bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Classification of Proliferative Pulmonary Lesions of the Mouse
Authors: Nikitin Alexander Yu. , Alcaraz Ana , Anver Miriam R. , Bronson Roderick T. , Cardiff Robert D. , Dixon Darlene , Fraire Armando E. , Gabrielson Edward W. , Gunning William T. , Haines Diana C. , Kaufman Matthew H. , Linnoila R. Ilona , Maronpot Robert R. , Rabson Alan S. , Reddick Robert L. , Rehm Sabine , Rozengurt Nora , Schuller Hildegard M. , Shmidt Elena N. , Travis William D. , Ward Jerrold M. , Jacks Tyler
Published: March 2023

Abstract
Rapid advances in generating new mouse genetic models for lung neoplasia provide a continuous challenge for pathologists and investigators. Frequently, phenotypes of new models either have no precedents or are arbitrarily attributed according to incongruent human and mouse classifications. Thus, comparative characterization and validation of novel models can be difficult. To address these issues, a series of discussions was initiated by a panel of human, veterinary, and experimental pathologists during the Mouse Models of Human Cancers Consortium (NIH/National Cancer Institute) workshop on mouse models of lung cancer held in Boston on June 20–22, 2001. The panel performed a comparative evaluation of 78 cases of mouse and human lung proliferative lesions, and recommended development of a new practical classification scheme that would (a) allow easier comparison between human and mouse lung neoplasms, (b) accommodate newly emerging mouse neoplasms, and (c) address the interpretation of benign and preinvasive lesions of the mouse lung. Subsequent discussions with additional experts in pulmonary pathology resulted in the current proposal of a new classification. It is anticipated that this classification, as well as the complementary digital atlas of virtual histological slides, will help investigators and pathologists in their characterization of new mouse models, as well as stimulate further research aimed at a better understanding of proliferative lesions of the lung.
Data from Differential Regulation of Noxa in Normal Melanocytes and Melanoma Cells by Proteasome Inhibition: Therapeutic Implications
Authors: Fernández Yolanda , Verhaegen Monique , Miller Thomas P. , Rush Jenny L. , Steiner Philipp , Opipari Anthony W. , Lowe Scott W. , Soengas María S.
Published: March 2023

Abstract
Melanoma is the most aggressive form of skin cancer and advanced stages are invariably resistant to conventional therapeutic agents. Using bortezomib as a prototypic proteasome inhibitor, we have identified a novel and critical role of the proteasome in the maintenance of the malignant phenotype of melanoma cells that could have direct translational implications. Thus, melanoma cells from early, intermediate, and late stages of the disease could not sustain proteasome inhibition and underwent an effective activation of caspase-dependent and -independent death programs. This effect was tumor cell selective, because under similar conditions, normal melanocytes remained viable. Intriguingly, and despite of interfering with a cellular machinery in charge of controlling the half-life of the vast majority of cellular proteins, bortezomib did not promote a generalized disruption of melanoma-associated survival factors (including NF-κB, Bcl-2, Bcl-xL, XIAP, TRAF-2, or FLIP). Instead, we identified a dramatic induction in vitro and in vivo of the BH3-only protein Noxa in melanoma cells (but not in normal melanocytes) in response to proteasome inhibition. RNA interference validated a critical role of Noxa for the cytotoxic effect of bortezomib. Notably, the proteasome-dependent regulation of Noxa was found to extend to other tumor types, and it could not be recapitulated by standard chemotherapeutic drugs. In summary, our results revealed Noxa as a new biomarker to gauge the efficacy of bortezomib specifically in tumor cells, and provide a new strategy to overcome tumor chemoresistance.
Data from Synergistic Suppression of Microtubule Dynamics by Discodermolide and Paclitaxel in Non-Small Cell Lung Carcinoma Cells
Authors: Honore Stéphane , Kamath Kathy , Braguer Diane , Horwitz Susan Band , Wilson Leslie , Briand Claudette , Jordan Mary Ann
Published: March 2023

Abstract
Discodermolide is a new microtubule-targeted antimitotic drug in Phase I clinical trials that, like paclitaxel, stabilizes microtubule dynamics and enhances microtubule polymer mass in vitro and in cells. Despite their apparently similar binding sites on microtubules, discodermolide acts synergistically with paclitaxel to inhibit proliferation of A549 human lung cancer cells (L. Martello et al., Clin. Cancer Res., 6: 1978–1987, 2000). To understand their synergy, we examined the effects of the two drugs singly and in combination in A549 cells and found that, surprisingly, their antiproliferative synergy is related to their ability to synergistically inhibit microtubule dynamic instability and mitosis. The combination of discodermolide and paclitaxel at their antiproliferative IC50s (7 nm for discodermolide and 2 nm for paclitaxel) altered all of the parameters of dynamic instability synergistically except the time-based rescue frequency. For example, together the drugs inhibited overall microtubule dynamicity by 71%, but each drug individually inhibited dynamicity by only 24%, giving a combination index (CI) of 0.23. Discodermolide and paclitaxel also synergistically blocked cell cycle progression at G2-M (41, 9.6, and 16% for both drugs together, for discodermolide alone, and for paclitaxel alone, respectively; CI = 0.59), and they synergistically enhanced apoptosis (CI = 0.85). Microtubules are unique receptors for drugs. The results suggest that ligands that bind to large numbers of binding sites on an individual microtubule can interact in a poorly understood manner to synergistically suppress microtubule dynamic instability and inhibit both mitosis and cell proliferation, with important consequences for combination clinical therapy with microtubule-targeted drugs.
Data from Somatic Mutations and Altered Expression of the Candidate Tumor Suppressors CSNK1ε, DLG1, and EDD/hHYD in Mammary Ductal Carcinoma
Authors: Fuja Tannin J. , Lin Fritz , Osann Kathryn E. , Bryant Peter J.
Published: March 2023

Abstract
We report somatic mutations in three genes (CSNK1ε, encoding the Ser/Thr kinase casein kinase I ε; DLG1, encoding a membrane-associated putative scaffolding protein; and EDD/hHYD, encoding a progestin induced putative ubiquitin-protein ligase) in mammary ductal carcinoma. These genes were suspected of playing a role in cancer because loss-of-function mutations in their Drosophila homologues cause excess tissue growth. Using DNA from 82 laser-microdissected tumor samples, followed by microsatellite analysis, denaturing HPLC and direct sequencing, we found multiple somatic point mutations in all three genes, and these mutations showed significant association with loss of heterozygosity of closely linked polymorphic microsatellite markers. For CSNK1ε and DLG1, most of the mutations affected highly conserved residues, some were found repetitively in different patients, and no synonymous mutations were found, indicating that the observed mutations were selected in tumors and may be functionally significant. Immunohistochemical reactivity of each protein was reduced in poorly differentiated tumors, and there was a positive association between altered protein reactivity, loss of heterozygosity, and somatic mutations. There was a statistically significant association of hDlg staining with p53 and Ki67 reactivity, whereas CSK1ε and EDD/hHYD staining levels were associated with progesterone receptor status. The results provide strong indications for a role of all three genes in mammary ductal carcinoma. They also justify additional studies of the functional significance of the changes, as well as a search for additional changes in these and other genes identified from studies on model systems.
Data from Transforming Growth Factor-β Suppresses Nonmetastatic Colon Cancer through Smad4 and Adaptor Protein ELF at an Early Stage of Tumorigenesis
Authors: Tang Yi , Katuri Varalakshmi , Srinivasan Radhika , Fogt Franz , Redman Robert , Anand Girish , Said Anan , Fishbein Thomas , Zasloff Michael , Reddy E. Premkumar , Mishra Bibhuti , Mishra Lopa
Published: March 2023

Abstract
Although transforming growth factor-β (TGF-β) is both a suppressor and promoter of tumorigenesis, its contribution to early tumor suppression and staging remains largely unknown. In search of the mechanism of early tumor suppression, we identified the adaptor protein ELF, a β-spectrin from stem/progenitor cells committed to foregut lineage. ELF activates and modulates Smad4 activation of TGF-β to confer cell polarity, to maintain cell architecture, and to inhibit epithelial-to-mesenchymal transition. Analysis of development of colon cancer in (adult) elf+/−/Smad4+/−, elf+/−, Smad4+/−, and gut epithelial cells from elf−/− mutant mouse embryos pinpoints the defect to hyperplasia/adenoma transition. Further analysis of the role of ELF in human colorectal cancer confirms reduced expression of ELF in Dukes' B1 stage tissues (P < 0.05) and of Smad4 in advanced colon cancers (P < 0.05). This study indicates that by modulating Smad 4, ELF has a key role in TGF-β signaling in the suppression of early colon cancer.
Data from High-Resolution Magnetic Resonance Imaging of Disparities in the Transcapillary Transfer Rates in Orthotopically Inoculated Invasive Breast Tumors
Authors: Dadiani Maya , Margalit Raanan , Sela Noa , Degani Hadassa
Published: March 2023

Abstract
In vivo mapping of the transcapillary fluxes in tumors can help predict the efficacy of delivery of blood-borne anticancer drugs. These fluxes are primarily affected by the vascular permeability and the pressure gradients across the blood vessels’ walls. We describe herein high-resolution dynamic contrast-enhanced magnetic resonance imaging of the influx and outflux transcapillary transfer rates in vivo in invasive MDA-MB-231 tumors orthotopically inoculated in severe combined immunodeficient mice. The tumors were noted for rapid growth, impaired drainage of fluid, and subsequent formation of cysts. Consequently, the time evolution of the contrast enhancement, induced by i.v. injection of Gadolinium diethylene-triamine-penta-acetate, exhibited two distinct patterns: transcapillary transfer in the cellular regions and simple diffusion in the cyst fluid. Both processes were analyzed at pixel resolution applying to each a physiological model and a corresponding algorithm. In the cellular region, the influx and outflux transcapillary transfer rates decreased during tumor growth; however, an increased disparity between the transfer constants was observed, with the outflux rate exceeding the influx rate. This quantitative spatial and temporal mapping of this disparity can provide a means to assess the physiological barriers to tracer delivery. It is hypothesized that both the increased disparity in transcapillary transfer rates and impaired fluid drainage in these tumors could arise from the development of interstitial hypertension.
Data from Selenium Deficiency Abrogates Inflammation-Dependent Plasma Cell Tumors in Mice
Authors: Felix Klaus , Gerstmeier Simone , Kyriakopoulos Antonios , Howard O. M. Zack , Dong Hui-Fang , Eckhaus Michael , Behne Dietrich , Bornkamm Georg W. , Janz Siegfried
Published: March 2023

Abstract
The role of the micronutrient, selenium, in human cancers associated with chronic inflammations and persistent infections is poorly understood. Peritoneal plasmacytomas (PCTs) in strain BALB/c (C), the premier experimental model of inflammation-dependent plasma cell transformation in mice, may afford an opportunity to gain additional insights into the significance of selenium in neoplastic development. Here, we report that selenium-depleted C mice (n = 32) maintained on a torula-based low-selenium diet (5–8 μg of selenium/kg) were totally refractory to pristane induction of PCT. In contrast, 11 of 26 (42.3%) control mice maintained on a selenium adequate torula diet (300 μg of selenium/kg) and 15 of 40 (37.5%) control mice fed standard Purina chow (440 μg of selenium/kg) developed PCT by 275 days postpristane. Abrogation of PCT was caused in part by the striking inhibition of the formation of the inflammatory tissue in which PCT develop (pristane granuloma). This was associated with the reduced responsiveness of selenium-deficient inflammatory cells (monocytes and neutrophils) to chemoattractants, such as thioredoxin and chemokines. Selenium-deficient C mice exhibited little evidence of disturbed redox homeostasis and increased mutant frequency of a transgenic lacZ reporter gene in vivo. These findings implicate selenium, via the selenoproteins, in the promotion of inflammation-induced PCT and suggest that small drug inhibitors of selenoproteins might be useful for preventing human cancers linked with chronic inflammations and persistent infections.
Data from Hypoxia-Inducible Protein 2 (HIG2), a Novel Diagnostic Marker for Renal Cell Carcinoma and Potential Target for Molecular Therapy
Authors: Togashi Akira , Katagiri Toyomasa , Ashida Shingo , Fujioka Tomoaki , Maruyama Osamu , Wakumoto Yoshiaki , Sakamoto Yoshiro , Fujime Makoto , Kawachi Yoshio , Shuin Taro , Nakamura Yusuke
Published: March 2023

Abstract
To identify molecules to serve as diagnostic markers for renal cell carcinoma (RCC) and as targets for novel therapeutic drugs, we investigated genome-wide expression profiles of RCCs using a cDNA microarray. We subsequently confirmed that hypoxia-inducible protein-2 (HIG2) was expressed exclusively in RCCs and fetal kidney. Induction of HIG2 cDNA into COS7 cells led to secretion of the gene product into culture medium and resulted in enhancement of cell growth. Small interfering RNA effectively inhibited expression of HIG2 in human RCC cells that endogenously expressed high levels of the protein and significantly suppressed cell growth. Moreover, addition of polyclonal anti-HIG2 antibody into culture medium induced apoptosis in RCC-derived cell lines. By binding to an extracellular domain of frizzled homologue 10 (FZD10), HIG2 protein enhanced oncogenic Wnt signaling and its own transcription, suggesting that this product is likely to function as an autocrine growth factor. ELISA analysis of clinical samples identified secretion of HIG2 protein into the plasma of RCC patients even at an early stage of tumor development, whereas it was detected at significantly lower levels in healthy volunteers or patients with chronic glomerulonephritis. The combined evidence suggests that this molecule represents a promising candidate for development of molecular-targeting therapy and could serve as a prominent diagnostic tumor marker for patients with renal carcinomas.
Data from Human CTL Epitopes Prostatic Acid Phosphatase-3 and Six-Transmembrane Epithelial Antigen of Prostate-3 as Candidates for Prostate Cancer Immunotherapy
Authors: Machlenkin Arthur , Paz Adrian , Bar Haim Erez , Goldberger Ofir , Finkel Eran , Tirosh Boaz , Volovitz Ilan , Vadai Ezra , Lugassy Gilles , Cytron Shmuel , Lemonnier Francois , Tzehoval Esther , Eisenbach Lea
Published: March 2023

Abstract
Specific immunotherapy of prostate cancer may be an alternative or be complementary to other approaches for treatment of recurrent or metastasized disease. This study aims at identifying and characterizing prostate cancer–associated peptides capable of eliciting specific CTL responses in vivo. Evaluation of peptide-induced CTL activity in vitro was done following immunization of HLA-A2 transgenic (HHD) mice. An in vivo tumor rejection was tested by adoptive transfer of HHD immune lymphocytes to nude mice bearing human tumors. To confirm the existence of peptide-specific CTL precursors in human, lymphocytes from healthy and prostate cancer individuals were stimulated in vitro in the presence of these peptides and CTL activities were assayed. Two novel immunogenic peptides derived from overexpressed prostate antigens, prostatic acid phosphatase (PAP) and six-transmembrane epithelial antigen of prostate (STEAP), were identified; these peptides were designated PAP-3 and STEAP-3. Peptide-specific CTLs lysed HLA-A2.1+ LNCaP cells and inhibited tumor growth on adoptive immunotherapy. Furthermore, peptide-primed human lymphocytes derived from healthy and prostate cancer individuals lysed peptide-pulsed T2 cells and HLA-A2.1+ LNCaP cells. Based on the results presented herein, PAP-3 and STEAP-3 are naturally processed CTL epitopes possessing anti–prostate cancer reactivity in vivo and therefore may constitute vaccine candidates to be investigated in clinical trials.
Data from Oncogene Expression and Genetic Background Influence the Frequency of DNA Copy Number Abnormalities in Mouse Pancreatic Islet Cell Carcinomas
Authors: Hager Jeffrey H. , Hodgson J. Graeme , Fridlyand Jane , Hariono Sujatmi , Gray Joe W. , Hanahan Douglas
Published: March 2023

Abstract
Quantitative measurements of tumor genome composition show remarkable heterogeneity in tumors arising from the same anatomical location and/or histopathological class and stage. The factors that contribute to genomic heterogeneity are not clear, but germ-line allelic variation and timing of initiating oncogenic events are likely candidates. We investigated these factors by using array comparative genomic hybridization to measure genomic aberrations in genetically engineered mouse models of pancreatic islet cell carcinoma, in which oncogenic transformation is elicited by the SV40 T antigens expressed under the control of the rat insulin promoter (RIP-Tag). Two distinct transgenic RIP-Tag lines, and three polymorphic sublines of one, enabled us to investigate the effects of genetic background and differing age of oncogene induction. Both parameters were found to bias the spectrum of genomic copy number abnormalities. Specifically, the frequency of losing portions of chromosomes 9 and 16 was significantly modulated by genetic background, with the former being lost at highest rates in the FVB/N background and the latter being lost to greatest extent in both FVB/N and C57Bl/6 tumors compared with C3HeB/Fe tumors. The frequency of losing a region of chromosome 6 varied according to the age when tumorigenesis was initiated; loss of chromosome 6 was significantly higher when oncogene expression was first activated in adulthood. These studies illustrate the utility of transgenic animal models for investigation of factors influencing genomic heterogeneity despite the commonalty of target cell type and initiating oncogene.
Data from The Tumor Suppressor hSNF5/INI1 Modulates Cell Growth and Actin Cytoskeleton Organization
Authors: Medjkane Souhila , Novikov Eugene , Versteege Isabella , Delattre Olivier
Published: March 2023

Abstract
hSNF5/INI1, which encodes a component of the ATP-dependent chromatin remodeling hSWI-SNF complex, is a tumor suppressor gene mutated in malignant rhabdoid tumors. We have developed a tetracycline-based hSNF5/INI1-inducible system in a hSNF5/INI1-deficient malignant rhabdoid tumor cell line and studied time course variation of 22,000 genes/expressed sequence tags upon hSNF5/INI1 induction. A total of 482 responsive genes were identified and further clustered into 9 groups of coregulated genes. Among genes with early and strong inductions, the use of a fusion protein with the hormone-binding domain of the estrogen receptor enabled the identification of a subset of direct targets regulated independently of de novo protein synthesis. We show that the G1 arrest induced by hSNF5/INI1 is reversible and associated with the down-regulation of components of the DNA replication complex. We also identify an unsuspected role of hSNF5/INI1 in cytoskeleton organization. Indeed, induction of hSNF5/INI1 induces dramatic modifications of the cell shape including complete disruption of the actin stress fiber network and disappearance of focal adhesions associated with up-regulation of genes involved in the organization of the actin cytoskeleton. We document a strong decrease of Rho activity upon hSNF5/INI1 expression, suggesting that the regulation of this activity constitutes a crucial step of the hSNF5/INI1-induced reorganization of the actin network. This study identifies hSNF5/INI1 target genes and provides evidence that hSNF5/INI1 may modulate the cell cycle control and cytoskeleton organization through the regulation of the retinoblastoma protein-E2F and Rho pathways.
Data from Gene Expression Profiling and Genetic Markers in Glioblastoma Survival
Authors: Rich Jeremy N. , Hans Christopher , Jones Beatrix , Iversen Edwin S. , McLendon Roger E. , Rasheed B.K. Ahmed , Dobra Adrian , Dressman Holly K. , Bigner Darell D. , Nevins Joseph R. , West Mike
Published: March 2023

Abstract
Despite the strikingly grave prognosis for older patients with glioblastomas, significant variability in patient outcome is experienced. To explore the potential for developing improved prognostic capabilities based on the elucidation of potential biological relationships, we did analyses of genes commonly mutated, amplified, or deleted in glioblastomas and DNA microarray gene expression data from tumors of glioblastoma patients of age >50 for whom survival is known. No prognostic significance was associated with genetic changes in epidermal growth factor receptor (amplified in 17 of 41 patients), TP53 (mutated in 11 of 41 patients), p16INK4A (deleted in 15 of 33 patients), or phosphatase and tensin homologue (mutated in 15 of 41 patients). Statistical analysis of the gene expression data in connection with survival involved exploration of regression models on small subsets of genes, based on computational search over multiple regression models with cross-validation to assess predictive validity. The analysis generated a set of regression models that, when weighted and combined according to posterior probabilities implied by the statistical analysis, identify patterns in expression of a small subset of genes that are associated with survival and have value in assessing survival risks. The dominant genes across such multiple regression models involve three key genes—SPARC (Osteonectin), Doublecortex, and Semaphorin3B—which play key roles in cellular migration processes. Additional analysis, based on statistical graphical association models constructed using similar computational analysis methods, reveals other genes which support the view that multiple mediators of tumor invasion may be important prognostic factor in glioblastomas in older patients.
Data from Twist Overexpression Induces In vivo Angiogenesis and Correlates with Chromosomal Instability in Breast Cancer
Authors: Mironchik Yelena , Winnard Paul T. , Vesuna Farhad , Kato Yoshinori , Wildes Flonne , Pathak Arvind P. , Kominsky Scott , Artemov Dmitri , Bhujwalla Zaver , Van Diest Paul , Burger Horst , Glackin Carlotta , Raman Venu
Published: March 2023

Abstract
Aggressive cancer phenotypes are a manifestation of many different genetic alterations that promote rapid proliferation and metastasis. In this study, we show that stable overexpression of Twist in a breast cancer cell line, MCF-7, altered its morphology to a fibroblastic-like phenotype, which exhibited protein markers representative of a mesenchymal transformation. In addition, it was observed that MCF-7/Twist cells had increased vascular endothelial growth factor (VEGF) synthesis when compared with empty vector control cells. The functional changes induced by VEGF in vivo were analyzed by functional magnetic resonance imaging (MRI) of MCF-7/Twist-xenografted tumors. MRI showed that MCF-7/Twist tumors exhibited higher vascular volume and vascular permeability in vivo than the MCF-7/vector control xenografts. Moreover, elevated expression of Twist in breast tumor samples obtained from patients correlated strongly with high-grade invasive carcinomas and with chromosome instability, particularly gains of chromosomes 1 and 7. Taken together, these results show that Twist overexpression in breast cancer cells can induce angiogenesis, correlates with chromosomal instability, and promotes an epithelial-mesenchymal-like transition that is pivotal for the transformation into an aggressive breast cancer phenotype.
Data from Dasatinib (BMS-354825) Selectively Induces Apoptosis in Lung Cancer Cells Dependent on Epidermal Growth Factor Receptor Signaling for Survival
Authors: Song Lanxi , Morris Mark , Bagui Tapan , Lee Francis Y. , Jove Richard , Haura Eric B.
Published: March 2023

Abstract
Mutations of the epidermal growth factor receptor (EGFR) selectively activate Akt and signal transducer and activator of transcription (STAT) pathways that are important in lung cancer cell survival. Src family kinases can cooperate with receptor tyrosine kinases to signal through downstream molecules, such as phosphatidylinositol 3-kinase/PTEN/Akt and STATs. Based on the importance of EGFR signaling in lung cancer, the known cooperation between EGFR and Src proteins, and evidence of elevated Src activity in human lung cancers, we evaluated the effectiveness of a novel orally bioavailable Src inhibitor dasatinib (BMS-324825) in lung cancer cell lines with defined EGFR status. Here, we show that cell fate (death versus growth arrest) in lung cancer cells exposed to dasatinib is dependent on EGFR status. In cells with EGFR mutation that are dependent on EGFR for survival, dasatinib reduces cell viability through the induction of apoptosis while having minimal apoptotic effect on cell lines with wild-type (WT) EGFR. The induction of apoptosis in these EGFR-mutant cell lines corresponds to down-regulation of activated Akt and STAT3 survival proteins. In cell lines with WT or resistant EGFR mutation that are not sensitive to EGFR inhibition, dasatinib induces a G1 cell cycle arrest with associated changes in cyclin D and p27 proteins, inhibits activated FAK, and prevents tumor cell invasion. Our results show that dasatinib could be effective therapy for patients with lung cancers through disruption of cell growth, survival, and tumor invasion. Our results suggest EGFR status is important in deciding cell fate in response to dasatinib. (Cancer Res 2006; 66(11): 5542-8)
Data from A Gene Expression Signature for Relapse of Primary Wilms Tumors
Authors: Li Wenliang , Kessler Patricia , Yeger Herman , Alami Jennifer , Reeve Anthony E. , Heathcott Rosemary , Skeen Jane , Williams Bryan R.G.
Published: March 2023

Abstract
Anaplastic histology and metastasis are each associated with higher relapse and mortality rates in Wilms tumor patients. However, not all anaplastic tumors relapse and some nonanaplastic tumors relapse unexpectedly. To identify more accurate early prognostic indicators, we analyzed expression of 4,900 cancer-related genes in 26 primary Wilms tumors. This analysis revealed that expression of a set of four genes predicts future relapse of primary Wilms tumors with high accuracy, independent of anaplasia. Random permutation testing of this prognostic gene expression signature yielded P = 0.003. Real-time reverse transcription-PCR analysis of the four genes in an independent primary tumor set resulted in correct prediction of future relapse with an accuracy of 92%. One of the four genes in the prognostic signature, CCAAT/enhancer binding protein β (C/EBPB), is expressed at higher levels in both primary relapsing tumors and metastatic tumors than in primary nonrelapsing tumors. Short interfering RNA–mediated down-regulation of C/EBPB expression in WiT49, a cell line derived from a metastatic Wilms tumor, resulted in spontaneous apoptosis. These findings suggest that C/EBPB is a critical survival factor for Wilms tumor cells and that its expression contributes to the prognosis of Wilms tumor patients.
Data from MYC Can Induce DNA Breaks In vivo and In vitro Independent of Reactive Oxygen Species
Authors: Ray Suma , Atkuri Kondala R. , Deb-Basu Debabrita , Adler Adam S. , Chang Howard Y. , Herzenberg Leonore A. , Felsher Dean W.
Published: March 2023

Abstract
MYC overexpression is thought to initiate tumorigenesis by inducing cellular proliferation and growth and to be restrained from causing tumorigenesis by inducing cell cycle arrest, cellular senescence, and/or apoptosis. Here we show that MYC can induce DNA breaks both in vitro and in vivo independent of increased production of reactive oxygen species (ROS). We provide an insight into the specific circumstances under which MYC generates ROS in vitro and propose a possible mechanism. We found that MYC induces DNA double-strand breaks (DSBs) independent of ROS production in murine lymphocytes in vivo as well as in normal human foreskin fibroblasts (NHFs) in vitro in normal (10%) serum, as measured by γH2AX staining. However, NHFs cultured in vitro in low serum (0.05%) and/or ambient oxygen saturation resulted in ROS-associated oxidative damage and DNA single-strand breaks (SSBs), as measured by Ape-1 staining. In NHFs cultured in low versus normal serum, MYC induced increased expression of CYP2C9, a gene product well known to be associated with ROS production. Specific inhibition of CYP2C9 by small interfering RNA was shown to partially inhibit MYC-induced ROS production. Hence, MYC overexpression can induce ROS and SSBs under some conditions, but generally induces widespread DSBs in vivo and in vitro independent of ROS production. (Cancer Res 2006; 66(13): 6598-605)
Data from Construction of a Minimal HIV-1 Variant that Selectively Replicates in Leukemic Derived T-Cell Lines: Towards a New Virotherapy Approach
Authors: Jeeninga Rienk E. , Jan Barbara , van der Linden Birgit , van den Berg Henk , Berkhout Ben
Published: March 2023

Abstract
T-cell acute lymphoblastic leukemia is a high-risk type of blood-cell cancer. We analyzed the possibility of developing virotherapy for T-cell acute lymphoblastic leukemia. Virotherapy is based on the exclusive replication of a virus in leukemic cells, leading to the selective removal of these malignant cells. We constructed a minimized derivative of HIV-1, a complex lentivirus encoding multiple accessory functions that are essential for virus replication in untransformed cells, but dispensable in leukemic T cells. This mini-HIV virus has five deletions (vif, vpR, vpU, nef, and U3) and replicated in the SupT1 cell line, but did not replicate in normal peripheral blood mononuclear cells. The stripped down mini-HIV variant was also able to efficiently remove leukemic cells from a mixed culture with untransformed control cells. In contrast to wild-type HIV-1, we did not observe bystander killing in mixed culture experiments with the mini-HIV variant. Furthermore, viral escape was not detected in long-term cultures. The mini-HIV variant that uses CD4 and CXCR4 for cell entry could potentially be used against CXCR4-expressing malignancies such as T-lymphoblastic leukemia/lymphoma, natural killer leukemia, and some myeloid leukemias.
Data from HIV-1 Vpr Induces DNA Double-Strand Breaks
Authors: Tachiwana Hiroaki , Shimura Mari , Nakai-Murakami Chikako , Tokunaga Kenzo , Takizawa Yoshimasa , Sata Tetsutaro , Kurumizaka Hitoshi , Ishizaka Yukihito
Published: March 2023

Abstract
Recent observations imply that HIV-1 infection induces chromosomal DNA damage responses. However, the precise molecular mechanism and biological relevance are not fully understood. Here, we report that HIV-1 infection causes double-strand breaks in chromosomal DNA. We further found that Vpr, an accessory gene product of HIV-1, is a major factor responsible for HIV-1–induced double-strand breaks. The purified Vpr protein promotes double-strand breaks when incubated with isolated nuclei, although it does not exhibit endonuclease activity in vitro. A carboxyl-terminally truncated Vpr mutant that is defective in DNA-binding activity is less capable of Vpr-dependent double-strand break formation in isolated nuclei. The data suggest that double-strand breaks induced by Vpr depend on its DNA-binding activity and that Vpr may recruit unknown nuclear factor(s) with positive endonuclease activity to chromosomal DNA. This is the first direct evidence that Vpr induces double-strand breaks in HIV-1–infected cells. We discuss the possible roles of Vpr-induced DNA damage in HIV-1 infection and the involvement of Vpr in further acquired immunodeficiency syndrome–related tumor development. (Cancer Res 2006; 66(2): 627-31)
Data from p73β-Mediated Apoptosis Requires p57kip2 Induction and IEX-1 Inhibition
Authors: Gonzalez Susana , Perez-Perez Manuel M. , Hernando Eva , Serrano Manuel , Cordon-Cardo Carlos
Published: March 2023

Abstract
Similarly to p53, p73α and p73β induce growth arrest and/or apoptosis in response to DNA damage or when exogenously expressed. However, how they trigger apoptosis remains unresolved. After stable transduction of either p73α or p73β, a greater apoptotic response was observed for p73β in both primary and tumor cells. Consistently, blocking ectopic and endogenous p73β expression by specific shRNA significantly decreased apoptotic levels after DNA damage. We found that p73β targets the apoptotic program at multiple levels: (i) facilitating caspase activation through p53-dependent signals and (ii) inducing p57KIP2, while down-regulating c-IPA1 and IEX1 through a p53-independent mechanism. p73β-mediated apoptosis was considerably reduced after inhibition of p57KIP2 by small interfering RNA, IEX-1 overexpression, and in mouse embryo fibroblasts derived from p57−/− mice. Data from this study offer evidence for the apoptotic activity exclusive of p73β. In the clinical context, these results might have potential therapeutic implications, because p73β could induce alternative apoptotic responses in tumors harboring p53 mutations.
Data from Analysis of Genetic Alterations and Clonal Proliferation in Children Treated for Acute Lymphocytic Leukemia
Authors: Kendall Heather E. , Vacek Pamela M. , Rivers Jami L. , Rice Sederick C. , Messier Terri L. , Finette Barry A.
Published: March 2023

Abstract
The development of risk-directed treatment protocols over the last 25 years has resulted in an increase in the survival rates of children treated for cancer. As a consequence, there is a growing population of pediatric cancer survivors in which the long-term genotoxic effects of chemotherapy is unknown. We previously reported that children treated for acute lymphocytic leukemia have significantly elevated somatic mutant frequencies at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene in their peripheral T cells. To understand the molecular etiology of the increase in mutant frequencies following chemotherapy, we investigated the HPRT mutation spectra and the extent of clonal proliferation in 562 HPRT T cell mutant isolates of 87 blood samples from 47 subjects at diagnosis, during chemotherapy, and postchemotherapy. We observed a significant increase in the proportion of CpG transitions following treatment (13.6-23.3%) compared with healthy controls (4.0%) and a significant decrease in V(D)J-mediated deletions following treatment (0-6.8%) compared with healthy controls (17.0%). There was also a significant change in the class type percentage of V(D)J-mediated HPRT deletions following treatment. In addition, there was a >5-fold increase in T cell receptor gene usage–defined mean clonal proliferation from diagnosis compared with the completion of chemotherapeutic intervention. These data indicate that unique genetic alterations and extensive clonal proliferation are occurring in children following treatment for acute lymphocytic leukemia that may influence long-term risks for multifactorial diseases, including secondary cancers. (Cancer Res 2006; 66(17): 8455-61)
Data from Glycogen Synthase Kinase-3β Participates in Nuclear Factor κB–Mediated Gene Transcription and Cell Survival in Pancreatic Cancer Cells
Authors: Ougolkov Andrei V. , Fernandez-Zapico Martin E. , Savoy Doris N. , Urrutia Raul A. , Billadeau Daniel D.
Published: March 2023

Abstract
Recent studies using glycogen synthase kinase-3β (GSK-3β)–deficient mouse embryonic fibroblasts suggest that GSK-3β positively regulates nuclear factor κB (NFκB)–mediated gene transcription. Because NFκB is suggested to participate in cell proliferation and survival pathways in pancreatic cancer, we investigated the role of GSK-3β in regulating these cellular processes. Herein, we show that pancreatic cancer cells contain a pool of active GSK-3β and that pharmacologic inhibition of GSK-3 kinase activity using small molecule inhibitors or genetic depletion of GSK-3β by RNA interference leads to decreased cancer cell proliferation and survival. Mechanistically, we show that GSK-3β influences NFκB-mediated gene transcription at a point distal to the Iκ kinase complex, as only ectopic expression of the NFκB subunits p65/p50, but not an Iκ kinase β constitutively active mutant, could rescue the decreased cellular proliferation and survival associated with GSK-3β inhibition. Taken together, our results simultaneously identify a previously unrecognized role for GSK-3β in cancer cell survival and proliferation and suggest GSK-3β as a potential therapeutic target in the treatment of pancreatic cancer.
Data from Aneuploidy-Dependent Massive Deregulation of the Cellular Transcriptome and Apparent Divergence of the Wnt/β-catenin Signaling Pathway in Human Rectal Carcinomas
Authors: Grade Marian , Ghadimi B. Michael , Varma Sudhir , Simon Richard , Wangsa Danny , Barenboim-Stapleton Linda , Liersch Torsten , Becker Heinz , Ried Thomas , Difilippantonio Michael J.
Published: March 2023

Abstract
To identify genetic alterations underlying rectal carcinogenesis, we used global gene expression profiling of a series of 17 locally advanced rectal adenocarcinomas and 20 normal rectal mucosa biopsies on oligonucleotide arrays. A total of 351 genes were differentially expressed (P < 1.0e−7) between normal rectal mucosa and rectal carcinomas, 77 genes had a >5-fold difference, and 85 genes always had at least a 2-fold change in all of the matched samples. Twelve genes satisfied all three of these criteria. Altered expression of genes such as PTGS2 (COX-2), WNT1, TGFB1, VEGF, and MYC was confirmed, whereas our data for other genes, like PPARD and LEF1, were inconsistent with previous reports. In addition, we found deregulated expression of many genes whose involvement in rectal carcinogenesis has not been reported. By mapping the genomic imbalances in the tumors using comparative genomic hybridization, we could show that DNA copy number gains of recurrently aneuploid chromosome arms 7p, 8q, 13q, 18q, 20p, and 20q correlated significantly with their average chromosome arm expression profile. Taken together, our results show that both the high-level, significant transcriptional deregulation of specific genes and general modification of the average transcriptional activity of genes residing on aneuploid chromosomes coexist in rectal adenocarcinomas. (Cancer Res 2006; 66(1): 267-82)
Data from Progression-Specific Genes Identified by Expression Profiling of Matched Ductal Carcinomas In situ and Invasive Breast Tumors, Combining Laser Capture Microdissection and Oligonucleotide Microarray Analysis
Authors: Schuetz Christina S. , Bonin Michael , Clare Susan E. , Nieselt Kay , Sotlar Karl , Walter Michael , Fehm Tanja , Solomayer Erich , Riess Olaf , Wallwiener Diethelm , Kurek Raffael , Neubauer Hans J.
Published: March 2023

Abstract
Becoming invasive is a crucial step in breast cancer oncogenesis. At this point, a lesion carries the potential for spreading and metastasis—a process, whose molecular characteristics still remain poorly understood. In this article, we describe a matched-pair analysis of ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) of nine breast ductal carcinomas to identify novel molecular markers characterizing the transition from DCIS to IDC. The purpose of this study was to better understand the molecular biology of this transition and to identify candidate genes whose products might serve as prognostic markers and/or as molecular targets for treatment. To obtain cellular-based gene expression profiles from epithelial tumor cells, we combined laser capture microdissection with a T7-based two-round RNA amplification and Affymetrix oligonucleotide microarray analysis. Altogether, a set of 24 tumor samples was analyzed, comprised of nine matched DCIS/IDC and replicate DCIS/IDC preparations from three of the nine tumors. Cluster analysis on expression data shows the robustness and reproducibility of the techniques we established. Using multiple statistical methods, 546 significantly differentially expressed probe sets were identified. Eighteen candidate genes were evaluated by RT-PCR. Examples of genes already known to be associated with breast cancer invasion are BPAG1, LRRC15, MMP11, and PLAU. The expression of BPAG1, DACT1, GREM1, MEF2C, SART2, and TNFAIP6 was localized to epithelial tumor cells by in situ hybridization and/or immunohistochemistry, confirming the accuracy of laser capture microdissection sampling and microarray analysis. (Cancer Res 2006; 66(10): 5278-86)
Data from Dissecting the Role of Matrix Metalloproteinases (MMP) and Integrin αvβ3 in Angiogenesis In vitro: Absence of Hemopexin C Domain Bioactivity, but Membrane-Type 1-MMP and αvβ3 Are Critical
Authors: Nisato Riccardo E. , Hosseini Ghamartaj , Sirrenberg Christian , Butler Georgina S. , Crabbe Thomas , Docherty Andrew J.P. , Wiesner Matthias , Murphy Gillian , Overall Christopher M. , Goodman Simon L. , Pepper Michael S.
Published: March 2023

Abstract
Matrix metalloproteinase (MMP)-2 and its hemopexin C domain autolytic fragment (also called PEX) have been proposed to be crucial for angiogenesis. Here, we have investigated the dependency of in vitro angiogenesis on MMP-mediated extracellular proteolysis and integrin αvβ3–mediated cell adhesion in a three-dimensional collagen I model. The hydroxamate-based synthetic inhibitors BB94, CT1399, and CT1847 inhibited endothelial cell invasion, as did neutralizing anti–membrane-type 1-MMP (MT1-MMP) antibodies and tissue inhibitor of MMP (TIMP)-2 and TIMP-3 but not TIMP-1. This confirmed the pivotal importance of MT1-MMP over other MMPs in this model. Invasion was also inhibited by a nonpeptidic antagonist of integrin αvβ3, EMD 361276. Although PEX strongly inhibited pro-MMP-2 activation, when contaminating lipopolysaccharide was neutralized, PEX neither affected angiogenesis nor bound integrin αvβ3. Moreover, no specific binding of pro-MMP-2 to integrin αvβ3 was found, whereas only one out of four independently prepared enzymatically active MMP-2 preparations could bind integrin αvβ3, and this in a PEX-independent manner. Likewise, integrin αvβ3–expressing cells did not bind MMP-2-coated surfaces. Hence, these findings show that endothelial cell invasion of collagen I gels is MT1-MMP and αvβ3- dependent but MMP-2 independent and does not support a role for PEX in αvβ3 integrin binding or in modulating angiogenesis in this system.
Data from Cyclin-Dependent Kinase 5 Activity Controls Cell Motility and Metastatic Potential of Prostate Cancer Cells
Authors: Strock Christopher J. , Park Jong-In , Nakakura Eric K. , Bova G. Steven , Isaacs John T. , Ball Douglas W. , Nelkin Barry D.
Published: March 2023

Abstract
We show here that cyclin-dependent kinase 5 (CDK5), a known regulator of migration in neuronal development, plays an important role in prostate cancer motility and metastasis. P35, an activator of CDK5 that is indicative of its activity, is expressed in a panel of human and rat prostate cancer cell lines, and is also expressed in 87.5% of the human metastatic prostate cancers we examined. Blocking of CDK5 activity with a dominant-negative CDK5 construct, small interfering RNA, or roscovitine resulted in changes in the microtubule cytoskeleton, loss of cellular polarity, and loss of motility. Expression of a dominant-negative CDK5 in the highly metastatic Dunning AT6.3 prostate cancer cell line also greatly impaired invasive capacity. CDK5 activity was important for spontaneous metastasis in vivo; xenografts of AT6.3 cells expressing dominant-negative CDK5 had less than one-fourth the number of lung metastases exhibited by AT6.3 cells expressing the empty vector. These results show that CDK5 activity controls cell motility and metastatic potential in prostate cancer. (Cancer Res 2006; 66(15): 7509-15) (Cancer Res 2006; 66(15): 7509-15)
Data from Frequent Alterations in the Expression of Serine/Threonine Kinases in Human Cancers
Authors: Capra Maria , Nuciforo Paolo Giovanni , Confalonieri Stefano , Quarto Micaela , Bianchi Marco , Nebuloni Manuela , Boldorini Renzo , Pallotti Francesco , Viale Giuseppe , Gishizky Mikhail L. , Draetta Giulio F. , Di Fiore Pier Paolo
Published: March 2023

Abstract
Protein kinases constitute a large family of regulatory enzymes involved in the homeostasis of virtually every cellular process. Subversion of protein kinases has been frequently implicated in malignant transformation. Within the family, serine/threonine kinases (STK) have received comparatively lesser attention, vis-a-vis tyrosine kinases, in terms of their involvement in human cancers. Here, we report a large-scale screening of 125 STK, selected to represent all major subgroups within the subfamily, on nine different types of tumors (∼200 patients), by using in situ hybridization on tissue microarrays. Twenty-one STK displayed altered levels of transcripts in tumors, frequently with a clear tumor type-specific dimension. We identified three patterns of alterations in tumors: (a) overexpression in the absence of expression in the normal tissues (10 kinases), (b) overexpression in the presence of expression by normal tissues (8 kinases), and (c) underexpression (3 kinases). Selected members of the three classes were subjected to in-depth analysis on larger case collections and showed significant correlations between their altered expression and biological and/or clinical variables. Our findings suggest that alteration in the expression of STK is a relatively frequent occurrence in human tumors. Among the overexpressed kinases, 10 were undetectable in normal controls and are therefore ideal candidates for further validation as potential targets of molecular cancer therapy. (Cancer Res 2006; 66(16): 8147-54)
Data from Genome-wide Hypomethylation in Human Glioblastomas Associated with Specific Copy Number Alteration, Methylenetetrahydrofolate Reductase Allele Status, and Increased Proliferation
Authors: Cadieux Benoît , Ching Tsui-Ting , VandenBerg Scott R. , Costello Joseph F.
Published: March 2023

Abstract
Genome-wide reduction in 5-methylcytosine is an epigenetic hallmark of human tumorigenesis. Experimentally induced hypomethylation in mice promotes genomic instability and is sufficient to initiate tumorigenesis. Here, we report that global hypomethylation is common in primary human glioblastomas [glioblastoma multiforme (GBM)] and can affect up to an estimated 10 million CpG dinucleotides per haploid tumor genome. Demethylation involves satellite 2 (Sat2) pericentromeric DNA at chromosomes 1 and 16, the subtelomeric repeat sequence D4Z4 at chromosomes 4q and 10q, and interspersed Alu elements. Severe hypomethylation of Sat2 sequences is associated with copy number alterations of the adjacent euchromatin, suggesting that hypomethylation may be one factor predisposing to specific genetic alterations commonly occurring in GBMs. An additional apparent consequence of global hypomethylation is reactivation of the cancer-testis antigen MAGEA1 via promoter demethylation, but only in GBMs and GBM cell lines exhibiting a 5-methylcytosine content below a threshold of ∼50%. Primary GBMs with significant hypomethylation tended to be heterozygous or homozygous for the low-functioning Val allele of the rate-limiting methyl group metabolism gene methylenetetrahydrofolate reductase (MTHFR), or had a deletion encompassing this gene at 1p36. Tumors with severe genomic hypomethylation also had an elevated proliferation index and deletion of the MTHFR gene. These data suggest a model whereby either excessive cell proliferation in the context of inadequate methyl donor production from MTHFR deficiency promotes genomic hypomethylation and further genomic instability, or that MTHFR deficiency–associated demethylation leads to increased proliferative activity in GBM. (Cancer Res 2006; 66(17): 8469-76)