bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of elevated serum uric acid on cisplatin-induced acute renal failure
Authors: Roncal Carlos A. , Mu Wei , Croker Byron , Reungjui Sirirat , Ouyang Xiaosen , Tabah-Fisch Isabelle , Johnson Richard J. , Ahsan Ejaz A.
Published: January 2007

Marked hyperuricemia is known to cause acute renal failure via intrarenal crystal deposition. However, recent studies suggest mild hyperuricemia may have vasoactive and proinflammatory effects independent of crystal formation. We therefore tested the hypothesis that mild hyperuricemia might exacerbate renal injury and dysfunction in a model of cisplatin-induced acute renal failure in the rat. Cisplatin was administered to normouricemic and hyperuricemic rats (the latter generated by administering the urate oxidase inhibitor, oxonic acid). Recombinant urate oxidase (rasburicase) was administered in a third group to assess the effect of lowering uric acid on outcomes. Other control groups include normal rats and hyperuricemic rats without cisplatin-induced injury. Cisplatin induced injury of the pars recta (S3) segment of the proximal tubule in association with a mild monocyte infiltration. Hyperuricemic rats showed significantly greater tubular injury and proliferation with significantly greater macrophage infiltration and increased expression of monocyte chemoattractant protein-1. However, renal function was not different between normouricemic and hyperuricemic rats with cisplatin injury. Treatment with rasburicase reversed the inflammatory changes and lessened tubular injury with an improvement in renal function (relative to the hyperuricemic group). No intrarenal crystals were observed in any groups. These data provide the first experimental evidence that uric acid, at concentrations that do not cause intrarenal crystal formation, may exacerbate renal injury in a model of acute renal failure. The mechanism may relate to a proinflammatory pathway involving chemokine expression with leukocyte infiltration.
Evidence for HSP-mediated cytoskeletal stabilization in mesothelial cells during acute experimental peritoneal dialysis
Authors: Endemann Michaela , Bergmeister Helga , Bidmon Bettina , Boehm Michael , Csaicsich Dagmar , Malaga-Dieguez Laura , Arbeiter Klaus , Regele Heinz , Herkner Kurt , Aufricht Christoph
Published: January 2007

Low biocompatibility of peritoneal dialysis fluid (PDF) injures mesothelial cells and activates their stress response. In this study, we investigated the role of heat shock proteins (HSP), the main cytoprotective effectors of the stress response, in cytoskeletal stabilization of mesothelial cells in experimental peritoneal dialysis. In cultured human mesothelial cells, cytoskeletal integrity was assessed by detergent extractability of marker proteins following in vitro PDF exposure. Effects of HSP on stabilization of ezrin were evaluated by a conditioning protocol (PDF pretreatment) and repair assay, based on coincubation of cytoskeletal protein fractions with recombinant HSP-72 or HSP-72 antibodies. In the rat model, detachment of mesothelial cells from their peritoneal monolayer during in vivo PDF exposure was assessed with and without overexpression of HSP-72 (by heat conditioning). In vitro, cytoskeletal disruption on sublethal PDF exposure was demonstrated by significantly altered detergent extractability of ezrin and ZO-1. Restoration was associated with significant induction and cytoskeletal redistribution of HSP during recovery. Both the conditioning protocol and in vitro repair assay provided evidence for HSP-72-mediated cytoskeletal stabilization. In the rat model, overexpression of HSP-72 following heat conditioning resulted in significantly reduced detachment of mesothelial cells on in vivo exposure to PDF. Our results establish an essential role of HSP in repair and cytoprotection of cytoskeletal integrity in mesothelial cells following acute in vitro and in vivo exposure to PDF. Repeated exposure to PDF, as is the rule in the clinical setting, may not only cause repeat injury to mesothelial cells but rather represents a kind of inadvertent conditioning treatment.
Effects of μ-Opioid Receptor Modulation on GABABReceptor Synaptic Function in Hippocampal CA1
Authors: McQuiston A. Rory
Published: January 2007

Activation of μ-opioid receptors (MORs) alters information coding, synaptic plasticity, and spatial memory in hippocampal CA1. In CA1, MORs act by inhibiting GABA release onto both GABAAand GABABreceptors exclusively. MOR activation can facilitate excitatory inputs in CA1 dendritic layers by inhibiting synaptic activation of GABAAreceptors. In this study, we use voltage-sensitive dye imaging to show that MOR activation by the MOR agonist DAMGO suppressed GABABinhibitory postsynaptic potentials in all layers of CA1. When stimulating excitatory input in stratum oriens (SO), stratum radiatum (SR), or stratum lacunosum-moleculare (SLM) with five pulses at 20 Hz in the presence of bicuculline (50 μM), DAMGO (1 μM) was most effective at increasing the amplitude of the last excitatory event. This effect was reversed by the MOR antagonist CTOP (1 μM) and occluded by the GABABreceptor agonist CGP 55845 (10 μM). DAMGO was less effective at increasing the amplitude of later excitatory events compared with the effect of CGP 55845. DAMGO was relatively ineffective at increasing the amplitude of excitatory inputs in SLM but had significantly greater effects on excitatory events as they propagated to stratum pyramidale (SP). When stimulating in SR, DAMGO was least effective at increasing excitatory amplitudes in SLM and most effective in SP and SO. Finally, DAMGO was equally effective at increasing excitatory activity amplitudes in all layers of CA1 after stimulating in SO. Therefore MOR suppresses GABABsynaptic hyperpolarizations in all layers of CA1 and most effectively facilitates excitatory activity in CA1 output layers.
Establishment of Human Colon Cancer Cell Lines from Fresh Tumors versus Xenografts: Comparison of Success Rate and Cell Line Features
Authors: Dangles-Marie Virginie , Pocard Marc , Richon Sophie , Weiswald Louis-Bastien , Assayag Franck , Saulnier Patrick , Judde Jean-Gabriel , Janneau Jean-Louis , Auger Nathalie , Validire Pierre , Dutrillaux Bernard , Praz Françoise , Bellet Dominique , Poupon Marie-France
Published: January 2007

Obtaining representative human colon cancer cell lines from fresh tumors is technically difficult. Using 32 tumor fragments from patients with colon cancer, the present study shows that prior xenograft leads to more efficient cell line establishment compared with direct establishment from fresh tumors (P < 0.05). From 26 tumor specimens, we successfully established 20 tumor xenografts in nude mice (77%); among 19 of these xenografts, 9 (47%) led to cell lines, including four from liver metastases. Only 3 of 31 tumor specimens (9.7%) grew immediately in vitro, and all were derived from primary tumors. To compare major phenotypic and genotypic characteristics of human colon cancer cell lines derived from the same tumor fragment using two protocols, the two pairs of cell lines obtained from 2 of 32 tumor fragments were extensively studied. They displayed similar morphology and were able to form compact spheroids. Chemosensitivity to 5-fluorouracil, CPT11, and L-OHP differed between cell lines obtained from patient tumors and those derived from xenografts. Matched cell lines shared a common core of karyotype alterations and distinctive additional chromosomal aberrations. Expression levels of genes selected for their role in oncogenesis evaluated by real-time quantitative PCR were found to be statistically correlated whatever the in vitro culture model used. In conclusion, xenotransplantation in mice of tumor fragments before establishment of cell lines enables generation of more novel human cancer cell lines for investigation of colon cancer cell biology, opening up the opportunity of reproducing the diversity of this disease. [Cancer Res 2007;67(1):398–407]
Credentialing Preclinical Pediatric Xenograft Models Using Gene Expression and Tissue Microarray Analysis
Authors: Whiteford Craig C. , Bilke Sven , Greer Braden T. , Chen Qingrong , Braunschweig Till A. , Cenacchi Nicola , Wei Jun S. , Smith Malcolm A. , Houghton Peter , Morton Christopher , Reynolds C. Patrick , Lock Richard , Gorlick Richard , Khanna Chand , Thiele Carol J. , Takikita Mikiko , Catchpoole Daniel , Hewitt Stephen M. , Khan Javed
Published: January 2007

Human tumor xenografts have been used extensively for rapid screening of the efficacy of anticancer drugs for the past 35 years. The selection of appropriate xenograft models for drug testing has been largely empirical and has not incorporated a similarity to the tumor type of origin at the molecular level. This study is the first comprehensive analysis of the transcriptome of a large set of pediatric xenografts, which are currently used for preclinical drug testing. Suitable models representing the tumor type of origin were identified. It was found that the characteristic expression patterns of the primary tumors were maintained in the corresponding xenografts for the majority of samples. Because a prerequisite for developing rationally designed drugs is that the target is expressed at the protein level, we developed tissue arrays from these xenografts and corroborated that high mRNA levels yielded high protein levels for two tested genes. The web database and availability of tissue arrays will allow for the rapid confirmation of the expression of potential targets at both the mRNA and the protein level for molecularly targeted agents. The database will facilitate the identification of tumor markers predictive of response to tested agents as well as the discovery of new molecular targets. [Cancer Res 2007;67(1):32–40]
RET/Papillary Thyroid Carcinoma Oncogenic Signaling through the Rap1 Small GTPase
Authors: De Falco Valentina , Castellone Maria Domenica , De Vita Gabriella , Cirafici Anna Maria , Hershman Jerome M. , Guerrero Carmen , Fusco Alfredo , Melillo Rosa Marina , Santoro Massimo
Published: January 2007

RET/papillary thyroid carcinoma (PTC) oncoproteins result from the in-frame fusion of the RET receptor tyrosine kinase with protein dimerization motifs encoded by heterologous genes. Here, we show that RET/PTC1 activates the Rap1 small GTPase. The activation of Rap1 was dependent on the phosphorylation of RET Tyr1062. RET/PTC1 recruited a complex containing growth factor receptor binding protein 2–associated binding protein 1 (Gab1), CrkII (v-crk sarcoma virus CT10 oncogene homologue II), and C3G (Rap guanine nucleotide exchange factor 1). By using dominant-negative and small interfering duplex (small interfering RNA) oligonucleotides, we show that RET/PTC1–mediated Rap1 activation was dependent on CrkII, C3G, and Gab1. Activation of Rap1 was involved in the RET/PTC1–mediated stimulation of the BRAF kinase and the p42/p44 mitogen-activated protein kinases. Proliferation and stress fiber formation of RET/PTC1–expressing PC Cl 3 thyroid follicular cells were inhibited by the dominant-negative Rap1(N17) and by Rap1–specific GTPase-activating protein. Thus, Rap1 is a downstream effector of RET/PTC and may contribute to the transformed phenotype of RET/PTC–expressing thyrocytes. [Cancer Res 2007;67(1):381–90]
Delivery of CCL21 to Metastatic Disease Improves the Efficacy of Adoptive T-Cell Therapy
Authors: Thanarajasingam Uma , Sanz Laura , Diaz Rosa , Qiao Jian , Sanchez-Perez Luis , Kottke Tim , Thompson Jill , Chester John , Vile Richard G.
Published: January 2007

Adoptive T-cell transfer has achieved significant clinical success in advanced melanoma. However, therapeutic efficacy is limited by poor T-cell survival after adoptive transfer and by inefficient trafficking to tumor sites. Here, we report that intratumoral expression of the chemokine CCL21 enhances the efficacy of adoptive T-cell therapy in a mouse model of melanoma. Based on our novel observation that CCL21 is highly chemotactic for activated OT-1 T cells in vitro and down-regulates expression of CD62L, we hypothesized that tumor cell–mediated expression of this chemokine might recruit, and retain, adoptively transferred T cells to the sites of tumor growth. Mice bearing metastatic tumors stably transduced with CCL21 survived significantly longer following adoptive T-cell transfer than mice bearing non–CCL21-expressing tumors. However, although we could not detect increased trafficking of the adoptively transferred T cells to tumors, tumor-expressed CCL21 promoted the survival and cytotoxic activity of the adoptively transferred T cells and led to the priming of antitumor immunity following T-cell transfer. To translate these observations into a protocol of real clinical usefulness, we showed that adsorption of a retrovirus encoding CCL21 to OT-1 T cells before adoptive transfer increased the therapeutic efficacy of a subsequently administered dose of OT-1 T cells, resulting in cure of metastatic disease and the generation of immunologic memory in the majority of treated mice. These studies indicate a promising role for CCL21 in enhancing the therapeutic efficacy of adoptive T-cell therapy. [Cancer Res 2007;67(1):300–8]
An Osteoprotegerin-like Peptidomimetic Inhibits Osteoclastic Bone Resorption and Osteolytic Bone Disease in Myeloma
Authors: Heath Deborah J. , Vanderkerken Karin , Cheng Xin , Gallagher Orla , Prideaux Matthew , Murali Ramachandran , Croucher Peter I.
Published: January 2007

Multiple myeloma is a B-cell malignancy characterized by the uncontrolled growth of plasma cells in the bone marrow and the development of osteolytic bone disease. Myeloma cells express the receptor activator of nuclear factor κB ligand (RANKL), induce RANKL expression in the bone marrow, and down-regulate expression of the decoy receptor osteoprotegerin, thereby promoting bone resorption. Targeting this system in myeloma has clear therapeutic potential. However, osteoprotegerin also binds tumor necrosis factor–related apoptosis inducing ligand (TRAIL) and prevents TRAIL-induced apoptosis of myeloma cells. Whether or not osteoprotegerin can bind TRAIL and prevent apoptosis in vivo and the relative importance of osteoprotegerin binding to TRAIL and RANKL are unclear. In the present study, we have investigated the ability of an osteoprotegerin-like peptidomimetic (OP3-4), designed to block the RANKL/RANK interaction, to inhibit osteoclastic bone resorption and TRAIL-induced apoptosis in vitro and myeloma bone disease in vivo. OP3-4 inhibited osteoclast formation (P < 0.01) and bone resorption (P < 0.01) in vitro. However, OP3-4 had no effect on TRAIL-induced apoptosis of RPMI 8226 myeloma cells. Treatment of 5T2MM myeloma–bearing mice with OP3-4 decreased osteoclast number and the proportion of bone surface covered by osteoclasts (P < 0.05). Treatment also prevented the tumor-induced decrease in cancellous bone area and the development of osteolytic lesions (P < 0.05). OP3-4 also reduced tumor burden when compared with the control (P < 0.05). These data suggest that OP3-4 and the selective inhibition of RANKL, but not TRAIL activity, are effective in preventing myeloma bone disease and offer a novel therapeutic approach to treating this aspect of myeloma. [Cancer Res 2007;67(1):202–8]
Dominant-Negative Fas Mutation Is Reversed by Down-expression of c-FLIP
Authors: Bénéteau Marie , Daburon Sophie , Moreau Jean-François , Taupin Jean-Luc , Legembre Patrick
Published: January 2007

Fas triggering by agonistic antibodies or by its cognate ligand, FasL, induces apoptotic cell death, whereas mutation in the Fas death domain is associated with lymphoma progression. On prolonged culture in the presence of an agonistic anti-Fas antibody, we raised a Jurkat cell line resistant to agonistic antibodies but still sensitive to soluble FasL, which carried at the heterozygous state, a point mutation into the Fas death domain. Down-modulation of c-FLIP expression reversed the blockade of the Fas pathway. We show that the activation threshold for the Fas receptor is more easily overcome by multimeric FasL than by agonistic antibodies and that the increase of this threshold due to mutation in the Fas death domain can be overcome by acting on a downstream effector of the Fas signal, c-FLIP. These findings put forward a new approach to eradicate Fas-resistant tumor cells. [Cancer Res 2007;67(1):108–15]
Gene Expression Profiling Reveals a Massive, Aneuploidy-Dependent Transcriptional Deregulation and Distinct Differences between Lymph Node–Negative and Lymph Node–Positive Colon Carcinomas
Authors: Grade Marian , Hörmann Patrick , Becker Sandra , Hummon Amanda B. , Wangsa Danny , Varma Sudhir , Simon Richard , Liersch Torsten , Becker Heinz , Difilippantonio Michael J. , Ghadimi B. Michael , Ried Thomas
Published: January 2007

To characterize patterns of global transcriptional deregulation in primary colon carcinomas, we did gene expression profiling of 73 tumors [Unio Internationale Contra Cancrum stage II (n = 33) and stage III (n = 40)] using oligonucleotide microarrays. For 30 of the tumors, expression profiles were compared with those from matched normal mucosa samples. We identified a set of 1,950 genes with highly significant deregulation between tumors and mucosa samples (P < 1e−7). A significant proportion of these genes mapped to chromosome 20 (P = 0.01). Seventeen genes had a >5-fold average expression difference between normal colon mucosa and carcinomas, including up-regulation of MYC and of HMGA1, a putative oncogene. Furthermore, we identified 68 genes that were significantly differentially expressed between lymph node–negative and lymph node–positive tumors (P < 0.001), the functional annotation of which revealed a preponderance of genes that play a role in cellular immune response and surveillance. The microarray-derived gene expression levels of 20 deregulated genes were validated using quantitative real-time reverse transcription-PCR in >40 tumor and normal mucosa samples with good concordance between the techniques. Finally, we established a relationship between specific genomic imbalances, which were mapped for 32 of the analyzed colon tumors by comparative genomic hybridization, and alterations of global transcriptional activity. Previously, we had conducted a similar analysis of primary rectal carcinomas. The systematic comparison of colon and rectal carcinomas revealed a significant overlap of genomic imbalances and transcriptional deregulation, including activation of the Wnt/β-catenin signaling cascade, suggesting similar pathogenic pathways. [Cancer Res 2007;67(1):41–56]
Role for Amplification and Expression of Glypican-5 in Rhabdomyosarcoma
Authors: Williamson Daniel , Selfe Joanna , Gordon Tony , Lu Yong-Jie , Pritchard-Jones Kathy , Murai Kasumi , Jones Phil , Workman Paul , Shipley Janet
Published: January 2007

Overexpression of genes, through genomic amplification and other mechanisms, can critically affect the behavior of tumor cells. Genomic amplification of the 13q31-32 region is reported in many tumors, including rhabdomyosarcomas that are primarily pediatric sarcomas resembling developing skeletal muscle. The minimum overlapping region of amplification at 13q31-32 in rhabdomyosarcomas was defined as containing two genes: Glypican-5 (GPC5) encoding a cell surface proteoglycan and C13orf25 encompassing the miR-17-92 micro-RNA cluster. Genomic copy number and gene expression analyses of rhabdomyosarcomas indicated that GPC5 was the only gene consistently expressed and up-regulated in all cases with amplification. Constitutive overexpression and knockdown of GPC5 expression in rhabdomyosarcoma cell lines increased and decreased cell proliferation, respectively. A correlation between expression levels of nascent pre-rRNA and GPC5 (P = 0.001), but not a C13orf25 transcript containing miR-17-92, in primary samples supports an association of GPC5 with proliferative capacity in vivo. We show that GPC5 increases proliferation through potentiating the action of the growth factors fibroblast growth factor 2 (FGF2), hepatocyte growth factor (HGF), and Wnt1A. GPC5 enhanced the intracellular signaling of FGF2 and HGF and altered the cellular distribution of FGF2. The mesoderm-inducing effect of FGF2 and FGF4 in Xenopus blastocysts was also enhanced. Our data are consistent with a role of GPC5, in the context of sarcomagenesis, in enhancing FGF signaling that leads to mesodermal cell proliferation without induction of myogenic differentiation. Furthermore, the properties of GPC5 make it an attractive target for therapeutic intervention in rhabdomyosarcomas and other tumors that amplify and/or overexpress the gene. [Cancer Res 2007;67(1):57–65]
Down-regulation of Type I Insulin-like Growth Factor Receptor Increases Sensitivity of Breast Cancer Cells to Insulin
Authors: Zhang Hua , Pelzer Alissa M. , Kiang David T. , Yee Douglas
Published: January 2007

The type I insulin-like growth factor receptor (IGF1R) and insulin receptor (IR) are structurally and functionally related heterotetrameric receptors. Activation of IGF1R has been shown to regulate breast cancer cell biology, and it has become an attractive therapeutic target. Most strategies have focused on targeting IGF1R alone without affecting IR levels given the known physiologic functions of IR. Human breast cancer cell lines and tissues revealed mRNA expression of both IGF1R and IR. Because αβ chains of IGF1R and IR form hybrid receptors, we hypothesized that agents solely targeting IGF1R may affect tumor biology mediated by IGF1R/IR hybrids and IR. We used small interfering RNA (siRNA) technology to specifically down-regulate IGF1R by 60% to 80% in the MDA-435/LCC6 cell line, which was sufficient to diminish activation of IGF1R by IGF-I. IGF1R down-regulation by siRNA did not affect IR levels but, interestingly, sensitized cells to insulin activation of downstream signaling pathways in several breast cancer cell lines. IGF1R siRNA treatment diminished hybrid receptor formation, suggesting that specific down-regulation of IGF1R resulted in enhanced holo-IR formation. In addition, IGF1R down-regulation increased insulin binding consistent with the formation of an increased number of holo-IR on the cell surface. Accordingly, insulin-stimulated glucose uptake was enhanced on IGF1R down-regulation. In conclusion, our data suggest that specific siRNA targeting of IGF1R alone in breast cancer increases insulin sensitivity. Because IR also activates signaling pathways similar to IGF1R in breast cancer cells, agents targeting both receptors may be necessary to disrupt the malignant phenotype regulated by this growth factor system. [Cancer Res 2007;67(1):391–7]
Adamantyl-Substituted Retinoid-Related Molecules Bind Small Heterodimer Partner and Modulate the Sin3A Repressor
Authors: Farhana Lulu , Dawson Marcia I. , Leid Mark , Wang Li , Moore David D. , Liu Gang , Xia Zeben , Fontana Joseph A.
Published: January 2007

6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalenecarboxylic acid (CD437/AHPN) and 4-[3-(1-adamantyl)-4-hydroxyphenyl]-3-chlorocinnamic acid (3-Cl-AHPC/MM002) are inducers of apoptosis of malignant cells both in vitro and in vivo. Numerous mechanisms have been proposed for how these compounds exert this effect. This report shows that AHPN/3-Cl-AHPC binds specifically to the orphan nuclear receptor small heterodimer partner (SHP; NR0B2), and this binding promotes interaction of the receptor with a corepressor complex that minimally contains Sin3A, N-CoR, histone deacetylase 4, and HSP90. Formation of the SHP-Sin3A complex is essential for the ability of AHPN and 3-Cl-AHPC to induce apoptosis, as both knockout SHP and knockdown of Sin3A compromise the proapoptotic activity of these compounds but not other apoptosis inducers. These results suggest that AHPN/3-Cl-AHPC and their analogues are SHP ligands and their induction of apoptosis is mediated by their binding to the SHP receptor. [Cancer Res 2007;67(1):318–25]
Extracellular Matrix Metalloproteinase Inducer Up-regulates the Urokinase-Type Plasminogen Activator System Promoting Tumor Cell Invasion
Authors: Quemener Cathy , Gabison Eric E. , Naïmi Benyoussef , Lescaille Géraldine , Bougatef Faten , Podgorniak Marie Pierre , Labarchède Géraldine , Lebbé Celeste , Calvo Fabien , Menashi Suzanne , Mourah Samia
Published: January 2007

Extracellular matrix metalloproteinase inducer (EMMPRIN) is a membrane glycoprotein overexpressed in many cancer tissues and is known for its ability to stimulate MMP expression. In this work, we show that EMMPRIN is also a regulator of the urokinase-type plasminogen activation (uPA) system of serine proteases, thus participating to the increase of the overall proteolytic function of the cancer cells. Enhanced EMMPRIN expression in a tumorigenic breast epithelial cell line NS2T2A increased the levels of uPA, uPA receptor, and the uPA inhibitor plasminogen activator inhibitor-1 (PAI-1), as measured by quantitative reverse transcription-PCR, Western blot, and plasminogen-casein zymography. This response was down-regulated by either EMMPRIN small interfering RNA or a blocking antibody to EMMPRIN. EMMPRIN-containing purified membrane fraction from Chinese hamster ovary cells when added exogenously to NS2T2A cells induced a similar activation of the uPA/PAI-1 system. Additionally, overexpression of EMMPRIN in NS2T2A cells increased uPA levels in cocultured endothelial cells, showing a paracrine regulation loop involving a tumor-stroma interaction. EMMPRIN-expressing cells also exhibited enhanced invasive potential in vitro, and the use of amiloride (uPA inhibitor) and marimastat (MMP inhibitor) showed that the two proteolytic systems reduced alone and in combination the invasive potential mediated through EMMPRIN. These data show a novel regulatory pathway for uPA activity and suggest that EMMPRIN is involved in uPA dysregulation observed in cancer. [Cancer Res 2007;67(1):9–15]
ADAM10 Inhibition of Human CD30 Shedding Increases Specificity of Targeted ImmunotherapyIn vitro
Authors: Eichenauer Dennis A. , Simhadri Vijaya Lakshmi , von Strandmann Elke Pogge , Ludwig Andreas , Matthews Vance , Reiners Katrin S. , von Tresckow Bastian , Saftig Paul , Rose-John Stefan , Engert Andreas , Hansen Hinrich P.
Published: January 2007

CD30 is a transmembrane protein selectively overexpressed on many human lymphoma cells and therefore an interesting target for antibody-based immunotherapy. However, binding of therapeutic antibodies stimulates a juxtamembrane cleavage of CD30 leading to a loss of target antigen and an enhanced release of the soluble ectodomain of CD30 (sCD30). Here, we show that sCD30 binds to CD30 ligand (CD153)–expressing non-target cells. Because antibodies bind to sCD30, this results in unwanted antibody binding to these cells via sCD30 bridging. To overcome shedding-dependent damage of normal cells in CD30-specific immunotherapy, we analyzed the mechanism involved in the release. Shedding of CD30 can be enhanced by protein kinase C (PKC) activation, implicating the disintegrin metalloproteinase ADAM17 but not free cytoplasmic calcium. However, antibody-induced CD30 shedding is calcium dependent and PKC independent. This shedding involved the related metalloproteinase ADAM10 as shown by the use of the preferential ADAM10 inhibitor GI254023X and by an ADAM10-deficient cell line generated from embryonically lethal ADAM10−/− mouse. In coculture experiments, the antibody-induced transfer of sCD30 from the human Hodgkin's lymphoma cell line L540 to the CD30-negative but CD153-expressing human mast cell line HMC-1 was inhibited by GI254023X. These findings suggest that selective metalloproteinase inhibitors blocking antibody-induced shedding of target antigens could be of therapeutic value to increase the specificity and reduce side effects of immunotherapy with monoclonal antibodies. [Cancer Res 2007;67(1):332–8]
Imaging Tumors with an Albumin-Binding Fab, a Novel Tumor-Targeting Agent
Authors: Dennis Mark S. , Jin Hongkui , Dugger Debra , Yang Renhui , McFarland Leanne , Ogasawara Annie , Williams Simon , Cole Mary J. , Ross Sarajane , Schwall Ralph
Published: January 2007

Association with albumin as a means to improve biodistribution and tumor deposition of a Fab was investigated using AB.Fab4D5, a bifunctional molecule derived from trastuzumab (HERCEPTIN) capable of binding albumin and tumor antigen HER2 (erbB2) simultaneously. AB.Fab4D5 was compared with trastuzumab and a trastuzumab-derived Fab (Fab4D5) for the ability to target tumors overexpressing HER2 in mouse mammary tumor virus/HER2 allograft models. Biodistribution was monitored using intravital microscopy, histology, and integrated single-photon emission computed tomography/computed tomography analysis. Fab4D5 tumor deposition was characterized by rapid but transient appearance in tumor at 2 h with little retention, followed by rapid accumulation in kidney by 6 h. Trastuzumab was slow to accumulate in tumors and slow to clear from normal tissues, although significant tumor deposition was achieved by 24 h. In contrast, AB.Fab4D5 was observed at 2 h in tumor and its presence was sustained beyond 24 h similar to trastuzumab. Intravital microscopy revealed that at peak tumor accumulation, tumor cell staining by AB.Fab4D5 was more uniform than for Fab4D5 or trastuzumab. Similar tumor deposition was achieved for both AB.Fab4D5 and trastuzumab at 48 h (35.9 ± 1.8% and 38.2 ± 3.1% injected dose/g); however, AB.Fab4D5 targeted tumors more rapidly and quickly cleared from blood, leading to a lower overall normal tissue exposure. Importantly, unlike Fab4D5, AB.Fab4D5 did not accumulate in kidney, suggesting that association with albumin leads to an altered route of clearance and metabolism. Rapid targeting, excellent tumor deposition and retention, coupled with high tumor to blood ratios may make AB.Fab an exceptional molecule for imaging and cancer therapy. [Cancer Res 2007;67(1):254–61]
Transcriptional Cooperation between the Transforming Growth Factor-β and Wnt Pathways in Mammary and Intestinal Tumorigenesis
Authors: Labbé Etienne , Lock Lisa , Letamendia Ainhoa , Gorska Agnieszka E. , Gryfe Robert , Gallinger Steven , Moses Harold L. , Attisano Liliana
Published: January 2007

Transforming growth factor-β (TGF-β) and Wnt ligands function in numerous developmental processes, and alterations of both signaling pathways are associated with common pathologic conditions, including cancer. To obtain insight into the extent of interdependence of the two signaling cascades in regulating biological responses, we used an oligonucleotide microarray approach to identify Wnt and TGF-β target genes using normal murine mammary gland epithelial cells as a model. Combination treatment of TGF-β and Wnt revealed a novel transcriptional program that could not have been predicted from single ligand treatments and included a cohort of genes that were cooperatively induced by both pathways. These included both novel and known components or modulators of TGF-β and Wnt pathways, suggesting that mutual feedback is a feature of the coordinated activities of the ligands. The majority of the cooperative targets display increased expression in tumors derived from either Min (many intestinal neoplasia) or mouse mammary tumor virus (MMTV)–Wnt1 mice, two models of Wnt-induced tumors, with nine of these genes (Ankrd1, Ccnd1, Ctgf, Gpc1, Hs6st2, IL11, Inhba, Mmp14, and Robo1) showing increases in both. Reduction of TGF-β signaling by expression of a dominant-negative TGF-β type II receptor in bigenic MMTV-Wnt1/DNIIR mice increased mammary tumor latency and was correlated with a decrease in expression of Gpc1, Inhba, and Robo1, three of the TGF-β/Wnt cooperative targets. Our results indicate that the TGF-β and Wnt/β-catenin pathways are firmly intertwined and generate a unique gene expression pattern that can contribute to tumor progression. [Cancer Res 2007;67(1):75–84]
Gene Expression Profile of Metastatic Human Pancreatic Cancer Cells Depends on the Organ Microenvironment
Authors: Nakamura Toru , Fidler Isaiah J. , Coombes Kevin R.
Published: January 2007

To determine the influence of the microenvironment on changes in gene expression, we did microarray analysis on three variant lines of a human pancreatic cancer (FG, L3.3, and L3.6pl) with different metastatic potentials. The variant lines were grown in tissue culture in the subcutis (ectopic) or pancreas (orthotopic) of nude mice. Compared with tissue culture, the number of genes of which the expression was affected by the microenvironment was up-regulated in tumors growing in the subcutis and pancreas. In addition, highly metastatic L3.6pl cells growing in the pancreas expressed significantly higher levels of 226 genes than did the L3.3 or FG variant cells. Growth of the variant lines in the subcutis did not yield similar results, indicating that the orthotopic microenvironment significantly influences gene expression in pancreatic cancer cells. These data suggest that investigations of the functional consequence of gene expression require accounting for experimental growth conditions. [Cancer Res 2007;67(1):139–48]
Tumor-Induced Oxidative Stress Perturbs Nuclear Factor-κB Activity-Augmenting Tumor Necrosis Factor-α–Mediated T-Cell Death: Protection by Curcumin
Authors: Bhattacharyya Sankar , Mandal Debaprasad , Sen Gouri Sankar , Pal Suman , Banerjee Shuvomoy , Lahiry Lakshmishri , Finke James H. , Tannenbaum Charles S. , Das Tanya , Sa Gaurisankar
Published: January 2007

Cancer patients often exhibit loss of proper cell-mediated immunity and reduced effector T-cell population in the circulation. Thymus is a major site of T-cell maturation, and tumors induce thymic atrophy to evade cellular immune response. Here, we report severe thymic hypocellularity along with decreased thymic integrity in tumor bearer. In an effort to delineate the mechanisms behind such thymic atrophy, we observed that tumor-induced oxidative stress played a critical role, as it perturbed nuclear factor-κB (NF-κB) activity. Tumor-induced oxidative stress increased cytosolic IκBα retention and inhibited NF-κB nuclear translocation in thymic T cells. These NF-κB–perturbed cells became vulnerable to tumor-secreted tumor necrosis factor (TNF)-α (TNF-α)–mediated apoptosis through the activation of TNF receptor-associated protein death domain–associated Fas-associated protein death domain and caspase-8. Interestingly, TNF-α–depleted tumor supernatants, either by antibody neutralization or by TNF-α-small interfering RNA transfection of tumor cells, were unable to kill T cell effectively. When T cells were overexpressed with NF-κB, the cells became resistant to tumor-induced apoptosis. In contrast, when degradation-defective IκBα (IκBα super-repressor) was introduced into T cells, the cells became more vulnerable, indicating that inhibition of NF-κB is the reason behind such tumor/TNF-α–mediated apoptosis. Curcumin could prevent tumor-induced thymic atrophy by restoring the activity of NF-κB. Further investigations suggest that neutralization of tumor-induced oxidative stress and restoration of NF-κB activity along with the reeducation of the TNF-α signaling pathway can be the mechanism behind curcumin-mediated thymic protection. Thus, our results suggest that unlike many other anticancer agents, curcumin is not only devoid of immunosuppressive effects but also acts as immunorestorer in tumor-bearing host. [Cancer Res 2007;67(1):362–70]
Identification of a Novel Tumor Suppressor Gene p34 on Human Chromosome 6q25.1
Authors: Wang Min , Vikis Haris G. , Wang Yian , Jia Dongmei , Wang Daolong , Bierut Laura J. , Bailey-Wilson Joan E. , Amos Christopher I. , Pinney Susan M. , Petersen Gloria M. , de Andrade Mariza , Yang Ping , Wiest Jonathan S. , Fain Pamela R. , Schwartz Ann G. , Gazdar Adi , Minna John , Gaba Colette , Rothschild Henry , Mandal Diptasri , Kupert Elena , Seminara Daniela , Liu Yan , Viswanathan Avinash , Govindan Ramaswamy , Anderson Marshall W. , You Ming
Published: January 2007

In this study, we observed loss of heterozygosity (LOH) in human chromosomal fragment 6q25.1 in sporadic lung cancer patients. LOH was observed in 65% of the 26 lung tumors examined and was narrowed down to a 2.2-Mb region. Single-nucleotide polymorphism (SNP) analysis of genes located within this region identified a candidate gene, termed p34. This gene, also designated as ZC3H12D, C6orf95, FLJ46041, or dJ281H8.1, carries an A/G nonsynonymous SNP at codon 106, which alters the amino acid from lysine to arginine. Nearly 73% of heterozygous lung cancer tissues with LOH and the A/G SNP also exhibited loss of the A allele. In vitro clonogenic and in vivo nude mouse studies showed that overexpression of the A allele exerts tumor suppressor function compared with the G allele. p34 is located within a recently mapped human lung cancer susceptibility locus, and association of the p34 A/G SNP was tested among these families. No significant association between the less frequent G allele and lung cancer susceptibility was found. Our results suggest that p34 may be a novel tumor suppressor gene involved in sporadic lung cancer but it seems not to be the candidate familial lung cancer susceptibility gene linked to chromosomal region 6q23-25. [Cancer Res 2007;67(1):93–9]
Anti-HER2 Cationic Immunoemulsion as a Potential Targeted Drug Delivery System for the Treatment of Prostate Cancer
Authors: Goldstein Danny , Gofrit Ofer , Nyska Abraham , Benita Simon
Published: January 2007

Present management of metastatic prostate cancer, which includes hormonal therapy, chemotherapy, and radiotherapy, are frequently palliative. Taxanes, and specifically docetaxel, are being extensively investigated to improve the survival of metastatic prostate cancer patients. Although paclitaxel exhibits a wide spectrum of antitumor activity, its therapeutic application is limited, in part, due to its low water solubility that necessitates the use of Cremophor EL, which is known to induce hypersensitivity reactions. Therefore, the objective of this present study was to assess the efficiency of paclitaxel palmitate–loaded anti-HER2 immunoemulsions, a targeted drug delivery system based on cationic emulsion covalently linked to anti-HER2 monoclonal antibody (Herceptin), in a well-established in vivo pharmacologic model of metastatic prostate cancer that overexpresses the HER2 receptor. It was clearly noted that the cationic emulsion and immunoemulsion did not activate the complement compared with the commercial and paclitaxel palmitate hydroalcoholic formulations. In addition, 10 mg/kg of paclitaxel palmitate–loaded immunoemulsion once weekly over 3 weeks inhibits the tumor growth in severe combined immunodeficient mice much more than the cationic emulsion (P < 0.05) and the paclitaxel palmitate formulation (P < 0.01). The histopathologic analysis suggested a therapeutic improvement trend in favor of the immunoemulsion. However, there was no significant difference in antimetastatic activity between the emulsion and the immunoemulsion despite the affinity of the immunoemulsion towards the HER2 receptor. Although the tumor growth was not fully inhibited, the actual results are encouraging and may lead to an improved therapeutic strategy of metastatic prostate cancer treatment. [Cancer Res 2007;67(1):269–75]
DNA Replication Licensing Factor Minichromosome Maintenance Deficient 5 Rescues p53-Mediated Growth Arrest
Authors: Agarwal Mukesh K. , Amin A.R.M. R. , Agarwal Munna L.
Published: January 2007

Inactivation of p53 signaling by mutation of p53 itself or abrogation of its normal function by other transfactors, such as MDM2, is a key event in the development of most human cancers. To identify novel regulators of p53, we have used a phenotype-based selection in which a total cDNA library in a retroviral vector has been introduced into TR9-7ER cells, which arrest when p53 is expressed from a tetracycline-regulated promoter. We have isolated several clones derived from cells that are not growth-arrested when p53 is overexpressed. In one clone, the levels of p53, p21, and MDM2 are comparable with those in TR9-7ER cells and, therefore, the abrogation of growth arrest by an exogenous cDNA is likely to be distal to p21. Using reverse transcription-PCR, we were able to isolate a cDNA of ∼2.2 kb, which was found to have 99% identity to the nucleotides between about 80 and 2,288 of the open reading frame of a gene encoding DNA replication licensing factor. It encodes complete peptide of 734 residues of this protein also called minichromosome maintenance deficient 5 (MCM5) or cell division cycle 46 (Saccharomyces cerevisiae). Northern and Western blot analyses revealed that the expression of MCM5 and its transcriptional regulator, E2F1, is negatively regulated by p53. When MCM5 cDNA was reintroduced into fresh TR9-7ER cells, numerous colonies that grow in the absence of tetracycline were formed. This novel observation establishes a role for MCM5 in negating the growth arrest function of p53. [Cancer Res 2007;67(1):116–21]
Vaccination against the Forkhead Family Transcription Factor Foxp3 Enhances Tumor Immunity
Authors: Nair Smita , Boczkowski David , Fassnacht Martin , Pisetsky David , Gilboa Eli
Published: January 2007

Depletion of CD4+CD25+ regulatory T cells (Treg) by treatment with αCD25 antibody synergizes with vaccination protocols to engender protective immunity in mice. The effectiveness of targeting CD25 to eliminate Treg is limited by the fact that CD25, the low-affinity interleukin-2 receptor, is up-regulated on conventional T cells. At present, foxp3 is the only product known to be exclusively expressed in Treg of mice. However, foxp3 is not expressed on the cell surface and hence cannot be targeted with antibodies. In this study, we tested the hypothesis that vaccination of mice against foxp3, a self-antigen expressed also in the thymus, is capable of stimulating foxp3-specific CTL that will cause the depletion of Treg and enhanced antitumor immunity. Vaccination of mice with foxp3 mRNA-transfected dendritic cells elicited a robust foxp3-specific CTL response and potentiated vaccine-induced protective immunity comparably with that of αCD25 antibody administration. In contrast to αCD25 antibody treatment, repeated foxp3 vaccination did not interfere with vaccine-induced protective immunity. Importantly, foxp3 vaccination led to the preferential depletion of foxp3-expressing Treg in the tumor but not in the periphery, whereas αCD25 antibody treatment led to depletion of Treg in both the tumor and the periphery. Targeting foxp3 by vaccination offers a specific and simpler protocol for the prolonged control of Treg that may be associated with reduced risk of autoimmunity, introducing an approach whereby specific depletion of cells is not limited to targeting products expressed on the cell surface. [Cancer Res 2006;67(1):371–80]
A Glycolytic Mechanism Regulating an Angiogenic Switch in Prostate Cancer
Authors: Wang Jianhua , Wang Jincheng , Dai Jinlu , Jung Younghun , Wei Chuen-Long , Wang Yu , Havens Aaron M. , Hogg Phillip J. , Keller Evan T. , Pienta Kenneth J. , Nor Jacques E. , Wang Cun-Yu , Taichman Russell S.
Published: January 2007

The generation of an ‘angiogenic switch’ is essential for tumor growth, yet its regulation is poorly understood. In this investigation, we explored the linkage between metastasis and angiogenesis through CXCL12/CXCR4 signaling. We found that CXCR4 regulates the expression and secretion of the glycolytic enzyme phosphoglycerate kinase 1 (PGK1). Overexpression of PGK1 reduced the secretion of vascular endothelial growth factor and interleukin-8 and increased the generation of angiostatin. At metastatic sites, however, high levels of CXCL12 signaling through CXCR4 reduced PGK1 expression, releasing the angiogenic response for metastastic growth. These data suggest that PGK1 is a critical downstream target of the chemokine axis and an important regulator of an ‘angiogenic switch’ that is essential for tumor and metastatic growth. [Cancer Res 2007;67(1):149–59]
Regulation of mTOR by Phosphatidic Acid?
Authors: Foster David A.
Published: January 2007

Interest in the regulation of the mammalian target of rapamycin (mTOR) has increased substantially in recent years largely because of an apparent link between mTOR and survival signals in human cancer cells. Much has been learned about the regulation of mTOR in response to survival signals generated by phosphatidylinositol 3-kinase (PI3K). However, another mechanism for regulating mTOR has been proposed involving the generation of phosphatidic acid (PA). PA is the metabolic product of phospholipase D (PLD), whose activity is elevated in a large number of human cancers, and, like PI3K, has been implicated in the survival of human cancer cells. Although the regulation of mTOR by the PI3K signaling pathway is well established, a role for PLD and PA in regulating mTOR has been controversial. In this review, the evidence implicating PLD and PA in the regulation of mTOR is summarized, and the implications of this novel and potentially important mechanism for regulating mTOR are discussed. [Cancer Res 2007;67(1):1–4]
Perspectives of γδ T Cells in Tumor Immunology
Authors: Kabelitz Dieter , Wesch Daniela , He Wei
Published: January 2007

Subsets of human γδ T cells recognize tumor cell–expressed ligands that are not seen by the T-cell receptor of conventional αβ T cells. Vδ1 T cells recognize MHC class I chain–related molecules A and B and UL-16–binding proteins expressed at variable levels on epithelial tumor cells and some leukemias and lymphomas. In addition, therapeutically used aminobisphosphonates and synthetic phosphoantigens activate Vδ2 T cells, the dominant subset of γδ T cells in human peripheral blood that display strong cytotoxicity towards various epithelial tumors. Intentional activation of γδ T cells in vivo and/or adoptive cell therapy with in vitro expanded γδ T cells holds considerable promise as a novel immunotherapy in certain types of cancer. [Cancer Res 2007;67(1):5–8]
Ribonucleotide Reductase Small Subunit p53R2 Facilitates p21 Induction of G1 Arrest under UV Irradiation
Authors: Xue Lijun , Zhou Bingsen , Liu Xiyong , Heung Yvonne , Chau Jennifer , Chu Emilie , Li Shan , Jiang Chunglin , Un Frank , Yen Yun
Published: January 2007

p53R2, which is one of the two known ribonucleotide reductase small subunits (the other being M2), is suggested to play an important role in supplying deoxynucleotide triphosphates (dNTP) for DNA repair during the G1 or G2 phase of the cell cycle. The ability of p53R2 to supply dNTPs for repairing DNA damages requires the presence of a functional p53 tumor suppressor. Here, we report in vivo physical interaction and colocalization of p53R2 and p21 before DNA damage. Mammalian two-hybrid assay further indicates that the amino acids 1 to 113 of p53R2 are critical for interacting with the NH2-terminal region (amino acids 1–93) of p21. The binding between p21 and p53R2 decreases inside the nucleus in response to UV, the time point of which corresponds to the increased binding of p21 with cyclin-dependent kinase-2 (Cdk2), and the decreased Cdk2 activity in the nucleus at G1. Interestingly, p53R2 dissociates from p21 but facilitates the accumulation of p21 in the nucleus in response to UV. On the other hand, the ribonucleotide reductase activity increases at the corresponding time in response to UV. These data suggest a new function of p53R2 of cooperating with p21 during DNA repair at G1 arrest. [Cancer Res 2007;67(1):16–21]