bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cancer and the Microenvironment
Authors: Yaccoby Shmuel , Wezeman Michele J. , Henderson Aminah , Cottler-Fox Michele , Yi Qing , Barlogie Bart , Epstein Joshua 
Published: September 2005

AbstractWe have investigated the interaction between tumor cells and specific cells in their microenvironment using myeloma as a model. The role of myeloma-induced osteoclastogenesis in the disease was studied ex vivo. Myeloma plasma cells freshly purified from patients’ bone marrow attracted committed osteoclast (OC) precursors (n = 9; P &lt; 0.01) and in 22 experiments directly induced their differentiation to multinucleated, bone-resorbing OCs (P &lt; 0.00002) in a receptor activator of nuclear factor-κB ligand-mediated mechanism that was inhibited by the receptor activator of nuclear factor-κB (RANK-Fc) in 13 experiments by 71 ± 12% (P &lt; 0.008). In contrast, myeloma cells did not induce differentiation of peripheral blood mononuclear cells. Myeloma plasma cells cocultured with OCs retained their viability and proliferative activity for &gt;13 weeks. After 14 days in coculture, the plasma cells from 29 patients had higher viability (P &lt; 2 × 10−6), fewer apoptotic cells (P &lt; 4 × 10−15), and a higher bromodeoxyuridine labeling index (P &lt; 0.0006) than controls. Physical contact between OCs and myeloma cells was required for these effects to take place. No differences were observed between OCs from healthy donors and those from myeloma patients. Blocking interleukin 6 activity, while reducing survival of myeloma cells, had no effect on their proliferative activity. These results support data obtained from animal models and clinical observations on the essential role of the microenvironment in tumor sustenance and progression.
Involvement of Illegitimate V(D)J Recombination or Microhomology-Mediated Nonhomologous End-Joining in the Formation of Intragenic Deletions of theNotch1Gene in Mouse Thymic Lymphomas
Authors: Tsuji Hideo , Ishii-Ohba Hiroko , Katsube Takanori , Ukai Hideki , Aizawa Shiro , Doi Masahiro , Hioki Kyoji , Ogiu Toshiaki 
Published: September 2005

AbstractDeregulated V(D)J recombination-mediated chromosomal rearrangements are implicated in the etiology of B- and T-cell lymphomagenesis. We describe three pathways for the formation of 5′-deletions of the Notch1 gene in thymic lymphomas of wild-type or V(D)J recombination-defective severe combined immune deficiency (scid) mice. A pair of recombination signal sequence-like sequences composed of heptamer- and nonamer-like motifs separated by 12- or 23-bp spacers (12- and 23-recombination signal sequence) were present in the vicinity of the deletion breakpoints in wild-type thymic lymphomas, accompanied by palindromic or nontemplated nucleotides at the junctions. In scid thymic lymphomas, the deletions at the recombination signal sequence-like sequences occurred at a significantly lower frequency than in wild-type mice, whereas the deletions did not occur in Rag2−/− thymocytes. These results show that the 5′-deletions are formed by Rag-mediated V(D)J recombination machinery at cryptic recombination signal sequences in the Notch1 locus. In contrast, one third of the deletions in radiation-induced scid thymic lymphomas had microhomology at both ends, indicating that in the absence of DNA-dependent protein kinase-dependent nonhomologous end-joining, the microhomology-mediated nonhomologous end-joining pathway functions as the main mechanism to produce deletions. Furthermore, the deletions were induced via a coupled pathway between Rag-mediated cleavage at a cryptic recombination signal sequence and microhomology-mediated end-joining in radiation-induced scid thymic lymphomas. As the deletions at cryptic recombination signal sequences occur spontaneously, microhomology-mediated pathways might participate mainly in radiation-induced lymphomagenesis. Recombination signal sequence-mediated deletions were present clonally in the thymocyte population, suggesting that thymocytes with a 5′-deletion of the Notch1 gene have a growth advantage and are involved in lymphomagenesis.
Synergy between Celecoxib and Radiotherapy Results from Inhibition of Cyclooxygenase-2-Derived Prostaglandin E2, a Survival Factor for Tumor and Associated Vasculature
Authors: Davis Thomas W. , O’Neal Janet M. , Pagel Mark D. , Zweifel Ben S. , Mehta Pramod P. , Heuvelman Deborah M. , Masferrer Jaime L. 
Published: September 2005

Abstract
Previous work has demonstrated that selective cyclooxygenase-2 (COX-2) inhibitors can act synergistically with radiotherapy to improve tumor debulking and control in preclinical models. The underlying mechanism of this remarkable activity has not yet been determined. Here, we report that radiation can elevate intratumoral levels of COX-2 protein and its products, particularly prostaglandin E2 (PGE2). Furthermore, inhibition of COX-2 activity or neutralization of PGE2 activity enhances radiotherapy even in tumors where COX-2 expression is restricted to the tumor neovasculature. Direct assessment of vascular function by direct contrast enhancement-magnetic resonance imaging showed that the combination of radiation and celecoxib lead to enhanced vascular permeability. These observations suggest that an important mechanism of celecoxib-induced radiosensitization involves inhibition of COX-2-derived PGE2, thus removing a survival factor for the tumor and its vasculature.
Restoration of Promyelocytic Leukemia Protein-Nuclear Bodies in Neuroblastoma Cells Enhances Retinoic Acid Responsiveness
Authors: Yu Jiang Hong , Nakajima Ayako , Nakajima Hiroshi , Diller Lisa R. , Bloch Kenneth D. , Bloch Donald B. 
Published: September 2005

Abstract
Neuroblastoma is the most common solid tumor of infancy and is believed to result from impaired differentiation of neuronal crest embryonal cells. The promyelocytic leukemia protein (PML)-nuclear body is a cellular structure that is disrupted during the pathogenesis of acute promyelocytic leukemia, a disease characterized by impaired myeloid cell differentiation. During the course of studies to examine the composition and function of PML-nuclear bodies, we observed that the human neuroblastoma cell line SH-SY5Y lacked these structures and that the absence of PML-nuclear bodies was a feature of N- and I-type, but not S-type, neuroblastoma cell lines. Induction of neuroblastoma cell differentiation with 5-bromo-2′deoxyuridine, all-trans-retinoic acid, or IFN-γ induced PML-nuclear body formation. PML-nuclear bodies were not detected in tissue sections prepared from undifferentiated neuroblastomas but were present in neuroblasts in differentiating tumors. Expression of PML in neuroblastoma cells restored PML-nuclear bodies, enhanced responsiveness to all-trans-retinoic acid, and induced cellular differentiation. Pharmacological therapies that increase PML expression may prove to be important components of combined modalities for the treatment of neuroblastoma.
Identification of Heme Oxygenase-1 As a Novel BCR/ABL-Dependent Survival Factor in Chronic Myeloid Leukemia
Authors: Mayerhofer Matthias , Florian Stefan , Krauth Maria-Theresa , Aichberger Karl J. , Bilban Martin , Marculescu Rodrig , Printz Dieter , Fritsch Gerhard , Wagner Oswald , Selzer Edgar , Sperr Wolfgang R. , Valent Peter , Sillaber Christian 
Published: September 2005

Abstract
Chronic myeloid leukemia (CML) is a stem cell disease in which BCR/ABL promotes the survival of leukemic cells. Heme oxygenase-1 (HO-1) is an inducible stress protein that catalyzes the degradation of heme and has recently been implicated in the regulation of growth and survival of various neoplastic cells. In the present study, we analyzed the expression and role of HO-1 in CML cells. As assessed by Northern and Western blot analysis as well as immunostaining, primary CML cells were found to express HO-1 mRNA and the HO-1 protein in a constitutive manner. Exposure of these cells to the BCR/ABL tyrosine kinase inhibitor STI571 resulted in decreased expression of HO-1 mRNA and protein. In addition, BCR/ABL was found to up-regulate HO-1 promoter activity, mRNA levels, and protein levels in Ba/F3 cells. To investigate the role of HO-1 for survival of primary CML cells, the HO-1 inducer hemin was used. Hemin-induced expression of HO-1 was found to protect CML cells from STI571-induced cell death. In addition, inhibition of HO-1 by zinc-(II)-deuteroporphyrin-IX-2,4-bisethyleneglycol resulted in a substantial decrease of cell viability. Furthermore, overexpression of HO-1 in the CML-derived cell line K562 was found to counteract STI571-induced apoptosis. Together, our data identify HO-1 as a novel BCR/ABL-driven survival molecule and potential target in leukemic cells in patients with CML. The pathogenetic and clinical implications of this observation remain to be elucidated.
Neural Progenitor Cell Lines Inhibit Rat Tumor Growth
in Vivo
Authors: Staflin Karin , Honeth Gabriella , Kalliomäki Suzanne , Kjellman Christian , Edvardsen Klaus , Lindvall Magnus 
Published: September 2005

Abstract
Current therapies for gliomas often fail to address their infiltrative nature. Conventional treatments leave behind small clusters of neoplastic cells, resulting in eventual tumor recurrence. In the present study, we have evaluated the antitumor activity of neural progenitor cells against gliomas when stereotactically injected into nucleus Caudatus of Fisher rats. We show that the rat neural progenitor cell lines HiB5 and ST14A, from embryonic hippocampus and striatum primordium, respectively, are able to prolong animal survival and, in 25% of the cases, completely inhibit the outgrowth of N29 glioma compared with control animals. Delayed tumor outgrowth was also seen when HiB5 cells were inoculated at the site of tumor growth 1 week after tumor inoculation or when a mixture of tumor cells and HiB5 cells were injected s.c. into Fisher rats. HiB5 cells were additionally coinoculated together with two alternative rat gliomas, N32 and N25. N32 was growth inhibited, but rats inoculated with N25 cells did not show a prolonged survival. To evaluate the possibility of the involvement of the immune system in the tumor outgrowth inhibition, we show that HiB5 cells do not evoke an immune response when injected into Fisher rats. Furthermore, the rat neural progenitor cells produce all transforming growth factor β isotypes, which could explain the observed immunosuppressive nature of these cells. Hence, some neural progenitor cells have the ability to inhibit tumor outgrowth when implanted into rats. These results indicate the usefulness of neural stem cells as therapeutically effective cells for the treatment of intracranial tumors.
Endothelin-1 Is a Critical Mediator of Myogenic Tone in Tumor Arterioles
Authors: Sonveaux Pierre , Dessy Chantal , Martinive Philippe , Havaux Xavier , Jordan Bénédicte F. , Gallez Bernard , Grégoire Vincent , Balligand Jean-Luc , Feron Olivier 
Published: September 2005

Abstract
Although derived from the host tissue, the tumor vasculature is under the influence of the tumor microenvironment and needs to adapt to the resistance to blood flow inherent to the dynamics of tumor growth. Such vascular remodeling can offer selective targets to pharmacologically modulate tumor perfusion and thereby improve the efficacy of conventional anticancer treatments. Radiotherapy and chemotherapy can, indeed, take advantage of a better tumor oxygenation and drug delivery, respectively, both partly dependent on the tumor blood supply.
Here, we showed that isolated tumor arterioles mounted in a pressure myograph have the ability, contrary to size-matched healthy arterioles, to contract in response to a transluminal pressure increase. This myogenic tone was exquisitely dependent on the endothelin-1 pathway because it was completely abolished by the selective endothelin receptor A (ETA) antagonist BQ123. This selectivity was additionally supported by the large increase in endothelin-1 abundance in tumors and the higher density of the ETA receptors in tumor vessels. We also documented by using laser Doppler microprobes and imaging that administration of the ETA antagonist led to a significant increase in tumor blood flow, whereas the perfusion in control healthy tissue was not altered. Finally, we provided evidence that acute administration of the ETA antagonist could significantly stimulate tumor oxygenation, as determined by electron paramagnetic resonance oximetry, and increase the efficacy of low-dose, clinically relevant fractionated radiotherapy.
Thus, blocking the tumor-selective increase in the vascular endothelin-1/ETA pathway led us to unravel an important reserve of vasorelaxation that can be exploited to selectively increase tumor response to radiotherapy.
Adeno-Associated Viral Vector-Mediated Expression of Endostatin Inhibits Tumor Growth and Metastasis in an Orthotropic Pancreatic Cancer Model in Hamsters
Authors: Noro Takuji , Miyake Koichi , Suzuki-Miyake Noriko , Igarashi Tsutomu , Uchida Eiji , Misawa Takeyuki , Yamazaki Yoji , Shimada Takashi 
Published: September 2005

Abstract
We examined the feasibility of using adeno-associated virus (AAV)-mediated systemic delivery of endostatin in gene therapy to treat metastasis of pancreatic cancer. We established an animal model of orthotopic metastatic pancreatic cancer in which the pancreatic cancer cell line PGHAM-1 was inoculated into the pancreas of Syrian golden hamsters. Transplanted cells proliferated rapidly and metastasized to the liver. An AAV vector expressing endostatin (5 × 1010 particles) was injected intramuscularly into the left quadriceps or intravenously into the portal vein. These routes of vector administration were evaluated by comparing various parameters of tumor development. Intramuscular injection of the vector modestly increased the serum endostatin level. The numbers of metastases and the incidence of hemorrhagic ascites were decreased in the treated animals. In contrast, the serum concentration of endostatin was significantly increased after intraportal injection of the vector. The antitumor effects on all parameters (including the size and microvessel density of primary pancreatic tumors, the sizes and number of liver metastases, and the incidence of hemorrhagic ascites) were significant. These results suggest that systemic delivery of endostatin represents a potentially effective treatment for pancreatic cancer and liver metastases. The route of vector administration influences the efficacy of AAV-mediated endostatin expression. Intraportal injection of the AAV vector appears to be more effective as an antiangiogenic gene therapy for pancreatic cancer.
Vascular Endothelial Growth Factor Contributes to the Prostate Cancer-Induced Osteoblast Differentiation Mediated by Bone Morphogenetic Protein
Authors: Dai Jinlu , Kitagawa Yasuhide , Zhang Jian , Yao Zhi , Mizokami Atsushi , Cheng Shiyuan , Nör Jacques , McCauley Laurie K. , Taichman Russell S. , Keller Evan T. 
Published: September 2005

Abstract
Human prostate cancer has a high predisposition to metastasize to bone, resulting in the formation of osteoblastic metastases. The mechanism through which prostate cancer cells promote osteoblastic lesions is undefined. Vascular endothelial growth factor (VEGF) has been implicated as a mediator of osteoblast activity. In the present study, we examined if prostate cancer cells promote osteoblastic activity through VEGF. We found that LNCaP and C4-2B prostate cancer cell lines and primary tumor and metastatic prostate cancer tissues from patients expressed VEGF. Bone morphogenetic proteins (BMPs), which are normally present in the bone environment, induced VEGF protein and mRNA expression in C4-2B cells. Furthermore, BMP-7 activated the VEGF promoter. Noggin, a BMP inhibitor, diminished VEGF protein expression and promoter activity in C4-2B cells. Conditioned media (CM) from C4-2B cells induced pro-osteoblastic activity (increased alkaline phosphatase, osteocalcin, and mineralization) in osteoblast cells. Both noggin alone and anti-VEGF antibody alone diminished C4-2B CM-induced pro-osteoblastic activity. Transfection of C4-2B cells with VEGF partially rescued the C4-2B CM-induced pro-osteoblastic activity from noggin inhibition. These observations indicate that BMPs promote osteosclerosis through VEGF in prostate cancer metastases. These results suggest a novel function for VEGF in skeletal metastases. Specifically, VEGF promotes osteoblastic lesion formation at prostate cancer bone metastatic sites.
Epstein-Barr Virus Infection of Human Natural Killer Cell Lines and Peripheral Blood Natural Killer Cells
Authors: Isobe Yasushi , Sugimoto Koichi , Yang Lixin , Tamayose Kenji , Egashira Motoki , Kaneko Takako , Takada Kenzo , Oshimi Kazuo 
Published: September 2005

Abstract
Although considerable part of natural killer (NK) cell neoplasms possess EBV genome, there has been no direct evidence that EBV infects human NK cells in vitro. In this study, we demonstrated EBV entry into NK cells using a recombinant EBV, which contains enhanced green fluorescent protein (EGFP) gene in its genome (EGFP-EBV). After 48 h of exposure to EGFP-EBV, we detected EGFP signals in ∼30% of NK-92 and NKL cells and &gt;40% of peripheral blood NK cells from three healthy volunteers. Reverse transcription-PCR analysis of various EBV-associated genes confirmed EBV infection. In situ hybridization for EBERs and BHLFs showed that latent and lytic infections coexisted at the early phase of EBV infection in two NK cell lines. Although BHLF-positive cells in the early lytic phase were round-shaped, EBER-positive cells in latent EBV infection tended to show a bizarre shape. Flow cytometric analysis of EGFP-EBV-exposed NK cell lines showed that most of EBV-infected cells entered early apoptosis after 72 h of EBV exposure, which explains the difficulties to establish EBV-carrying NK clones. Flow cytometry and reverse transcription-PCR analysis indicated that two NK cell lines may fuse with EBV using HLA class II after binding to the virus through a distinct molecule from CD21. We established two EBV-carrying NKL clones showing latency types I and II, both of which are recognized in EBV-associated NK cell neoplasms. Because EBV-infected NKL cells showed only type I latency during the early phase of infection, the temporal profile of latent gene expression is similar to that of T cells. We first report in vitro EBV infection of human NK cells and establishment of EBV-carrying NK clones, which should contribute to elucidate the role of EBV in the development of NK cell neoplasms.
Sensitization for Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand-Induced Apoptosis by the Chemopreventive Agent Resveratrol
Authors: Fulda Simone , Debatin Klaus-Michael 
Published: September 2005

Abstract
Survivin is a member of the inhibitor of apoptosis proteins that is expressed at high levels in most human cancers and may facilitate evasion from apoptosis and aberrant mitotic progression. Naturally occurring dietary compounds such as resveratrol have gained considerable attention as cancer chemopreventive agents. Here, we discovered a novel function of the chemopreventive agent resveratrol: resveratrol is a potent sensitizer of tumor cells for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis through p53-independent induction of p21 and p21-mediated cell cycle arrest associated with survivin depletion. Concomitant analysis of cell cycle, survivin expression, and apoptosis revealed that resveratrol-induced G1 arrest was associated with down-regulation of survivin expression and sensitization for TRAIL-induced apoptosis. Accordingly, G1 arrest using the cell cycle inhibitor mimosine or induced by p21 overexpression reduced survivin expression and sensitized cells for TRAIL treatment. Likewise, resveratrol-mediated cell cycle arrest followed by survivin depletion and sensitization for TRAIL was impaired in p21- deficient cells. Also, down-regulation of survivin using survivin antisense oligonucleotides sensitized cells for TRAIL-induced apoptosis. Importantly, resveratrol sensitized various tumor cell lines, but not normal human fibroblasts, for apoptosis induced by death receptor ligation or anticancer drugs. Thus, this combined sensitizer (resveratrol)/inducer (e.g., TRAIL) strategy may be a novel approach to enhance the efficacy of TRAIL-based therapies in a variety of human cancers.
α7-Nicotinic Acetylcholine Receptors Affect Growth Regulation of Human Mesothelioma Cells
Authors: Trombino Sonya , Cesario Alfredo , Margaritora Stefano , Granone PierLuigi , Motta Giovanni , Falugi Carla , Russo Patrizia 
Published: September 2005

AbstractThis study presents data suggesting that both human mesothelioma (cell lines and human mesothelioma biopsies) and human normal mesothelial cells express receptors for acetylcholine and that stimulation of these receptors by nicotine prompted cell growth via activation of nicotinic cholinergic receptors. Thus, these data demonstrate that: (a) human mesothelioma cells and human biopsies of mesothelioma as well as of normal pleural mesothelial cells express functionally α-7 nicotinic acethlycholine receptors, evaluated by α-bungarotoxin-FITC binding, receptor binding assay, Western blot, and reverse transcription-PCR; (b) choline acetyltransferase immunostaining is present in mesothelioma cells; (c) mesothelioma cell growth is modulated by the cholinergic system in which agonists (i.e., nicotine) has a proliferative effect, and antagonists (i.e., curare) has an inhibitory effect, evaluated by cell cloning, DNA synthesis and cell cycle; (d) nicotine induces Ca+2 influx, evaluated by [45Ca2+] uptake, and consequently activation of mitogen-activated protein kinase pathway (extracellular signal-regulated kinase and p90RSK phosphorylation), evaluated by Western blot; and (e) apoptosis mechanisms in mesothelioma cells are under the control of the cholinergic system (nicotine antiapoptotic via induction of nuclear factor-κB complexes and phosphorylation of Bad at Ser112; curare proapoptotic via G0-G1 arrest p21waf-1 dependent but p53 independent). The involvement of the nonneuronal cholinergic system in mesothelioma appears reasonable and open up new therapeutic strategies.
Impaired Expression of the Cell Cycle Regulator
BTG2
Is Common in Clear Cell Renal Cell Carcinoma
Authors: Struckmann Kirsten , Schraml Peter , Simon Ronald , Elmenhorst Katja , Mirlacher Martina , Kononen Juha , Moch Holger 
Published: September 2005

Abstract
The prognosis of patients with renal cell carcinoma (RCC) is poor. A full understanding of the molecular genetics and signaling pathways involved in renal cancer development and in the metastatic process is of central importance for developing innovative and novel treatment options. In this study, BD Atlas Human Cancer 1.2 cDNA microarrays were used to identify genes involved in renal tumorigenesis. By analyzing gene expression patterns of four clear cell RCC (cRCC) cell lines and normal renal tissue, 25 genes were found differentially expressed. To determine the relevance of these genes, RNA in situ hybridization was performed on a tissue microarray generated from 61 snap-frozen primary renal cell carcinomas and 12 normal renal cortex biopsies. B-cell translocation gene 2 (BTG2), a negative cell cycle regulator, which was expressed in normal renal tissue but down-regulated in cRCC cell lines and primary cRCCs, was selected for additional experiments. Quantitative BTG2 mRNA expression analysis in 42 primary cRCCs and 18 normal renal cortex biopsies revealed up to 44-fold reduced expression in the tumor tissues. Decrease of BTG2 expression was not associated with tumor stage, grade, and survival. Cell culture experiments demonstrated that BTG2 expression was weakly inducible by the phorbolester 12-O-tetradecanoylphorbol-13-acetate in one of four cRCC cell lines. In contrast, increasing cell density led to elevated BTG2 mRNA expression in three of four cRCC cell lines. In both experiments, BTG2 mRNA levels did not reach values observed in normal renal tissue. These data suggest that down-regulation of BTG2 is an important step in renal cancer development.