bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of Tumorigenicity and Metastasis of Human Melanoma Cells by Anti-Cathepsin L Single Chain Variable Fragment
Authors: Rousselet Nathalie , Mills Lisa , Jean Didier , Tellez Carmen , Bar-Eli Menashe , Frade Raymond 
Published: September 2005

Abstract
We demonstrated previously that the switch from nonmetastatic to highly metastatic phenotype of human melanoma cells is directly related to secretion of procathepsin L form. This cysteine proteinase was identified on the basis of its property to cleave human C3, the third component of complement. In an attempt to control procathepsin L secretion, we have recently generated an anti-cathepsin L single chain variable fragment (ScFv) from an anti-cathepsin L monoclonal antibody generated against recombinant cathepsin L. We herein selected clones stably transfected with this anti-cathepsin L ScFv and analyzed them for changes in tumor growth and metastasis. We show that in stably transfected clones, anti-cathepsin L ScFv strongly inhibited the secretion of procathepsin L without modifying the intracellular amount or processing pattern of cathepsin L forms. Confocal analysis demonstrated colocalization of endogenous cathepsin L and anti-cathepsin L ScFv. In addition, expression of this ScFv strongly inhibited generation of tumor and metastasis by these human melanoma clones in nude mice. In vivo, the anti-cathepsin L ScFv-transfected cells produced tumors with decreased vascularization (angiogenesis) concomitant with increased apoptosis of tumor cells. Matrigel assay also demonstrated that melanoma invasiveness was completely abolished. Thus, this is the first demonstration that anti-cathepsin L ScFv could be used to inhibit the tumorigenic and metastatic phenotype of human melanoma, depending on procathepsin L secretion, and could therefore be used as a molecular tool in a therapeutic cellular approach.
Coupling Tumor Necrosis Factor-α with αV Integrin Ligands Improves Its Antineoplastic Activity
Authors: Curnis Flavio , Gasparri Anna , Sacchi Angelina , Longhi Renato , Corti Angelo 
Published: September 2005

Abstract
Despite the impressive results obtained in animal models, the clinical use of tumor necrosis factor-α (TNF) as an anticancer drug is limited by severe toxicity. We have shown previously that targeted delivery of TNF to aminopeptidase N (CD13), a marker of angiogenic vessels, improved the therapeutic index of this cytokine in tumor-bearing mice. To assess whether the vascular-targeting approach could be extended to other markers of tumor blood vessels, in this work, we have fused TNF with the ACDCRGDCFCG peptide, a ligand of αV integrins by recombinant DNA technology. We have found that subnanogram doses of this conjugate are sufficient to induce antitumor effects in tumor-bearing mice when combined with melphalan, a chemotherapeutic drug. Cell adhesion assays and competitive binding experiments with anti-integrin antibodies showed that the Arg-Gly-Asp moiety interacts with cell adhesion receptors, including αVβ3 integrin, as originally postulated. In addition, ACGDRGDCFCG-mouse TNF conjugate induced cytotoxic effects in standard cytolytic assays, implying that ACGDRGDCFCG-mouse TNF conjugate can also bind TNF receptors and trigger death signals. These results indicate that coupling TNF with αV integrin ligands improves its antineoplastic activity and supports the concept that vascular targeting is a strategy potentially applicable to different endothelial markers, not limited to CD13.
Interaction of the Aryl Hydrocarbon Receptor Ligand 6-Methyl-1,3,8-trichlorodibenzofuran with Estrogen Receptor α
Authors: Pearce Sandra Timm , Liu Hong , Radhakrishnan Ishwar , Abdelrahim Maen , Safe Stephen , Jordan V. Craig 
Published: September 2005

Abstract
The polycyclic aromatic hydrocarbon 6-methyl-1,3,8-trichlorodibenzofuran (MCDF) is related to the industrial byproduct dioxin and is a weak agonist and partial antagonist at the aryl hydrocarbon receptor (AhR). Tamoxifen is used for the treatment and prevention of breast cancer and interferes with the interaction of estrogen with estrogen receptor α (ER). The combination of MCDF and tamoxifen lowered the effective dose of both drugs required to inhibit 7,12-dimethylbenz(a)anthracene-induced mammary tumor growth in rats and protected against the estrogenic effects of tamoxifen on the uterus in rats (A. McDougal et al., Cancer Res 2001;61:3902–7), pointing to the potential use of MCDF in breast cancer treatment. Potential AhR-ER cross-talk is evidenced by the antiestrogenic activity of MCDF and the degradative effect of MCDF on ER protein levels. Our studies confirmed that MCDF degraded the ER. MCDF displayed antiestrogenic activity at higher concentrations in MCF-7 human breast cancer cells, but MCDF alone (10−6 m) stimulated the growth of MCF-7 cells. MCDF also activated an estrogen response element (ERE)-luciferase reporter and increased mRNA levels of the estrogen-responsive gene transforming growth factor (TGF)-α. The estrogenic effects of MCDF are ER dependent because they were blocked by the pure antiestrogen ICI 182,780. MCDF induced ER-coactivator interaction in glutathione S-transferase pull-down assays and the formation of an ER·ERE complex in gel mobility shift assays, further indicating that the estrogenic actions of MCDF are mediated by the ER. In addition, knockdown of the AhR with small interfering RNA did not affect MCDF-induced ERE-luciferase activity. Overall, these data support the conclusion that MCDF is a partial agonist at the ER. This study provides the first evidence for the direct interaction of the ER with MCDF and challenges the view that MCDF is simply an AhR-specific ligand.
Adeno-Associated Virus 2-Mediated Antiangiogenic Cancer Gene Therapy
Authors: Ponnazhagan Selvarangan , Mahendra Gandham , Kumar Sanjay , Shaw Denise R. , Stockard Cecil R. , Grizzle William E. , Meleth Sreelatha 
Published: September 2005

Abstract
Angiogenesis is characteristic of solid tumor growth and a surrogate marker for metastasis in many human cancers. Inhibition of tumor angiogenesis using antiangiogenic drugs and gene transfer approaches has suggested the potential of this form of therapy in controlling tumor growth. However, for long-term tumor-free survival by antiangiogenic therapy, the factors controlling tumor neovasculature need to be systemically maintained at stable therapeutic levels. Here we show sustained expression of the antiangiogenic factors angiostatin and endostatin as secretory proteins by recombinant adeno-associated virus 2 (rAAV)-mediated gene transfer. Both vectors provided significant protective efficacy in a mouse tumor xenograft model. Stable transgene persistence and systemic levels of both angiostatin and endostatin were confirmed by in situ hybridization of the vector-injected tissues and by serum ELISA measurements, respectively. Whereas treatment with rAAV containing either endostatin or angiostatin alone resulted in moderate to significant protection, the combination of endostatin and angiostatin gene transfer from a single vector resulted in a complete protection. These data suggest that AAV-mediated long-term expression of both endostatin and angiostatin may have clinical utility against recurrence of cancers after primary therapies and may represent rational adjuvant therapies in combination with radiation or chemotherapy.
Tumor Cell-Derived Nitric Oxide Is Involved in the Immune-Rejection of an Immunogenic Murine Lymphoma
Authors: Hu De-En , Dyke Stephanie O. M. , Moore Alistair M. , Thomsen Lindy L. , Brindle Kevin M. 
Published: September 2005

AbstractThe roles played by host-derived nitric oxide (NO) in the growth and subsequent immune rejection of a immunogenic murine lymphoma were investigated by growing the tumor in mice in which the gene for either inducible NO synthase (iNOS) or endothelial NOS (eNOS) had been ablated. This showed that NO from tumor-infiltrating host cells had no significant effect on either tumor growth or immune rejection, although measurements of tumor nitrite levels and protein nitration showed that there had been significant NO production in the rejected tumors, in both the eNOS and iNOS knockout mice. Inhibition of both tumor and host NOS activities, with an iNOS-selective inhibitor (1400W), a nonselective NOS inhibitor [Nω-nitro-l-arginine methyl ester (L-NAME)], or scavenging NO with a ruthenium-based scavenger, significantly delayed tumor rejection, while having no appreciable effect on tumor growth. Incubation of tumor cells with medium taken from cultured splenocytes, that had been isolated from immunized animals and activated by incubating them with irradiated tumor cells, resulted in an increase in tumor cell NOS activity and an increase in tumor cell apoptosis, which could be inhibited using L-NAME. We propose that, during the immune rejection of this tumor model, there is induction of tumor NOS activity by cytokines secreted by activated lymphocytes within the tumor and that this results in increased levels of tumor NO that induce tumor cell apoptosis and facilitate immune rejection of the tumor.
Membrane Type 1 Matrix Metalloproteinase Regulates Collagen-Dependent Mitogen-Activated Protein/Extracellular Signal-Related Kinase Activation and Cell Migration
Authors: Takino Takahisa , Miyamori Hisashi , Watanabe Yumi , Yoshioka Katsuji , Seiki Motoharu , Sato Hiroshi 
Published: September 2005

Abstract
Mitogen-activated protein kinase-extracellular signal-related kinase (ERK) kinase 1 (MEK1)/ERK signaling has been implicated in the regulation of tumor cell invasion and metastasis. Migration of HT1080 cells on type I collagen was suppressed by the matrix metalloproteinase (MMP) inhibitors BB94 and tissue inhibitor of metalloproteinase (TIMP)-2 but not by TIMP-1. TIMP-2-specific inhibition suggests that membrane type 1 MMP (MT1-MMP) is likely involved in this process. Activation of ERK was induced in HT1080 cells adhered on dishes coated with type I collagen, and this was inhibited by BB94. MMP-2 processing in HT1080 cells, which also was stimulated by cultivation on type I collagen, was inhibited by MEK inhibitor PD98059. Expression of a constitutively active form of MEK1 promoted MMP-2 processing concomitant with the increase of MT1-MMP levels, suggesting that MT1-MMP is regulated by MEK/ERK signaling. In addition, expression of the hemopexin-like domain of MT1-MMP in HT1080 cells interfered with MMP-2 processing, ERK activation, and cell migration, implying that the enzymatic activity of MT1-MMP is involved in collagen-induced ERK activation, which results in enhanced cell migration. Thus, adhesion of HT1080 cells to type I collagen induces MT1-MMP-dependent ERK activation, which in turn causes an increase in MT1-MMP levels and subsequent cell migration.
Roles of Phosphatidylinositol 3′-Kinase and Mammalian Target of Rapamycin/p70 Ribosomal Protein S6 Kinase in K-Ras-Mediated Transformation of Intestinal Epithelial Cells
Authors: Shao Jinyi , Evers B. Mark , Sheng Hongmiao 
Published: September 2005

Abstract
Phosphatidylinositol 3′-kinase (PI3K) activity is required for Ras- mediated transformation of intestinal epithelial cells (IECs). The mammalian target of rapamycin (mTOR) and its downstream pathways control the translation of specific mRNAs that are required for cell proliferation and transformation. Here, we elucidated the roles of PI3K and mTOR in K-Ras-mediated transformation of IECs (IEC-6). Induction of K-Ras activated PI3K and mTOR in IECs. p70 ribosomal protein S6 kinase activity was induced by K-Ras in a PI3K- and mTOR-dependent manner. K-Ras did not significantly alter the phosphorylation of eukaryotic initiation factor 4E-binding protein 1. Treatment with either LY-294002 or rapamycin inhibited IEC proliferation and resulted in G1 growth arrest. However, it was noted that inhibition of mTOR enhanced K-Ras-mediated morphological transformation and increased invasiveness of IECs in a mitogen-activated protein/extracellular signal-regulated kinase-dependent manner. Furthermore, inhibition of PI3K or mTOR impaired the growth of an array of colon cancer cells. Spindle transformation, reduced E-cadherin, and increased invasiveness were observed in LY-294002-treated Moser cells. Thus, our results suggest that K-Ras-mediated transformation of IECs involves activation of the PI3K/mTOR pathway. Inhibition of PI3K/mTOR activity leads to G1 growth arrest of transformed IECs. On the other hand, inhibition of PI3K or mTOR may induce the epithelial to mesenchymal transdifferentiation of IECs under certain circumstances.
Apoptotic Signaling Pathways Induced by Nitric Oxide in Human Lymphoblastoid Cells Expressing Wild-Type or Mutant p53
Authors: Li Chun-Qi , Robles Ana I. , Hanigan Christin L. , Hofseth Lorne J. , Trudel Laura J. , Harris Curtis C. , Wogan Gerald N. 
Published: September 2005

Abstract
Loss of p53 function by inactivating mutations results in abrogation of NO·-induced apoptosis in human lymphoblastoid cells. Here we report characterization of apoptotic signaling pathways activated by NO· in these cells by cDNA microarray expression and immunoblotting. A p53-mediated transcriptional response to NO· was observed in p53-wild-type TK6, but not in closely related p53-mutant WTK1, cells. Several previously characterized p53 target genes were up-regulated transcriptionally in TK6 cells, including phosphatase PPM1D (WIP1), oxidoreductase homolog PIG3, death receptor TNFRSF6 (Fas/CD95), and BH3-only proteins BBC3 (PUMA) and PMAIP1 (NOXA). NO· also modulated levels of several gene products in the mitochondria-dependent and death-receptor-mediated apoptotic pathways. Inhibitors of apoptosis proteins X-chromosome-linked inhibitor of apoptosis, cellular inhibitor of apoptosis protein-1, and survivin were significantly down-regulated in TK6 cells, but not in WTK1 cells. Smac release from mitochondria was induced in both cell types, but release of apoptosis-inducing factor and endonuclease G was detected only in TK6 cells. Fas/CD95 was increased, and levels of the antiapoptotic proteins Bcl-2 and Bcl-x/L were reduced in TK6 cells. Activation of procaspases 3, 8, 9, and 10, as well as Bid and poly(ADP-ribose) polymerase cleavage, were observed only in TK6 cells. NO· treatment did not alter levels of death receptors 4 and 5, Fas-associated death domain or proapoptotic Bax and Bak proteins in either cell line. Collectively, these data show that NO· exposure activated a complex network of responses leading to p53-dependent apoptosis via both mitochondrial and Fas receptor pathways, which were abrogated in the presence of mutant p53.
Matrix Metalloproteinase-7 Facilitates Insulin-Like Growth Factor Bioavailability through Its Proteinase Activity on Insulin-Like Growth Factor Binding Protein 3
Authors: Miyamoto Shin’ichi , Yano Keiichi , Sugimoto Seiji , Ishii Genichiro , Hasebe Takahiro , Endoh Yasushi , Kodama Keiji , Goya Masato , Chiba Tsutomu , Ochiai Atsushi 
Published: September 2005

Abstract
Matrix metalloproteinase-7 (MMP-7) secreted by cancer cells has been implicated classically in the basement membrane destruction associated with tumor cell invasion and metastasis. Recent epidemiologic studies have established a correlation between high levels of circulating insulin-like growth factor (IGF) and low levels of IGF binding protein 3 (IGFBP-3), and relative risk of developing colon, breast, prostate, and lung cancer, which are known to produce MMP-7. In this study, IGFBP-3 was assessed as a candidate for the physiologic substrate of MMP-7. MMP-7 proteolysis generated four major fragments (26 kDa, 17 kDa, 15.5 kDa, and 15.5 kDa), and two cleavage sites were identified: one at the site of hydrolysis of the K144-I145 peptide bond and one at the R95-L96 peptide bond. The former site is different from the previously reported site of cleavage of IGFBP-3 by other proteases. Addition of IGFBP-3 inhibited IGF-I-mediated IGF type 1 receptor (IGF-IR) phosphorylation and activation of the downstream molecule Akt in BALB/c 3T3 fibroblasts overexpressing human IGF-IR (3T3-IGF-IR) and in two human colon cancer cell lines (COLO201 and HT29). Coincubation of the IGF-I/IGFBP-3 complex with MMP-7 restored IGF-I-mediated IGF-IR phosphorylation and activation of Akt in these cell lines. The IGF-I signal recovered by MMP-7 protected against apoptosis induced by anoikis in 3T3-IGF-IR cells. These results indicate that MMP-7 proteolysis of IGFBP-3 plays a crucial role in regulating IGF-I bioavailability, thereby promoting cell survival. This mechanism may contribute to the tumorigenesis of MMP-7-producing IGF-IR-expressing tumors in the primary site and to organ-specific metastasis in a paracrine manner.
Endometase/Matrilysin-2 in Human Breast Ductal Carcinoma
in Situ
and Its Inhibition by Tissue Inhibitors of Metalloproteinases-2 and -4
Authors: Zhao Yun-Ge , Xiao Ai-Zhen , Park Hyun I. , Newcomer Robert G. , Yan Mei , Man Yan-Gao , Heffelfinger Sue C. , Sang Qing-Xiang Amy 
Published: September 2005

Abstract
Local disruption of the integrity of both the myoepithelial cell layer and the basement membrane is an indispensable prerequisite for the initiation of invasion and the conversion of human breast ductal carcinoma in situ (DCIS) to infiltrating ductal carcinoma (IDC). We previously reported that human endometase/matrilysin-2/matrix metalloproteinase (MMP) 26-mediated pro-gelatinase B (MMP-9) activation promoted invasion of human prostate carcinoma cells by dissolving basement membrane proteins (Y. G. Zhao et al., J. Biol. Chem., 278: 15056–15064, 2003). Here we report that tissue inhibitor of metalloproteinases (TIMP)-2 and TIMP-4 are potent inhibitors of MMP-26, with apparent Ki values of 1.6 and 0.62 nm, respectively. TIMP-2 and TIMP-4 also inhibited the activation of pro-MMP-9 by MMP-26 in vitro. The expression levels of MMP-26, MMP-9, TIMP-2, and TIMP-4 proteins in DCIS were significantly higher than those in IDC, atypical intraductal hyperplasia, and normal breast epithelia adjacent to DCIS and IDC by immunohistochemistry and integrated morphometry analysis. Double immunofluorescence labeling and confocal laser scanning microscopy revealed that MMP-26 was colocalized with MMP-9, TIMP-2, and TIMP-4 in DCIS cells. Higher levels of MMP-26 mRNA were also detected in DCIS cells by in situ hybridization.
Dickkopf 3 Inhibits Invasion and Motility of Saos-2 Osteosarcoma Cells by Modulating the Wnt-β-Catenin Pathway
Authors: Hoang Bang H. , Kubo Tadahiko , Healey John H. , Yang Rui , Nathan Saminathan S. , Kolb E. Anders , Mazza BethAnne , Meyers Paul A. , Gorlick Richard 
Published: September 2005

Abstract
Osteosarcoma (OS) is a primary malignancy of bone with a tendency to metastasize early. Despite intensive chemotherapy and surgical resection, ∼30% of patients still develop distant metastasis. Our previous work using clinical OS samples suggested that expression of the Wnt receptor LRP5 might be associated with tumor metastasis. In the present study, we used a Dickkopf (Dkk) family member and a dominant-negative LRP5 receptor construct to modulate Wnt signaling in OS cells. Saos-2 cells, which ectopically express Dkk-3, do not undergo apoptosis and exhibit enhanced resistance to serum starvation and chemotherapy-induced cytotoxicity. Transfection of Dkk-3 and dominant-negative LRP5 into Saos-2 cells significantly reduces invasion capacity and cell motility. This blockade is associated with changes in cell morphology consistent with a less invasive phenotype. In addition, Dkk-3 and dominant-negative LRP5 also induce changes in β-catenin localization consistent with an increase in cell-cell adhesion. Taken together, these results support a possible role for Wnt signaling in the pathobiology and progression of human OS.
Myc-Transformed Epithelial Cells Down-Regulate Clusterin, Which Inhibits Their Growth
in Vitro
and Carcinogenesis
in Vivo
Authors: Thomas-Tikhonenko Andrei , Viard-Leveugle Isabelle , Dews Michael , Wehrli Philippe , Sevignani Cinzia , Yu Duonan , Ricci Stacey , el-Deiry Wafik , Aronow Bruce , Kaya Gürkan , Saurat Jean-Hilaire , French Lars E. 
Published: September 2005

Abstract
Effective treatment of malignant carcinomas requires identification of proteins regulating epithelial cell proliferation. To this end, we compared gene expression profiles in murine colonocytes and their c-Myc-transformed counterparts, which possess enhanced proliferative potential. A surprisingly short list of deregulated genes included the cDNA for clusterin, an extracellular glycoprotein without a firmly established function. We had previously demonstrated that in organs such as skin, clusterin expression is restricted to differentiating but not proliferating cell layers, suggesting a possible negative role in cell division. Indeed, its transient overexpression in Myc-transduced colonocytes decreased cell accumulation. Furthermore, clusterin was down-regulated in rapidly dividing human keratinocytes infected with a Myc-encoding adenovirus. Its knockdown via antisense RNA in neoplastic epidermoid cells enhanced proliferation. Finally, recombinant human clusterin suppressed, in a dose-dependent manner, DNA replication in keratinocytes and other cells of epithelial origin. Thus, clusterin appears to be an inhibitor of epithelial cell proliferation in vitro. To determine whether it also affects neoplastic growth in vivo, we compared wild-type and clusterin-null mice with respect to their sensitivity to 7, 12-dimethylbenz(a)anthracene /12-Otetradecanoylphorbol-13-acetate (DMBA/TPA)-induced skin carcinogenesis. We observed that the mean number of papillomas/mouse was higher in clusterin-null animals. Moreover, these papillomas did not regress as readily as in wild-type mice and persisted beyond week 35. The rate of progression toward squamous cell carcinoma was not altered, although those developing in clusterin-null mice were on average better differentiated. These data suggest that clusterin not only suppresses epithelial cell proliferation in vitro but also interferes with the promotion stage of skin carcinogenesis.