bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hedgehog Signaling Pathway is a New Therapeutic Target for Patients with Breast Cancer
Authors: Kubo Makoto , Nakamura Masafumi , Tasaki Akira , Yamanaka Naoki , Nakashima Hiroshi , Nomura Masatoshi , Kuroki Syoji , Katano Mitsuo 
Published: September 2005

Abstract
The Hedgehog (Hh) signaling pathway functions as an organizer in embryonic development. Genetic analysis has demonstrated a critical role for the Hh pathway in mammary gland morphogenesis. Disruption of Patched1, a component of the Hh pathway, results in abnormal growth of mammary duct. Recent studies have shown constitutive activation of the Hh pathway in various types of malignancies. However, it remains unclear whether this pathway is activated in human breast cancer. Here, we determined the expression of the components, including Sonic Hh, Patched1, and Gli1, of the Hh pathway by immunohistochemical staining in a series of 52 human breast carcinomas. All of 52 tumors display staining of high intensity for Gli1 when compared with adjacent normal tissue. The nuclear staining ratio of Gli1 correlates with expression of estrogen receptor and histologic type. Exposure to cyclopamine, a steroidal alkaloid that blocks the Hh pathway, suppresses expression of Gli1 and the growth of the Hh pathway-activated breast carcinoma cells. These data indicate that the Hh pathway is a new candidate for therapeutic target of breast cancer.
PT-100, a Small Molecule Dipeptidyl Peptidase Inhibitor, Has Potent Antitumor Effects and Augments Antibody-Mediated Cytotoxicity via a Novel Immune Mechanism
Authors: Adams Sharlene , Miller Glenn T. , Jesson Michael I. , Watanabe Takeshi , Jones Barry , Wallner Barbara P. 
Published: September 2005

Abstract
The amino boronic dipeptide, PT-100 (Val-boro-Pro), a dipeptidyl peptidase (DPP) inhibitor, has been shown to up-regulate gene expression of certain cytokines in hematopoietic tissue via a high-affinity interaction, which appears to involve fibroblast activation protein. Because fibroblast activation protein is also expressed in stroma of lymphoid tissue and tumors, the effect of PT-100 on tumor growth was studied in mice in vivo. PT-100 has no direct cytotoxic effect on tumors in vitro. Oral administration of PT-100 to mice slowed growth of syngeneic tumors derived from fibrosarcoma, lymphoma, melanoma, and mastocytoma cell lines. In WEHI 164 fibrosarcoma and EL4 and A20/2J lymphoma models, PT-100 caused regression and rejection of tumors. The antitumor effect appeared to involve tumor-specific CTL and protective immunological memory. PT-100 treatment of WEHI 164-inoculated mice increased mRNA expression of cytokines and chemokines known to promote T-cell priming and chemoattraction of T cells and innate effector cells. The role of innate activity was further implicated by observation of significant, although reduced, inhibition of WEHI 164 and A20/2J tumors in immunodeficient mice. PT-100 also demonstrated ability to augment antitumor activity of rituximab and trastuzumab in xenograft models of human CD20+ B-cell lymphoma and HER-2+ colon carcinoma where antibody-dependent cytotoxicity can be mediated by innate effector cells responsive to the cytokines and chemokines up-regulated by PT-100. Although CD26/DPP-IV is a potential target for PT-100 in the immune system, it appeared not to be involved because antitumor activity and stimulation of cytokine and chemokine production was undiminished in CD26−/− mice.
Disappearance of the Telomere Dysfunction-Induced Stress Response in Fully Senescent Cells
Authors: Bakkenist Christopher J. , Drissi Rachid , Wu Jing , Kastan Michael B. , Dome Jeffrey S. 
Published: September 2005

Abstract
Replicative senescence is a natural barrier to cellular proliferation that is triggered by telomere erosion and dysfunction. Here, we demonstrate that ATM activation and H2AX-γ nuclear focus formation are sensitive markers of telomere dysfunction in primary human fibroblasts. Whereas the activated form of ATM and H2AX-γ foci were rarely observed in early-passage cells, they were readily detected in late-passage cells. The ectopic expression of telomerase in late-passage cells abrogated ATM activation and H2AX-γ focus formation, suggesting that these stress responses were the consequence of telomere dysfunction. ATM activation was induced in quiescent fibroblasts by inhibition of TRF2 binding to telomeres, indicating that telomere uncapping is sufficient to initiate the telomere signaling response; breakage of chromosomes with telomeric associations is not required for this activation. Although ATM activation and H2AX-γ foci were readily observed in late-passage cells, they disappeared once cells became fully senescent, indicating that constitutive signaling from dysfunctional telomeres is not required for the maintenance of senescence.
Specific Recognition and Killing of Glioblastoma Multiforme by Interleukin 13-Zetakine Redirected Cytolytic T Cells
Authors: Kahlon Kanwarpal S. , Brown Christine , Cooper Laurence J. N. , Raubitschek Andrew , Forman Stephen J. , Jensen Michael C. 
Published: September 2005

AbstractThe interleukin (IL) 13 receptor α2 (IL13Rα2) is a glioma-restricted cell-surface epitope not otherwise detected within the central nervous system. Here, we describe a novel approach for targeting glioblastoma multiforme (GBM) with IL13Rα2-specific cytolytic T cells (CTLs) by their genetic modification to express a membrane-tethered IL13 cytokine chimeric T-cell antigen receptor, or zetakine. Our prototype zetakine incorporates an IL13 E13Y mutein for selective binding to IL13Rα2. Human IL13-zetakine+CD8+ CTL transfectants display IL13Rα2-specific antitumor effector function including tumor cell cytolysis, TC1 cytokine production, and zetakine-regulated autocrine proliferation. The E13Y amino acid substitution of the IL13 mutein of the zetakine endows CTL transfectants with the capacity to discriminate between IL13Rα2+ GBM targets from targets expressing IL13Rα1. In vivo, the adoptive transfer of IL13-zetakine+CD8+ CTL clones results in the regression of established human glioblastoma orthotopic xenografts. Pilot clinical trials have been initiated to evaluate the feasibility and safety of local-regional delivery of autologous IL13-zetakine redirected CTL clones in patients with recurrent GBM. Our IL13-zetakine is a prototype of a new class of chimeric immunoreceptors that signal through an engineered immune synapse composed of membrane-tethered cytokine muteins bound to cell-surface cytokine receptors on tumors.
Chromosome Transfer Induced Aneuploidy Results in Complex Dysregulation of the Cellular Transcriptome in Immortalized and Cancer Cells
Authors: Upender Madhvi B. , Habermann Jens K. , McShane Lisa M. , Korn Edward L. , Barrett J. Carl , Difilippantonio Michael J. , Ried Thomas 
Published: September 2005

Abstract
Chromosomal aneuploidies are observed in essentially all sporadic carcinomas. These aneuploidies result in tumor-specific patterns of genomic imbalances that are acquired early during tumorigenesis, continuously selected for and faithfully maintained in cancer cells. Although the paradigm of translocation induced oncogene activation in hematologic malignancies is firmly established, it is not known how genomic imbalances affect chromosome-specific gene expression patterns in particular and how chromosomal aneuploidy dysregulates the genetic equilibrium of cells in general. To model specific chromosomal aneuploidies in cancer cells and dissect the immediate consequences of genomic imbalances on the transcriptome, we generated artificial trisomies in a karyotypically stable diploid yet mismatch repair-deficient, colorectal cancer cell line and in telomerase immortalized, cytogenetically normal human breast epithelial cells using microcell-mediated chromosome transfer. The global consequences on gene expression levels were analyzed using cDNA arrays. Our results show that regardless of chromosome or cell type, chromosomal trisomies result in a significant increase in the average transcriptional activity of the trisomic chromosome. This increase affects the expression of numerous genes on other chromosomes as well. We therefore postulate that the genomic imbalances observed in cancer cells exert their effect through a complex pattern of transcriptional dysregulation.
Choline Kinase Activation Is a Critical Requirement for the Proliferation of Primary Human Mammary Epithelial Cells and Breast Tumor Progression
Authors: de Molina Ana Ramírez , Báñez-Coronel Mónica , Gutiérrez Ruth , Rodríguez-González Agustín , Olmeda David , Megías Diego , Lacal Juan Carlos 
Published: September 2005

Abstract
Breast cancer is still one of the most important tumors among women in industrialized countries. Improvement in both understanding the molecular events associated with the disease and the development of new additional treatments is still an important goal to be achieved. Choline kinase (ChoK) is increased in human mammary tumors with high incidence, and this activation is associated with clinical variable indicators of greater malignancy. Here, we have investigated the role of ChoK in the development of breast cancer and found that ChoK is both necessary and sufficient for growth factor-induced proliferation in primary human mammary epithelial cells and an absolute requirement for the specific mitogenic response to heregulin in breast tumor-derived cells. These results demonstrate that ChoK plays an essential role in both normal human mammary epithelial cell proliferation and breast tumor progression. Furthermore, inhibition of ChoK shows a strong in vivo antitumor activity against human breast cancer xenografts. Thus, ChoK constitutes a novel bona fide molecular target for the treatment of breast cancer patients.
Oncolytic Activity of p53-Expressing Conditionally Replicative Adenovirus AdΔ24-p53 against Human Malignant Glioma
Authors: Geoerger Birgit , Vassal Gilles , Opolon Paule , Dirven Clemens M. F. , Morizet Jackie , Laudani Lysiane , Grill Jacques , Giaccone Giuseppe , Vandertop W. Peter , Gerritsen Winald R. , van Beusechem Victor W. 
Published: September 2005

Abstract
Prognosis of malignant glioma is poor, and results of treatment remain mediocre. Conditionally replicative adenoviruses hold promise as alternative anticancer agents for the treatment of malignant glioma. Here, we evaluated the conditionally replicative adenovirus AdΔ24 and its recently developed derivative AdΔ24-p53, which expresses functional p53 tumor suppressor protein while replicating in cancer cells, for treatment of malignant glioma. In comparison to its parent AdΔ24, AdΔ24-p53 killed most malignant glioma cell lines and primary glioblastoma multiforme short-term cultures more effectively, irrespective of their p53 status. Moreover, AdΔ24-p53 caused more frequent regression and more delayed growth of IGRG121 xenografts derived from a glioblastoma multiforme in vivo. Five intratumoral injections of 107 pfu AdΔ24 gave 24 days median tumor growth delay (P &lt; 0.01), 30% tumor regressions, and 30% animals surviving &gt;120 days tumor-free or with a minimal tumor residual. The same dose of AdΔ24-p53 caused &gt;113 days of median tumor growth delay (P &lt; 0.001), 70% tumor regressions, and 60% animals surviving &gt;120 days tumor-free or with a minimal tumor residual. Antitumor effects in vivo were associated with extensive conditionally replicative adenovirus replication, apoptosis induction, and tumor morphology changes, including dissociation, inflammatory cell infiltration, and necrosis. We conclude that conditionally replicative adenoviruses expressing p53 are promising new agents for treatment of malignant glioma.
Src Family Kinases Mediate Epidermal Growth Factor Receptor Ligand Cleavage, Proliferation, and Invasion of Head and Neck Cancer Cells
Authors: Zhang Qing , Thomas Sufi M. , Xi Sichuan , Smithgall Thomas E. , Siegfried Jill M. , Kamens Joanne , Gooding William E. , Grandis Jennifer Rubin 
Published: September 2005

Abstract
Head and neck squamous cell carcinomas (HNSCCs) are characterized by up-regulation of the epidermal growth factor receptor (EGFR). We previously reported that a gastrin-releasing peptide/gastrin-releasing peptide receptor (GRP/GRPR) autocrine growth pathway is activated early in HNSCC carcinogenesis. GRP can induce rapid phosphorylation of EGFR and p42/44 mitogen-activated protein kinase (MAPK) activation in part via extracellular release of transforming growth factor α (TGF-α) by matrix metalloproteinases (MMPs). It has been reported that Src family kinases are activated by G-protein–coupled receptors (GPCRs), followed by downstream EGFR and MAPK activation. To further elucidate the mechanism of activation of EGFR by GRP in HNSCC, we investigated the role of Src family kinases. Blockade of Src family kinases using an Src-specific tyrosine kinase inhibitor A-419259 decreased GRP-induced EGFR phosphorylation and MAPK activation. GRP also failed to induce MAPK activation in dominant-negative c-Src–transfected HNSCC cells. Invasion and growth assays showed that c-Src was required for GRP-induced proliferation or invasion of HNSCC cells. In addition to TGF-α release, GRP induced amphiregulin, but not EGF, secretion into HNSCC cell culture medium, an effect that was blocked by the MMP inhibitor marimastat. TGF-α and amphiregulin secretion by GRP stimulation also was inhibited by blockade of Src family kinases. These results suggest that Src family kinases contribute to GRP-mediated EGFR growth and invasion pathways by facilitating cleavage and release of TGF-α and amphiregulin in HNSCC.
Autocrine Secretion of Fas Ligand Shields Tumor Cells from Fas-Mediated Killing by Cytotoxic Lymphocytes
Authors: Hallermalm Kristian , De Geer Anna , Kiessling Rolf , Levitsky Victor , Levitskaya Jelena 
Published: September 2005

Abstract
Mechanisms responsible for resistance of tumors to death receptor-mediated damage by cytotoxic lymphocytes are not well understood. Uveal melanoma cells expressed Fas but were insensitive to Fas triggering induced by bystander cytotoxic T lymphocytes or a Fas-specific agonistic antibody; this could not be ascribed to tumor counterattack against T cells or general resistance of the tumors to apoptosis. Treatment with inhibitors of metalloproteases rendered uveal melanomas sensitive to Fas-mediated cytotoxicity. Metalloprotease inhibitors did not affect the expression of Fas but increased the surface expression of Fas ligand (FasL), which correlated with the disappearance of soluble FasL from culture supernatants of tumor cells. FasL eluted from the surface of uveal melanomas specifically inhibited cytotoxic T lymphocyte lysis of tumor cells pretreated with an inhibitor of metalloproteases. In addition to uveal melanomas, a number of other tumor cell lines of various cellular origins were sensitized to Fas-mediated cytotoxicity by metalloprotease inhibitors. Our results show that autocrine secretion of FasL shields tumor cells from Fas-mediated killing by cytotoxic lymphocytes. This defines a novel mechanism of tumor escape from immune surveillance.
Dependence of the Cytotoxicity of DNA-Damaging Agents on the Mismatch Repair Status of Human Cells
Authors: Papouli Efterpi , Cejka Petr , Jiricny Josef 
Published: September 2005

Abstract
Mismatch repair (MMR) deficiency was reported to increase resistance of mammalian cells to killing by several genotoxic substances. However, although MMR-deficient cells are ∼100-fold more resistant to killing by SN1 type methylating agents than MMR-proficient controls, the sensitivity differences reported for the other agents were typically &lt;2-fold. To test whether these differences were linked to factors other than MMR status, we studied the cytotoxicities of mitomycin C, chloroethylcyclohexyl nitrosourea, melphalan, psoralen-UVA, etoposide, camptothecin, ionizing radiation, and cis-dichlorodiaminoplatinum (cisplatin) in a strictly isogenic system. We now report that MMR deficiency reproducibly desensitized cells solely to cisplatin.
Identification of Human Autologous Cytotoxic T-Lymphocyte-Defined Osteosarcoma Gene That Encodes a Transcriptional Regulator, Papillomavirus Binding Factor
Authors: Tsukahara Tomohide , Nabeta Yuki , Kawaguchi Satoshi , Ikeda Hideyuki , Sato Yuriko , Shimozawa Kumiko , Ida Kazunori , Asanuma Hiroko , Hirohashi Yoshihiko , Torigoe Toshihiko , Hiraga Hiroaki , Nagoya Satoshi , Wada Takuro , Yamashita Toshihiko , Sato Noriyuki 
Published: September 2005

Abstract
The prognosis for patients with osteosarcoma who do not respond to current chemotherapy protocols still remains poor. Toward the goal of establishing efficacious peptide-based immunotherapy for those patients, we previously developed an autologous pair of CTLs and an osteosarcoma cell line. In the current study, we screened the cDNA library of this osteosarcoma cell line using an autologous CTL clone and identified cDNA encoding an antigen. The isolated cDNA was identical to papillomavirus binding factor (PBF), which was recently reported as a DNA binding transcription factor cooperating with RUNX1. Reverse transcription-PCR analysis revealed that PBF was expressed in 16 of 19 cases of bone and soft-tissue sarcoma cell lines (5 of 6 of osteosarcoma lines) and 57 of 76 sarcoma tissue samples (11 of 14 of osteosarcoma tissues). Also, PBF was expressed in 10 of 13 epithelial cancer cell lines and 20 of 34 of cancer tissues. In contrast, PBF was detected in some normal organs including ovary, pancreas, spleen, and liver by reverse transcription-PCR but was restricted in the cytoplasm by immunostaining and undetectable by Western blotting. Furthermore, a 12-mer peptide, CTACRWKKACQR, located at the COOH terminus of PBF, was found to be a minimum requirement for recognition by the CTL clone in the context of the HLA-B*5502 molecule. These findings suggest that PBF is a shared tumor-associated antigen, which may serve as a source of peptides applicable to peptide-based immunotherapy for osteosarcoma and other malignant tumors.
Dual-Agent Molecular Targeting of the Epidermal Growth Factor Receptor (EGFR)
Authors: Huang Shyhmin , Armstrong Eric A. , Benavente Sergio , Chinnaiyan Prakash , Harari Paul M. 
Published: September 2005

Abstract
Molecular inhibition of epidermal growth factor receptor (EGFR/HER1) signaling is under active investigation as a promising cancer treatment strategy. We examined the potency of EGFR inhibition achieved by combining anti-EGFR monoclonal antibody and tyrosine kinase inhibitor, which target extracellular and intracellular domains of the receptor, respectively. We specifically studied the combination of cetuximab (Erbitux, C225; ImClone Systems, New York, NY) with either gefitinib (Iressa, ZD1839; AstraZeneca, Macclesfield, UK) or erlotinib (Tarceva, OSI-774; Genentech, South San Francisco, CA) across a variety of human cancer cells. The combination of cetuximab plus gefitinib or erlotinib enhanced growth inhibition over that observed with either agent alone. As measured by immunostaining, inhibition of EGFR phosphorylation with the combination of cetuximab plus gefitinib or erlotinib was augmented over that obtained with single-agent therapy in head and neck (H&N) cancer cell lines. Phosphorylation inhibition of downstream effector molecules [mitogen-activated protein kinase (MAPK) and AKT] also was enhanced in tumor cells treated with the combination of cetuximab plus gefitinib or erlotinib. Flow cytometry and immunoblot analysis demonstrated that treatment of H&N tumor cells with cetuximab in combination with either gefitinib or erlotinib amplified the induction of apoptosis. Following establishment of cetuximab-resistant cell lines, we observed that gefitinib or erlotinib retained the capacity to inhibit growth of lung and H&N tumor cells that were highly resistant to cetuximab. Treatment with gefitinib or erlotinib, but not cetuximab, also could further inhibit the activation of downstream effectors of EGFR signaling in cetuximab-resistant cells, including MAPK and AKT. These data suggest that tyrosine kinase inhibitors may further modulate intracellular signaling that is not fully blocked by extracellular anti-EGFR antibody treatment. Finally, animal studies confirmed that single EGFR inhibitor treatment resulted in partial and transient tumor regression in human lung cancer xenografts. In contrast, more profound tumor regression and regrowth delay were observed in mice treated with the combination of cetuximab and gefitinib or erlotinib. Immunohistochemical staining, which demonstrated significant reduction of the proliferative marker proliferating cell nuclear antigen in mice treated with dual EGFR inhibitors, further supported this in vivo observation. Together, these data suggest that combined treatment with distinct EGFR inhibitory agents can augment the potency of EGFR signaling inhibition. This approach suggests potential new strategies to maximize effective target inhibition, which may improve the therapeutic ratio for anti-EGFR-targeted therapies in developing clinical trials.
A Comparative Analysis of Low-Dose Metronomic Cyclophosphamide Reveals Absent or Low-Grade Toxicity on Tissues Highly Sensitive to the Toxic Effects of Maximum Tolerated Dose Regimens
Authors: Emmenegger Urban , Man Shan , Shaked Yuval , Francia Giulio , Wong John W. , Hicklin Daniel J. , Kerbel Robert S. 
Published: September 2005

Abstract
The survival benefits of traditional maximum tolerated dose (MTD) cytotoxic therapy have been modest for the treatment of most types of metastatic malignancy and, moreover, often come with increased acute and chronic toxicity. Recent studies have demonstrated that the frequent administration of comparatively low doses of cytotoxic agents, with no extended breaks [low-dose metronomic (LDM) chemotherapy], may not only be at least as efficient as MTD therapy but also less toxic. This coincides with an apparent selectivity for “activated” endothelial cells of the tumor vasculature. However, the impact of LDM chemotherapy on the most sensitive target cell populations normally affected by MTD therapy (i.e., bone marrow progenitors, gut mucosa, and hair follicle cells) has not been analyzed in experimental detail. Therefore, we compared effects of LDM and MTD cyclophosphamide (CTX) on bone marrow and gut mucosa. Furthermore, we studied the potential impact of LDM CTX on angiogenesis in the context of wound healing and evidence of organ toxicity. We show absent or moderate hematologic and intestinal toxicity of LDM as opposed to MTD CTX. Of note was the finding of sustained lymphopenia, which is not unexpected given the use of CTX as immunosuppressive drug. There was no negative impact on wound healing or evidence of organ toxicity. LDM offers clear safety advantages over conventional MTD chemotherapy and therefore would appear to be ideal for long-term combination therapy with targeted antiangiogenic drugs.