]
Immune Rejection of Mouse Tumors Expressing Mutated Self
Authors: Duan Fei , Lin Yun , Liu Cailian , Engelhorn Manuel E. , Cohen Adam D. , Curran Michael , Sakaguchi Shimon , Merghoub Taha , Terzulli Stephanie , Wolchok Jedd D. , Houghton Alan N.
Published: April 2009

How the immune system recognizes and responds to mutations expressed by cancer cells is a critical issue for cancer immunology. Mutated self-polypeptides are particularly strong tumor-specific rejection antigens for natural tumor immunity, but we know remarkably little about T-cell responses to mutated self during tumor growth in vivo, including levels of response, kinetics, and correlates that predict tumor rejection. To address these questions, a mutated self-antigen, designated tyrosinase-related protein 1 (Tyrp1)-WM, derived from Tyrp1 was expressed in the poorly immunogenic, spontaneously arising B16 melanoma and the immunogenic, chemically induced LiHa fibrosarcoma. Syngeneic mice challenged with LiHa fibrosarcoma cells expressing Tyrp1-WM, but not native Tyrp1, induced specific CD8+ and CD4+ T-cell responses against defined mutated epitopes in tumor-draining lymph nodes and in tumors. Subsequently, specific CD8+ T-cell responses contracted as a minority of tumors progressed. B16 melanomas expressing Tyrp1-WM induced minimal T-cell responses, and no tumor immunity was detected. Treatment with an agonist monoclonal antibody against glucocorticoid-induced tumor necrosis factor receptor family–related gene (GITR) increased the level of CD8+ T cells recognizing a peptide derived from the Tyrp1-WM sequence and the proportion of mice rejecting tumors. These results show that B16 tumors expressing mutations that generate strongly immunogenic epitopes naturally induce T-cell responses, which are insufficient to reject tumors. Immune modulation, such as inducing GITR signaling, is required to enhance CD8+ T-cell responses to specific mutations and to lead to tumor rejection. [Cancer Res 2009;69(8):3545–53]
Mirk/Dyrk1B Maintains the Viability of Quiescent Pancreatic Cancer Cells by Reducing Levels of Reactive Oxygen Species
Authors: Deng Xiaobing , Ewton Daina Z. , Friedman Eileen
Published: April 2009

The kinase Mirk/dyrk1B mediated the clonogenic growth of pancreatic cancer cells in earlier studies. It is now shown that Mirk levels increased 7-fold in SU86.86 pancreatic cancer cells when over a third of the cells were accumulated in a quiescent G0 state, defined by Hoechst/Pyronin Y staining. Depletion of Mirk by a doxycycline-inducible short hairpin RNA increased the G0 fraction to ∼50%, suggesting that Mirk provided some function in G0. Mirk reduced the levels of reactive oxygen species (ROS) in quiescent cultures of SU86.86 cells and of Panc1 cells by increasing transcription of the antioxidant genes ferroxidase, superoxide dismutase (SOD)2, and SOD3. These genes were functional antioxidant genes in pancreatic cancer cells because ectopic expression of SOD2 and ferroxidase in Mirk-depleted cells lowered ROS levels. Quiescent pancreatic cancer cells quickly lost viability when depleted of Mirk because of elevated ROS levels, exhibiting up to 4-fold less colony-forming activity and 4-fold less capability for dye exclusion. As a result, reduction of ROS by N-acetyl cysteine led to more viable cells. Mirk also destabilizated cyclin D1 and D3 in quiescent cells. Thus, quiescent pancreatic cancer cells depleted of Mirk became less viable because they were damaged by ROS, and had increased levels of G1 cyclins to prime cells to escape quiescence. [Cancer Res 2009;69(8):3317–24]
Osteoblast-Derived Factors Induce an Expression Signature that Identifies Prostate Cancer Metastasis and Hormonal Progression
Authors: Wang Gang , Haile Simon , Comuzzi Barbara , Tien Amy H. , Wang Jun , Yong Theresa M.K. , Jelescu-Bodos Anca E. , Blaszczyk Natalie , Vessella Robert L. , Masri Bassam A. , Sadar Marianne D.
Published: April 2009

Identification of gene expression signatures associated with metastases provides a tool to discern mechanisms and potential therapeutic targets and may lead toward a molecular classification system in pathology. Prostate cancer (CaP) frequently metastasizes to the bone to form osteoblastic lesions. Correlative clinical data and in vitro evidence have led to the hypothesis that osteoblast-derived factors promote hormonal progression of CaP cells. Here, the gene expression signature of CaP exposed to osteoblast-derived factors was identified. This signature included known androgen-regulated genes, oncogenes, tumor suppressors, and genes whose products are involved in apoptosis and cell cycle. A comparative functional genomic approach involved the application of this responsive gene expression signature to clinical samples of human CaP, melanomas, and oral cancers. Cluster analysis revealed that this gene expression signature had specificity for CaP and could resolve clinical specimens according to stage (benign, localized, and metastatic) and androgen sensitivity with an accuracy of 100% and 80%, respectively. Together, these results suggest that factors derived from osteoblasts induce a more advanced phenotype of CaP and promotes hormonal progression. [Cancer Res 2009;69(8):3433–42]
Identification of Copy Number Abnormalities and Inactivating Mutations in Two Negative Regulators of Nuclear Factor-κB Signaling Pathways in Waldenström's Macroglobulinemia
Authors: Braggio Esteban , Keats Jonathan J. , Leleu Xavier , Van Wier Scott , Jimenez-Zepeda Victor H. , Valdez Riccardo , Schop Roelandt F.J. , Price-Troska Tammy , Henderson Kimberly , Sacco Antonio , Azab Feda , Greipp Philip , Gertz Morie , Hayman Suzanne , Rajkumar S. Vincent , Carpten John , Chesi Marta , Barrett Michael , Stewart A. Keith , Dogan Ahmet , Bergsagel P. Leif , Ghobrial Irene M. , Fonseca Rafael
Published: April 2009

Waldenström's macroglobulinemia (WM) is a distinct clinicobiological entity defined as a B-cell neoplasm characterized by a lymphoplasmacytic infiltrate in bone marrow (BM) and IgM paraprotein production. Cytogenetic analyses were historically limited by difficulty in obtaining tumor metaphases, and the genetic basis of the disease remains poorly defined. Here, we performed a comprehensive analysis in 42 WM patients by using a high-resolution, array-based comparative genomic hybridization approach to unravel the genetic mechanisms associated with WM pathogenesis. Overall, 83% of cases have chromosomal abnormalities, with a median of three abnormalities per patient. Gain of 6p was the second most common abnormality (17%), and its presence was always concomitant with 6q loss. A minimal deleted region, including MIRN15A and MIRN16-1, was delineated on 13q14 in 10% of patients. Of interest, we reported biallelic deletions and/or inactivating mutations with uniparental disomy in tumor necrosis factor (TNF) receptor–associated factor 3 and TNFα-induced protein 3, two negative regulators of the nuclear factor-κB (NF-κB) signaling pathway. Furthermore, we confirmed the association between TRAF3 inactivation and increased transcriptional activity of NF-κB target genes. Mutational activation of the NF-κB pathway, which is normally activated by ligand receptor interactions within the BM microenvironment, highlights its biological importance, and suggests a therapeutic role for inhibitors of NF-κB pathway activation in the treatment of WM. [Cancer Res 2009;69(8):3579–88]
Attenuated Transforming Growth Factor β Signaling Promotes Nuclear Factor-κB Activation in Head and Neck Cancer
Authors: Cohen Jonah , Chen Zhong , Lu Shi-Long , Yang Xin Ping , Arun Pattatheyil , Ehsanian Reza , Brown Matthew S. , Lu Hai , Yan Bin , Diallo Oumou , Wang Xiao-Jing , Van Waes Carter
Published: April 2009

Although constitutively activated nuclear factor-κB (NF-κB), attenuated transforming growth factor β (TGFβ) signaling, and TP53 mutations frequently occur in human cancers, how these pathways interact and together contribute to malignancy remains uncertain. Here, we found an association between overexpression of NF-κB–related genes, reduced expression of TGFβ receptor (TβR) subunits and downstream targets, and TP53 genotype in head and neck squamous cell carcinoma (HNSCC). In response to recombinant TGFβ1, both growth inhibition and TGFβ target gene modulation were attenuated or absent in a panel of human HNSCC lines. However, in HNSCC cells that retained residual TGFβ signaling, TGFβ1 inhibited both constitutive and tumor necrosis factor α–stimulated NF-κB activity. Furthermore, HNSCC lines overexpressing mutant (mt) TP53 and human tumor specimens with positive TP53 nuclear staining exhibited reduced TβRII and knocking down mtTP53 induced TβRII, increasing TGFβ downstream gene expression while inhibiting proinflammatory NF-κB target gene expression. Transfection of ectopic TβRII directly restored TGFβ signaling while inhibiting inhibitor κBα degradation and suppressing serine-536 phosphorylation of NF-κB p65 and NF-κB transcriptional activation, linking these alterations. Finally, experiments with TβRII conditional knockout mice show that abrogation of TGFβ signaling promotes the sustained induction of NF-κB and its proinflammatory target genes during HNSCC tumorigenesis and progression. Together, these findings elucidate a regulatory framework in which attenuated TGFβ signaling promotes NF-κB activation and squamous epithelial malignancy in the setting of altered TP53 status. [Cancer Res 2009;69(8):3415–24]
The Cell Fate Determination Factor Dachshund Inhibits Androgen Receptor Signaling and Prostate Cancer Cellular Growth
Authors: Wu Kongming , Katiyar Sanjay , Witkiewicz Agnes , Li Anping , McCue Peter , Song Liang-Nian , Tian Lifeng , Jin Ming , Pestell Richard G.
Published: April 2009

Initially isolated as the dominant suppressor of the mutant epidermal growth factor receptor (ellipse), the Dachshund gene plays a key role in metazoan development regulating the Retinal Determination Gene Network. Herein, the DACH1 gene was expressed in normal prostate epithelial cells with reduced expression in human prostate cancer. DACH1 inhibited prostate cancer cellular DNA synthesis, growth in colony forming assays, and blocked contact-independent growth in soft agar assays. DACH1 inhibited androgen receptor (AR) activity, requiring a conserved DS Domain (Dachshund domain conserved with Ski/Sno) that bound NCoR/HDAC and was recruited to an androgen-responsive gene promoter. DACH1 inhibited ligand-dependent activity of AR mutations identified in patients with androgen-insensitive prostate cancer. The DS domain was sufficient for repression of the AR wild-type but failed to repress an AR acetylation site point mutant. These studies show a role for the Retinal Determination Gene Network in regulating cellular growth and signaling in prostate cancer. [Cancer Res 2009;69(8):3347–55]
Human Glioblastoma–Derived Cancer Stem Cells: Establishment of Invasive Glioma Models and Treatment with Oncolytic Herpes Simplex Virus Vectors
Authors: Wakimoto Hiroaki , Kesari Santosh , Farrell Christopher J. , Curry William T. , Zaupa Cecile , Aghi Manish , Kuroda Toshihiko , Stemmer-Rachamimov Anat , Shah Khalid , Liu Ta-Chiang , Jeyaretna Deva S. , Debasitis Jason , Pruszak Jan , Martuza Robert L. , Rabkin Samuel D.
Published: April 2009

Glioblastoma, the most malignant type of primary brain tumor, is one of the solid cancers where cancer stem cells have been isolated, and studies have suggested resistance of those cells to chemotherapy and radiotherapy. Here, we report the establishment of CSC-enriched cultures derived from human glioblastoma specimens. They grew as neurospheres in serum-free medium with epidermal growth factor and fibroblast growth factor 2, varied in the level of CD133 expression and very efficiently formed highly invasive and/or vascular tumors upon intracerebral implantation into immunodeficient mice. As a novel therapeutic strategy for glioblastoma-derived cancer stem–like cells (GBM-SC), we have tested oncolytic herpes simplex virus (oHSV) vectors. We show that although ICP6 (UL39)–deleted mutants kill GBM-SCs as efficiently as wild-type HSV, the deletion of γ34.5 significantly attenuated the vectors due to poor replication. However, this was significantly reversed by the additional deletion of α47. Infection with oHSV G47Δ (ICP6−, γ34.5−, α47−) not only killed GBM-SCs but also inhibited their self-renewal as evidenced by the inability of viable cells to form secondary tumor spheres. Importantly, despite the highly invasive nature of the intracerebral tumors generated by GBM-SCs, intratumoral injection of G47Δ significantly prolonged survival. These results for the first time show the efficacy of oHSV against human GBM-SCs, and correlate this cytotoxic property with specific oHSV mutations. This is important for designing new oHSV vectors and clinical trials. Moreover, the new glioma models described in this study provide powerful tools for testing experimental therapeutics and studying invasion and angiogenesis. [Cancer Res 2009;69(8):3472–81]
Oxidation Status of Human OGG1-S326C Polymorphic Variant Determines Cellular DNA Repair Capacity
Authors: Bravard Anne , Vacher Monique , Moritz Eva , Vaslin Laurence , Hall Janet , Epe Bernd , Radicella J. Pablo
Published: April 2009

The hOGG1 gene encodes the DNA glycosylase that removes the mutagenic lesion 7,8-dihyro-8-oxoguanine (8-oxoG) from DNA. A frequently found polymorphism resulting in a serine to cysteine substitution at position 326 of the OGG1 protein has been associated in several molecular epidemiologic studies with cancer development. To investigate whether the variant allele encodes a protein with altered OGG1 function, we compared the 8-oxoG repair activity, both in vivo and in cell extracts, of lymphoblastoid cell lines established from individuals carrying either Ser/Ser or Cys/Cys genotypes. We show that cells homozygous for the Cys variant display increased genetic instability and reduced in vivo 8-oxoG repair rates. Consistently, their extracts have an almost 2-fold lower basal 8-oxoG DNA glycosylase activity when compared with the Ser variant. Treatment with reducing agents of either the Cys variant cells directly or of protein extracts from these cells increases the repair capacity to the level of the Ser variant, whereas it does not affect the activity in cells or extracts from the latter. Furthermore, the DNA glycosylase activity of cells carrying the Cys/Cys alleles is more sensitive to inactivation by oxidizing agents when compared with that of the Ser/Ser cells. Analysis of the redox status of the OGG1 protein in the cells confirms that the lower activity of OGG1-Cys326 is associated with the oxidation of Cys326 to form a disulfide bond. Our findings support the idea that individuals homozygous for the OGG1-Cys variant could more readily accumulate mutations under conditions of oxidative stress. [Cancer Res 2009;69(8):3642–9]
Clinical Predictors for Germline Mutations in Head and Neck Paraganglioma Patients: Cost Reduction Strategy in Genetic Diagnostic Process as Fall-Out
Authors: Neumann Hartmut P.H. , Erlic Zoran , Boedeker Carsten C. , Rybicki Lisa A. , Robledo Mercedes , Hermsen Mario , Schiavi Francesca , Falcioni Maurizio , Kwok Pingling , Bauters Catherine , Lampe Karen , Fischer Markus , Edelman Emily , Benn Diana E. , Robinson Bruce G. , Wiegand Stefanie , Rasp Gerd , Stuck Boris A. , Hoffmann Michael M. , Sullivan Maren , Sevilla Maria A. , Weiss Marjan M. , Peczkowska Mariola , Kubaszek Agata , Pigny Pascal , Ward Robyn L. , Learoyd Diana , Croxson Michael , Zabolotny Dmitry , Yaremchuk Svetlana , Draf Wolfgang , Muresan Mihaela , Lorenz Robert R. , Knipping Stephan , Strohm Michael , Dyckhoff Gerhard , Matthias Christoph , Reisch Nicole , Preuss Simon F. , Eβer Dirk , Walter Martin A. , Kaftan Holger , Stöver Timo , Fottner Christian , Gorgulla Harald , Malekpour Mahdi , Zarandy Masoud Motasaddi , Schipper Jörg , Brase Christoph , Glien Alexander , Kühnemund Matthias , Koscielny Sven , Schwerdtfeger Peter , Välimäki Matti , Szyfter Witold , Finckh Ulrich , Zerres Klaus , Cascon Alberto , Opocher Giuseppe , Ridder Gerd J. , Januszewicz Andrzej , Suarez Carlos , Eng Charis
Published: April 2009

Multiple genes and their variants that lend susceptibility to many diseases will play a major role in clinical routine. Genetics-based cost reduction strategies in diagnostic processes are important in the setting of multiple susceptibility genes for a single disease. Head and neck paraganglioma (HNP) is caused by germline mutations of at least three succinate dehydrogenase subunit genes (SDHx). Mutation analysis for all 3 costs ∼US$2,700 per patient. Genetic classification is essential for downstream management of the patient and preemptive management of family members. Utilizing HNP as a model, we wanted to determine predictors to prioritize the most heritable clinical presentations and which gene to begin testing in HNP presentations, to reduce costs of genetic screening. Patients were tested for SDHB, SDHC, and SDHD intragenic mutations and large deletions. Clinical parameters were analyzed as potential predictors for finding germline mutations. Cost reduction was calculated between prioritized gene testing compared with that for all genes. Of 598 patients, 30.6% had SDHx germline mutations: 34.4% in SDHB, 14.2% SDHC, and 51.4% SDHD. Predictors for an SDHx mutation are family history [odds ratio (OR), 37.9], previous pheochromocytoma (OR, 10.9), multiple HNP (OR, 10.6), age ≤40 years (OR, 4.0), and male gender (OR, 3.5). By screening only preselected cases and a stepwise approach, 60% cost reduction can be achieved, with 91.8% sensitivity and 94.5% negative predictive value. Our data give evidence that clinical parameters can predict for mutation and help prioritize gene testing to reduce costs in HNP. Such strategy is cost-saving in the practice of genetics-based personalized health care. [Cancer Res 2009;69(8):3650–6]
A Primary Xenograft Model of Small-Cell Lung Cancer Reveals Irreversible Changes in Gene Expression Imposed by CultureIn vitro
Authors: Daniel Vincent C. , Marchionni Luigi , Hierman Jared S. , Rhodes Jonathan T. , Devereux Wendy L. , Rudin Charles M. , Yung Rex , Parmigiani Giovanni , Dorsch Marion , Peacock Craig D. , Watkins D. Neil
Published: April 2009

Traditional approaches to the preclinical investigation of cancer therapies rely on the use of established cell lines maintained in serum-based growth media. This is particularly true of small-cell lung cancer (SCLC), where surgically resected tissue is rarely available. Recent attention has focused on the need for better models that preserve the integrity of cancer stem cell populations, as well as three-dimensional tumor-stromal interactions. Here we describe a primary xenograft model of SCLC in which endobronchial tumor specimens obtained from chemo-naive patients are serially propagated in vivo in immunodeficient mice. In parallel, cell lines grown in conventional tissue culture conditions were derived from each xenograft line, passaged for 6 months, and then reimplanted to generate secondary xenografts. Using the Affymetrix platform, we analyzed gene expression in primary xenograft, xenograft-derived cell line, and secondary xenograft, and compared these data to similar analyses of unrelated primary SCLC samples and laboratory models. When compared with normal lung, primary tumors, xenografts, and cell lines displayed a gene expression signature specific for SCLC. Comparison of gene expression within the xenograft model identified a group of tumor-specific genes expressed in primary SCLC and xenografts that was lost during the transition to tissue culture and that was not regained when the tumors were reestablished as secondary xenografts. Such changes in gene expression may be a common feature of many cancer cell culture systems, with functional implications for the use of such models for preclinical drug development. [Cancer Res 2009;69(8):3364–71]
The miR-17/92 Polycistron Is Up-regulated in Sonic Hedgehog–Driven Medulloblastomas and Induced by N-myc in Sonic Hedgehog–Treated Cerebellar Neural Precursors
Authors: Northcott Paul A. , Fernandez-L Africa , Hagan John P. , Ellison David W. , Grajkowska Wesia , Gillespie Yancey , Grundy Richard , Van Meter Timothy , Rutka James T. , Croce Carlo M. , Kenney Anna Marie , Taylor Michael D.
Published: April 2009

Medulloblastoma is the most common malignant pediatric brain tumor, and mechanisms underlying its development are poorly understood. We identified recurrent amplification of the miR-17/92 polycistron proto-oncogene in 6% of pediatric medulloblastomas by high-resolution single-nucleotide polymorphism genotyping arrays and subsequent interphase fluorescence in situ hybridization on a human medulloblastoma tissue microarray. Profiling the expression of 427 mature microRNAs (miRNA) in a series of 90 primary human medulloblastomas revealed that components of the miR-17/92 polycistron are the most highly up-regulated miRNAs in medulloblastoma. Expression of miR-17/92 was highest in the subgroup of medulloblastomas associated with activation of the sonic hedgehog (Shh) signaling pathway compared with other subgroups of medulloblastoma. Medulloblastomas in which miR-17/92 was up-regulated also had elevated levels of MYC/MYCN expression. Consistent with its regulation by Shh, we observed that Shh treatment of primary cerebellar granule neuron precursors (CGNP), proposed cells of origin for the Shh-associated medulloblastomas, resulted in increased miR-17/92 expression. In CGNPs, the Shh effector N-myc, but not Gli1, induced miR-17/92 expression. Ectopic miR-17/92 expression in CGNPs synergized with exogenous Shh to increase proliferation and also enabled them to proliferate in the absence of Shh. We conclude that miR-17/92 is a positive effector of Shh-mediated proliferation and that aberrant expression/amplification of this miR confers a growth advantage to medulloblastomas. [Cancer Res 2009;69(8):3249–55]
Dual Inhibition of Class IA Phosphatidylinositol 3-Kinase and Mammalian Target of Rapamycin as a New Therapeutic Option for T-Cell Acute Lymphoblastic Leukemia
Authors: Chiarini Francesca , Falà Federica , Tazzari Pier Luigi , Ricci Francesca , Astolfi Annalisa , Pession Andrea , Pagliaro Pasqualepaolo , McCubrey James A. , Martelli Alberto M.
Published: April 2009

Recent investigations have documented that constitutively activated phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling is a common feature of T-cell acute lymphoblastic leukemia (T-ALL), where it strongly influences growth and survival. These findings lend compelling weight for the application of PI3K/Akt/mTOR inhibitors in T-ALL. However, our knowledge of PI3K/Akt/mTOR signaling in T-ALL is limited and it is not clear whether it could be an effective target for innovative therapeutic strategies. Here, we have analyzed the therapeutic potential of the dual PI3K/mTOR inhibitor PI-103, a small synthetic molecule of the pyridofuropyrimidine class, on both T-ALL cell lines and patient samples, which displayed constitutive activation of PI3K/Akt/mTOR signaling. PI-103 inhibited the growth of T-ALL cells, including 170-kDa P-glycoprotein overexpressing cells. PI-103 cytotoxicity was independent of p53 gene status. PI-103 was more potent than inhibitors that are selective only for PI3K (Wortmannin, LY294002) or for mTOR (rapamycin). PI-103 induced G0-G1 phase cell cycle arrest and apoptosis, which was characterized by activation of caspase-3 and caspase-9. PI-103 caused Akt dephosphorylation, accompanied by dephosphorylation of the Akt downstream target, glycogen synthase kinase-3β. Also, mTOR downstream targets were dephosphorylated in response to PI-103, including p70S6 kinase, ribosomal S6 protein, and 4E-BP1. PI-103 strongly synergized with vincristine. These findings indicate that multitargeted therapy toward PI3K and mTOR alone or with existing drugs may serve as an efficient treatment toward T-ALL cells, which require up-regulation of PI3K/Akt/mTOR signaling for their survival and growth. [Cancer Res 2009;69(8):3520–28]
MicroRNA Signature of Primary Pigmented Nodular Adrenocortical Disease: Clinical Correlations and Regulation of Wnt Signaling
Authors: Iliopoulos Dimitrios , Bimpaki Eirini I. , Nesterova Maria , Stratakis Constantine A.
Published: April 2009

MicroRNAs comprise a novel group of gene regulators implicated in the development of different types of cancer; however, their role in primary pigmented nodular adrenocortical disease (PPNAD) has not been investigated. PPNAD is a bilateral adrenal hyperplasia often associated with Carney complex, a multiple neoplasia syndrome; both disorders are caused by protein kinase A (PKA) regulatory subunit type 1A (PRKARIA)–inactivating mutations. We identified a 44-microRNA gene signature of PPNAD after comparing PPNAD with normal adrenal samples. Specifically, 33 microRNAs were up-regulated and 11 down-regulated in PPNAD relative to normal tissues. These results were validated by stem loop real-time PCR analysis. Comparison of microRNA microarray data with clinicopathologic variables revealed a negative correlation (r = −0.9499) between let-7b expression and cortisol levels in patients with PPNAD. Integration of microRNA microarray with serial analysis of gene expression data together with bioinformatic algorithm predictions revealed nine microRNA-gene target pairs with a potential role in adrenal pathogenesis. Using a PPNAD cell line, we showed that miR-449 was up-regulated and identified its direct target, WNT1-inducible signaling pathway protein 2 (WISP2); in addition, pharmacologic inhibition of PKA resulted in the up-regulation of miR-449 leading to the suppression of WISP2. Overall, we investigated, for the first time, the microRNA profile and its clinical significance in PPNAD; these data also suggest that PKA, via microRNA regulation, affects the Wnt signaling pathway, which through expression and clinical studies is suspected to be a primary mediator of PRKAR1A-related tumorigenesis. [Cancer Res 2009;69(8):3278–82]
Replication of the 10q11 and Xp11 Prostate Cancer Risk Variants: Results from a Utah Pedigree-Based Study
Authors: Camp Nicola J. , Farnham James M. , Wong Jathine , Christensen G. Bryce , Thomas Alun , Cannon-Albright Lisa A.
Published: April 2009

A recent genome-wide association study suggested seven new loci as associated with prostate cancer susceptibility. The strongest associated single nucleotide polymorphism (SNP) in each region was identified (rs2660753, rs9364554, rs6465657, rs10993994, rs7931342, rs2735839, rs5945619). We studied these seven SNPs in a replication study consisting of 169 familial prostate cancer cases selected from Utah high-risk prostate cancer pedigrees and 805 controls. We performed subset analyses for aggressive and early-onset prostate cancer. At a nominal significance level, two SNPs were found to be associated with prostate cancer: rs10993994 on chromosome 10q11 [odds ratio (OR), 1.42; 95% confidence interval (95% CI), 1.05-1.90; P = 0.022] and rs5945619 on chromosome Xp11 (OR, 1.54; 95% CI, 1.03-2.31; P = 0.035). Restricting analysis to familial prostate cancer cases with aggressive disease yielded very similar risk estimates at both SNPs. However, subset analysis for familial, early-onset disease indicated highly significant association evidence and substantially higher risk estimates for rs10993994 (OR, 2.20; 95% CI, 1.48-3.27; P < 0.0001). This result suggests that the higher risk estimates from the stage 1 cohort in the original study for rs10993994 may have been due to the early-onset and familial nature of the prostate cancer cases in that cohort. In conclusion, in a small case-control study of prostate cancer cases from Utah high-risk pedigrees, we have significantly replicated association of prostate cancer with rs10993994 (10q11) upon study-wide correction for multiple comparisons. We also nominally replicated the association of prostate cancer with rs5945619 (Xp11). In particular, it seems that the susceptibility locus at 10q11 maybe involved in familial, early-onset disease. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1290–4)
Genetic Models for the Familial Aggregation of Mammographic Breast Density
Authors: Kataoka Masako , Antoniou Antonis , Warren Ruth , Leyland Jean , Brown Judith , Audley Tina , Easton Doug
Published: April 2009

Background: Mammographic breast density (MBD) has a strong genetic component. Investigating the genetic models for mammographic density may provide further insights into the genetic factors affecting breast cancer risk.

Purpose: To evaluate the familial aggregation of MBD and investigate the genetic models of susceptibility.

Methods: We used data on 746 women from 305 families participating in the Sisters in Breast Screening study. Retrieved mammograms were digitized, and percent mammographic density was determined using the Cumulus software. Linear regression analysis was done to identify the factors that are associated with mammographic density and a multivariate regression model was constructed. Familial correlations between relative pairs were calculated using the residuals from these models. Genetic models of susceptibility were investigated using segregation analysis.

Results: After adjusting for covariates, the intraclass correlation coefficient among the residuals was 0.26 (95% confidence interval, 0.16-0.36) in sister-sister pairs and 0.67 (0.27-1.00) among the monozygotic twin pairs. The most parsimonious model was a Mendelian single major gene model in which an allele with population frequency 0.39 (95% confidence interval, 0.33-0.46) influenced mammographic density in an additive fashion. This model explained 66% of the residual variance.

Conclusion: These results confirm that MBD has a strong heritable basis, and suggest that major genes may explain some of the familial aggregation. These results may have implications for the search of genes that control mammographic density. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1277–84)
Afamin and Apolipoprotein A-IV: Novel Protein Markers for Ovarian Cancer
Authors: Dieplinger Hans , Ankerst Donna Pauler , Burges Alexander , Lenhard Miriam , Lingenhel Arno , Fineder Linda , Buchner Hannes , Stieber Petra
Published: April 2009

Comparative proteomics identified the vitamin E-binding plasma protein afamin as a potential novel tumor marker for ovarian cancer. In addition, we observed in a previous small study decreased plasma concentrations of apolipoprotein A-IV (apoA-IV) in preoperative patients with kidney cancer. The aim of this study was therefore to analyze afamin and apoA-IV in a large case-control study to evaluate the diagnostic utility of the two potential novel tumor markers in ovarian cancer patients. We measured plasma concentrations of afamin and apoA-IV by means of a specific sandwich-type ELISA using affinity-purified polyclonal and monoclonal antibodies in 181 ovarian cancer patients of various clinical stages, 399 patients with benign gynecologic diseases, including endometriosis, and 177 controls and compared results with those for the conventional ovarian cancer tumor marker cancer antigen 125 (CA125). Afamin concentrations decreased from a median of 70.7 mg/L (range, 34.6-116.1 mg/L) in healthy controls to 65.2 mg/L (range, 20.2-206.6 mg/L) in patients with benign gynecologic diseases to 56.0 mg/L (range, 4.7-96.0 mg/L) in ovarian cancer patients (P < 0.001 for all pairwise comparisons). Similar results were obtained with apoA-IV concentrations decreasing from 13.0 mg/dL (range, 5.5-34.0 mg/dL) in controls to 11.7 mg/dL (range, 2.0-32.3 mg/dL) in benign conditions to 9.4 mg/dL (range, 0.3-29.5 mg/dL) in ovarian cancer (all P < 0.001). Receiver operating characteristic analysis for differentiating ovarian cancer patients from healthy controls revealed for a specificity of 90% sensitivity values of 92.4%, 42.4%, and 40.8% for CA125, afamin, and apoA-IV, respectively. Afamin, but not apoA-IV, added independent diagnostic information to CA125 and age for differentiating ovarian cancer from benign and healthy samples; the odds ratio of ovarian cancer was reduced by 44% for each doubling of afamin (P = 0.032). The relatively low sensitivity, however, clearly indicates that afamin and apoA-IV alone are not sufficiently suitable as diagnostic markers for ovarian cancer. Afamin contributes, however, independent diagnostic information to CA125, thus establishing its potential as an adjunct marker to CA125. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1127–33)
Prenatal X-ray Exposure and Rhabdomyosarcoma in Children: A Report from the Children's Oncology Group
Authors: Grufferman Seymour , Ruymann Frederick , Ognjanovic Simona , Erhardt Erik B. , Maurer Harold M.
Published: April 2009

The association between antenatal diagnostic X-ray exposure and risk of rhabdomyosarcoma in children was assessed in a national case-control study of 319 rhabdomyosarcoma cases and 319 matched controls. Data were collected by telephone interviews of subjects' parents. Overall, an odds ratio (OR) of 1.9 [95% confidence interval (CI), 1.1-3.4] was found for any X-ray examination of the mother during pregnancy. Risk was greatest for X-ray exposure during the first trimester (OR, 5.7; 95% CI, 1.2-27.8) and was also increased for the third trimester (OR, 2.0; 95% CI, 0.9-4.6), whereas second trimester exposure was not associated with increased risk. A nonsignificant increase in risk was found for any X-rays of the abdomen, pelvis, chest, or back. Increased risk was significantly associated with “other” X-ray exposures (relative risk, 2.9; 95% CI, 1.1-7.7), primarily composed of dental X-rays. The association was strongest between embryonal rhabdomyosarcoma and first trimester exposure (relative risk, 10.5; 95% CI, 1.5-458.4). This observation regarding embryonal rhabdomyosarcoma, and our previous report of an increased frequency of major malformations in rhabdomyosarcoma are compatible with findings from animal studies in which Ptc heterozygous knockout mice exhibited an increased risk of radiation-induced development defects and of spontaneously occurring embryonal rhabdomyosarcoma. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1271–6)
Ductal Lavage in Women from BRCA1/2 Families: Is There a Future for Ductal Lavage in Women at Increased Genetic Risk of Breast Cancer?
Authors: Loud Jennifer T. , Thiébaut Anne C.M. , Abati Andrea D. , Filie Armando C. , Nichols Kathryn , Danforth David , Giusti Ruthann , Prindiville Sheila A. , Greene Mark H.
Published: April 2009

Purpose: Ductal lavage has been used for risk stratification and biomarker development and to identify intermediate endpoints for risk-reducing intervention trials. Little is known about patient characteristics associated with obtaining nipple aspirate fluid (NAF) and adequate cell counts (≥10 cells) in ductal lavage specimens from BRCA mutation carriers.

Methods: We evaluated patient characteristics associated with obtaining NAF and adequate cell counts in ductal lavage specimens from the largest cohort of women from BRCA families yet studied (BRCA1/2 = 146, mutation-negative = 23, untested = 2). Fisher's exact test was used to evaluate categorical variables; Wilcoxon nonparametric test was used to evaluate continuous variables associated with NAF or ductal lavage cell count adequacy. Logistic regression was used to identify independent correlates of NAF and ductal lavage cell count adequacy.

Results: From 171 women, 45 (26%) women had NAF and 70 (41%) women had ductal lavage samples with ≥10 cells. Postmenopausal women with intact ovaries compared with premenopausal women [odds ratio (OR), 4.8; P = 0.03] and women without a prior breast cancer history (OR, 5.2; P = 0.04) had an increased likelihood of yielding NAF. Having breast-fed (OR, 3.4; P = 0.001), the presence of NAF before ductal lavage (OR, 3.2; P = 0.003), and being premenopausal (OR, 3.0; P = 0.003) increased the likelihood of ductal lavage cell count adequacy. In known BRCA1/2 mutation carriers, only breast-feeding (OR, 2.5; P = 0.01) and the presence of NAF (OR, 3.0; P = 0.01) were independent correlates of ductal lavage cell count adequacy.

Conclusions: Ductal lavage is unlikely to be useful in breast cancer screening among BRCA1/2 mutation carriers because the procedure fails to yield adequate specimens sufficient for reliable cytologic diagnosis or to support translational research activities. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1243–51)
Serum Retinol and Prostate Cancer Risk: a Nested Case-Control Study in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial
Authors: Schenk Jeannette M. , Riboli Elio , Chatterjee Nilanjan , Leitzmann Michael F. , Ahn Jiyoung , Albanes Demetrius , Reding Douglas J. , Wang Yinghui , Friesen Marlin D. , Hayes Richard B. , Peters Ulrike
Published: April 2009

Vitamin A (retinol) plays a key role in the regulation of cell growth and differentiation, and has been studied as a potential chemopreventive agent for prostate cancer. However, findings from epidemiologic studies on the association between circulating retinol concentrations and the risk of prostate cancer are inconsistent. We examined whether serum concentrations of retinol were associated with the risk of prostate cancer in a nested case-control study using 692 prostate cancer cases and 844 matched controls from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. We estimated the risk of prostate cancer using multivariate, conditional logistic regression to calculate odds ratios and 95% confidence intervals for overall prostate cancer and aggressive disease (stage III or IV or Gleason >7; n = 269). Serum retinol concentrations were not associated with overall prostate cancer risk; however, the highest versus lowest concentrations of serum retinol were associated with a 42% reduction in aggressive prostate cancer risk (Ptrend = 0.02), with the strongest inverse association for high-grade disease (Gleason sum >7; odds ratio, 0.52; 95% confidence interval, 0.32-0.84; Ptrend = 0.01). Our results suggest that higher circulating concentrations of retinol are associated with a decreased risk of aggressive prostate cancer. Further research is needed to better understand the significance of elevations in serum retinol concentrations and the possible biological mechanisms through which retinol affects prostate cancer. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1227–31)
A Prospective Study of Relative Telomere Length and Postmenopausal Breast Cancer Risk
Authors: De Vivo Immaculata , Prescott Jennifer , Wong Jason Y.Y. , Kraft Peter , Hankinson Susan E. , Hunter David J.
Published: April 2009

During breast cancer progression, a substantial increase in chromosomal aberrations is observed in the transition from ductal hyperplasia to carcinoma in situ. Telomeres are essential structures to chromosomal integrity. Consequently, telomere dysfunction, which leads to genomic instability, is hypothesized to play a causal role in the progression of breast cancer. However, the few epidemiologic studies that have assessed the relationship between telomere length and breast cancer risk have been inconsistent. We used quantitative real-time PCR to measure relative telomere length in genomic DNA extracted from peripheral blood leukocytes and examined its association with postmenopausal breast cancer risk in 1,122 invasive breast cancer cases and 1,147 matched controls free of diagnosed cancer nested within the prospective Nurses' Health Study. Our data show that relative telomere length was not associated with a significant elevation in postmenopausal breast cancer risk [below versus above median; odds ratio, 1.23; 95% confidence interval, 0.94-1.60; Ptrend = 0.20]. Estrone and estradiol hormone levels were significantly inversely associated with relative telomere length (P = 0.02). Other established breast cancer risk factors such as family history of breast cancer and history of benign breast disease were not associated with relative telomere length in separate linear regression models each adjusted for age and disease status (P ≥ 0.07). Our results provide little support for an important role of telomere length, as measured in peripheral blood leukocytes, as a biomarker of breast cancer risk. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1152–6)
The Association between Diabetes, Insulin Use, and Colorectal Cancer among Whites and African Americans
Authors: Vinikoor Lisa C. , Long Millie D. , Keku Temitope O. , Martin Christopher F. , Galanko Joseph A. , Sandler Robert S.
Published: April 2009

Colorectal cancer and diabetes are common diseases that share many risk factors. It has been hypothesized that diabetes is a risk factor for colorectal cancer. We used two large population-based case-control studies from North Carolina to determine whether diabetes and/or insulin therapy was associated with colon cancer and/or rectal cancer (defined as cancer of the sigmoid colon, rectosigmoid, or rectum) and whether this association differed by race. Cases and matched controls from the North Carolina Colon Cancer Studies I and II were interviewed about demographics, dietary factors, diagnosis of diabetes, and use of medications to treat diabetes. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using unconditional logistic regression. Colon and rectal cancer cases reported a higher prevalence of diabetes than their respective control groups. Compared with Whites without diabetes, Whites with diabetes had adjusted ORs of 1.40 (95% CI, 0.93-2.12) for colon cancer and 1.38 (95% CI, 1.00-1.90) for rectal cancer. Diabetes was not associated with colon or rectal cancer among African Americans [OR, 1.17 (95% CI, 0.81-1.70) and 0.75 (95% CI, 0.44-1.28), respectively]. Among Whites with diabetes, insulin use was positively associated with rectal cancer. The same association was not seen for African American diabetics using insulin; however, the number of African Americans using insulin was small. In sum, diabetes was positively associated with rectal cancer and approached a positive association with colon cancer among Whites. No association was present among African Americans. Insulin use was also positively associated with rectal cancer among Whites. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1239–42)
Performance of Prediction Models for BRCA Mutation Carriage in Three Racial/Ethnic Groups: Findings from the Northern California Breast Cancer Family Registry
Authors: Kurian Allison W. , Gong Gail D. , John Esther M. , Miron Alexander , Felberg Anna , Phipps Amanda I. , West Dee W. , Whittemore Alice S.
Published: April 2009

Purpose: Patients with early-onset breast and/or ovarian cancer frequently wish to know if they inherited a mutation in one of the cancer susceptibility genes, BRCA1 or BRCA2. Accurate carrier prediction models are needed to target costly testing. Two widely used models, BRCAPRO and BOADICEA, were developed using data from non-Hispanic Whites (NHW), but their accuracies have not been evaluated in other racial/ethnic populations.

Methods: We evaluated the BRCAPRO and BOADICEA models in a population-based series of African American, Hispanic, and NHW breast cancer patients tested for BRCA1 and BRCA2 mutations. We assessed model calibration by evaluating observed versus predicted mutations and attribute diagrams, and model discrimination using areas under the receiver operating characteristic curves.

Results: Both models were well-calibrated within each racial/ethnic group, with some exceptions. BOADICEA overpredicted mutations in African Americans and older NHWs, and BRCAPRO underpredicted in Hispanics. In all racial/ethnic groups, the models overpredicted in cases whose personal and family histories indicated >80% probability of carriage. The two models showed similar discrimination in each racial/ethnic group, discriminating least well in Hispanics. For example, BRCAPRO's areas under the receiver operating characteristic curves were 83% (95% confidence interval, 63-93%) for NHWs, compared with 74% (59-85%) for African Americans and 58% (45-70%) for Hispanics.

Conclusions: The poor performance of the model for Hispanics may be due to model misspecification in this racial/ethnic group. However, it may also reflect racial/ethnic differences in the distributions of personal and family histories among breast cancer cases in the Northern California population. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1084–91)