bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from A Novel Type of p53 Pathway Dysfunction in Chronic Lymphocytic Leukemia Resulting from Two Interacting Single Nucleotide Polymorphisms within the p21 Gene
Authors: Johnson Gillian G. , Sherrington Paul D. , Carter Anthony , Lin Ke , Liloglou Triantafillos , Field John K. , Pettitt Andrew R.
Published: March 2024

Abstract
The ATM-p53 pathway plays an important role in the biology of chronic lymphocytic leukemia (CLL). Its functional integrity can be probed by exposing CLL cells to ionizing radiation (IR) and measuring levels of p53 protein and one of its transcriptional targets, the cyclin-dependent kinase inhibitor p21. We have previously identified two abnormal p53/p21 response patterns associated with inactivating mutations of TP53 and ATM, respectively. Here, we describe a third abnormal response pattern characterized by failure of p21 protein accumulation despite a normal p53 protein response. This so-called "type C" response was detected in 10.6% of unselected patients and was associated with resistance of CLL cells to p53-dependent killing by IR, with the clinically more aggressive variant of CLL characterized by unmutated immunoglobulin heavy-chain genes and with a single nucleotide polymorphism at codon 31 of the p21 gene in which Ser is replaced by Arg. CLL samples with this allelic variant displayed impaired IR-induced up-regulation of total p21 mRNA and did not express the Arg-encoding transcript, except in those cases harboring an additional single nucleotide polymorphism (T instead of C) in the 3′-untranslated region of the same p21 allele. Our data provide new insight into the importance of p21 in CLL biology. [Cancer Res 2009;69(12):5210–17]
Data from Stimulating the GPR30 Estrogen Receptor with a Novel Tamoxifen Analogue Activates SF-1 and Promotes Endometrial Cell Proliferation
Authors: Lin Benjamin C. , Suzawa Miyuki , Blind Raymond D. , Tobias Sandra C. , Bulun Serdar E. , Scanlan Thomas S. , Ingraham Holly A.
Published: March 2024

Abstract
Estrogens and selective estrogen receptor (ER) modulators such as tamoxifen are known to increase uterine cell proliferation. Mounting evidence suggests that estrogen signaling is mediated not only by ERα and ERβ nuclear receptors, but also by GPR30 (GPER), a seven transmembrane (7TM) receptor. Here, we report that primary human endometriotic H-38 cells express high levels of GPR30 with no detectable ERα or ERβ. Using a novel tamoxifen analogue, STX, which activates GPR30 but not ERs, significant stimulation of the phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways was observed in H-38 cells and in Ishikawa endometrial cancer cells expressing GPR30; a similar effect was observed in JEG3 choriocarcinoma cells. STX treatment also increased cellular pools of phosphatidylinositol (3,4,5) triphosphate, a proposed ligand for the nuclear hormone receptor SF-1 (NR5A1). Consistent with these findings, STX, tamoxifen, and the phytoestrogen genistein were able to increase SF-1 transcription, promote Ishikawa cell proliferation, and induce the SF-1 target gene aromatase in a GPR30-dependent manner. Our findings suggest a novel signaling paradigm that is initiated by estrogen activation of the 7TM receptor GPR30, with signal transduction cascades (PI3K and MAPK) converging on nuclear hormone receptors (SF-1/LRH-1) to modulate their transcriptional output. We propose that this novel GPR30/SF-1 pathway increases local concentrations of estrogen, and together with classic ER signaling, mediate the proliferative effects of synthetic estrogens such as tamoxifen, in promoting endometriosis and endometrial cancers. [Cancer Res 2009;69(13):5415–23]
Data from Multimodal Assessment of Protein Functional Deficiency Supports Pathogenicity of BRCA1 p.V1688del
Authors: De Nicolo Arcangela , Parisini Emilio , Zhong Quan , Dalla Palma Maurizia , Stoeckert Kathryn A. , Domchek Susan M. , Nathanson Katherine L. , Caligo Maria A. , Vidal Marc , Cusick Michael E. , Garber Judy E.
Published: March 2024

Abstract
Unequivocal discrimination between neutral variants and deleterious mutations is crucial for appropriate counseling of individuals with a BRCA1 or BRCA2 sequence change. An increasing number of variants of uncertain significance (VUS) are being identified, the unclassified biological effect of which poses clinical concerns. A multifactorial likelihood–based approach recently suggested disease causality for BRCA1 p.V1688del, a VUS recurrent in Italian breast/ovarian cancer families. Whether and how this single amino acid deletion in the BRCA1 COOH terminus (BRCT) domain affects the function of the mutant protein (ΔValBRCA1) has not been elucidated. We undertook comprehensive functional characterization of ΔValBRCA1, comprising comparative structural modeling, analysis of protein stability and associations, and analysis of DNA repair function. Our model predicted BRCT domain destabilization and folding disruption caused by BRCA1 p.V1688del. Consistently, the recombinant ΔValBRCA1 was less stable than wild-type BRCA1 and, unlike the latter, failed to associate with BRIP1, CtIP, and Rap80 and to relocalize to sites of DNA damage. Yeast two-hybrid analysis revealed a compromised interaction with FHL2 and KPNA2, which is likely responsible for improper subcellular localization of ΔValBRCA1. In addition, we found four new breast/ovarian cancer families of Italian ancestry who carried this sequence alteration. These results provide the first evidence of the effect of BRCA1 p.V1688del on protein stability and function, supporting the view that it is a deleterious mutation. Multimodal analyses like ours could advance understanding of tumor suppression by BRCA1 and ultimately contribute to developing efficient strategies for screening and characterization of VUS. [Cancer Res 2009;69(17):7030–7]
Data from N-myc Downstream Regulated Gene 1/Cap43 Suppresses Tumor Growth and Angiogenesis of Pancreatic Cancer through Attenuation of Inhibitor of κB Kinase β Expression
Authors: Hosoi Fumihito , Izumi Hiroto , Kawahara Akihiko , Murakami Yuichi , Kinoshita Hisafumi , Kage Masayoshi , Nishio Kazuto , Kohno Kimitoshi , Kuwano Michihiko , Ono Mayumi
Published: March 2024

Abstract
N-myc downstream regulated gene 1 (NDRG1)/Cap43 expression is a predictive marker of good prognosis in patients with pancreatic cancer as we reported previously. In this study, NDRG1/Cap43 decreased the expression of various chemoattractants, including CXC chemokines for inflammatory cells, and the recruitment of macrophages and neutrophils with suppression of both angiogenesis and growth in mouse xenograft models. We further found that NDRG1/Cap43 induced nuclear factor-κB (NF-κB) signaling attenuation through marked decreases in inhibitor of κB kinase (IKK) β expression and IκBα phosphorylation. Decreased IKKβ expression in cells overexpressing NDRG1/Cap43 resulted in reduction of both nuclear translocation of p65 and p50 and their binding to the NF-κB motif. The introduction of an exogenous IKKβ gene restored NDRG1/Cap43-suppressed expression of melanoma growth-stimulating activity α/CXCL1, epithelial-derived neutrophil activating protein-78/CXCL5, interleukin-8/CXCL8 and vascular endothelial growth factor-A, accompanied by increased phosphorylation of IκBα in NDRG1/Cap43-expressing cells. In patients with pancreatic cancer, NDRG1/Cap43 expression levels were also inversely correlated with the number of infiltrating macrophages in the tumor stroma. This study suggests a novel mechanism by which NDRG1/Cap43 modulates tumor angiogenesis/growth and infiltration of macrophages/neutrophils through attenuation of NF-κB signaling. [Cancer Res 2009;69(12):4983–91]
Data from Activation of Rap1 Promotes Prostate Cancer Metastasis
Authors: Bailey Candice L. , Kelly Patrick , Casey Patrick J.
Published: March 2024

Abstract
Elucidating the mechanisms of prostate cancer (CaP) survival and metastasis are critical to the discovery of novel therapeutic targets. The monomeric G protein Rap1 has been implicated in cancer tumorigenesis. Rap1 signals to pathways involved in cell adhesion, migration, and survival, suggesting Rap1 may promote several processes associated with cancer cell metastasis. Examination of CaP cell lines revealed cells with a high metastatic ability exhibited increased Rap1 activity and reduced expression of the negative regulator Rap1GAP. Rap1 can be further stimulated in these cells by stromal-derived factor (SDF-1), an agonist known to regulate tumor cell metastasis and tropism to bone. Activation of Rap1 increased CaP cell migration and invasion, and inhibition of Rap1A activity via RNAi-mediated knockdown or ectopic expression of Rap1GAP markedly impaired CaP cell migration and invasion. Additional studies implicate integrins α4, β3, and αvβ3 in the mechanism of Rap1-mediated CaP migration and invasion. Extending the effect of Rap1 activity in CaP metastasis in vivo, introduction of activated Rap1 into CaP cells dramatically enhanced the rate and incidence of CaP metastasis in a xenograft mouse model. These studies provide compelling evidence to support a role for aberrant Rap1 activation in CaP progression, and suggest that targeting Rap1 signaling could provide a means to control metastatic progression of this cancer. [Cancer Res 2009;69(12):4962–8]
Data from Low Concentrations of Diindolylmethane, a Metabolite of Indole-3-Carbinol, Protect against Oxidative Stress in a BRCA1-Dependent Manner
Authors: Fan Saijun , Meng Qinghui , Saha Tapas , Sarkar Fazlul H. , Rosen Eliot M.
Published: March 2024

Abstract
The indole-3-carbinol (I3C) metabolite 3,3′-diindolylmethane (DIM) is a proposed cancer prevention agent for various tumor types, including breast cancer. Here, we show that DIM up-regulates expression of the tumor suppressor protein BRCA1 in carcinoma and normal cell types. Up-regulation of BRCA1 was dose and time dependent, and it was observed at physiologically relevant micromolar and submicromolar DIM concentrations when cells were exposed for 72 hours. Treatment with the parent compound (I3C) or DIM (1 μmol/L) protected against cell killing due to H2O2 and other oxidants, and the protection was abrogated by knockdown of BRCA1. DIM stimulated signaling by the antioxidant transcription factor NFE2L2 (NRF2) through the antioxidant response element in a BRCA1-dependent manner. We further showed that DIM rapidly stimulated phosphorylation of BRCA1 on Ser 1387 and Ser 1524 and that these phosphorylations are required for protection against oxidative stress. DIM-induced phosphorylation of BRCA1 on Ser 1387 was dependent on ataxia-telangiectasia mutated. Finally, in our assay systems, H2O2-induced cell death was not due to apoptosis. However, a significant component of cell death was attributable to autophagy, and both DIM and BRCA1 inhibited H2O2-induced autophagy. Our findings suggest that low concentrations of DIM protect cells against oxidative stress via the tumor suppressor BRCA1 by several distinct mechanisms. [Cancer Res 2009;69(15):6083–91]
Data from Fyn and Src Are Effectors of Oncogenic Epidermal Growth Factor Receptor Signaling in Glioblastoma Patients
Authors: Lu Kan V. , Zhu Shaojun , Cvrljevic Anna , Huang Tiffany T. , Sarkaria Shawn , Ahkavan David , Dang Julie , Dinca Eduard B. , Plaisier Seema B. , Oderberg Isaac , Lee Yohan , Chen Zugen , Caldwell Jeremy S. , Xie Yongmin , Loo Joseph A. , Seligson David , Chakravari Arnab , Lee Francis Y. , Weinmann Roberto , Cloughesy Timothy F. , Nelson Stanley F. , Bergers Gabriele , Graeber Thomas , Furnari Frank B. , James C. David , Cavenee Webster K. , Johns Terrance G. , Mischel Paul S.
Published: March 2024

Abstract
Activating epidermal growth factor receptor (EGFR) mutations are common in many cancers including glioblastoma. However, clinical responses to EGFR inhibitors are infrequent and short-lived. We show that the Src family kinases (SFK) Fyn and Src are effectors of oncogenic EGFR signaling, enhancing invasion and tumor cell survival in vivo. Expression of a constitutively active EGFR mutant, EGFRvIII, resulted in activating phosphorylation and physical association with Src and Fyn, promoting tumor growth and motility. Gene silencing of Fyn and Src limited EGFR- and EGFRvIII-dependent tumor cell motility. The SFK inhibitor dasatinib inhibited invasion, promoted tumor regression, and induced apoptosis in vivo, significantly prolonging survival of an orthotopic glioblastoma model expressing endogenous EGFRvIII. Dasatinib enhanced the efficacy of an anti-EGFR monoclonal antibody (mAb 806) in vivo, further limiting tumor growth and extending survival. Examination of a large cohort of clinical samples showed frequent coactivation of EGFR and SFKs in glioblastoma patients. These results establish a mechanism linking EGFR signaling with Fyn and Src activation to promote tumor progression and invasion in vivo and provide rationale for combined anti-EGFR and anti-SFK targeted therapies. [Cancer Res 2009;69(17):6889–98]
Data from Sin3B Expression Is Required for Cellular Senescence and Is Up-regulated upon Oncogenic Stress
Authors: Grandinetti Kathryn B. , Jelinic Petar , DiMauro Teresa , Pellegrino Jessica , Fernández Rodríguez Rubén , Finnerty Patricia M. , Ruoff Rachel , Bardeesy Nabeel , Logan Susan K. , David Gregory
Published: March 2024

Abstract
Serial passage of primary mammalian cells or strong mitogenic signals induce a permanent exit from the cell cycle called senescence. A characteristic of senescent cells is the heterochromatinization of loci encoding pro-proliferative genes, leading to their transcriptional silencing. Senescence is thought to represent a defense mechanism against uncontrolled proliferation and cancer. Consequently, genetic alterations that allow senescence bypass are associated with susceptibility to oncogenic transformation. We show that fibroblasts genetically inactivated for the chromatin-associated Sin3B protein are refractory to replicative and oncogene-induced senescence. Conversely, overexpression of Sin3B triggers senescence and the formation of senescence-associated heterochromatic foci. Although Sin3B is strongly up-regulated upon oncogenic stress, decrease in expression of Sin3B is associated with tumor progression in vivo, suggesting that expression of Sin3B may represent a barrier against transformation. Together, these results underscore the contribution of senescence in tumor suppression and suggest that expression of chromatin modifiers is modulated at specific stages of cellular transformation. Consequently, these findings suggest that modulation of Sin3B-associated activities may represent new therapeutic opportunities for treatment of cancers. [Cancer Res 2009;69(16):6430–7]
Data from Overexpression of Extracellular Superoxide Dismutase Attenuates Heparanase Expression and Inhibits Breast Carcinoma Cell Growth and Invasion
Authors: Teoh Melissa L.T. , Fitzgerald Matthew P. , Oberley Larry W. , Domann Frederick E.
Published: March 2024

Abstract
Increased expression of heparanase stimulates the progression of various human cancers, including breast cancer. Therefore, a deeper understanding of the mechanisms involved in regulating heparanase is critical in developing effective treatments for heparanase-overexpressing cancers. In this study, we investigated the potential use of extracellular superoxide dismutase (EcSOD) to enhance the inhibitory effects of heparin/low molecular weight heparin (LMWH) in breast cancer cells. EcSOD binds to cell surfaces and the extracellular matrix through heparin-binding domain (HBD). Deleting this HBD rendered the protein a more potent inhibitor of breast cancer growth, survival, and invasion. Among the treatment combinations examined, EcSODΔHBD plus LMWH provided the best tumor suppressive effects in inhibiting breast cancer growth and invasion in vitro. We have further shown that overexpression of EcSOD decreased accumulation of vascular endothelial growth factor in the culture medium and increased the level of intact cell surface-associated heparan sulfate, thus implicating inhibition of heparanase expression as a potential mechanism. Overexpression of EcSOD inhibited steady-state heparanase mRNA levels by >50% as determined by quantitative reverse transcription-PCR. Moreover, heparanase promoter activation was suppressed by EcSOD as indicated by a luciferase reporter assay. These findings reveal a previously unrecognized molecular pathway showing that regulation of heparanase transcription can be mediated by oxidative stress. Our study implies that overexpression of EcSOD is a promising strategy to enhance the efficacy of heparin/LMWH by inhibiting heparanase as a novel treatment for breast cancer. [Cancer Res 2009;69(15):6355–63]
Data from β1 Integrin Cytoplasmic Variants Differentially Regulate Expression of the Antiangiogenic Extracellular Matrix Protein Thrombospondin 1
Authors: Goel Hira Lal , Moro Loredana , Murphy-Ullrich Joanne E. , Hsieh Chung-Cheng , Wu Chin-Lee , Jiang Zhong , Languino Lucia R.
Published: March 2024

Abstract
β1 integrins play an important role in regulating cell proliferation and survival. Using small interfering RNA or an inhibitory antibody to β1, we show here that, in vivo, β1 integrins are essential for prostate cancer growth. Among the five known β1 integrin cytoplasmic variants, two have been shown to differentially affect prostate cell functions. The β1A variant promotes normal and cancer cell proliferation, whereas the β1C variant, which is down-regulated in prostate cancer, inhibits tumor growth and appears to have a dominant effect on β1A. To investigate the mechanism by which β1C inhibits the tumorigenic potential of β1A, we analyzed changes in gene expression in cells transfected with either β1C or β1A. The results show that β1C expression increases the levels of an extracellular matrix protein, thrombospondin 1 (TSP1), an angiogenesis inhibitor. TSP1 protein levels are increased upon β1C expression in prostate cancer cells as well as in β1-null GD25 cells. We show that TSP1 does not affect proliferation, apoptosis, or anchorage-independent growth of prostate cancer cells. In contrast, the newly synthesized TSP1, secreted by prostate cancer cells expressing β1C, prevents proliferation of endothelial cells. In conclusion, our novel findings indicate that expression of the β1C integrin variant in prostate glands prevents cancer progression by up-regulation of TSP1 levels and inhibition of angiogenesis. [Cancer Res 2009;69(13):5374–82]
Data from MicroRNA Expression, Chromosomal Alterations, and Immunoglobulin Variable Heavy Chain Hypermutations in Mantle Cell Lymphomas
Authors: Navarro Alba , Beà Sílvia , Fernández Verónica , Prieto Miriam , Salaverria Itziar , Jares Pedro , Hartmann Elena , Mozos Anna , López-Guillermo Armando , Villamor Neus , Colomer Dolors , Puig Xavier , Ott German , Solé Francesc , Serrano Sergi , Rosenwald Andreas , Campo Elías , Hernández Luis
Published: March 2024

Abstract
The contribution of microRNAs (miR) to the pathogenesis of mantle cell lymphoma (MCL) is not well known. We investigated the expression of 86 mature miRs mapped to frequently altered genomic regions in MCL in CD5+/CD5− normal B cells, reactive lymph nodes, and purified tumor cells of 17 leukemic MCL, 12 nodal MCL, and 8 MCL cell lines. Genomic alterations of the tumors were studied by single nucleotide polymorphism arrays and comparative genomic hybridization. Leukemic and nodal tumors showed a high number of differentially expressed miRs compared with purified normal B cells, but only some of them were commonly deregulated in both tumor types. An unsupervised analysis of miR expression profile in purified leukemic MCL cells revealed two clusters of tumors characterized by different mutational status of the immunoglobulin genes, proliferation signature, and number of genomic alterations. The expression of most miRs was not related to copy number changes in their respective chromosomal loci. Only the levels of miRs included in the miR-17-92 cluster were significantly related to genetic alterations at 13q31. Moreover, overexpression of miR-17-5p/miR-20a from this cluster was associated with high MYC mRNA levels in tumors with a more aggressive behavior. In conclusion, the miR expression pattern of MCL is deregulated in comparison with normal lymphoid cells and distinguishes two subgroups of tumors with different biological features. [Cancer Res 2009;69(17):7071–8]
Data from Molecular Distinctions between Stasis and Telomere Attrition Senescence Barriers Shown by Long-term Culture of Normal Human Mammary Epithelial Cells
Authors: Garbe James C. , Bhattacharya Sanchita , Merchant Batul , Bassett Ekaterina , Swisshelm Karen , Feiler Heidi S. , Wyrobek Andrew J. , Stampfer Martha R.
Published: March 2024

Abstract
Normal human epithelial cells in culture have generally shown a limited proliferative potential of ∼10 to 40 population doublings before encountering a stress-associated senescence barrier (stasis) associated with elevated levels of cyclin-dependent kinase inhibitors p16 and/or p21. We now show that simple changes in medium composition can expand the proliferative potential of human mammary epithelial cells (HMEC) initiated as primary cultures to 50 to 60 population doublings followed by p16-positive, senescence-associated β-galactosidase–positive stasis. We compared the properties of growing and senescent pre-stasis HMEC with growing and senescent post-selection HMEC, that is, cells grown in a serum-free medium that overcame stasis via silencing of p16 expression and that display senescence associated with telomere dysfunction. Cultured pre-stasis populations contained cells expressing markers associated with luminal and myoepithelial HMEC lineages in vivo in contrast to the basal-like phenotype of the post-selection HMEC. Gene transcript and protein expression, DNA damage–associated markers, mean telomere restriction fragment length, and genomic stability differed significantly between HMEC populations at the stasis versus telomere dysfunction senescence barriers. Senescent isogenic fibroblasts showed greater similarity to HMEC at stasis than at telomere dysfunction, although their gene transcript profile was distinct from HMEC at both senescence barriers. These studies support our model of the senescence barriers encountered by cultured HMEC in which the first barrier, stasis, is retinoblastoma-mediated and independent of telomere length, whereas a second barrier (agonescence or crisis) results from telomere attrition leading to telomere dysfunction. Additionally, the ability to maintain long-term growth of genomically stable multilineage pre-stasis HMEC populations can greatly enhance experimentation with normal HMEC. [Cancer Res 2009;69(19):7557–68]
Data from Kinome Profiling of Chondrosarcoma Reveals Src-Pathway Activity and Dasatinib as Option for Treatment
Authors: Schrage Yvonne M. , Briaire-de Bruijn Inge H. , de Miranda Noel F.C.C. , van Oosterwijk Jolieke , Taminiau Antonie H.M. , van Wezel Tom , Hogendoorn Pancras C.W. , Bovée Judith V.M.G.
Published: March 2024

Abstract
Chondrosarcomas are notorious for their resistance to conventional chemotherapy and radiotherapy, indicating there are no curative treatment possibilities for patients with inoperable or metastatic disease. We therefore explored the existence of molecular targets for systemic treatment of chondrosarcoma using kinome profiling. Peptide array was performed for four chondrosarcoma cell lines and nine primary chondrosarcoma cultures with GIST882, MSCs, and colorectal cancer cell lines as controls. Activity of kinases was verified using immunoblot, and active Src- and platelet-derived growth factor receptor (PDGFR) signaling were further explored using imatinib and dasatinib on chondrosarcoma in vitro. The AKT1/GSK3B pathway was clearly active in chondrosarcoma. In addition, the PDGFR pathway and the Src kinase family were active. PDGFR and Src kinases can be inhibited by imatinib and dasatinib, respectively. Although imatinib did not show any effect on chondrosarcoma cell cultures, dasatinib showed a decrease in cell viability at nanomolar concentrations in seven of nine chondrosarcoma cultures. However, inhibition of phosphorylated Src (Y419) was found both in responsive and nonresponsive cells. In conclusion, using kinome profiling, we found the Src pathway to be active in chondrosarcoma. Moreover, we showed in vitro that the inhibitor of the Src pathway, dasatinib, may provide a potential therapeutic benefit for chondrosarcoma patients who are not eligible for surgery. [Cancer Res 2009;69(15):6216–22]
Data from Rifampicin as an Oral Angiogenesis Inhibitor Targeting Hepatic Cancers
Authors: Shichiri Masayoshi , Fukai Nozomi , Kono Yutaka , Tanaka Yujiro
Published: March 2024

Abstract
Angiogenesis is an important therapeutic target in cancer, and to fully exploit its therapeutic potential, combination chemotherapeutic/antiangiogenic regimens should be optimized and delivered earlier to more patients. Ideally, this could be done by a single potent oral agent with established safety. Rifampicin, a semisynthetic antibiotic derived from the rifamycins, is one of the most commonly used pharmaceutical compounds worldwide in the treatment of tuberculosis. Here, we present the effects of oral rifampicin on human cancer progression and its antiangiogenic properties, which were comparable to the angiogenesis inhibitor endostatin. Clinically, low-dose p.o. administration of rifampicin to six high-risk patients with hepatitis C virus–related liver cirrhosis resulted in a single occurrence of hepatocellular carcinoma during the follow-up period of 97.3 ± 29.1 (mean ± SD) months. Experimentally, rifampicin rapidly and markedly down-regulated the expression of a wide spectrum of angiogenesis-associated genes in growing human microvascular endothelial cells, thereby suppressing endothelial cell proliferation and migration. Rifampicin, at higher concentrations, also directly inhibited the growth of a variety of human cancer cells. P.o. administration of rifampicin significantly inhibited in vivo growth and metastases of subcutaneous human cancer xenografts. Thus, the potent antiangiogenic properties of oral rifampicin therapy were effective in suppressing cancer progression. It provides a promising new addition to antiangiogenic strategies for designing human cancer therapies. Considering the clinical pharmacokinetics of rifampicin, which enters the enterohepatic circulation and undergoes subsequent hepatic accumulation, it may be especially beneficial as an antitumor agent targeting hepatobiliary tumors. [Cancer Res 2009;69(11):4760–8]
Data from De novo Induction of Genetically Engineered Brain Tumors in Mice Using Plasmid DNA
Authors: Wiesner Stephen M. , Decker Stacy A. , Larson Jon D. , Ericson Katya , Forster Colleen , Gallardo Jose L. , Long Chunmei , Demorest Zachary L. , Zamora Edward A. , Low Walter C. , SantaCruz Karen , Largaespada David A. , Ohlfest John R.
Published: March 2024

Abstract
Spontaneous mouse models of cancer show promise to more accurately recapitulate human disease and predict clinical efficacy. Transgenic mice or viral vectors have been required to generate spontaneous models of glioma, a lethal brain tumor, because nonviral gene transfer is typically transient. To overcome this constraint, we used the Sleeping Beauty transposable element to achieve chromosomal integration of human oncogenes into endogenous brain cells of immunocompetent mice. Genetically engineered, spontaneous brain tumors were induced with plasmid DNA in a matter of weeks in three separate mouse strains. The phenotype of tumors was influenced by the combination of oncogenes delivered, resembling human astrocytoma or glioblastoma in the majority of cases. At least five different genes can be cotransfected simultaneously including reporters, allowing measurement of tumor viability by in vivo imaging. This model can accelerate brain tumor research in a variety of ways such as generation of “humanized” models for high throughput drug screening and candidate gene validation with exceptional speed and flexibility. [Cancer Res 2009;69(2):431–9]
Data from Multiparameter Computational Modeling of Tumor Invasion
Authors: Bearer Elaine L. , Lowengrub John S. , Frieboes Hermann B. , Chuang Yao-Li , Jin Fang , Wise Steven M. , Ferrari Mauro , Agus David B. , Cristini Vittorio
Published: March 2024

Abstract
Clinical outcome prognostication in oncology is a guiding principle in therapeutic choice. A wealth of qualitative empirical evidence links disease progression with tumor morphology, histopathology, invasion, and associated molecular phenomena. However, the quantitative contribution of each of the known parameters in this progression remains elusive. Mathematical modeling can provide the capability to quantify the connection between variables governing growth, prognosis, and treatment outcome. By quantifying the link between the tumor boundary morphology and the invasive phenotype, this work provides a quantitative tool for the study of tumor progression and diagnostic/prognostic applications. This establishes a framework for monitoring system perturbation towards development of therapeutic strategies and correlation to clinical outcome for prognosis.[Cancer Res 2009;69(10):4493–501]

Major Findings

We apply a biologically founded, multiscale, mathematical model to identify and quantify tumor biologic and molecular properties relating to clinical and morphological phenotype and to demonstrate that tumor growth and invasion are predictable processes governed by biophysical laws, and regulated by heterogeneity in phenotypic, genotypic, and microenvironmental parameters. This heterogeneity drives migration and proliferation of more aggressive clones up cell substrate gradients within and beyond the central tumor mass, while often also inducing loss of cell adhesion. The model predicts that this process triggers a gross morphologic instability that leads to tumor invasion via individual cells, cell chains, strands, or detached clusters infiltrating into adjacent tissue producing the typical morphologic patterns seen, e.g., in the histopathology of glioblastoma multiforme. The model further predicts that these different morphologies of infiltration correspond to different stages of tumor progression regulated by heterogeneity.
Data from From Chronic Feed-Induced Intestinal Inflammation to Adenocarcinoma with Metastases in Salmonid Fish
Authors: Dale Ole B. , Tørud Brit , Kvellestad Agnar , Koppang Hanna S. , Koppang Erling O.
Published: March 2024

Abstract
Neoplasms in fish normally show poor abilities for metastasis, and there are no reports on intestinal cancer with metastasis to other organs. In aquaculture production, carnivorous salmonids in Northern Europe receive commercial feeds with plant ingredients. Such contents have been shown to cause chronic intestinal inflammation. Inflammation provokes carcinogenesis in the human gut, and here, we report a similar pathologic progression in salmonids. Nine commercially farmed groups of Atlantic salmon and rainbow trout (n = 39,160) and one experimental positive group (n = 789) fed the same commercial feed and two negative control groups (n = 3009) were investigated for the occurrence of intestinal tumors and metastases. Exposure period, gender, and sexual maturation were registered. Autopsy revealed an overall intestinal tumor occurrence of 10.62%, of which liver metastasis varied from 0% to 11.35% between the groups. Intestinal cancer prevalence increased from 0.50% to 14.81% during 4 months of feeding in the experimental group. A significant gender effect was registered in the commercially farmed groups but not in the experimental group. Histologic examination showed adenocarcinomas evolving through progressive epithelial dysplasia associated with severe chronic inflammation. One intestinal tumor was registered in one individual in the negative control groups. This is the first report on feed-induced intestinal carcinogenesis and metastasizing adenocarcinomas in fish fed an approved commercial diet. The pathogenesis was associated with a certain commercial diet provoking the inflammation-dysplasia-carcinoma sequence. The histologic progression was analogous to that of human colorectal cancer associated with inflammatory bowel disease. [Cancer Res 2009;69(10):4355–62]
Data from The Receptor Tyrosine Kinase EPHB4 Has Tumor Suppressor Activities in Intestinal Tumorigenesis
Authors: Dopeso Higinio , Mateo-Lozano Silvia , Mazzolini Rocco , Rodrigues Paulo , Lagares-Tena Laura , Ceron Julian , Romero Jordi , Esteves Marielle , Landolfi Stefania , Hernández-Losa Javier , Castaño Julio , Wilson Andrew J. , Ramon y Cajal Santiago , Mariadason John M. , Schwartz Simo , Arango Diego
Published: March 2024

Abstract
Colorectal cancer is the second cause of cancer-related death in the western world, and although the genetic and molecular mechanisms involved in the initiation and progression of these tumors are among the best characterized, there are significant gaps in our understanding of this disease. The role of EPHB signaling in colorectal cancer has only recently been realized. Here, we use animal models to investigate the role of EphB4 in intestinal tumorigenesis. Modulation of EPHB4 levels in colon cancer cell lines resulted in significant differences in tumor growth in a xenograft model, with low levels of EPHB4 associated with faster growth. In addition, using a genetic model of intestinal tumorigenesis where adenomatous polyposis coli (Apc) mutations lead to initiation of the tumorigenic process (Apcmin mice), we show that inactivation of a single allele of EphB4 results in higher proliferation in both the normal epithelium and intestinal tumors, significantly larger tumors in the small intestine, and a 10-fold increase in the number of tumors in the large intestine. This was associated with a 25% reduction in the lifespan of Apcmin mice (P < 0.0001). Gene expression analysis showed that EphB4 mutations result in a profound transcriptional reprogramming, affecting genes involved in cell proliferation, remodeling of the extracellular matrix, and cell attachment to the basement membrane among other functional groups of genes. Importantly, in agreement with the expression profiling experiments, using an in vitro assay, we show that loss of EPHB4 in colon cancer cells results in a significantly increased potential to invade through a complex extracellular matrix. Collectively, these results indicate that EphB4 has tumor suppressor activities and that regulation of cell proliferation, extracellular matrix remodeling, and invasive potential are important mechanisms of tumor suppression. [Cancer Res 2009;69(18):7430–8]
Data from Prediction of Drug Response in Breast Cancer Using Integrative Experimental/Computational Modeling
Authors: Frieboes Hermann B. , Edgerton Mary E. , Fruehauf John P. , Rose Felicity R.A.J. , Worrall Lisa K. , Gatenby Robert A. , Ferrari Mauro , Cristini Vittorio
Published: March 2024

Abstract
Nearly 30% of women with early-stage breast cancer develop recurrent disease attributed to resistance to systemic therapy. Prevailing models of chemotherapy failure describe three resistant phenotypes: cells with alterations in transmembrane drug transport, increased detoxification and repair pathways, and alterations leading to failure of apoptosis. Proliferative activity correlates with tumor sensitivity. Cell-cycle status, controlling proliferation, depends on local concentration of oxygen and nutrients. Although physiologic resistance due to diffusion gradients of these substances and drugs is a recognized phenomenon, it has been difficult to quantify its role with any accuracy that can be exploited clinically. We implement a mathematical model of tumor drug response that hypothesizes specific functional relationships linking tumor growth and regression to the underlying phenotype. The model incorporates the effects of local drug, oxygen, and nutrient concentrations within the three-dimensional tumor volume, and includes the experimentally observed resistant phenotypes of individual cells. We conclude that this integrative method, tightly coupling computational modeling with biological data, enhances the value of knowledge gained from current pharmacokinetic measurements, and, further, that such an approach could predict resistance based on specific tumor properties and thus improve treatment outcome. [Cancer Res 2009;69(10):4484–92]

Major Findings

By extracting mathematical model parameter values for drug and nutrient delivery from monolayer (one-dimensional) experiments and using the functional relationships to compute drug delivery in MCF-7 spheroid (three-dimensional) experiments, we use the model to quantify the diffusion barrier effect, which alone can result in poor response to chemotherapy both from diminished drug delivery and from lack of nutrients required to maintain proliferative conditions.
Data from Targeting LMO2 with a Peptide Aptamer Establishes a Necessary Function in Overt T-Cell Neoplasia
Authors: Appert Alex , Nam Chang-Hoon , Lobato Natividad , Priego Eva , Miguel Ricardo Nunez , Blundell Tom , Drynan Lesley , Sewell Helen , Tanaka Tomoyuki , Rabbitts Terence
Published: March 2024

Abstract
LMO2 is a transcription regulator involved in human T-cell leukemia, including some occurring in X-SCID gene therapy trials, and in B-cell lymphomas and prostate cancer. LMO2 functions in transcription complexes via protein-protein interactions involving two LIM domains and causes a preleukemic T-cell development blockade followed by clonal tumors. Therefore, LMO2 is necessary but not sufficient for overt neoplasias, which must undergo additional mutations before frank malignancy. An open question is the importance of LMO2 in tumor development as opposed to sustaining cancer. We have addressed this using a peptide aptamer that binds to the second LIM domain of the LMO2 protein and disrupts its function. This specificity is mediated by a conserved Cys-Cys motif, which is similar to the zinc-binding LIM domains. The peptide inhibits Lmo2 function in a mouse T-cell tumor transplantation assay by preventing Lmo2-dependent T-cell neoplasia. Lmo2 is, therefore, required for sustained T-cell tumor growth, in addition to its preleukemic effect. Interference with LMO2 complexes is a strategy for controlling LMO2-mediated cancers, and the finger structure of LMO2 is an explicit focus for drug development. [Cancer Res 2009;69(11):4784–90]
Data from A Genetic Variant of Aurora Kinase A Promotes Genomic Instability Leading to Highly Malignant Skin Tumors
Authors: Torchia Enrique C. , Chen Yiyun , Sheng Hong , Katayama Hiroshi , Fitzpatrick James , Brinkley William R. , Caulin Carlos , Sen Subrata , Roop Dennis R.
Published: March 2024

Abstract
Aurora kinase A (Aurora-A) belongs to a highly conserved family of mitotis-regulating serine/threonine kinases implicated in epithelial cancers. Initially we examined Aurora-A expression levels at different stages of human skin cancer. Nuclear Aurora-A was detected in benign lesions and became more diffused but broadly expressed in well and poorly differentiated squamous cell carcinomas (SCC), indicating that Aurora-A deregulation may contribute to SCC development. To mimic the overexpression of Aurora-A observed in human skin cancers, we established a gene-switch mouse model in which the human variant of Aurora-A (Phe31Ile) was expressed in the epidermis upon topical application of the inducer RU486 (Aurora-AGS). Overexpression of Aurora-A alone or in combination with the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA), did not result in SCC formation in Aurora-AGS mice. Moreover, Aurora-A overexpression in naive keratinocytes resulted in spindle defects in vitro and marked cell death in vivo, suggesting that the failure of Aurora-A to initiate tumorigenesis was due to induction of catastrophic cell death. However, Aurora-A overexpression combined with exposure to TPA and the mutagen 7,12-dimethylbenz(a)anthracene accelerated SCC development with greater metastastic activity than control mice, indicating that Aurora-A cannot initiate skin carcinogenesis but rather promotes the malignant conversion of skin papillomas. Further characterization of SCCs revealed centrosome amplification and genomic alterations by array CGH analysis, indicating that Aurora-A overexpression induces a high level of genomic instability that favors the development of aggressive and metastatic tumors. Our findings strongly implicate Aurora-A overexpression in the malignant progression of skin tumors and suggest that Aurora-A may be an important therapeutic target. [Cancer Res 2009;69(18):7207–15]
Data from Cathepsin D and Eukaryotic Translation Elongation Factor 1 as Promising Markers of Cellular Senescence
Authors: Byun Hae-Ok , Han Na-Kyung , Lee Hae-June , Kim Ki-Bum , Ko Young-Gyu , Yoon Gyesoon , Lee Yun-Sil , Hong Seok-Il , Lee Jae-Seon
Published: March 2024

Abstract
Induction of premature senescence may be a promising strategy for cancer treatment. However, biomarkers for senescent cancer cells are lacking. To identify such biomarkers, we performed comparative proteomic analysis of MCF7 human breast cancer cells undergoing cellular senescence in response to ionizing radiation (IR). IR-induced senescence was associated with up-regulation of cathepsin D (CD) and down-regulation of eukaryotic translation elongation factor 1β2 (eEF1B2), as confirmed by Western blot. The other elongation factor, eukaryotic translation elongation factor 1α1 (eEF1A1), was also down-regulated. IR-induced senescence was associated with similar changes of CD and eEF1 (eEF1A1 and eEF1B2) levels in the HCT116 colon cancer cell line and the H460 lung cancer cell line. Up-regulation of CD and down-regulation of eEF1 seemed to be specific to senescence, as they were observed during cellular senescence induced by hydrogen peroxide or anticancer drugs (camptothecin, etoposide, or 50 ng doxorubicin) but not during apoptosis induced by Taxol or 10 μg doxorubicin or autophagy induced by tamoxifen. The same alterations in CD and eEF1A1 levels were observed during replicative senescence and Ras oncogene-induced senescence. Transient cell cycle arrest did not alter levels of eEF1 or CD. Chemical inhibition of CD (pepstatin A) and small interfering RNA–mediated knockdown of CD and eEF1 revealed that these factors participate in cell proliferation. Finally, the senescence-associated alteration in CD and eEF1 levels observed in cell lines was also observed in IR-exposed xenografted tumors. These findings show that CD and eEF1 are promising markers for the detection of cellular senescence induced by a variety of treatments. [Cancer Res 2009;69(11):4638–47]
Data from p18Ink4c and p53 Act as Tumor Suppressors in Cyclin D1–Driven Primitive Neuroectodermal Tumor
Authors: Saab Raya , Rodriguez-Galindo Carlos , Matmati Kelly , Rehg Jerold E. , Baumer Shannon H. , Khoury Joseph D. , Billups Catherine , Neale Geoffrey , Helton Kathleen J. , Skapek Stephen X.
Published: March 2024

Abstract
The retinoblastoma (RB) tumor suppressor pathway is likely important in primitive neuroectodermal tumors (PNET) of the brain. In fact, 10% to 15% of children born with RB mutations develop brain PNETs, commonly in the pineal gland. Cyclin D1, which in association with cyclin-dependent kinase (Cdk) 4 and Cdk6 phosphorylates and inactivates the RB protein, is expressed in 40% of sporadic medulloblastoma, a PNET of the cerebellum. To understand tumorigenic events cooperating with RB pathway disruption in brain PNET, we generated a transgenic mouse where cyclin D1 was expressed in pineal cells. Cyclin D1 enhanced pinealocyte proliferation, causing pineal gland enlargement. However, proliferation ceased beyond 2 weeks of age with reversal of Cdk4-mediated Rb phosphorylation despite continued expression of the transgene, and the pineal cells showed heterochromatin foci suggestive of a senescent-like state. In the absence of the p53 tumor suppressor, cell proliferation continued, resulting in pineal PNET that limited mouse survival to ∼4 months. Interestingly, the Cdk inhibitor p18Ink4c was induced in the transgenic pineal glands independently of p53, and transgenic mice that lacked Ink4c developed invasive PNET, although at an older age than those lacking p53. Analogous to our mouse model, we found that children with heritable RB often had asymptomatic pineal gland enlargement that only rarely progressed to PNET. Our finding that the Cdk4 inhibitor p18Ink4c is a tumor suppressor in cyclin D1–driven PNET suggests that pharmacologic interventions to inhibit Cdk4 activity may be a useful chemoprevention or therapeutic strategy in cancer driven by primary RB pathway disruption. [Cancer Res 2009;69(2):440–8]
Data from A Regulatory Mechanism for RSK2 NH2-Terminal Kinase Activity
Authors: Cho Yong-Yeon , Yao Ke , Pugliese Angelo , Malakhova Margarita L. , Bode Ann M. , Dong Zigang
Published: March 2024

Abstract
Our previous findings indicated that RSK2 plays a critical role in proliferation and cell transformation induced by tumor promoters, such as epidermal growth factor or 12-O-tetradecanoylphorbol-13-acetate, and that kaempferol, a natural compound found in edible plants, selectively inhibits RSK2 activity. However, the molecular mechanism for RSK2 activation is unclear. Herein, we provide evidence showing that NH2-terminal kinase domain (NTD) activation of RSK2 is required for the activation of the extracellular signal-regulated kinase–mediated COOH-terminal kinase domain (CTD). We also found that the NTD plays a key role in substrate phosphorylation and that kaempferol binds with the NTD but not the CTD in both the active and inactive forms. Homology modeling of the RSK2 NH2-terminal domain and small-molecule docking, validated by mutagenesis experiments, clearly showed that Val82 and Lys100 are critical amino acids for kaempferol binding and RSK2 activity. Furthermore, immunohistofluorescence and Western blot results indicated that the RSK2 protein level is markedly higher in cancer cell lines as well as cancer tissues compared with nonmalignant cell lines or normal tissues. In addition, kaempferol inhibited proliferation of malignant human cancer cell lines, including A431, SK-MEL-5 and SK-MEL-28, and HCT-116. These results indicate that targeting RSK2 with natural compounds, such as kaempferol, might be a good strategy for chemopreventive or chemotherapeutic application. [Cancer Res 2009;69(10):4398–406]
Data from Lack of T-Cell Receptor–Induced Signaling Is Crucial for CD95 Ligand Up-regulation and Protects Cutaneous T-Cell Lymphoma Cells from Activation-Induced Cell Death
Authors: Klemke Claus-Detlev , Brenner Dirk , Weiβ Eva-Maria , Schmidt Marc , Leverkus Martin , Gülow Karsten , Krammer Peter H.
Published: March 2024

Abstract
Restimulation of previously activated T cells via the T-cell receptor (TCR) leads to activation-induced cell death (AICD), which is, at least in part, dependent on the death receptor CD95 (APO-1, FAS) and its natural ligand (CD95L). Here, we characterize cutaneous T-cell lymphoma (CTCL) cells (CTCL tumor cell lines and primary CTCL tumor cells from CTCL patients) as AICD resistant. We show that CTCL cells have elevated levels of the CD95-inhibitory protein cFLIP. However, cFLIP is not responsible for CTCL AICD resistance. Instead, our data suggest that reduced TCR-proximal signaling in CTCL cells is responsible for the observed AICD resistance. CTCL cells exhibit no PLC-γ1 activity, resulting in an impaired Ca2+release and reduced generation of reactive oxygen species upon TCR stimulation. Ca2+ and ROS production are crucial for up-regulation of CD95L and reconstitution of both signals resulted in AICD sensitivity of CTCL cells. In accordance with these data, CTCL tumor cells from patients with Sézary syndrome do not up-regulate CD95L upon TCR-stimulation and are therefore resistant to AICD. These results show a novel mechanism of AICD resistance in CTCL that could have future therapeutic implications to overcome apoptosis resistance in CTCL patients. [Cancer Res 2009;69(10):4175–83]