bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from A Survivin Gene Signature Predicts Aggressive Tumor Behavior
Authors: Salz Whitney , Eisenberg Dan , Plescia Janet , Garlick David S. , Weiss Robert M. , Wu Xue-Ru , Sun Tung-Tien , Altieri Dario C.
Published: March 2023

Abstract
Gene signatures that predict aggressive tumor behavior at the earliest stages of disease, ideally before overt tissue abnormalities, are urgently needed. To search for such genes, we generated a transgenic model of survivin, an essential regulator of cell division and apoptosis overexpressed in cancer. Transgenic expression of survivin in the urinary bladder did not cause histologic abnormalities of the urothelium. However, microarray analysis revealed that survivin-expressing bladders exhibited profound changes in gene expression profile affecting extracellular matrix and inflammatory genes. Following exposure to a bladder carcinogen, N-butyl-N-(4-hydroxybutyl) nitrosamine (OH-BBN), survivin transgenic animals exhibited accelerated tumor progression, preferential incidence of tumors as compared with premalignant lesions, and dramatically abbreviated survival. Conversely, transgenic expression of a survivin Thr34→Ala dominant-negative mutant did not cause changes in gene expression or accelerated tumor progression after OH-BBN treatment. Therefore, survivin expression induces global transcriptional changes in the tissue microenvironment that may promote tumorigenesis. Detection of survivin or its associated gene signature may provide an early biomarker of aggressive tumor behavior before the appearance of tissue abnormalities.
Data from Controlling Tumor Growth by Modulating Endogenous Production of Reactive Oxygen Species
Authors: Laurent Alexis , Nicco Carole , Chéreau Christiane , Goulvestre Claire , Alexandre Jérôme , Alves Arnaud , Lévy Eva , Goldwasser Francois , Panis Yves , Soubrane Olivier , Weill Bernard , Batteux Frédéric
Published: March 2023

Abstract
Paradoxically, reactive oxygen species (ROS) can promote normal cellular proliferation and carcinogenesis, and can also induce apoptosis of tumor cells. In this report, we study the contribution of ROS to various cellular signals depending on the nature and the level of ROS produced. In nontransformed NIH 3T3 cells, ROS are at low levels and originate from NADPH oxidase. Hydrogen peroxide (H2O2), controlled by the glutathione system, is pivotal for the modulation of normal cell proliferation. In CT26 (colon) and Hepa 1-6 (liver) tumor cells, high levels of ROS, close to the threshold of cytotoxicity, are produced by mitochondria and H2O2 is controlled by catalase. N-acetylcysteine, which decreases H2O2 levels, inhibits mitogen-activated protein kinase and normal cell proliferation but increases tumor cell proliferation as H2O2 concentration drops from the toxicity threshold. In contrast, antioxidant molecules, such as mimics of superoxide dismutase (SOD), increase H2O2 levels through superoxide anion dismutation, as well as in vitro proliferation of normal cells, but kill tumor cells. CT26 tumors were implanted in mice and treated by oxaliplatin in association with one of the three SOD mimics manganese(III)tetrakis(4-benzoic acid) porphyrin, copper(II)(3,5-diisopropylsalicylate)2, or manganese dipyridoxyl diphosphate. After 1 month, the volumes of tumors were respectively 35%, 31%, and 63% smaller than with oxaliplatin alone (P < 0.001). Similar data were gained with Hepa 1-6 tumors. In conclusion, antioxidant molecules may have opposite effects on tumor growth. SOD mimics can act in synergy with cytotoxic drugs to treat colon and liver cancers.
Data from Quantifying the Activity of Adenoviral E1A CR2 Deletion Mutants Using Renilla Luciferase Bioluminescence and 3′-Deoxy-3′-[18F]Fluorothymidine Positron Emission Tomography Imaging
Authors: Leyton Julius , Lockley Michelle , Aerts Joeri L. , Baird Sarah K. , Aboagye Eric O. , Lemoine Nicholas R. , McNeish Iain A.
Published: March 2023

Abstract
The adenoviral E1A CR2 mutant dl922-947 has potent activity in ovarian cancer. We have used Renilla luciferase bioluminescence imaging to monitor viral E1A expression and replication and [18F]fluorothymidine positron emission tomography ([18F]FLT-PET) to quantify the activity of dl922-947 in vivo. We created dlCR2 Ren, with the same E1A CR2 deletion as dl922-947 and the luciferase gene from Renilla reniformis downstream of E1. Light emitted from s.c. and i.p. IGROV1 ovarian carcinoma xenografts was measured following treatment with dlCR2 Ren. Mice bearing s.c. IGROV1 xenografts were injected with 2.96 to 3.7 MBq of [18F]FLT 48 and 168 hours following i.t. injection of dl922-947 or control virus Ad LM-X. The presence of Renilla luciferase in dlCR2 Ren did not reduce in vitro nor in vivo potency compared with dl922-947. Light emission correlated closely with E1A expression in vitro and peaked 48 hours after dlCR2 Ren injection in both s.c. and i.p. IGROV1 xenografts. It diminished by 168 hours in s.c. tumors but persisted for at least 2 weeks in i.p. models. Normalized tumor [18F]FLT uptake at 60 minutes (NUV60), fractional retention, and area under radioactivity curve all decreased marginally 48 hours after dl922-947 treatment and significantly at 168 hours compared with controls. There was a close linear correlation between NUV60 and both tumor proliferation (Ki67 labeling index) and thymidine kinase 1 expression. Renilla luciferase bioluminescence and [18F]FLT-PET imaging are capable of quantifying the activity and effectiveness of E1A CR2–deleted adenoviral mutants in ovarian cancer. (Cancer Res 2006; 66(18): 9178-85)
Data from Evolution of the Androgen Receptor Pathway during Progression of Prostate Cancer
Authors: Hendriksen Peter J.M. , Dits Natasja F.J. , Kokame Koichi , Veldhoven Antoine , van Weerden Wytske M. , Bangma Chris H. , Trapman Jan , Jenster Guido
Published: March 2023

Abstract
The present work focused on the potential involvement of selective adaptations of the androgen receptor pathway in the initiation and progression of prostate cancer. We defined the androgen receptor pathway by selecting 200 genes that were androgen responsive in prostate cancer cell lines and/or xenografts. This androgen receptor pathway gene signature was then used for profiling prostate cancer xenografts and patient-derived samples. Approximately half of the androgen receptor pathway genes were up-regulated in well-differentiated prostate cancer compared with normal prostate. Functionally distinct parts of the androgen receptor pathway were specifically down-regulated in high-grade cancers. Unexpectedly, metastases have down-regulated the vast majority of androgen receptor pathway genes. The significance of this progressive down-regulation of androgen receptor pathway genes was shown for a few androgen receptor–regulated genes. Lower mRNA expression of HERPUD1, STK39, DHCR24, and SOCS2 in primary prostate tumors was correlated with a higher incidence of metastases after radical prostatectomy. HERPUD1 mRNA expression predicted the occurrence of metastases almost perfectly. In vitro experiments showed that overexpression of the stress response gene HERPUD1 rapidly induces apoptosis. Based on the functions of the genes within the distinct subsets, we propose the following model. Enhanced androgen receptor activity is involved in the early stages of prostate cancer. In well-differentiated prostate cancer, the androgen receptor activates growth-promoting as well as growth-inhibiting and cell differentiation genes resulting in a low growth rate. The progression from low-grade to high-grade prostate carcinoma and metastases is mediated by a selective down-regulation of the androgen receptor target genes that inhibit proliferation, induce differentiation, or mediate apoptosis. (Cancer Res 2006; 66(10): 5012-20)
Data from BRCA1 Mutation Analysis of 41 Human Breast Cancer Cell Lines Reveals Three New Deleterious Mutants
Authors: Elstrodt Fons , Hollestelle Antoinette , Nagel Jord H.A. , Gorin Michael , Wasielewski Marijke , van den Ouweland Ans , Merajver Sofia D. , Ethier Stephen P. , Schutte Mieke
Published: March 2023

Abstract
Germ line mutations of the BRCA1 gene confer a high risk of breast cancer and ovarian cancer to female mutation carriers. The BRCA1 protein is involved in the regulation of DNA repair. How specific tumor-associated mutations affect the molecular function of BRCA1, however, awaits further elucidation. Cell lines that harbor BRCA1 gene mutations are invaluable tools for such functional studies. Up to now, the HCC1937 cell line was the only human breast cancer cell line with an identified BRCA1 mutation. In this study, we identified three other BRCA1 mutants from among 41 human breast cancer cell lines by sequencing of the complete coding sequence of BRCA1. Cell line MDA-MB-436 had the 5396 + 1G>A mutation in the splice donor site of exon 20. Cell line SUM149PT carried the 2288delT mutation and SUM1315MO2 carried the 185delAG mutation. All three mutations were accompanied by loss of the other BRCA1 allele. The 185delAG and 5396 + 1G>A mutations are both classified as pathogenic mutations. In contrast with wild-type cell lines, none of the BRCA1 mutants expressed nuclear BRCA1 proteins as detected with Ab-1 and Ab-2 anti-BRCA1 monoclonal antibodies. These three new human BRCA1 mutant cell lines thus seem to be representative breast cancer models that could aid in further unraveling of the function of BRCA1. (Cancer Res 2006; 66(1): 41-5)
Data from Molecular Inversion Probe Analysis of Gene Copy Alterations Reveals Distinct Categories of Colorectal Carcinoma
Authors: Ji Hanlee , Kumm Jochen , Zhang Michael , Farnam Kyle , Salari Keyan , Faham Malek , Ford James M. , Davis Ronald W.
Published: March 2023

Abstract
Genomic instability is a major feature of neoplastic development in colorectal carcinoma and other cancers. Specific genomic instability events, such as deletions in chromosomes and other alterations in gene copy number, have potential utility as biologically relevant prognostic biomarkers. For example, genomic deletions on chromosome arm 18q are an indicator of colorectal carcinoma behavior and potentially useful as a prognostic indicator. Adapting a novel genomic technology called molecular inversion probes which can determine gene copy alterations, such as genomic deletions, we designed a set of probes to interrogate several hundred individual exons of >200 cancer genes with an overall distribution covering all chromosome arms. In addition, >100 probes were designed in close proximity of microsatellite markers on chromosome arm 18q. We analyzed a set of colorectal carcinoma cell lines and primary colorectal tumor samples for gene copy alterations and deletion mutations in exons. Based on clustering analysis, we distinguished the different categories of genomic instability among the colorectal cancer cell lines. Our analysis of primary tumors uncovered several distinct categories of colorectal carcinoma, each with specific patterns of 18q deletions and deletion mutations in specific genes. This finding has potential clinical ramifications given the application of 18q loss of heterozygosity events as a potential indicator for adjuvant treatment in stage II colorectal carcinoma. (Cancer Res 2006; 66(16): 7910-9)
Data from High Expression of ErbB Family Members and Their Ligands in Lung Adenocarcinomas That Are Sensitive to Inhibition of Epidermal Growth Factor Receptor
Authors: Fujimoto Nobukazu , Wislez Marie , Zhang Jie , Iwanaga Kentaro , Dackor Jennifer , Hanna Amy E. , Kalyankrishna Shailaja , Cody Dianna D. , Price Roger E. , Sato Mitsuo , Shay Jerry W. , Minna John D. , Peyton Michael , Tang Ximing , Massarelli Erminia , Herbst Roy , Threadgill David W. , Wistuba Ignacio I. , Kurie Jonathan M.
Published: March 2023

Abstract
Recent findings in tumor biopsies from lung adenocarcinoma patients suggest that somatic mutations in the genes encoding epidermal growth factor receptor (EGFR) and Kirsten ras (KRAS) confer sensitivity and resistance, respectively, to EGFR inhibition. Here, we provide evidence that these genetic mutations are not sufficient to modulate the biological response of lung adenocarcinoma cells to EGFR inhibition. We found high expression of ErbB family members, ErbB ligands, or both in three models that were sensitive to EGFR inhibition, including alveolar epithelial neoplastic lesions in mice that develop lung adenocarcinoma by oncogenic KRAS, human lung adenocarcinoma cell lines, and tumor biopsies from lung adenocarcinoma patients. Thus, lung adenocarcinoma cells that depend on EGFR for survival constitutively activate the receptor through a combination of genetic mutations and overexpression of EGFR dimeric partners and their ligands. (Cancer Res 2005; 65(24): 11478-85)
Data from Selective Expansion of Marginal Zone B Cells in Eμ-API2-MALT1 Mice Is Linked to Enhanced IκB Kinase γ Polyubiquitination
Authors: Baens Mathijs , Fevery Sabine , Sagaert Xavier , Noels Heidi , Hagens Sofie , Broeckx Vicky , Billiau An D. , De Wolf-Peeters Christiane , Marynen Peter
Published: March 2023

Abstract
The translocation t(11;18)(q21;q21) that generates an API2-MALT1 fusion protein is the most common structural abnormality among the genetic defects reported in mucosa-associated lymphoid tissue (MALT)-type lymphomas, and its presence correlates with the apparent lack of further genetic instability or chromosomal imbalances. Hence, constitutive nuclear factor-κB (NF-κB) activation induced by the API2-MALT1 fusion protein is considered essential for B-cell transformation. To examine its role in B-cell development and lymphomagenesis, Eμ-API2-MALT1 transgenic mice were produced. Our data show that expression of the API2-MALT1 fusion protein alone is not sufficient for the development of lymphoma masses within 50 weeks. Nevertheless, API2-MALT1 expression affected B-cell maturation in the bone marrow and triggered the specific expansion of splenic marginal zone B cells. Polyubiquitination of IκB kinase γ (IKKγ), indicative for enhanced NF-κB activation, was increased in splenic lymphocytes and promoted the survival of B cells ex vivo. In addition, we show that the API2-MALT1 fusion resided in the cholesterol- and sphingolipid-enriched membrane microdomains, termed lipid rafts. We provide evidence that association of the MALT1 COOH terminal with the lipid rafts, which is mediated by the API2 portion, is sufficient to trigger NF-κB activation via enhanced polyubiquitination of IKKγ. Taken together, these data support the hypothesis that the API2-MALT1 fusion protein can contribute to MALT lymphoma formation via increased NF-κB activation. (Cancer Res 2006; 66(10): 5270-7)
Data from Endogenous Retrovirus Expression Is Required for Murine Melanoma Tumor Growth In vivo
Authors: Mangeney Marianne , Pothlichet Julien , Renard Martial , Ducos Bertrand , Heidmann Thierry
Published: March 2023

Abstract
Tumor development is a multistep process in which both genetic and epigenetic events cooperate for the emergence of a malignant clone. The possibility that endogenous retroviruses promote the expansion of a neoplastic clone by subverting immune surveillance has been proposed, but remained elusive. Here we show that knocking down—by RNA interference—an endogenous retrovirus spontaneously induced in the B16 murine melanoma results in the rejection of the tumor cells in immunocompetent mice, under conditions where control melanoma cells grow into lethal tumors. The knockdown does not modify the transformed phenotype of the cells, as measured both in vitro by a soft agar assay and in vivo by tumor cell proliferation in immunoincompetent (X-irradiated and severe combined immunodeficiency) mice. Tumor rejection can be reverted upon adoptive transfer of regulatory T cells from control melanoma-engrafted mice, as well as upon reexpression of the sole envelope gene of the endogenous retrovirus in the knocked down cells. These results show that endogenous retroviruses can be essential for a regulatory T-cell–mediated subversion of immune surveillance and could be relevant to human tumors where such elements—and especially their envelope gene—are induced.
Data from Nucleophosmin Mutations in De novo Acute Myeloid Leukemia: The Age-Dependent Incidences and the Stability during Disease Evolution
Authors: Chou Wen-Chien , Tang Jih-Luh , Lin Liang-In , Yao Ming , Tsay Woei , Chen Chien-Yuan , Wu Shang-Ju , Huang Chi-Fei , Chiou Rong-Jing , Tseng Mei-Hsuan , Lin Dong-Tsamn , Lin Kai-Hsin , Chen Yao-Chang , Tien Hwei-Fang
Published: March 2023

Abstract
Nucleophosmin (NPM) mutations have been found in a significant proportion of adults with de novo acute myeloid leukemia (AML), especially in those of a normal karyotype. These results provide a basis for studies of the pathogenesis in this specific subgroup of AML. In this study, NPM mutations were analyzed in 173 Chinese patients of de novo AML, including adults and children. We found that NPM mutations were present in 19.1% of the overall population and 40.3% of those with a normal karyotype. Adults had a significantly higher incidence of NPM mutations than children [32 of 126 (25.4%) versus 1 of 47 (2.1%), P < 0.001]. NPM mutations were closely associated with normal karyotype (P < 0.001) and internal tandem duplication of FLT3 (P = 0.002), but negatively associated with CEBPA mutations (P = 0.032) and expression of CD34 (P < 0.001) and HLA-DR (P = 0.003). Serial analyses of NPM mutations showed the mutation disappeared at complete remission, but the same mutation reappeared at relapse, except for one who lost the mutation at the second relapse, when new cytogenetic abnormalities emerged. None acquired novel mutations during the follow-up period. In conclusion, NPM mutations occur in an age-dependent fashion. Moreover, the findings that NPM mutations are stable during disease evolution and closely associated with disease status make it a potential marker for monitoring minimal residual disease. (Cancer Res 2006; 66(6): 3310-6)
Data from Constitutive Activation of Extracellular Signal-Regulated Kinase Predisposes Diffuse Large B-Cell Lymphoma Cell Lines to CD40-Mediated Cell Death
Authors: Hollmann C. Annette , Owens Trevor , Nalbantoglu Josephine , Hudson Thomas J. , Sladek Robert
Published: March 2023

Abstract
CD40 promotes survival, proliferation, and differentiation of normal B cells but can cause activation-induced cell death in malignant B lymphocytes. CD40 ligand and anti-CD40 antibodies have been used successfully to induce apoptosis in lymphoma lines both in vitro and in xenograft tumor models. Although this makes CD40 an attractive target for antitumor therapies, the response of malignant B cells to CD40 signaling is variable, and CD40 stimulation can enhance proliferation and can increase chemoresistance in some cell lines. It would therefore be useful to identify markers that predict whether a specific cell line or tumor will undergo apoptosis when stimulated with CD40 and to identify targets downstream of CD40 that affect only the apoptotic arm of CD40 signaling. We have analyzed gene expression patterns in CD40-sensitive and CD40-resistant diffuse large B-cell lymphoma (DLBCL) cell lines to identify signaling pathways that are involved in CD40-mediated apoptosis. CD40-resistant lines expressed pre-B-cell markers, including RAG and VPREB, whereas CD40-sensitive cells resembled mature B cells and expressed higher levels of transcripts encoding several members of the CD40 signaling pathway, including LCK and VAV. In addition, CD40-sensitive DLBCL cell lines also displayed constitutive activation of extracellular signal-regulated kinase (ERK) and failed to undergo apoptosis when ERK phosphorylation was inhibited. In contrast, CD40-resistant lines showed no constitutive activation of ERK and no increase in ERK activity in response to CD40 stimulation. Our results suggest that constitutive activation of ERK may be required for death signaling by CD40. (Cancer Res 2006; 66(77):3550-7)
Data from Repression of Sestrin Family Genes Contributes to Oncogenic Ras-Induced Reactive Oxygen Species Up-regulation and Genetic Instability
Authors: Kopnin Pavel B. , Agapova Larissa S. , Kopnin Boris P. , Chumakov Peter M.
Published: March 2023

Abstract
Oncogenic mutations within RAS genes and inactivation of p53 are the most common events in cancer. Earlier, we reported that activated Ras contributes to chromosome instability, especially in p53-deficient cells. Here we show that an increase in intracellular reactive oxygen species (ROS) and oxidative DNA damage represents a major mechanism of Ras-induced mutagenesis. Introduction of oncogenic H- or N-Ras caused elevated intracellular ROS, accumulation of 8-oxo-2′-deoxyguanosine, and increased number of chromosome breaks in mitotic cells, which were prevented by antioxidant N-acetyl-l-cysteine. By using Ras mutants that selectively activate either of the three major targets of Ras (Raf, RalGDS, and phosphatidylinositol-3-kinase) as well as dominant-negative Rac1 and RalA mutants and inhibitors of mitogen-activated protein kinase (MAPK)/extracellular signal–regulated kinases kinase-1 and p38 MAPKs, we have shown that several Ras effectors independently mediate ROS up-regulation. Introduction of oncogenic RAS resulted in repression of transcription from sestrin family genes SESN1 and SESN3, which encode antioxidant modulators of peroxiredoxins. Inhibition of mRNAs from these genes in control cells by RNA interference substantially increased ROS levels and mutagenesis. Ectopic expression of SESN1 and SESN3 from lentiviral constructs interfered with Ras-induced ROS increase, suggesting their important contribution to the effect. The stability of Ras-induced increase in ROS was dependent on a p53 function: in the p53-positive cells displaying activation of p53 in response to Ras, only transient (4–7 days) elevation of ROS was observed, whereas in the p53-deficient cells the up-regulation was permanent. The reversion to normal ROS levels in the Ras-expressing p53-positive cells correlated with up-regulation of p53-responsive genes, including reactivation of SESN1 gene. Thus, changes in expression of sestrins can represent an important determinant of genetic instability in neoplastic cells showing simultaneous dysfunctions of Ras and p53. [Cancer Res 2007;67(10):4671–8]
Data from Antiangiogenic Concentrations of Vinflunine Increase the Interphase Microtubule Dynamics and Decrease the Motility of Endothelial Cells
Authors: Pourroy Bertrand , Honoré Stéphane , Pasquier Eddy , Bourgarel-Rey Véronique , Kruczynski Anna , Briand Claudette , Braguer Diane
Published: March 2023

Abstract
Angiogenesis is a key event in tumor progression and metastasis. This complex process, which constitutes a potent target for cancer therapy, is inhibited by very low concentrations of microtubule-targeting drugs (MTD). However, the intimate mechanisms of the antiangiogenic activity of MTDs remain unclear. Recently, we have shown that low antiangiogenic and noncytotoxic concentrations of paclitaxel induced an unexpected increase in microtubule dynamics in endothelial cells. In this study, we showed that vinflunine, the newest Vinca alkaloid, increased microtubule dynamic instability in human endothelial cells after 4-hour incubation at low concentrations (29% and 54% at 0.1 and 2 nmol/L). The growth and shortening rates were increased, and the percentage of time spent in pause and the mean duration of pauses were decreased, as previously observed with paclitaxel. As opposed to paclitaxel, the transition frequencies were not significantly disturbed by vinflunine. Moreover, low concentrations of vinflunine did not affect mitotic index and anaphase/metaphase ratio. Interestingly, these low vinflunine concentrations that increased microtubule dynamics exhibited an antiangiogenic effect through the inhibition of both morphogenesis and random motility. Capillary tube formation on Matrigel was decreased up to 44%. The cell speed and the random motility coefficient were decreased (13% and 19% and 13% and 33% at 0.1 and 2 nmol/L, respectively) and the persistent time was statistically increased. Altogether, our results confirm that the increase in microtubule dynamics is involved in MTD antiangiogenic activity and highlight the crucial role of interphase microtubule dynamics in angiogenesis. (Cancer Res 2006; 66(6): 3256-63)
Data from Large-Scale Molecular Comparison of Human Schwann Cells to Malignant Peripheral Nerve Sheath Tumor Cell Lines and Tissues
Authors: Miller Shyra J. , Rangwala Fatima , Williams Jon , Ackerman Peter , Kong Sue , Jegga Anil G. , Kaiser Sergio , Aronow Bruce J. , Frahm Silke , Kluwe Lan , Mautner Victor , Upadhyaya Meena , Muir David , Wallace Margaret , Hagen Jussara , Quelle Dawn E. , Watson Mark A. , Perry Arie , Gutmann David H. , Ratner Nancy
Published: March 2023

Abstract
Malignant peripheral nerve sheath tumors (MPNST) are highly invasive soft tissue sarcomas that arise within the peripheral nerve and frequently metastasize. To identify molecular events contributing to malignant transformation in peripheral nerve, we compared eight cell lines derived from MPNSTs and seven normal human Schwann cell samples. We found that MPNST lines are heterogeneous in their in vitro growth rates and exhibit diverse alterations in expression of pRb, p53, p14Arf, and p16INK4a proteins. All MPNST cell lines express the epidermal growth factor receptor and lack S100β protein. Global gene expression profiling using Affymetrix oligonucleotide microarrays identified a 159-gene molecular signature distinguishing MPNST cell lines from normal Schwann cells, which was validated in Affymetrix microarray data generated from 45 primary MPNSTs. Expression of Schwann cell differentiation markers (SOX10, CNP, PMP22, and NGFR) was down-regulated in MPNSTs whereas neural crest stem cell markers, SOX9 and TWIST1, were overexpressed in MPNSTs. Previous studies have implicated TWIST1 in apoptosis inhibition, resistance to chemotherapy, and metastasis. Reducing TWIST1 expression in MPNST cells using small interfering RNA did not affect apoptosis or chemoresistance but inhibited cell chemotaxis. Our results highlight the use of gene expression profiling in identifying genes and molecular pathways that are potential biomarkers and/or therapeutic targets for treatment of MPNST and support the use of the MPNST cell lines as a primary analytic tool. (Cancer Res 2006; 66(5): 2584-91)
Data from The Internalization and Degradation of Human Copper Transporter 1 following Cisplatin Exposure
Authors: Holzer Alison K. , Howell Stephen B.
Published: March 2023

Abstract
The human copper transporter 1 (hCTR1), the major transporter responsible for copper influx, mediates one component of the cellular accumulation of cisplatin (DDP). Both copper and DDP cause rapid down-regulation of hCTR1 expression in human ovarian carcinoma cells. In this study, we investigated the mechanism of this effect using digital deconvolution microscopy and Western blot analysis of cells stained with antibodies directed at both ends of the protein. Treatment of 2008 cells with DDP in combination with inhibitors of various endosomal pathways (amiloride, cytochalasin D, nystatin, and methyl-β-cyclodextrin) showed that hCTR1 degradation was blocked by amiloride and cytochalasin D, indicating that hCTR1 was internalized primarily by macropinocytosis. Expression of transdominant-negative forms of dynamin I and Rac showed that loss of hCTR1 was not dependent on pathways regulated by either of these proteins. DDP-induced loss of hCTR1 was blocked by the proteasome inhibitors lactacystin, proteasome inhibitor 1, and MG132. This study confirms that DDP triggers the rapid loss of hCTR1 from ovarian carcinoma cells at clinically relevant concentrations. The results indicate that DDP-induced loss of hCTR1 involves internalization from the plasma membrane by macropinocytosis followed by proteasomal degradation. Because hCTR1 is a major determinant of early DDP uptake, prevention of its degradation offers a potential approach to enhancing tumor sensitivity. (Cancer Res 2006; 66(22): 10944-52)
Data from Activated Checkpoint Kinase 2 Provides a Survival Signal for Tumor Cells
Authors: Ghosh Jagadish C. , Dohi Takehiko , Raskett Christopher M. , Kowalik Timothy F. , Altieri Dario C.
Published: March 2023

Abstract
Tumor cells often become resistant to DNA damage–based therapy; however, the underlying mechanisms are not yet understood. Here, we show that tumor cells exposed to DNA damage counteract cell death by releasing the antiapoptotic protein, survivin, from mitochondria. This is independent of p53, and requires activated checkpoint kinase 2 (Chk2), a putative tumor suppressor. Molecular or genetic targeting of Chk2 prevents the release of survivin from mitochondria, enhances DNA damage–induced tumor cell apoptosis, and inhibits the growth of resistant in vivo tumors. Therefore, activated Chk2 circumvents its own tumor-suppressive functions by promoting tumor cell survival. Inhibiting Chk2 in combination with DNA-damaging agents may provide a rational approach for treating resistant tumors. (Cancer Res 2006; 66(24): 11576-9)
Data from Ku70 and Poly(ADP-Ribose) Polymerase-1 Competitively Regulate β-Catenin and T-Cell Factor-4–Mediated Gene Transactivation: Possible Linkage of DNA Damage Recognition and Wnt Signaling
Authors: Idogawa Masashi , Masutani Mitsuko , Shitashige Miki , Honda Kazufumi , Tokino Takashi , Shinomura Yasuhisa , Imai Kohzoh , Hirohashi Setsuo , Yamada Tesshi
Published: March 2023

Abstract
Formation of the T-cell factor-4 (TCF-4) and β-catenin nuclear complex is considered crucial to embryonic development and colorectal carcinogenesis. We previously reported that poly(ADP-ribose) polymerase-1 (PARP-1) interacts with the TCF-4 and β-catenin complex and enhances its transcriptional activity. However, its biological significance remains unexplained. Using immunoprecipitation and mass spectrometry, we found that two Ku proteins, Ku70 and Ku80, were also associated with the complex. Knockdown of Ku70 by RNA interference increased the amount of β-catenin associated with TCF-4 and enhanced the transcriptional activity. PARP-1 competed with Ku70 for binding to TCF-4. Treatment with bleomycin, a DNA-damaging alkylating agent, induced polyADP-ribosylation of PARP-1 protein and inhibited its interaction with TCF-4. Bleomycin conversely increased the amounts of Ku70 coimmunoprecipitated with TCF-4 and removed β-catenin from TCF-4. We propose a working model in which the transcriptional activity of TCF-4 is regulated by the relative amount of Ku70, PARP-1, and β-catenin proteins binding to TCF-4. Identification of the functional interaction of Ku70 as well as PARP-1 with the TCF-4 and β-catenin transcriptional complex may provide insights into a novel linkage between DNA damage recognition/repair and Wnt signaling. [Cancer Res 2007;67(3):911–8]
Data from Bin1 Ablation in Mammary Gland Delays Tissue Remodeling and Drives Cancer Progression
Authors: Chang Mee Young , Boulden Janette , Sutanto-Ward Erika , Duhadaway James B. , Soler Alejandro Peralta , Muller Alexander J. , Prendergast George C.
Published: March 2023

Abstract
Genes that modify oncogenesis may influence dormancy versus progression in cancer, thereby affecting clinical outcomes. The Bin1 gene encodes a nucleocytosolic adapter protein that interacts with and suppresses the cell transforming activity of Myc. Bin1 is often attenuated in breast cancer but its ability to negatively modify oncogenesis or progression in this context has not been gauged directly. In this study, we investigated the effects of mammary gland–specific deletion of Bin1 on initiation and progression of breast cancer in mice. Bin1 loss delayed the outgrowth and involution of the glandular ductal network during pregnancy but had no effect on tumor susceptibility. In contrast, in mice where tumors were initiated by the ras-activating carcinogen 7,12-dimethylbenz(a)anthracene, Bin1 loss strongly accentuated the formation of poorly differentiated tumors characterized by increased proliferation, survival, and motility. This effect was specific as Bin1 loss did not accentuate progression of tumors initiated by an overexpressed mouse mammary tumor virus-c-myc transgene, which on its own produced poorly differentiated and aggressive tumors. These findings suggest that Bin1 loss cooperates with ras activation to drive progression, establishing a role for Bin1 as a negative modifier of oncogenicity and progression in breast cancer. [Cancer Res 2007;67(1):100–7]
Data from Relation of a Hypoxia Metagene Derived from Head and Neck Cancer to Prognosis of Multiple Cancers
Authors: Winter Stuart C. , Buffa Francesca M. , Silva Priyamal , Miller Crispin , Valentine Helen R. , Turley Helen , Shah Ketan A. , Cox Graham J. , Corbridge Rogan J. , Homer Jarrod J. , Musgrove Brian , Slevin Nick , Sloan Philip , Price Pat , West Catharine M.L. , Harris Adrian L.
Published: March 2023

Abstract
Affymetrix U133plus2 GeneChips were used to profile 59 head and neck squamous cell cancers. A hypoxia metagene was obtained by analysis of genes whose in vivo expression clustered with the expression of 10 well-known hypoxia-regulated genes (e.g., CA9, GLUT1, and VEGF). To minimize random aggregation, strongly correlated up-regulated genes appearing in >50% of clusters defined a signature comprising 99 genes, of which 27% were previously known to be hypoxia associated. The median RNA expression of the 99 genes in the signature was an independent prognostic factor for recurrence-free survival in a publicly available head and neck cancer data set, outdoing the original intrinsic classifier. In a published breast cancer series, the hypoxia signature was a significant prognostic factor for overall survival independent of clinicopathologic risk factors and a trained profile. The work highlights the validity and potential of using data from analysis of in vitro stress pathways for deriving a biological metagene/gene signature in vivo. [Cancer Res 2007;67(7):3441–9]
Data from Survival Signaling by Notch1: Mammalian Target of Rapamycin (mTOR)–Dependent Inhibition of p53
Authors: Mungamuri Sathish Kumar , Yang XiaoHe , Thor Ann D. , Somasundaram Kumaravel
Published: March 2023

Abstract
Notch signaling is believed to promote cell survival in general. However, the mechanism is not clearly understood. Here, we show that cells expressing intracellular domain of human Notch1 (NIC-1) are chemoresistant in a wild-type p53-dependent manner. NIC-1 inhibited p53 by inhibiting its activating phosphorylations at Ser15, Ser20, and Ser392 as well as nuclear localization. In addition, we found that inhibition of p53 by NIC-1 mainly occurs through mammalian target of rapamycin (mTOR) using phosphatidylinositol 3-kinase (PI3K)-Akt/protein kinase B (PKB) pathway as the mTOR inhibitor, rapamycin treatment abrogated NIC-1 inhibition of p53 and reversed the chemoresistance. Consistent with this, rapamycin failed to reverse NIC-1-induced chemoresistance in cells expressing rapamycin-resistant mTOR. Further, ectopic expression of eukaryotic initiation factor 4E (eIF4E), a translational regulator that acts downstream of mTOR, inhibited p53-induced apoptosis and conferred protection against p53-mediated cytotoxicity to similar extent as that of NIC-1 overexpression but was not reversed by rapamycin, which indicates that eIF4E is the major target of mTOR in Notch1-mediated survival signaling. Finally, we show that MCF7 (breast cancer) and MOLT4 (T-cell acute lymphoblastic leukemia) cells having aberrant Notch1 signaling are chemoresistant, which can be reversed by both PI3K and mTOR inhibitors. These results establish that Notch1 signaling confers chemoresistance by inhibiting p53 pathway through mTOR-dependent PI3K-Akt/PKB pathway and imply that p53 status perhaps is an important determinant in combination therapeutic strategies, which use mTOR inhibitors and chemotherapy. (Cancer Res 2006; 66(9): 4715-24)
Data from Retinoic Acid Induces p27Kip1 Nuclear Accumulation by Modulating Its Phosphorylation
Authors: Borriello Adriana , Cucciolla Valeria , Criscuolo Maria , Indaco Stefania , Oliva Adriana , Giovane Alfonso , Bencivenga Debora , Iolascon Achille , Zappia Vincenzo , Della Ragione Fulvio
Published: March 2023

Abstract
All-trans-retinoic acid (ATRA), the most biologically active metabolite of vitamin A, controls cell proliferation, apoptosis, and differentiation depending on the cellular context. These activities point to ATRA as a candidate for cancer therapy. A pivotal effect of the molecule is the modulation of p27Kip1, a cyclin-dependent kinase (CDK) inhibitor (CDKI). Here, we investigate the mechanisms by which ATRA regulates p27Kip1 level in LAN-5, a neuroblastoma cell line. When added to the cells, ATRA causes a rapid nuclear increase of p27Kip1, which clearly precedes growth arrest. The early buildup is not due to impairment of the CDKI degradation, in contrast to previous observations. Particularly, we did not detect the down-regulation of Skp2 and Cks1, two proteins involved in the nuclear ubiquitin-dependent p27Kip1 removal. Moreover, the morphogen does not impair the CDKI nuclear export and does not cause CDK2 relocalization. The characterization of CDKI isoforms by two-dimensional PAGE/immunoblotting showed that ATRA induces an early nuclear up-regulation of monophosphorylated p27Kip1. Immunologic studies established that this isoform corresponds to p27Kip1 phosphorylated on S10. The buildup of phospho(S10)p27Kip1 precedes the CDKI accumulation and increases its half-life. Finally, ATRA-treated nuclear LAN-5 extracts showed an enhanced capability of phosphorylating p27Kip1 on S10, thus explaining the nuclear up-regulation of the isoform. In conclusion, our data suggest a novel mechanism of ATRA antiproliferative activity, in which the morphogen rapidly up-regulates a nuclear kinase activity that phosphorylates p27Kip1 on S10. In turn, this event causes the stabilization of p27Kip1 and its accumulation in the nuclear compartment. (Cancer Res 2006; 66(8): 4240-8)
Data from BRCA1 Ubiquitinates RPB8 in Response to DNA Damage
Authors: Wu Wenwen , Nishikawa Hiroyuki , Hayami Ryosuke , Sato Ko , Honda Akeri , Aratani Satoko , Nakajima Toshihiro , Fukuda Mamoru , Ohta Tomohiko
Published: March 2023

Abstract
The breast and ovarian tumor suppressor BRCA1 catalyzes untraditional polyubiquitin chains that could be a signal for processes other than proteolysis. However, despite intense investigations, the mechanisms regulated by the enzyme activity remain only partially understood. Here, we report that BRCA1-BARD1 mediates polyubiquitination of RPB8, a common subunit of RNA polymerases, in response to DNA damage. A proteomics screen identified RPB8 as a protein modified after epirubicin treatment in BRCA1-dependent manner. RPB8 interacted with BRCA1-BARD1 and was polyubiquitinated by BRCA1-BARD1 in vivo and in vitro. BRCA1-BARD1 did not destabilize RPB8 in vivo but rather caused an increase in the amount of soluble RPB8. Importantly, RPB8 was polyubiquitinated immediately after UV irradiation in a manner sensitive to BRCA1 knockdown by RNA interference. Substitution of five lysine residues of RPB8 with arginine residues abolished its ability to be ubiquitinated while preserving its polymerase activity. HeLa cell lines stably expressing this ubiquitin-resistant form of RPB8 exhibited UV hypersensitivity accompanied by up-regulated caspase activity. Our findings suggest that ubiquitination of a common subunit of RNA polymerases is a mechanism underlying BRCA1-dependent cell survival after DNA damage. [Cancer Res 2007;67(3):951–8]
Data from c-Jun NH2-Terminal Kinase–Related Na+/H+ Exchanger Isoform 1 Activation Controls Hexokinase II Expression in Benzo(a)Pyrene-Induced Apoptosis
Authors: Huc Laurence , Tekpli Xavier , Holme Jørn A. , Rissel Mary , Solhaug Anita , Gardyn Claire , Le Moigne Gwénaelle , Gorria Morgane , Dimanche-Boitrel Marie-Thérèse , Lagadic-Gossmann Dominique
Published: March 2023

Abstract
Regulation of the balance between survival, proliferation, and apoptosis on carcinogenic polycyclic aromatic hydrocarbon (PAH) exposure is still poorly understood and more particularly the role of physiologic variables, including intracellular pH (pHi). Although the involvement of the ubiquitous pHi regulator Na+/H+ exchanger isoform 1 (NHE1) in tumorigenesis is well documented, less is known about its role and regulation during apoptosis. Our previous works have shown the primordial role of NHE1 in carcinogenic PAH-induced apoptosis. This alkalinizing transporter was activated by an early CYP1-dependent H2O2 production, subsequently promoting mitochondrial dysfunction leading to apoptosis. The aim of this study was to further elucidate how NHE1 was activated by benzo(a)pyrene (BaP) and what the downstream events were in the context of apoptosis. Our results indicate that the mitogen-activated protein kinase kinase 4/c-Jun NH2-terminal kinase (MKK4/JNK) pathway was a link between BaP-induced H2O2 production and NHE1 activation. This activation, in combination with BaP-induced phosphorylated p53, promoted mitochondrial superoxide anion production, supporting the existence of a common target for NHE1 and p53. Furthermore, we showed that the mitochondrial expression of glycolytic enzyme hexokinase II (HKII) was decreased following a combined action of NHE1 and p53 pathways, thereby enhancing the BaP-induced apoptosis. Taken together, our findings suggest that, on BaP exposure, MKK4/JNK targets NHE1 with consequences on HKII protein, which might thus be a key protein during carcinogenic PAH apoptosis. [Cancer Res 2007;67(4):1696–705]
Data from Dimethylfumarate Impairs Melanoma Growth and Metastasis
Authors: Loewe Robert , Valero Teresa , Kremling Silvia , Pratscher Barbara , Kunstfeld Rainer , Pehamberger Hubert , Petzelbauer Peter
Published: March 2023

Abstract
Dimethylfumarate (DMF) inhibits signals transmitted by Rel proteins and is used for the treatment of inflammatory skin diseases such as psoriasis, but potential effects of DMF on tumor progression have yet not been analyzed. We show that DMF reduced melanoma growth and metastasis in severe combined immunodeficient mouse models. To identify targets of DMF action, we analyzed mRNA expression in DMF-treated melanomas by gene chip arrays. Using BiblioSphere software for data analysis, significantly regulated genes were mapped to Gene Ontology terms cell death, cell growth, and cell cycle. Indeed, we found that DMF inhibited proliferation of human melanoma cells A375 and M24met in vitro. The cell cycle was arrested at the G2-M boundary. Moreover, DMF was proapoptotic, as shown by cell cycle analysis and by Annexin V and Apo2.7 staining. These results were confirmed in vivo. DMF reduced proliferation rates of tumor cells as assessed by Ki-67 immunostaining and increased apoptosis as assessed by terminal deoxyribonucleotidyl transferase–mediated dUTP nick end labeling staining. In conclusion, DMF is antiproliferative and proapoptotic and reduces melanoma growth and metastasis in animal models. (Cancer Res 2006; 66(24): 11888-96)
Data from Inhibition of Indoleamine 2,3-Dioxygenase in Dendritic Cells by Stereoisomers of 1-Methyl-Tryptophan Correlates with Antitumor Responses
Authors: Hou De-Yan , Muller Alexander J. , Sharma Madhav D. , DuHadaway James , Banerjee Tinku , Johnson Maribeth , Mellor Andrew L. , Prendergast George C. , Munn David H.
Published: March 2023

Abstract
Indoleamine 2,3-dioxygenase (IDO) is an immunosuppressive enzyme that contributes to tolerance in a number of biological settings. In cancer, IDO activity may help promote acquired tolerance to tumor antigens. The IDO inhibitor 1-methyl-tryptophan is being developed for clinical trials. However, 1-methyl-tryptophan exists in two stereoisomers with potentially different biological properties, and it has been unclear which isomer might be preferable for initial development. In this study, we provide evidence that the d and l stereoisomers exhibit important cell type–specific variations in activity. The l isomer was the more potent inhibitor of IDO activity using the purified enzyme and in HeLa cell–based assays. However, the d isomer was significantly more effective in reversing the suppression of T cells created by IDO-expressing dendritic cells, using both human monocyte–derived dendritic cells and murine dendritic cells isolated directly from tumor-draining lymph nodes. In vivo, the d isomer was more efficacious as an anticancer agent in chemo-immunotherapy regimens using cyclophosphamide, paclitaxel, or gemcitabine, when tested in mouse models of transplantable melanoma and transplantable and autochthonous breast cancer. The d isomer of 1-methyl-tryptophan specifically targeted the IDO gene because the antitumor effect of d-1-methyl-tryptophan was completely lost in mice with a disruption of the IDO gene (IDO-knockout mice). Taken together, our findings support the suitability of d-1-methyl-tryptophan for human trials aiming to assess the utility of IDO inhibition to block host-mediated immunosuppression and enhance antitumor immunity in the setting of combined chemo-immunotherapy regimens. [Cancer Res 2007;67(2):792–801]
Data from G-Quadruplexes Induce Apoptosis in Tumor Cells
Authors: Qi Haiyan , Lin Chao-Po , Fu Xuan , Wood Laurence M. , Liu Angela A. , Tsai Yuan-Chin , Chen Yongjie , Barbieri Christopher M. , Pilch Daniel S. , Liu Leroy F.
Published: March 2023

Abstract
Several G-rich oligodeoxynucleotides (ODNs), which are capable of forming G-quadruplexes, have been shown to exhibit antiproliferative activity against tumor cell lines and antitumor activity in nude mice carrying prostate and breast tumor xenografts. However, the molecular basis for their antitumor activity remains unclear. In the current study, we showed that a variety of telomeric G-tail oligodeoxynucleotides (TG-ODNs) exhibited antiproliferative activity against many tumor cells in culture. Systematic mutational analysis of the TG-ODNs suggests that the antiproliferative activity depends on the G-quadruplex conformation of these TG-ODNs. TG-ODNs were also shown to induce poly(ADP-ribose) polymerase-1 cleavage, phosphatidylserine flipping, and caspase activation, indicative of induction of apoptosis. TG-ODN–induced apoptosis was largely ataxia telangiectasia mutated (ATM) dependent. Furthermore, TG-ODN–induced apoptosis was inhibited by the c-Jun NH2-terminal kinase (JNK) inhibitor SP600125. Indeed, TG-ODNs were shown to activate the JNK pathway in an ATM-dependent manner as evidenced by elevated phosphorylation of JNK and c-Jun. Interestingly, a number of G-quadruplex ODNs (GQ-ODN) derived from nontelomeric sequences also induced ATM/JNK-dependent apoptosis, suggesting a possible common mechanism of tumor cell killing by GQ-ODNs. (Cancer Res 2006; 66(24): 11808-16)