bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regression of Experimental Medulloblastoma following Transfer of HER2-Specific T Cells
Authors: Ahmed Nabil , Ratnayake Maheshika , Savoldo Barbara , Perlaky Laszlo , Dotti Gianpietro , Wels Winfried S. , Bhattacharjee Meenakshi B. , Gilbertson Richard J. , Shine H. David , Weiss Heidi L. , Rooney Cliona M. , Heslop Helen E. , Gottschalk Stephen 
Published: June 2007

AbstractMedulloblastoma is a common malignant brain tumor of childhood. Human epidermal growth factor receptor 2 (HER2) is expressed by 40% of medulloblastomas and is a risk factor for poor outcome with current aggressive multimodal therapy. In contrast to breast cancer, HER2 is expressed only at low levels in medulloblastomas, rendering monoclonal antibodies ineffective. We determined if T cells grafted with a HER2-specific chimeric antigen receptor (CAR; HER2-specific T cells) recognized and killed HER2-positive medulloblastomas. Ex vivo, stimulation of HER2-specific T cells with HER2-positive medulloblastomas resulted in T-cell proliferation and secretion of IFN-γ and interleukin 2 (IL-2) in a HER2-dependent manner. HER2-specific T cells killed autologous HER2-positive primary medulloblastoma cells and medulloblastoma cell lines in cytotoxicity assays, whereas HER2-negative tumor cells were not killed. No functional difference was observed between HER2-specific T cells generated from medulloblastoma patients and healthy donors. In vivo, the adoptive transfer of HER2-specific T cells resulted in sustained regression of established medulloblastomas in an orthotopic, xenogenic severe combined immunodeficiency model. In contrast, delivery of nontransduced T cells did not change the tumor growth pattern. Adoptive transfer of HER2-specific T cells may represent a promising immunotherapeutic approach for medulloblastoma. [Cancer Res 2007;67(12):5957–64]
Background Mutation Frequency in Microsatellite-Unstable Colorectal Cancer
Authors: Sammalkorpi Heli , Alhopuro Pia , Lehtonen Rainer , Tuimala Jarno , Mecklin Jukka-Pekka , Järvinen Heikki J. , Jiricny Josef , Karhu Auli , Aaltonen Lauri A. 
Published: June 2007

Abstract
Microsatellite instability (MSI) is observed in ∼12% of colorectal cancers. Genes containing a mononucleotide microsatellite in the coding sequence are particularly prone to inactivation in MSI tumorigenesis, and much work has been conducted to identify genes with high repetitive tract mutation rates in these tumors. Much less attention has been paid to background mutation frequencies, and no work has focused on nontranscribed regions. Here, we studied 114 nontranscribed intergenic A/T and C/G repeats 6 to 10 bp in length, located distant from known genes, to examine background mutation frequencies in MSI colorectal cancers. A strong correlation with tract length was observed, and mutation frequencies of up to 87% were observed in 8 to 10 bp tracts. Subsequently, to compare the background mutation rate in transcribed and nontranscribed noncoding repeats, we screened nine randomly selected intronic C/G8 repeats. In addition, the coding repeats of seven suggested MSI target genes, and nine previously published intronic A8 and G8 repeats were analyzed. Intronic repeats seemed to mutate less frequently than nontranscribed intergenic repeats. Our results show that strand slippage mutations in mismatch repair–deficient cells are as abundant in short intergenic repeats as in many proposed MSI target genes. However, under mismatch repair deficiency, strand slippage mutations in transcribed sequences seem to be repaired more efficiently than in intergenic nontranscribed sequences. The mechanisms causing these differences are not yet understood and should be a subject for further studies. For MSI target gene identification, repeats in transcribed sequences seem to be the most appropriate reference group for coding region repeat mutations. [Cancer Res 2007;67(12):5691–8]
Activation of FOXO3a by the Green Tea Polyphenol Epigallocatechin-3-Gallate Induces Estrogen Receptor α Expression Reversing Invasive Phenotype of Breast Cancer Cells
Authors: Belguise Karine , Guo Shangqin , Sonenshein Gail E. 
Published: June 2007

AbstractPreviously, we showed that the bioactive green tea polyphenol epigallocatechin-3-gallate (EGCG) inhibits growth in soft agar of breast cancer cells with Her-2/neu overexpression. Using gene expression profiling, here we show that EGCG treatment of Her-2/neu–driven mammary tumor cells alters the expression of key regulators in the epithelial to mesenchymal transition (EMT) pathway, reducing invasive phenotype. Specifically, the epithelial genes E-cadherin, γ-catenin, MTA3, and estrogen receptor α (ERα) were up-regulated by EGCG, whereas the proinvasive snail gene was down-regulated. Consistently, EGCG inhibited branching colony growth and invasion in Matrigel. EGCG treatment similarly inhibited invasive phenotype of mouse mammary tumor cells driven by Nuclear Factor-κB c-Rel and protein kinase CK2, frequently found overexpressed in human breast disease. Recently, we identified the Forkhead box O transcription factor FOXO3a as a major transcriptional regulator of ERα. Given the pivotal role of ERα in preventing EMT, we hypothesized that the activation of FOXO3a by EGCG plays an important role in the observed reversal of invasive phenotype in ERα-positive breast cancer cells. EGCG treatment activated FOXO3a. Ectopic expression of a constitutively active FOXO3a overrode transforming growth factor-β1–mediated invasive phenotype and induced a more epithelial phenotype, which was dependent on ERα expression and signaling. Conversely, a dominant negative FOXO3a reduced epithelial phenotype of ERα-low breast cancer cells. These results identify, for the first time, a role for FOXO3a in the inhibition of invasive phenotype in breast cancer cells with active ERα signaling and elucidate a novel mechanism whereby EGCG represses EMT of breast cancer cells. [Cancer Res 2007;67(12):5763–70]
The Tumor Suppressor Gene hCDC4 Is Frequently Mutated in Human T-Cell Acute Lymphoblastic Leukemia with Functional Consequences for Notch Signaling
Authors: Malyukova Alena , Dohda Takeaki , von der Lehr Natalie , Akhondi Shahab , Corcoran Martin , Heyman Mats , Spruck Charles , Grandér Dan , Lendahl Urban , Sangfelt Olle 
Published: June 2007

Abstract
Notch signaling is of crucial importance in normal T-cell development and Notch 1 is frequently mutated in T-cell acute lymphoblastic leukemias (T-ALL), leading to aberrantly high Notch signaling. In this report, we determine whether T-ALL mutations occur not only in Notch1 but also in the F-box protein hCdc4 (Sel-10, Ago, or Fbxw7), a negative regulator of Notch1. We show that the hCDC4 gene is mutated in leukemic cells from more than 30% of patients with pediatric T-ALL and derived cell lines. Most hCDC4 mutations found were missense substitutions at critical arginine residues (Arg465, Arg479, and Arg505) localized in the substrate-binding region of hCdc4. Cells inactivated for hCdc4 and T-ALL cells containing hCDC4 mutations exhibited an increased Notch1 protein half-life, consistent with the proposed role of hCdc4 in ubiquitin-dependent proteolysis of Notch1. Furthermore, restoration of wild-type but not mutant hCdc4 in HCT 116 hCDC4-negative cells led to an increased Notch1 ubiquitylation and decreased Notch1 signaling. These results show that hCdc4 mutations interfere with normal Notch1 regulation in vivo. Finally, we found that mutations in hCDC4 and NOTCH1 can occur in the same cancers and that patients carrying hCDC4 and/or NOTCH1 mutations have a favorable overall survival. Collectively, these data show that mutation of hCDC4 is a frequent event in T-ALL and suggest that hCDC4 mutations and gain-of-function mutations in NOTCH1 might synergize in contributing to the development of pediatric T-ALL leukemogenesis. [Cancer Res 2007;67(12):5611–6]
Membrane-Bound Interleukin (IL)-15 on Renal Tumor Cells Rescues Natural Killer Cells from IL-2 Starvation-Induced Apoptosis
Authors: Wittnebel Sebastian , Da Rocha Sylvie , Giron-Michel Julien , Jalil Abdelali , Opolon Paule , Escudier Bernard , Validire Pierre , Khawam Krystel , Chouaib Salem , Azzarone Bruno , Caignard Anne 
Published: June 2007

Abstract
Renal cell carcinoma primary tumors and lung metastases are infiltrated by activated natural killer (NK) cells. Interleukin (IL)-15, a major cytokine involved in cross-talk between accessory cells (dendritic cells and macrophages) and NK cells, is produced by epithelial renal cells. We show that renal cell carcinoma cells and normal renal cells express IL-15 mRNA and membrane-bound IL-15 (MbIL-15). These cells also express IL-15 receptor α (IL-15Rα). Silencing of IL-15Rα by specific small interfering RNA in renal cell carcinoma had no effect on MbIL-15 production, indicating that the cytokine is not cross-presented by IL-15Rα in renal cell carcinoma cells but anchored to the membrane. Furthermore, we show that MbIL-15 from renal cell carcinoma cells is functional and involved in rapid nuclear translocation of phosphorylated signal transducers and activators of transcription 3 in IL-2–starved NK cells. MbIL-15 on the target did not interfere with resting NK cell activation and target cell cytolysis but rescued NK cells from IL-2 starvation-induced apoptosis through contact-dependent interaction. Masking of MbIL-15 with soluble IL-15Rα molecules restored NK cell apoptosis. These findings suggest that IL-15 produced by renal tumor cells is involved in the maintenance of active NK cells at the tumor site. [Cancer Res 2007;67(12):5594–9]
Oncogenic Potential of the miR-106-363 Cluster and Its Implication in Human T-Cell Leukemia
Authors: Landais Séverine , Landry Sébastien , Legault Philippe , Rassart Eric 
Published: June 2007

Abstract
We previously reported the identification of the Kis2 common retrovirus integration site, located on mouse chromosome X, in radiation leukemia virus–induced T-cell leukemias. Tumors with a provirus at the Kis2 locus overexpressed a novel noncoding RNA (ncRNA) with a complex splicing pattern and no polyA tail. Database upgrade revealed the presence of a microRNA (miRNA) cluster, miR-106-363, just downstream of the Kis2 ncRNAs. We found that Kis2 ncRNAs are the pri-miRNA of miR-106-363, and we present evidence that Kis2 ncRNA overexpression in mouse tumors results in miR-106a, miR-19b-2, miR-92-2, and miR-20b accumulation. We show the oncogenic potential of those miRNAs in anchorage independence assay and confirm pri-miR-106-363 overexpression in 46% of human T-cell leukemias tested. This overexpression contributes in rising miR-92 and miR-19 levels, as this is the case for miR-17-92 cluster overexpression. Furthermore, we identified myosin regulatory light chain–interacting protein, retinoblastoma-binding protein 1-like, and possibly homeodomain-interacting protein kinase 3 as target genes of this miRNA cluster, which establishes a link between these genes and T-cell leukemia for the first time. [Cancer Res 2007;67(12):5699–707]
MutantPIK3CA-Bearing Colon Cancer Cells Display Increased Metastasis in an Orthotopic Model
Authors: Guo Xiao-Ning , Rajput Ashwani , Rose Rebecca , Hauser Jennie , Beko Alexander , Kuropatwinski Karen , LeVea Charles , Hoffman Robert M. , Brattain Michael G. , Wang Jing 
Published: June 2007

AbstractMutations in the PIK3CA gene are common in human cancers, including colon cancer. We compared two pairs of colon cancer cells (HCT116 and DLD1) bearing only the wild-type (WT) or mutant (MUT) PIK3CA allele for their survival capacity under stress conditions in vitro as well as their metastatic properties in an in vivo orthotopic model. When subjected to growth factor deprivation stress (GFDS), the MUT PIK3CA cells displayed resistance to GFDS-induced apoptosis relative to the WT cells. Phosphatidylinositol 3-kinase (PI3K) and its downstream effector AKT were constitutively activated during stress conditions in the MUT PIK3CA cells but not in the WT cells. The MUT cells showed hypersensitivity to PI3K inhibition. Moreover, the proapoptotic protein Bax was expressed at a very high level in the WT PIK3CA cells, whereas it was almost undetectable in the MUT cells. Inhibition of Bax expression by small interfering RNA protected the WT PIK3CA cells from GFDS-induced apoptosis, suggesting an important role of Bax in GFDS-induced apoptosis. These results indicated that the MUT PI3K confers resistance to GFDS-induced apoptosis and that the MUT cells are more dependent on the PI3K pathway for survival. In vivo studies showed that the MUT PIK3CA-bearing cells were more metastatic than the WT cells in an orthotopic model of colon cancer. Taken together, these results suggest that MUT PI3K imparts a more aggressive phenotype in colon cancer cells and could be a potential therapeutic target for treatment of colon cancer patients bearing PIK3CA mutations. [Cancer Res 2007;67(12):5851–8]
Effects of Tetramethoxystilbene on Hormone-Resistant Breast Cancer Cells: Biological and Biochemical Mechanisms of Action
Authors: Park Hoyong , Aiyar Sarah E. , Fan Ping , Wang Jiping , Yue Wei , Okouneva Tatiana , Cox Corey , Jordan Mary Ann , Demers Laurence , Cho Hyungjun , Kim Sanghee , Song Robert X.-D. , Santen Richard J. 
Published: June 2007

AbstractSecondary resistance to hormonal therapy for breast cancer commonly develops after an initial response to tamoxifen or aromatase inhibitors. Agents to abrogate these adaptive changes would substantially enhance the long-term benefits of hormonal therapy. Our studies with a stilbene derivative called TMS (2,3′,4,5′-tetramethoxystilbene) identified unexpected effects with potential utility for treatment of breast tumors secondarily resistant to hormonal therapy. TMS was originally developed as an inhibitor of cytochrome P450 1B1 to block the conversion of estradiol to 4-OH-estradiol. While studying this agent in three models of hormone resistance, we detected direct antitumor effects not related to its role as an inhibitor of catecholestrogens. During examination of the mechanisms involved, we showed that treatment with 3 μmol/L TMS for 24 h inhibited tubulin polymerization and microtubule formation, caused a cell cycle block at the G2-M phase, and induced apoptosis. TMS also inhibited activated focal adhesion kinase (FAK), Akt, and mammalian target of rapamycin (mTOR) and stimulated c-jun-NH2-kinase and p38 mitogen-activated protein kinase activity. With respect to antitumor effects, TMS at a concentrations of 0.2 to 0.3 μmol/L inhibited the growth of long-term tamoxifen-treated MCF-7 cells by 80% and fulvestrant-treated MCF-7 cells by 70%. In vivo studies, involving 8 weeks of treatment with TMS via a 30-mg s.c. implant, reduced tumor volume of tamoxifen-resistant MCF-7 breast cancer xenografts by 53%. Our data suggest that TMS is a promising therapeutic agent because of its unique ability to block several pathways involved in the development of hormone resistance. [Cancer Res 2007;67(12):5717–26]
Evaluation of CD20, CD22, and HLA-DR Targeting for Radioimmunotherapy of B-Cell Lymphomas
Authors: Pagel John M. , Pantelias Anastasia , Hedin Nathan , Wilbur Shani , Saganic Laura , Lin Yukang , Axworthy Donald , Hamlin Donald K. , Wilbur D. Scott , Gopal Ajay K. , Press Oliver W. 
Published: June 2007

Abstract
Despite the promise of radioimmunotherapy using anti-CD20 antibodies (Ab) for the treatment of relapsed patients with indolent non-Hodgkin lymphoma (NHL), most patients treated with conventional doses of 131I-tositumomab or 90Y-ibritumomab eventually relapse. We did comparative assessments using conventional radioimmunotherapy targeting CD20, CD22, and HLA-DR on human Ramos, Raji, and FL-18 lymphoma xenografts in athymic mice to assess the potential for improving the efficacy of radioimmunotherapy by targeting other NHL cell surface antigens. Results of biodistribution studies showed significant differences in tumor localization consistent with variable antigenic expression on the different lymphoma cell lines. Interestingly, the radioimmunoconjugate that yielded the best tumor-to-normal organ ratios differed in each tumor model. We also explored administering all three 111In-1,4,7,10-tetra-azacylododecane N,N′,N″,N‴-tetraacetic acid antibodies in combination, but discovered, surprisingly, that this approach did not augment the localization of radioactivity to tumors compared with the administration of the best single radiolabeled Ab alone. These data suggest that conventional radioimmunotherapy using anti-CD20, anti–HLA-DR, or anti-CD22 Abs is effective when used singly and provides targeted uptake of radiolabel into the tumor that is dependent on the levels of antigen expression. Improvements in tumor-to-normal organ ratios of radioactivity cannot be achieved using directly labeled Abs in combination but may be afforded by novel pretargeting methods. [Cancer Res 2007;67(12):5921–8]
MPC-6827: A Small-Molecule Inhibitor of Microtubule Formation That Is Not a Substrate for Multidrug Resistance Pumps
Authors: Kasibhatla Shailaja , Baichwal Vijay , Cai Sui Xiong , Roth Bruce , Skvortsova Ira , Skvortsov Sergej , Lukas Peter , English Nicole M. , Sirisoma Nilantha , Drewe John , Pervin Azra , Tseng Ben , Carlson Robert O. , Pleiman Christopher M. 
Published: June 2007

Abstract
A novel series of 4-arylaminoquinazolines were identified from a cell-based screening assay as potent apoptosis inducers. Through structure-activity relationship studies, MPC-6827 and its close structural analogue, MPI-0441138, were discovered as proapoptotic molecules and mitotic inhibitors with potencies at low nanomolar concentrations in multiple tumor cell lines. Photoaffinity and radiolabeled analogues of MPC-6827 were found to bind a 55-kDa protein, and this binding was competed by MPC-6827, paclitaxel, and colchicine, but not vinblastine. MPC-6827 effectively inhibited the polymerization of tubulin in vitro, competed with colchicine binding, and disrupted the formation of microtubules in a variety of tumor cell lines, which together showed the molecular target as tubulin. Treatment of MCF-7 breast carcinoma or Jurkat leukemia cells with MPC-6827 led to pronounced G2-M cell cycle arrest followed by apoptosis. Apoptosis, as determined by terminal deoxyribonucleotidyl transferase–mediated dUTP nick end labeling assay, was preceded by loss of mitochondrial membrane potential, cytochrome c translocation from mitochondria to nuclei, activation of caspase-3, and cleavage of poly(ADP-ribose) polymerase. MPC-6827 was equipotent in an in vitro growth inhibition assay in several cancer cell lines regardless of the expression levels of the multidrug resistance ABC transporters MDR-1 (Pgp-1), MRP-1, and BCRP-1. In B16-F1 allografts and in OVCAR-3, MIAPaCa-2, MCF-7, HT-29, MDA-MB-435, and MX-1 xenografts, statistically significant tumor growth inhibition was observed with MPC-6827. These studies show that MPC-6827 is a microtubule-disrupting agent with potent and broad-spectrum in vitro and in vivo cytotoxic activities and, therefore, MPC-6827 is a promising candidate for development as a novel therapeutic for multiple cancer types. [Cancer Res 2007;67(12):5865–71]
CD133 Is Not Present on Neurogenic Astrocytes in the Adult Subventricular Zone, but on Embryonic Neural Stem Cells, Ependymal Cells, and Glioblastoma Cells
Authors: Pfenninger Cosima V. , Roschupkina Teona , Hertwig Falk , Kottwitz Denise , Englund Elisabet , Bengzon Johan , Jacobsen Sten Eirik , Nuber Ulrike A. 
Published: June 2007

Abstract
Human brain tumor stem cells have been enriched using antibodies against the surface protein CD133. An antibody recognizing CD133 also served to isolate normal neural stem cells from fetal human brain, suggesting a possible lineage relationship between normal neural and brain tumor stem cells. Whether CD133-positive brain tumor stem cells can be derived from CD133-positive neural stem or progenitor cells still requires direct experimental evidence, and an important step toward such investigations is the identification and characterization of normal CD133-presenting cells in neurogenic regions of the embryonic and adult brain. Here, we present evidence that CD133 is a marker for embryonic neural stem cells, an intermediate radial glial/ependymal cell type in the early postnatal stage, and for ependymal cells in the adult brain, but not for neurogenic astrocytes in the adult subventricular zone. Our findings suggest two principal possibilities for the origin of brain tumor stem cells: a derivation from CD133-expressing cells, which are normally not present in the adult brain (embryonic neural stem cells and an early postnatal intermediate radial glial/ependymal cell type), or from CD133-positive ependymal cells in the adult brain, which are, however, generally regarded as postmitotic. Alternatively, brain tumor stem cells could be derived from proliferative but CD133-negative neurogenic astrocytes in the adult brain. In the latter case, brain tumor development would involve the production of CD133. [Cancer Res 2007;67(12):5727–36]
Cytoplasmic Irradiation Induces Mitochondrial-Dependent 53BP1 Protein Relocalization in Irradiated and Bystander Cells
Authors: Tartier Laurence , Gilchrist Stuart , Burdak-Rothkamm Susanne , Folkard Melvyn , Prise Kevin M. 
Published: June 2007

Abstract
The accepted paradigm for radiation effects is that direct DNA damage via energy deposition is required to trigger the downstream biological consequences. The radiation-induced bystander effect is the ability of directly irradiated cells to interact with their nonirradiated neighbors, which can then show responses similar to those of the targeted cells. p53 binding protein 1 (53BP1) forms foci at DNA double-strand break sites and is an important sensor of DNA damage. This study used an ionizing radiation microbeam approach that allowed us to irradiate specifically the nucleus or cytoplasm of a cell and quantify response in irradiated and bystander cells by studying ionizing radiation-induced foci (IRIF) formation of 53BP1 protein. Our results show that targeting only the cytoplasm of a cell is capable of eliciting 53BP1 foci in both hit and bystander cells, independently of the dose or the number of cells targeted. Therefore, direct DNA damage is not required to trigger 53BP1 IRIF. The use of common reactive oxygen species and reactive nitrogen species (RNS) inhibitors prevent the formation of 53BP1 foci in hit and bystander cells. Treatment with filipin to disrupt membrane-dependent signaling does not prevent the cytoplasmic irradiation-induced 53BP1 foci in the irradiated cells, but it does prevent signaling to bystander cells. Active mitochondrial function is required for these responses because pseudo-ρ0 cells, which lack mitochondrial DNA, could not produce a bystander signal, although they could respond to a signal from normal ρ+ cells. [Cancer Res 2007;67(12):5872–9]