bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Arginase I–Producing Myeloid-Derived Suppressor Cells in Renal Cell Carcinoma Are a Subpopulation of Activated Granulocytes
Authors: Rodriguez Paulo C. , Ernstoff Marc S. , Hernandez Claudia , Atkins Michael , Zabaleta Jovanny , Sierra Rosa , Ochoa Augusto C.
Published: March 2024

Abstract
Myeloid-derived suppressor cells (MDSC) producing arginase I are increased in the peripheral blood of patients with renal cell carcinoma (RCC). MDSC inhibit T-cell function by reducing the availability of l-arginine and are therefore considered an important tumor escape mechanism. We aimed to determine the origin of arginase I–producing MDSC in RCC patients and to identify the mechanisms used to deplete extracellular l-arginine. The results show that human MDSC are a subpopulation of activated polymorphonuclear (PMN) cells expressing high levels of CD66b, CD11b, and VEGFR1 and low levels of CD62L and CD16. In contrast to murine MDSC, human MDSC do not deplete l-arginine by increasing its uptake but instead release arginase I into the circulation. Activation of normal PMN induces phenotypic and functional changes similar to MDSC and also promotes the release of arginase I from intracellular granules. Interestingly, although activation of normal PMN usually ends with apoptosis, MDSC showed no increase in apoptosis compared with autologous PMN or PMN obtained from normal controls. High levels of VEGF have been shown to increase suppressor immature myeloid dendritic cells in cancer patients. Treatment of RCC patients with anti-VEGF antibody bevacizumab, however, did not reduce the accumulation of MDSC in peripheral blood. In contrast, the addition of interleukin-2 to the treatment increased the number of MDSC in peripheral blood and the plasma levels of arginase I. These results may provide new insights on the mechanisms of tumor-induced anergy/tolerance and may help explain why some immunotherapies fail to induce an antitumor response. [Cancer Res 2009;69(4):1553–60]
Data from PME-1 Protects Extracellular Signal-Regulated Kinase Pathway Activity from Protein Phosphatase 2A–Mediated Inactivation in Human Malignant Glioma
Authors: Puustinen Pietri , Junttila Melissa R. , Vanhatupa Sari , Sablina Anna A. , Hector Melissa E. , Teittinen Kaisa , Raheem Olayinka , Ketola Kirsi , Lin Shujun , Kast Juergen , Haapasalo Hannu , Hahn William C. , Westermarck Jukka
Published: March 2024

Abstract
Extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase pathway activity is regulated by the antagonist function of activating kinases and inactivating protein phosphatases. Sustained ERK pathway activity is commonly observed in human malignancies; however, the mechanisms by which the pathway is protected from phosphatase-mediated inactivation in the tumor tissue remain obscure. Here, we show that methylesterase PME-1–mediated inhibition of the protein phosphatase 2A promotes basal ERK pathway activity and is required for efficient growth factor response. Mechanistically, PME-1 is shown to support ERK pathway signaling upstream of Raf, but downstream of growth factor receptors and protein kinase C. In malignant gliomas, PME-1 expression levels correlate with both ERK activity and cell proliferation in vivo. Moreover, PME-1 expression significantly correlates with disease progression in human astrocytic gliomas (n = 222). Together, these observations identify PME-1 expression as one mechanism by which ERK pathway activity is maintained in cancer cells and suggest an important functional role for PME-1 in the disease progression of human astrocytic gliomas. [Cancer Res 2009;69(7):2870–7]
Data from Cross-talk between Tumor and Endothelial Cells Involving the Notch3-Dll4 Interaction Marks Escape from Tumor Dormancy
Authors: Indraccolo Stefano , Minuzzo Sonia , Masiero Massimo , Pusceddu Irene , Persano Luca , Moserle Lidia , Reboldi Andrea , Favaro Elena , Mecarozzi Marco , Di Mario Giuseppina , Screpanti Isabella , Ponzoni Maurilio , Doglioni Claudio , Amadori Alberto
Published: March 2024

Abstract
The Notch ligand Dll4 has a recognized role during both physiologic and tumor angiogenesis, as it contributes to regulate Notch activity in endothelial cells (EC). The effects of Dll4 on Notch signaling in tumor cells expressing Notch receptors remain, however, largely unknown. Here, we report that escape of human T-cell acute lymphoblastic leukemia (T-ALL) cells or colorectal cancer cells from dormancy is associated with Dll4 expression in the tumor microenvironment and increased Notch3 signaling in tumor cells. Dll4 was expressed at early time points during the angiogenic process, and its expression preceded perfusion of the newly established vessels. Treatment of EC with angiogenic factors induced Dll4 expression and increased Notch3 activation in cocultured T-ALL cells. Neutralization of Dll4 greatly reduced EC-mediated activation of Notch 3 signaling in T-ALL cells and blocked tumorigenesis. Moreover, silencing Notch3 by RNA interference had marked antiproliferative and proapoptotic effects on T-ALL cells in vitro and reduced tumorigenicity in vivo. Our results elucidate a novel mechanism by which a direct interplay between endothelial and tumor cells promotes survival and triggers tumor growth. [Cancer Res 2009;69(4):1314–23]
Data from Hepatocyte Growth Factor Activator Inhibitor Type 1 Regulates Epithelial to Mesenchymal Transition through Membrane-Bound Serine Proteinases
Authors: Cheng Haixia , Fukushima Tsuyoshi , Takahashi Nobuyasu , Tanaka Hiroyuki , Kataoka Hiroaki
Published: March 2024

Abstract
Hepatocyte growth factor activator inhibitor-1 (HAI-1), encoded by the serine protease inhibitor Kunitz type 1 (SPINT1) gene, is a membrane-associated proteinase inhibitor that potently inhibits a variety of serine proteinases, including those that are membrane bound. Although HAI-1/SPINT1 is widely expressed by epithelial cells and cancer cells, its functional role is still unclear, particularly in cancer. Here, we show that stable knockdown of HAI-1/SPINT1 in the human pancreatic cancer cell line SUIT-2 induces an elongated spindle-like morphology associated with accelerated invasion, thereby mimicking an epithelial to mesenchymal transition (EMT). We found that HAI-1/SPINT1 knockdown significantly reduced the expression of E-cadherin and was accompanied by up-regulation of Smad-interacting protein 1 (SIP1), an E-cadherin transcriptional repressor. In addition, matrix metalloproteinase-9 (MMP-9) was up-regulated. Similar results were obtained in the HLC-1 lung carcinoma cell line. Moreover, a metastatic variant of SUIT-2 (S2-CP8) that showed loss of E-cadherin expression also showed a significantly reduced level of HAI-1/SPINT1. Engineered overexpression of HAI-1/SPINT1 in S2-CP8 resulted in reversion of E-cadherin expression and SIP1 down-regulation, which accompanied reestablishment of epithelial morphology in culture. The EMT caused by HAI-1/SPINT1 knockdown seemed to be mediated, at least partly, by membrane-bound serine proteinases, matriptase/ST14 and TMPRSS4, as knockdown of matriptase/ST14 or TMPRSS4 in HAI-1/SPINT1 knockdown SUIT-2 cells and HLC-1 cells resulted in reversion of SIP1 and/or MMP-9 expression levels. We suggest that interactions between HAI-1/SPINT1 and membrane-bound serine proteinases contribute to transcriptional and functional changes involved in EMT in certain carcinoma cells. [Cancer Res 2009;69(5):1828–35]
Data from Unsupervised Analysis of Transcriptomic Profiles Reveals Six Glioma Subtypes
Authors: Li Aiguo , Walling Jennifer , Ahn Susie , Kotliarov Yuri , Su Qin , Quezado Martha , Oberholtzer J. Carl , Park John , Zenklusen Jean C. , Fine Howard A.
Published: March 2024

Abstract
Gliomas are the most common type of primary brain tumors in adults and a significant cause of cancer-related mortality. Defining glioma subtypes based on objective genetic and molecular signatures may allow for a more rational, patient-specific approach to therapy in the future. Classifications based on gene expression data have been attempted in the past with varying success and with only some concordance between studies, possibly due to inherent bias that can be introduced through the use of analytic methodologies that make a priori selection of genes before classification. To overcome this potential source of bias, we have applied two unsupervised machine learning methods to genome-wide gene expression profiles of 159 gliomas, thereby establishing a robust glioma classification model relying only on the molecular data. The model predicts for two major groups of gliomas (oligodendroglioma-rich and glioblastoma-rich groups) separable into six hierarchically nested subtypes. We then identified six sets of classifiers that can be used to assign any given glioma to the corresponding subtype and validated these classifiers using both internal (189 additional independent samples) and two external data sets (341 patients). Application of the classification system to the external glioma data sets allowed us to identify previously unrecognized prognostic groups within previously published data and within The Cancer Genome Atlas glioblastoma samples and the different biological pathways associated with the different glioma subtypes offering a potential clue to the pathogenesis and possibly therapeutic targets for tumors within each subtype. [Cancer Res 2009;69(5):2091–9]
Data from Whole Genome Comparison of Allelic Imbalance between Noninvasive and Invasive Small-Sized Lung Adenocarcinomas
Authors: Nakanishi Hirofumi , Matsumoto Shingo , Iwakawa Reika , Kohno Takashi , Suzuki Kenji , Tsuta Koji , Matsuno Yoshihiro , Noguchi Masayuki , Shimizu Eiji , Yokota Jun
Published: March 2024

Abstract
Seventy-two small-sized (≤2 cm in diameter) lung adenocarcinomas consisting of 15 noninvasive and 57 invasive tumors were subjected to whole genome allelic imbalance (AI) scanning and mutational analysis of the EGFR, KRAS, and TP53 genes to elucidate genetic pathways of early-stage lung adenocarcinomas. The chromosome 13q13 region showed the most frequent AI (58%) and was affected at similar frequencies between noninvasive and invasive tumors (53% and 60%, respectively), as EGFR and KRAS mutations were. The number of AI regions as well as the frequency of TP53 mutations in invasive tumors was significantly higher than those in noninvasive ones [9.8 ± 5.6 versus 4.8 ± 2.8 (P = 0.00002) and 61% versus 13% (P = 0.001), respectively]. In particular, AIs at the chromosome 11p11-p12, 17p12-p13, and 18p11 regions in invasive tumors were significantly more frequent than those in noninvasive ones (P < 0.01). The results indicated that noninvasive tumors were developed by EGFR, KRAS, and 13q alterations and progressed to invasive ones by subsequent alterations of several tumor suppressor genes, including those on 11p11-p12, 17p12-p13, and 18p11 and TP53. AI at 8p21 was significantly more frequent in advanced stages (>IA) and associated with worse prognoses (P = 0.04) and, thus, would be involved in invasion and/or metastasis of adenocarcinoma cells and useful for the prediction of prognosis of patients with small-sized lung adenocarcinoma. [Cancer Res 2009;69(4):1615–23]
Data from NADPH Oxidase 4 Contributes to Transformation Phenotype of Melanoma Cells by Regulating G2-M Cell Cycle Progression
Authors: Yamaura Maki , Mitsushita Junji , Furuta Shuichi , Kiniwa Yukiko , Ashida Atsuko , Goto Yasuhumi , Shang Wei H. , Kubodera Makoto , Kato Masayoshi , Takata Minoru , Saida Toshiaki , Kamata Tohru
Published: March 2024

Abstract
Generation of reactive oxygen species (ROS) has been implicated in carcinogenic development of melanoma, but the underlying molecular mechanism has not been fully elucidated. We studied the expression and function of the superoxide-generating NADPH oxidase (Nox)4 in human melanoma cells. Nox4 was up-regulated in 13 of 20 melanoma cell lines tested. Silencing of Nox4 expression in melanoma MM-BP cells by small interfering RNAs decreased ROS production and thereby inhibited anchorage-independent cell growth and tumorigenecity in nude mice. Consistently, a general Nox inhibitor, diphenylene iodonium, and antioxidants vitamine E and pyrrolidine dithiocarbamate blocked cell proliferation of MM-BP cells. Flow cytometric analysis indicated that Nox4 small interfering RNAs and diphenylene iodonium induced G2-M cell cycle arrest, which was also observed with another melanoma cell line, 928mel. This was accompanied by induction of the Tyr-15 phosphorylated, inactive form of cyclin-dependent kinase 1 (a hallmark of G2-M checkpoint) and hyperphosphorylation of cdc25c leading to its increased binding to 14-3-3 proteins. Ectopic expression of catalase, a scavenger of ROS, also caused accumulation of cells in G2-M phase. Immunohistochemistry revealed that expression of Nox4 was detected in 31.0% of 13 melanoma patients samples, suggesting the association of Nox4 expression with some steps of melanoma development. The findings suggest that Nox4-generated ROS are required for transformation phenotype of melanoma cells and contribute to melanoma growth through regulation of G2-M cell cycle progression. [Cancer Res 2009;69(6):2647–54]
Data from Senescence-Associated Oxidative DNA Damage Promotes the Generation of Neoplastic Cells
Authors: Gosselin Karo , Martien Sébastien , Pourtier Albin , Vercamer Chantal , Ostoich Peter , Morat Luc , Sabatier Laure , Duprez Laurence , T'Kint de Roodenbeke Claire , Gilson Eric , Malaquin Nicolas , Wernert Nicolas , Slijepcevic Predrag , Ashtari Marjan , Chelli Fazia , Deruy Emeric , Vandenbunder Bernard , De Launoit Yvan , Abbadie Corinne
Published: March 2024

Abstract
Studies on human fibroblasts have led to viewing senescence as a barrier against tumorigenesis. Using keratinocytes, we show here that partially transformed and tumorigenic cells systematically and spontaneously emerge from senescent cultures. We show that these emerging cells are generated from senescent cells, which are still competent for replication, by an unusual budding-mitosis mechanism. We further present data implicating reactive oxygen species that accumulate during senescence as a potential mutagenic motor of this post-senescence emergence. We conclude that senescence and its associated oxidative stress could be a tumor-promoting state for epithelial cells, potentially explaining why the incidence of carcinogenesis dramatically increases with advanced age. [Cancer Res 2009;69(20):7917–24]
Data from Immune-Induced Epithelial to Mesenchymal Transition In vivo Generates Breast Cancer Stem Cells
Authors: Santisteban Marta , Reiman Jennifer M. , Asiedu Michael K. , Behrens Marshall D. , Nassar Aziza , Kalli Kimberly R. , Haluska Paul , Ingle James N. , Hartmann Lynn C. , Manjili Masoud H. , Radisky Derek C. , Ferrone Soldano , Knutson Keith L.
Published: March 2024

Abstract
The breast cancer stem cell (BCSC) hypotheses suggest that breast cancer is derived from a single tumor-initiating cell with stem-like properties, but the source of these cells is unclear. We previously observed that induction of an immune response against an epithelial breast cancer led in vivo to the T-cell–dependent outgrowth of a tumor, the cells of which had undergone epithelial to mesenchymal transition (EMT). The resulting mesenchymal tumor cells had a CD24−/loCD44+ phenotype, consistent with BCSCs. In the present study, we found that EMT was induced by CD8 T cells and the resulting tumors had characteristics of BCSCs, including potent tumorigenicity, ability to reestablish an epithelial tumor, and enhanced resistance to drugs and radiation. In contrast to the hierarchal cancer stem cell hypothesis, which suggests that breast cancer arises from the transformation of a resident tissue stem cell, our results show that EMT can produce the BCSC phenotype. These findings have several important implications related to disease progression and relapse. [Cancer Res 2009;69(7):2887–95]
Data from The ITK-SYK Fusion Oncogene Induces a T-Cell Lymphoproliferative Disease in Mice Mimicking Human Disease
Authors: Dierks Christine , Adrian Francisco , Fisch Paul , Ma Hong , Maurer Helga , Herchenbach Dieter , Forster Christine Ulrike , Sprissler Clara , Liu Guoxun , Rottmann Sabine , Guo Gui-Rong , Katja Zirlik , Veelken Hendrik , Warmuth Markus
Published: March 2024

Abstract
Peripheral T-cell lymphomas (PTCL) constitute a major treatment problem with high mortality rates due to the minimal effectiveness of conventional chemotherapy. Recent findings identified ITK-SYK as the first recurrent translocation in 17% of unspecified PTCLs and showed the overexpression of SYK in more than 90% of PTCLs. Here, we show that the expression of ITK-SYK in the bone marrow of BALB/c mice causes a T-cell lymphoproliferative disease in all transplanted mice within 8 weeks after transplantation. The disease was characterized by the infiltration of spleen, lymph nodes, bone marrow, and skin with CD3+CD4+CD8− and CD3+CD4−CD8− ITK-SYK–positive T-cells accompanied by a systemic inflammatory reaction with upregulation of interleukin 5 and INF-γ. ITK-SYK–positive T-cells showed enhanced apoptosis resistance and INF-γ production in vitro. The disease was serially transplantable, inducing clonal T-cell expansion in secondary recipients. The action of ITK-SYK in vivo was dependent on SYK kinase activity and disease development could be inhibited by the treatment of mice with SYK inhibitors. Interestingly, the translocation of ITK-SYK from the membrane to the cytoplasm, using a point mutation in the pleckstrin homology domain (ITK-SYK R29C), did not abolish, but rather, enhanced disease development in transplanted mice. CBL binding was strongly enhanced in membrane-associated ITK-SYK E42K and was causative for delayed disease development. Our results show that ITK-SYK causes a T-cell lymphoproliferative disease in mice, supporting its role in T-cell lymphoma development in humans. Therefore, pharmacologic inhibition of SYK in patients with U-PTCLs carrying the ITK-SYK fusion protein might be an effective treatment strategy. Cancer Res; 70(15); 6193–204. ©2010 AACR.
Data from Non–Small Cell Lung Cancer Exhibits Transcript Overexpression of Genes Associated with Homologous Recombination and DNA Replication Pathways
Authors: Saviozzi Silvia , Ceppi Paolo , Novello Silvia , Ghio Paolo , Lo Iacono Marco , Borasio Piero , Cambieri Alberto , Volante Marco , Papotti Mauro , Calogero Raffaele A. , Scagliotti Giorgio V.
Published: March 2024

Abstract
Genes involved in DNA repair and replication have been recently investigated as predictive markers of response to chemotherapy in non–small cell lung cancer (NSCLC). However, few data on the expression of these genes in tumor compared with corresponding normal lung are available. The aim of this study was to evaluate differential mRNA levels of 22 DNA repair genes of five different DNA repair pathways: direct, base excision, nucleotide excision (NER), double-strand break (DSBR), and postreplicative repair. In addition, six genes involved in DNA replication (REP) and three telomere maintenance genes were investigated. Total RNAs extracted from fresh-frozen tumors and corresponding normal tissues of 50 consecutive chemo-naïve resected NSCLC patients were analyzed. Transcript levels were quantified by real-time PCR. A significant overexpression was detected in 20 of 30 (67%) genes, mostly belonging to DSBR pathways, whereas others (XPA, XPC, and UBE2N; 10%) were significantly underexpressed. For 7 of 30 (23%) genes, mostly belonging to NER pathway, no significant difference between paired tumor and normal samples was observed. Transcript overexpression of DSBR and REP genes was significantly higher in poorly differentiated carcinomas and DSBR levels were higher in men compared with women. The transcriptional overexpression of four genes (XRCC5, TOP3B, TYMS, and UNG) showed significant correlation with a shorter patients' outcome at the univariate, whereas only stage of disease appeared as an independent factor affecting prognosis, as assessed by multivariate analysis. In conclusion, genes belonging to DNA repair/replication pathways are overexpressed in NSCLC and are associated with a more aggressive phenotype. [Cancer Res 2009;69(8):3390–6]
Data from p53-Altered FBXW7 Expression Determines Poor Prognosis in Gastric Cancer Cases
Authors: Yokobori Takehiko , Mimori Koshi , Iwatsuki Masaaki , Ishii Hideshi , Onoyama Ichiro , Fukagawa Takeo , Kuwano Hiroyuki , Nakayama Keiichi I. , Mori Masaki
Published: March 2024

Abstract
A molecular target associated with the progression of gastric cancer has not yet been uncovered. FBXW7 is a tumor suppressor gene transcriptionally controlled by p53 that plays a role in the regulation of cell cycle exit and reentry via c-Myc degradation. Few studies have addressed the clinical significance of FBXW7 expression in gastric cancer. Therefore, we examined FBXW7 mRNA expression to determine its clinicopathologic significance in 100 cases of gastric cancer. Low expression levels of FBXW7 in primary gastric cancer contributed to malignant potential, such as lymph node metastasis (P = 0.0012), tumor size (P = 0.0003), and poor prognosis (P = 0.018). In comparison with 52 cases of gastric cancer without the p53 mutation, 29 cases with the mutation exhibited lower expression levels of FBXW7 (P = 0.0034), revealing a significant relationship between p53 mutation and FBXW7 expression. Furthermore, we found that gastric cancer patients who had low FBXW7 expression levels and p53 mutation had a distinctively poor prognosis in comparison with other subgroups (P = 0.0033). In conclusion, we showed a role for p53 in the transcriptional regulation of FBXW7 expression in clinical gastric cancer cases and showed that disruption of both p53 and FBXW7 contributes to poor prognosis. [Cancer Res 2009;69(9):3788–94]
Data from Ligand-Dependent Platelet-Derived Growth Factor Receptor (PDGFR)-α Activation Sensitizes Rare Lung Cancer and Sarcoma Cells to PDGFR Kinase Inhibitors
Authors: McDermott Ultan , Ames Rachel Y. , Iafrate A. John , Maheswaran Shyamala , Stubbs Hannah , Greninger Patricia , McCutcheon Kaitlin , Milano Randy , Tam Angela , Lee Diana Y. , Lucien Laury , Brannigan Brian W. , Ulkus Lindsey E. , Ma Xiao-Jun , Erlander Mark G. , Haber Daniel A. , Sharma Sreenath V. , Settleman Jeffrey
Published: March 2024

Abstract
Platelet-derived growth factor (PDGF) receptors (PDGFR) and their ligands play critical roles in several human malignancies. Sunitinib is a clinically approved multitargeted tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor, c-KIT, and PDGFR, and has shown clinical activity in various solid tumors. Activation of PDGFR signaling has been described in gastrointestinal stromal tumors (PDGFRA mutations) as well as in chronic myeloid leukemia (BCR-PDGFRA translocation), and sunitinib can yield clinical benefit in both settings. However, the discovery of PDGFR activating mutations or gene rearrangements in other tumor types could reveal additional patient populations who might benefit from treatment with anti-PDGFR therapies, such as sunitinib. Using a high-throughput cancer cell line screening platform, we found that only 2 of 637 tested human tumor-derived cell lines show significant sensitivity to single-agent sunitinib exposure. These two cell lines [a non–small-cell lung cancer (NSCLC) and a rhabdomyosarcoma] showed expression of highly phosphorylated PDGFRA. In the sunitinib-sensitive adenosquamous NSCLC cell line, PDGFRA expression was associated with focal PFGRA gene amplification, which was similarly detected in a small fraction of squamous cell NSCLC primary tumor specimens. Moreover, in this NSCLC cell line, focal amplification of the gene encoding the PDGFR ligand PDGFC was also detected, and silencing PDGFRA or PDGFC expression by RNA interference inhibited proliferation. A similar codependency on PDGFRA and PDGFC was observed in the sunitinib-sensitive rhabdomyosarcoma cell line. These findings suggest that, in addition to gastrointestinal stromal tumors, rare tumors that show PDGFC-mediated PDGFRA activation may also be clinically responsive to pharmacologic PDGFRA or PDGFC inhibition. [Cancer Res 2009;69(9):3937–46]
Data from Identification of SULF2 as a Novel Transcriptional Target of p53 by Use of Integrated Genomic Analyses
Authors: Chau B. Nelson , Diaz Robert L. , Saunders Matthew A. , Cheng Chun , Chang Aaron N. , Warrener Paul , Bradshaw Jeffrey , Linsley Peter S. , Cleary Michele A.
Published: March 2024

Abstract
Microarray analysis has been useful for identifying the targets of many transcription factors. However, gene expression changes in response to transcription factor perturbation reveal both direct transcriptional targets and secondary gene regulation. By integrating RNA interference, gene expression profiling, and chromatin immunoprecipitation technologies, we identified a set of 32 direct transcriptional targets of the tumor suppressor p53. Of these 32 genes, 11 are not currently associated with the core p53 pathway. From among these novel pathway members, we focused on understanding the connection between p53 and SULF2, which encodes an extracellular heparan sulfate 6-O-endosulfatase that modulates the binding of growth factors to their cognate receptors and that has been shown to function as a tumor suppressor. Genetic and pharmacologic perturbation of p53 directly influences SULF2 expression, and similar to silencing of TP53, RNA interference–mediated suppression of SULF2 results in an impaired senescence response of cells to genotoxic stress. Thus, our integrated genomic approach has led to the identification of a novel mediator of p53 network biology. [Cancer Res 2009;69(4):1368–74]
Data from Angiotensinogen Delays Angiogenesis and Tumor Growth of Hepatocarcinoma in Transgenic Mice
Authors: Vincent François , Bonnin Philippe , Clemessy Maud , Contrerès Jean-Olivier , Lamandé Noël , Gasc Jean-Marie , Vilar José , Hainaud Patricia , Tobelem Gérard , Corvol Pierre , Dupuy Evelyne
Published: March 2024

Abstract
Angiotensinogen, a member of the serpin family, is involved in the suppression of tumor growth and metastasis. To investigate whether human angiotensinogen protects against tumor progression in vivo, we established an original bitransgenic model in which transgenic mice expressing human angiotensinogen (Hu-AGT-TG mice) were crossed with a transgenic mouse model of hepatocellular carcinoma (HCC-TG mice). Bitransgenic mice overexpressing human angiotensinogen (HCC/Hu-AGT-TG) had a significantly longer survival time than the HCC-TG mice and a reduction of both tumor growth and blood flow velocities in the liver. This antitumor effect of angiotensinogen is related to a reduced angiogenesis, impaired expression of endothelial arterial markers (active Notch4, Delta-like 4 ligand, and ephrin B2) with a decrease of arterial vessel density in HCC/Hu-AGT-TG mice liver. Overexpression of human angiotensinogen decreases angiogenesis, and prevents tumor sinusoids from remodeling and arterialization, thus delaying tumor progression in vivo. [Cancer Res 2009;69(7):2853–60]
Data from FMS-Like Tyrosine Kinase 3–Internal Tandem Duplication Tyrosine Kinase Inhibitors Display a Nonoverlapping Profile of Resistance Mutations In vitro
Authors: von Bubnoff Nikolas , Engh Richard A. , Åberg Espen , Sänger Jana , Peschel Christian , Duyster Justus
Published: March 2024

Abstract
FMS-like tyrosine kinase 3 (FLT3) inhibitors have shown activity in the treatment of acute myelogenous leukemia (AML). Secondary mutations in target kinases can cause clinical resistance to therapeutic kinase inhibition. We have previously shown that sensitivity toward tyrosine kinase inhibitors varies between different activating FLT3 mutations. We therefore intended to determine whether different FLT3 inhibitors would produce distinct profiles of secondary, FLT3 resistance mutations. Using a cell-based screening approach, we generated FLT3–internal tandem duplication (ITD)–expressing cell lines resistant to the FLT3 inhibitors SU5614, PKC412, and sorafenib. Interestingly, the profile of resistance mutations emerging with SU5614 was limited to exchanges in the second part of the kinase domain (TK2) with exchanges of D835 predominating. In contrast, PKC412 exclusively produced mutations within tyrosine kinase domain 1 (TK1) at position N676. A mutation at N676 recently has been reported in a case of PKC412-resistant AML. TK1 mutations exhibited a differential response to SU5614, sorafenib, and sunitinib but strongly impaired response to PKC412. TK2 exchanges identified with SU5614 were sensitive to PKC412, sunitinib, or sorafenib, with the exception of Y842D, which caused a strong resistance to sorafenib. Of note, sorafenib also produced a highly distinct profile of resistance mutations with no overlap to SU5614 or PKC412, including F691L in TK1 and exchanges at position Y842 of TK2. Thus, different FLT3 kinase inhibitors generate distinct, nonoverlapping resistance profiles. This is in contrast to Bcr-Abl kinase inhibitors such as imatinib, nilotinib, and dasatinib, which display overlapping resistance profiles. Therefore, combinations of FLT3 inhibitors may be useful to prevent FLT3 resistance mutations in the setting of FLT3-ITD–positive AML. [Cancer Res 2009;69(7):3032–41]
Data from Mitogen-Activated Protein Kinase Inhibition Induces Translocation of Bmf to Promote Apoptosis in Melanoma
Authors: VanBrocklin Matthew W. , Verhaegen Monique , Soengas Maria S. , Holmen Sheri L.
Published: March 2024

Abstract
Constitutive activation of the mitogen-activated protein kinase (MAPK) pathway is implicated in the development and progression of many human cancers, including melanoma. Mutually exclusive activating mutations in NRAS or BRAF have been identified in ∼85% of melanomas, and components of this pathway have been developed as molecular targets for therapeutic intervention. We and others have shown that inhibition of this pathway with specific small molecule MAPK/extracellular signal-regulated kinase kinase (MEK) inhibitors induces a wide range of apoptotic responsiveness in human melanoma cells both in vitro and in vivo. To define the molecular mechanism underlying variable apoptotic sensitivity of melanoma cells to MEK inhibition, we examined the expression and subcellular localization of Bcl-2 family members in a comprehensive set of human melanoma cell lines. Whereas the proapoptotic protein Bim was activated and localized to the mitochondrial membrane in all cell lines regardless of apoptotic sensitivity, Bmf activation and cytosolic translocation was exclusive to sensitive cells. In resistant cells, Bmf remained sequestered to the cytoskeleton through dynein light chain 2 (DLC2) binding. Overexpression of Bmf in resistant cells did not enhance apoptosis, whereas expression of mutant BmfA69P, which has decreased binding to DLC2, promoted cell death. Expression of BmfA69P mutants possessing the Bcl-2 homology 3 (BH3) domain mutation L138A, which impairs BH3 interactions, did not enhance apoptosis in resistant cells. RNA interference targeting Bim and Bmf provided protection from apoptosis induced by MEK inhibition. These results show a novel role for Bmf in promoting apoptosis and provide insight into the mechanism of apoptotic resistance to MEK inhibition in melanoma. [Cancer Res 2009;69(5):1985–94]
Data from WNT16B Is a New Marker of Cellular Senescence That Regulates p53 Activity and the Phosphoinositide 3-Kinase/AKT Pathway
Authors: Binet Romuald , Ythier Damien , Robles Ana I. , Collado Manuel , Larrieu Delphine , Fonti Claire , Brambilla Elisabeth , Brambilla Christian , Serrano Manuel , Harris Curtis C. , Pedeux Rémy
Published: March 2024

Abstract
Senescence is a tumor suppression mechanism that is induced by several stimuli, including oncogenic signaling and telomere shortening, and controlled by the p53/p21WAF1 signaling pathway. Recently, a critical role for secreted factors has emerged, suggesting that extracellular signals are necessary for the onset and maintenance of senescence. Conversely, factors secreted by senescent cells may promote tumor growth. By using expression profiling techniques, we searched for secreted factors that were overexpressed in fibroblasts undergoing replicative senescence. We identified WNT16B, a member of the WNT family of secreted proteins. We found that WNT16B is overexpressed in cells undergoing stress-induced premature senescence and oncogene-induced senescence in both MRC5 cell line and the in vivo murine model of K-RasV12–induced senescence. By small interfering RNA experiments, we observed that both p53 and WNT16B are necessary for the onset of replicative senescence. WNT16B expression is required for the full transcriptional activation of p21WAF1. Moreover, WNT16B regulates activation of the phosphoinositide 3-kinase (PI3K)/AKT pathway. Overall, we identified WNT16B as a new marker of senescence that regulates p53 activity and the PI3K/AKT pathway and is necessary for the onset of replicative senescence. [Cancer Res 2009;69(24):9183–91]
Data from Epidermal Growth Factor Receptor Signaling Synergizes with Hedgehog/GLI in Oncogenic Transformation via Activation of the MEK/ERK/JUN Pathway
Authors: Schnidar Harald , Eberl Markus , Klingler Stefan , Mangelberger Doris , Kasper Maria , Hauser-Kronberger Cornelia , Regl Gerhard , Kroismayr Renate , Moriggl Richard , Sibilia Maria , Aberger Fritz
Published: March 2024

Abstract
Persistent activation of the Hedgehog (HH)/GLI signaling pathway has been implicated in the development of a number of human cancers. The GLI zinc finger transcription factors act at the end of the HH signaling cascade to control gene expression, and recent studies have shown that the activity of GLI proteins can be additionally modified by integration of distinct signals, such as the MEK/extracellular signal-regulated kinase (ERK) and phosphinositide-3 kinase (PI3K)/AKT pathway. However, little is known about the identity of the upstream activators of these HH/GLI interacting signaling pathways in cancer. Here, we provide evidence that integration of the HH/GLI and epidermal growth factor receptor (EGFR) pathway synergistically induces oncogenic transformation, which depends on EGFR-mediated activation of the RAS/RAF/MEK/ERK but not of the PI3K/AKT pathway. EGFR/MEK/ERK signaling induces JUN/activator protein 1 activation, which is essential for oncogenic transformation, in combination with the GLI activator forms GLI1 and GLI2. Furthermore, pharmacologic inhibition of EGFR and HH/GLI efficiently reduces growth of basal cell carcinoma (BCC) cell lines derived from mice with activated HH/GLI signaling. The results identify the synergistic integration of GLI activator function and EGFR signaling as a critical step in oncogenic transformation and provide a molecular basis for therapeutic opportunities relying on combined inhibition of the HH/GLI and EGFR/MEK/ERK/JUN pathway in BCC. [Cancer Res 2009;69(4):1284–92]
Data from Androgen Receptor Controls EGFR and ERBB2 Gene Expression at Different Levels in Prostate Cancer Cell Lines
Authors: Pignon Jean-Christophe , Koopmansch Benjamin , Nolens Gregory , Delacroix Laurence , Waltregny David , Winkler Rosita
Published: March 2024

Abstract
EGFR or ERBB2 contributes to prostate cancer (PCa) progression by activating the androgen receptor (AR) in hormone-poor conditions. Here, we investigated the mechanisms by which androgens regulate EGFR and ERBB2 expression in PCa cells. In steroid-depleted medium (SDM), EGFR protein was less abundant in androgen-sensitive LNCaP than in androgen ablation–resistant 22Rv1 cells, whereas transcript levels were similar. Dihydrotestosterone (DHT) treatment increased both EGFR mRNA and protein levels and stimulated RNA polymerase II recruitment to the EGFR gene promoter, whereas it decreased ERBB2 transcript and protein levels in LNCaP cells. DHT altered neither EGFR or ERBB2 levels nor the abundance of prostate-specific antigen (PSA), TMEPA1, or TMPRSS2 mRNAs in 22Rv1 cells, which express the full-length and a shorter AR isoform deleted from the COOH-terminal domain (ARΔCTD). The contribution of both AR isoforms to the expression of these genes was assessed by small interfering RNAs targeting only the full-length or both AR isoforms. Silencing of both isoforms strongly reduced PSA, TMEPA1, and TMPRSS2 transcript levels. Inhibition of both AR isoforms did not affect EGFR and ERBB2 transcript levels but decreased EGFR and increased ERBB2 protein levels. Proliferation of 22Rv1 cells in SDM was inhibited in the absence of AR and ARΔCTD. A further decrease was obtained with PKI166, an EGFR/ERBB2 kinase inhibitor. Overall, we showed that ARΔCTD is responsible for constitutive EGFR expression and ERBB2 repression in 22Rv1 cells and that ARΔCTD and tyrosine kinase receptors are necessary for sustained 22Rv1 cell growth. [Cancer Res 2009;69(7):2941–9]
Data from Fibroblast Growth Factor Receptor 1–Transformed Mammary Epithelial Cells Are Dependent on RSK Activity for Growth and Survival
Authors: Xian Wa , Pappas Leontios , Pandya Darshan , Selfors Laura M. , Derksen Patrick W. , de Bruin Michiel , Gray Nathanael S. , Jonkers Jos , Rosen Jeffrey M. , Brugge Joan S.
Published: March 2024

Abstract
Fibroblast growth factor receptor 1 (FGFR1) is frequently amplified and highly expressed in lobular carcinomas of the breast. In this report, we evaluated the biological activity of FGFR1 in a wide range of in vitro assays. Conditional activation of FGFR1 in the nontransformed MCF10A human mammary cell line, MCF10A, resulted in cellular transformation marked by epidermal growth factor–independent cell growth, anchorage-independent cell proliferation and survival, loss of cell polarity, and epithelial-to-mesenchymal transition. Interestingly, small-molecule or small interfering RNA inhibition of ribosomal S6 kinase (RSK) activity induced death of the FGFR1-transformed cells, but not of the parental MCF10A cell line. The dependence of FGFR1-transformed cells on RSK activity was further confirmed in cell lines derived from mouse and human lobular carcinomas that possess high FGFR1 activity. Taken together, these results show the transforming activity of FGFR1 in mammary epithelial cells and identify RSK as a critical component of FGFR1 signaling in lobular carcinomas, thus implicating RSK as a candidate therapeutic target in FGFR1-expressing tumors. [Cancer Res 2009;69(6):2244–51]
Data from Improved Expression and Reactivity of Transduced Tumor-Specific TCRs in Human Lymphocytes by Specific Silencing of Endogenous TCR
Authors: Okamoto Sachiko , Mineno Junichi , Ikeda Hiroaki , Fujiwara Hiroshi , Yasukawa Masaki , Shiku Hiroshi , Kato Ikunoshin
Published: March 2024

Abstract
Adoptive T-cell therapy using lymphocytes genetically engineered to express tumor antigen-specific TCRs is an attractive strategy for treating patients with malignancies. However, there are potential drawbacks to this strategy: mispairing of the introduced TCR α/β chains with the endogenous TCR subunits and competition of CD3 molecules between the introduced and endogenous TCRs can impair cell surface expression of the transduced TCR, resulting in insufficient function and potential generation of autoreactive T cells. In addition, the risk of tumor development following the infusion of cells with aberrant vector insertion sites increases with the vector copy number in the transduced cells. In this study, we developed retroviral vectors encoding both small interfering RNA constructs that specifically down-regulate endogenous TCR and a codon-optimized, small interfering RNA–resistant TCR specific for the human tumor antigens MAGE-A4 or WT1. At low copy numbers of the integrated vector, the transduced human lymphocytes exhibited high surface expression of the introduced tumor-specific TCR and reduced expression of endogenous TCRs. In consequence, the vector-transduced lymphocytes showed enhanced cytotoxic activity against antigen-expressing tumor cells. Therefore, our novel TCR gene therapy may open a new gate for effective immunotherapy in cancer patients. [Cancer Res 2009;69(23):9003–11]
Data from Heterozygosity for Hypoxia Inducible Factor 1α Decreases the Incidence of Thymic Lymphomas in a p53 Mutant Mouse Model
Authors: Bertout Jessica A. , Patel Shetal A. , Fryer Benjamin H. , Durham Amy C. , Covello Kelly L. , Olive Kenneth P. , Goldschmidt Michael H. , Simon M. Celeste
Published: March 2024

Abstract
Hypoxia inducible factors (HIF) are critical mediators of the cellular response to decreased oxygen tension and are overexpressed in a number of tumors. Although HIF1α and HIF2α share a high degree of sequence homology, recent work has shown that the two α subunits can have contrasting and tissue-specific effects on tumor growth. To directly compare the role of each HIFα subunit in spontaneous tumorigenesis, we bred a mouse model of expanded HIF2α expression and Hif1α+/− mice to homozygotes for the R270H mutation in p53. Here, we report that p53R270H/R270H mice, which have not been previously described, develop a unique tumor spectrum relative to p53R270H/− mice, including a high incidence of thymic lymphomas. Heterozygosity for Hif1α significantly reduced the incidence of thymic lymphomas observed in this model. Moreover, reduced Hif1α levels correlated with decreased stabilization of activated Notch1 and expression of the Notch target genes, Dtx1 and Nrarp. These observations uncover a novel role for HIF1α in Notch pathway activation during T-cell lymphomagenesis. [Cancer Res 2009;69(7):3213–20]
Data from Poly(ADP-Ribose) Polymerase-1 Inhibitor Treatment Regresses Autochthonous Brca2/p53-Mutant Mammary Tumors In vivo and Delays Tumor Relapse in Combination with Carboplatin
Authors: Hay Trevor , Matthews James R. , Pietzka Lucie , Lau Alan , Cranston Aaron , Nygren Anders O.H. , Douglas-Jones Anthony , Smith Graeme C.M. , Martin Niall M.B. , O’Connor Mark , Clarke Alan R.
Published: March 2024

Abstract
Germ-line heterozygosity of the BRCA2 gene in women predisposes to breast and ovarian cancers. Successful therapies targeted specifically at these neoplasms have thus far remained elusive. Recent studies in mice have shown that inhibition of poly(ADP-ribose) polymerase-1 (PARP-1) targets cells lacking Brca2 and xenografts derived from BRCA2-deficient ES cells or Chinese hamster ovary cells. We set out to develop a more relevant preclinical model that will inform and accelerate translation into the clinic. As such, we conditionally deleted Brca2 and p53 within murine mammary epithelium and treated the resulting tumors in situ with a highly potent PARP-1 inhibitor (AZD2281) alone or in combination with carboplatin. Daily exposure to AZD2281 for 28 days caused significant regression or growth inhibition in 46 of 52 tumors. This response was shown to be specific to tumors lacking both Brca2and p53. AZD2281/carboplatin combination therapy for 28 days showed no advantage over carboplatin monotherapy. However, if PARP inhibitor treatment was continued, this significantly increased the time to tumor relapse and death in these mice. This preclinical study is the first to show in vivo hypersensitivity of spontaneously arising Brca2-deficient mammary tumors to PARP-1 inhibition monotherapy or combination therapy. As such, our data add substantial weight to the argument for the use of PARP inhibitors as therapeutic agents against human breast cancers in which BRCA2 is mutated. Moreover, the specificity that we have shown further suggests that PARP inhibitors will be generally effective against tumors caused by dysregulation of components of the homologous recombination pathway. [Cancer Res 2009;69(9):3850–55]
Data from Human ZNF312b Promotes the Progression of Gastric Cancer by Transcriptional Activation of the K-ras Gene
Authors: Song In-Sung , Oh Nang Su , Kim Hyun-Taek , Ha Ga-Hee , Jeong So-Young , Kim Jeong-Min , Kim Dong-Il , Yoo Hyang-Sook , Kim Cheol-Hee , Kim Nam-Soon
Published: March 2024

Abstract
Gastric cancer ranks second among the most common causes of cancer deaths worldwide. Recent studies reported target molecules that are candidates for new therapeutic interventions; however, their molecular mechanism has not been clearly defined. In this study, we found that ZNF312b plays a role in tumor progression and metastasis in gastric cancer via transcriptional activation of the K-ras oncogene. ZNF312b seems to be specifically overexpressed in gastric cancer tissues and cell lines. The overexpression of ZNF312b induces cancer-like phenotypes, including accelerated proliferation and increased tumor masses in nude mice, which are completely reversed by its knockdown in gastric cancer cell lines, implying direct involvement in gastric tumor progression. From analyses using deletion mutants of ZNF312b and K-ras promoter-driven luciferase reporters, we found that it translocates into the nucleus via the proline-rich domain of its COOH terminus to activate transcription of the K-ras gene, resulting in an enhancement of the extracellular signal-regulated kinase signaling pathway that governs cell proliferation. Taken together, these results suggest that ZNF312b contributes to the promotion of gastric cancer by triggering K-ras oncogene expression. The current study is the first to report that ZNF312b, a novel transcription factor, was associated with tumorigenicity of gastric cancer. This might be a valuable target that could provide new insight into the development of new therapeutic modalities for patients with gastric cancer. [Cancer Res 2009;69(7):3131–9]
Data from Inhibiting the Cyclin-Dependent Kinase CDK5 Blocks Pancreatic Cancer Formation and Progression through the Suppression of Ras-Ral Signaling
Authors: Feldmann Georg , Mishra Anjali , Hong Seung-Mo , Bisht Savita , Strock Christopher J. , Ball Douglas W. , Goggins Michael , Maitra Anirban , Nelkin Barry D.
Published: March 2024

Abstract
Cyclin-dependent kinase 5 (CDK5), a neuronal kinase that functions in migration, has been found to be activated in some human cancers in which it has been implicated in promoting metastasis. In this study, we investigated the role of CDK5 in pancreatic cancers in which metastatic disease is most common at diagnosis. CDK5 was widely active in pancreatic cancer cells. Functional ablation significantly inhibited invasion, migration, and anchorage-independent growth in vitro, and orthotopic tumor formation and systemic metastases in vivo. CDK5 blockade resulted in the profound inhibition of Ras signaling through its critical effectors RalA and RalB. Conversely, restoring Ral function rescued the effects of CDK5 inhibition in pancreatic cancer cells. Our findings identify CDK5 as a pharmacologically tractable target to degrade Ras signaling in pancreatic cancer. Cancer Res; 70(11); 4460–9. ©2010 AACR.
Data from TORC-Specific Phosphorylation of Mammalian Target of Rapamycin (mTOR): Phospho-Ser2481 Is a Marker for Intact mTOR Signaling Complex 2
Authors: Copp Jeremy , Manning Gerard , Hunter Tony
Published: March 2024

Abstract
The mammalian target of rapamycin (mTOR) serine/threonine kinase is the catalytic component of two evolutionarily conserved signaling complexes. mTOR signaling complex 1 (mTORC1) is a key regulator of growth factor and nutrient signaling. S6 kinase is the best-characterized downstream effector of mTORC1. mTOR signaling complex 2 (mTORC2) has a role in regulating the actin cytoskeleton and activating Akt through S473 phosphorylation. Herein, we show that mTOR is phosphorylated differentially when associated with mTORC1 and mTORC2 and that intact complexes are required for these mTORC-specific mTOR phosphorylations. Specifically, we find that mTORC1 contains mTOR phosphorylated predominantly on S2448, whereas mTORC2 contains mTOR phosphorylated predominantly on S2481. Using S2481 phosphorylation as a marker for mTORC2 sensitivity to rapamycin, we find that mTORC2 formation is in fact rapamycin sensitive in several cancer cell lines in which it had been previously reported that mTORC2 assembly and function were rapamycin insensitive. Thus, phospho-S2481 on mTOR serves as a biomarker for intact mTORC2 and its sensitivity to rapamycin. [Cancer Res 2009;69(5):1821–7]