bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clusterin Isoforms Differentially Affect Growth and Motility of Prostate Cells: Possible Implications in Prostate Tumorigenesis
Authors: Moretti Roberta M. , Marelli Marina Montagnani , Mai Stefania , Cariboni Anna , Scaltriti Maurizio , Bettuzzi Saverio , Limonta Patrizia 
Published: November 2007

Abstract
Besides a fully processed, secreted form of clusterin (sCLU), an alternative proapoptotic form of the protein targeting the nucleus (nCLU) was recently described. The possible differential roles played by the two clusterin forms in growth and motility of nonmalignant and malignant prostate cells are investigated here. sCLU or nCLU was transiently transfected in both androgen-independent prostate cancer cells (PC3 and DU 145) and immortalized prostate epithelial cells (PNT1A, a nontumoral control). Then, cell growth, motility, and cytoskeleton organization were studied. We found that (a) in PNT1A cells, both sCLU and nCLU significantly decreased cell proliferation and motility; (b) in PC3 and DU 145 cancer cells, only nCLU inhibited cell growth and migration, with sCLU being ineffective; and (c) the antimotility effect of nCLU was accompanied by a dramatic dismantling of the actin cytoskeleton. Moreover, transfection with “full-length” CLU cDNA produced both sCLU and nCLU in nonmalignant PNT1A cells, whereas only sCLU was found in cancer cells. Thus, CLU gene expression might play a crucial role in prostate tumorigenesis by exerting differential biological effects on normal versus tumor cells through differential processing of CLU isoforms in the two cell systems. We also found that nCLU binds to α-actinin, a key protein for the regulation of actin cytoskeleton, and that nCLU and α-actinin colocalize in the cytoplasm. Thus, the antimotility activity of nCLU and its ability to cause dismantling of the actin cytoskeleton seem to be mediated by its binding to α-actinin. [Cancer Res 2007;67(21):10325–33]
BAG3 Regulates Motility and Adhesion of Epithelial Cancer Cells
Authors: Iwasaki Masahiro , Homma Sachiko , Hishiya Akinori , Dolezal Samuel J. , Reed John C. , Takayama Shinichi 
Published: November 2007

AbstractBAG3 protein binds to and regulates Hsp70 chaperone activity. The BAG3 protein contains a WW domain and a proline-rich region with SH3-binding motifs, suggesting that it may interact with proteins relevant to signal transduction, recruiting Hsp70 to signaling complexes and altering cell responses. BAG3 overexpression has been observed in human cancers. We show here that homozygous BAG3-deficient mouse embryonic fibroblasts (MEF) exhibit delayed formation of filopodia and focal adhesion complexes when freshly plated. BAG3-deficient MEFs show reduced cell motility in culture. We observed that endogenous BAG3 protein is highly expressed in many human epithelial cancer cell lines, especially adenocarcinomas. Gene transfer–mediated overexpression of BAG3 increased motility of Cos7 cell and several human cancer cell lines, including breast cancer MCF7 and prostate cancer DU145 and ALVA31 cell lines. Conversely, reduction of BAG3 protein by RNA interference (RNAi) decreased cell motility in four of four epithelial tumor lines tested. We observed an influence of BAG3 on cell adhesion in culture. In Cos7 kidney epithelial cells, BAG3 protein partially colocalizes with actin at the leading edge of migrating cells, wherein active actin polymerization and nucleation occur. RNAi-mediated reductions in BAG3 expression were associated with decreased Rac1 activity, suggesting a role for BAG3 in regulating this small GTPase involved in actin-cytoskeleton dynamics. In mice, RNAi-mediated reductions in BAG3 in a human tumor xenograft suppressed invasion and metastasis in vivo. Thus, the high levels of BAG3 protein seen in some epithelial cancer cell lines may be relevant to mechanisms of tumor invasion and metastasis. [Cancer Res 2007;67(21):10252–8]
Resistance to an Irreversible Epidermal Growth Factor Receptor (EGFR) Inhibitor in EGFR-Mutant Lung Cancer Reveals Novel Treatment Strategies
Authors: Yu Zhiwei , Boggon Titus J. , Kobayashi Susumu , Jin Cheng , Ma Patrick C. , Dowlati Afshin , Kern Jeffrey A. , Tenen Daniel G. , Halmos Balázs 
Published: November 2007

Abstract
Patients with epidermal growth factor receptor (EGFR)–mutant non–small cell lung cancer derive significant clinical benefit from treatment with the EGFR tyrosine kinase inhibitors gefitinib and erlotinib. Secondary EGFR mutations such as EGFR T790M commonly lead to resistance to these agents, limiting their long-term efficacy. Irreversible EGFR inhibitors such as CL-387,785 can overcome resistance and are in clinical development, yet acquired resistance against these agents is anticipated. We carried out a cell-based, in vitro random mutagenesis screen to identify EGFR mutations that confer resistance to CL-387,785 using T790M-mutant H1975 lung adenocarcinoma cells. Mutations at several residues occurred repeatedly leading to functional resistance to CL-387,785. These variants showed uninhibited cell growth, reduced apoptosis, and persistent EGFR activation in the presence of CL-387,785 as compared with parental H1975 cells, thus confirming their role in resistance. A screen of alternative agents showed that both an alternative EGFR inhibitor and a cyclin-dependent kinase 4 inhibitor led to significant inhibition of cell growth of the resistant mutants, suggestive of potential alternative treatment strategies. These results identify novel mutations mediating resistance to irreversible EGFR inhibitors and reveal alternative strategies to overcome or prevent the development of resistance in EGFR-mutant non–small cell lung cancers. [Cancer Res 2007;67(21):10417–27]
The Endothelin Receptor Blocker Bosentan Inhibits Doxorubicin-Induced Cardiomyopathy
Authors: Bien Sandra , Riad Alexander , Ritter Christoph A. , Gratz Matthias , Olshausen Florian , Westermann Dirk , Grube Markus , Krieg Thomas , Ciecholewski Sabine , Felix Stephan B. , Staudt Alexander , Schultheiss Heinz-Peter , Ewert Ralf , Völker Uwe , Tschöpe Carsten , Kroemer Heyo K. 
Published: November 2007

Abstract
Doxorubicin is a frequently used anticancer drug, but its therapeutic benefit is limited by acute and chronic cardiotoxicity, often leading to heart failure. The mechanisms underlying doxorubicin-induced cardiotoxicity remain unclear. It was previously shown in men that doxorubicin leads to increased endothelin-1 plasma levels. In addition, cardiac-specific overexpression of endothelin-1 in mice resulted in a cardiomyopathy resembling the phenotype following doxorubicin administration. We therefore hypothesized that endothelin-1 is involved in the pathogenesis of doxorubicin cardiotoxicity. In mice (C57Bl/10), we found that doxorubicin (20 mg/kg body weight, i.p.) impaired cardiac function with decreased ejection fraction, diminished cardiac output, and decreased end-systolic pressure points recorded by a microconductance catheter. This impaired function was accompanied by the up-regulation of endothelin-1 expression on mRNA and protein level. In vitro investigations confirmed the regulation of endothelin-1 by doxorubicin and indicated that the doxorubicin-mediated increase of endothelin-1 expression involves epidermal growth factor receptor signaling via the MEK1/2-ERK1/2 cascade, which was further confirmed by immunoblotting studies in the left ventricle of treated animals. Pretreatment of mice with the endothelin receptor antagonist bosentan (100 mg/kg body weight, p.o.) strikingly inhibited doxorubicin-induced cardiotoxicity with preserved indices of contractility. Moreover, bosentan pretreatment resulted in reduced tumor necrosis factor-α content, lipid peroxidation, and Bax expression, as well as increased GATA-4 expression. Thus, endothelin-1 plays a key role in mediating the cardiotoxic effects of doxorubicin and its inhibition may be of therapeutic benefit for patients receiving doxorubicin. [Cancer Res 2007;67(21):10428–35]
Identification of Human Aldehyde Dehydrogenase 1 Family Member A1 as a Novel CD8+ T-Cell–Defined Tumor Antigen in Squamous Cell Carcinoma of the Head and Neck
Authors: Visus Carmen , Ito Diasuke , Amoscato Andrew , Maciejewska-Franczak Malgorzata , Abdelsalem Ahmed , Dhir Rajiv , Shin Dong M. , Donnenberg Vera S. , Whiteside Theresa L. , DeLeo Albert B. 
Published: November 2007

Abstract
Few epitopes are available for vaccination therapy of patients with squamous cell carcinoma of the head and neck (SCCHN). Using a tumor-specific CTL, aldehyde dehydrogenase 1 family member A1 (ALDH1A1) was identified as a novel tumor antigen in SCCHN. Mass spectral analysis of peptides in tumor-derived lysates was used to determine that the CTL line recognized the HLA-A*0201 (HLA-A2) binding ALDH1A188-96 peptide. Expression of ALDH1A1 in established SCCHN cell lines, normal mucosa, and primary keratinocytes was studied by quantitative reverse transcription-PCR and immunostaining. Protein expression was further defined by immunoblot analysis, whereas ALDH1A1 activity was measured using ALDEFLUOR. ALDH1A188-96 peptide was identified as an HLA-A2–restricted, naturally presented, CD8+ T-cell–defined tumor peptide. ALDH1A188-96 peptide-specific CD8+ T cells recognized only HLA-A2+ SCCHN cell lines, which overexpressed ALDH1A1, as well as targets transfected with ALDH1A1 cDNA. Target recognition was blocked by anti-HLA class I and anti-HLA-A2 antibodies. SCCHN cell lines overexpressing ALDH1 had high enzymatic activity. ALDH1A1 protein was expressed in 12 of 17 SCCHN, and 30 of 40 dysplastic mucosa samples, but not in normal mucosa. ALDH1A1 expression levels in target cells correlated with their recognition by ALDH1A188-96 peptide-specific CD8+ T cells. Our findings identify ALDH1A1, a metabolic antigen, as a potential target for vaccination therapy in the cohort of SCCHN subjects with tumors overexpressing this protein. A smaller cohort of subjects with SCCHN, whose tumors express little to no ALDH1A1, and thus are deficient in conversion of retinal to retinoic acid, could benefit from chemoprevention therapy. [Cancer Res 2007;67(21):10538–45]
A Role for Endoglin as a Suppressor of Malignancy during Mouse Skin Carcinogenesis
Authors: Pérez-Gómez Eduardo , Villa-Morales María , Santos Javier , Fernández-Piqueras José , Gamallo Carlos , Dotor Javier , Bernabéu Carmelo , Quintanilla Miguel 
Published: November 2007

Abstract
Endoglin is a membrane glycoprotein that acts as a coreceptor for transforming growth factor-β. We and others have previously suggested a function of endoglin as a tumor suppressor in epithelial cancer. Here, we study the expression of endoglin during chemical mouse skin carcinogenesis. We find that shedding of membrane endoglin, allowing the secretion of a soluble endoglin form, is a late event associated with progression from squamous to spindle cell carcinomas. Knockdown of endoglin in transformed keratinocytes activates the Smad2/3 signaling pathway resulting in cell growth arrest, delayed tumor latencies, and a squamous to spindle phenotypic conversion. Forced expression of the long endoglin isoform in spindle carcinoma cells blocks transforming growth factor-β1 stimulation of Smad2/3 signaling and prevents tumor formation. In contrast, expression of the short endoglin isoform has no effect on spindle cell growth in vitro or in vivo. Our results show that endoglin behaves as a suppressor of malignancy during the late stages of carcinogenesis. Therefore, disruption of membrane endoglin emerges as a crucial event for progression to spindle cell carcinomas. [Cancer Res 2007;67(21):10268–77]
Association ofMatrix Metalloproteinase-8Gene Variation with Breast Cancer Prognosis
Authors: Decock Julie , Long Ji-Rong , Laxton Ross C. , Shu Xiao-Ou , Hodgkinson Conrad , Hendrickx Wouter , Pearce Eve G. , Gao Yu-Tang , Pereira Andresa C. , Paridaens Robert , Zheng Wei , Ye Shu 
Published: November 2007

AbstractAnimal and cell studies indicate an inhibitory effect of matrix metalloproteinase-8 (MMP8) on tumorigenesis and metastasis. We investigated whether MMP8 gene variation was associated with breast cancer metastasis and prognosis in humans. We first studied nine tagging single nucleotide polymorphisms (SNP) in the MMP8 gene in 140 clinically and pathologically well-characterized breast cancer patients. Four of the SNPs were found to be associated with lymph node metastasis, the most pronounced being a promoter SNP (rs11225395) with its minor allele (T) associating with reduced susceptibility to lymph node metastasis (P = 0.02). This SNP was further evaluated for association with cancer relapse and survival among a cohort of ∼1,100 breast cancer patients who had been followed for cancer recurrence and mortality for a median of 7.1 years. The T allele was associated with reduced cancer relapse and greater survival, particularly among patients with earlier stage cancer. Among patients of tumor-node-metastasis stage 0 to II, the adjusted hazard ratio of disease-free survival was 0.7 [95% confidence interval (95% CI), 0.5–0.9] for patients carrying T allele compared with those homozygous for the C allele (P = 0.02). In vitro experiments showed that the T allele had higher promoter activity than the C allele in breast cancer cells. Electrophoretic mobility shift assays showed binding of nuclear proteins to the DNA sequence at the SNP site of the T allele but not that of the C allele. The data suggest that MMP8 gene variation may influence breast cancer prognosis and support the notion that MMP8 has an inhibitory effect on cancer metastasis. [Cancer Res 2007;67(21):10214–21]
In vivoTargeting of Human Neutralizing Antibodies against CD55 and CD59 to Lymphoma Cells Increases the Antitumor Activity of Rituximab
Authors: Macor Paolo , Tripodo Claudio , Zorzet Sonia , Piovan Erich , Bossi Fleur , Marzari Roberto , Amadori Alberto , Tedesco Francesco 
Published: November 2007

AbstractAn in vivo model of human CD20+ B-lymphoma was established in severe combined immunodeficiency mice to test the ability of human neutralizing miniantibodies to CD55 and CD59 (MB55 and MB59) to enhance the therapeutic effect of rituximab. The miniantibodies contained single-chain fragment variables and the hinge-CH2-CH3 domains of human IgG1. LCL2 cells were selected for the in vivo study among six B-lymphoma cell lines for their high susceptibility to rituximab-dependent complement-mediated killing enhanced by MB55 and MB59. The cells injected i.p. primarily colonized the liver and spleen, leading to the death of the animals within 30 to 40 days. Thirty percent of mice receiving biotin-labeled rituximab (25 μg) i.p. on days 4 and 11 after cell injection survived to 120 days. Administration of biotin-labeled rituximab, followed by avidin (40 μg) and biotin-labeled MB55–MB59 (100 μg) at 4-h intervals after each injection resulted in the survival of 70% of mice. Surprisingly, 40% of mice survived after the sole injection of avidin and biotin-labeled MB55–MB59, an observation consistent with the in vitro data showing that the miniantibodies induced killing of ∼25% cells through antibody-dependent cell cytotoxicity. In conclusion, MB55 and MB59 targeted to tumor cells represent a valuable tool to enhance the therapeutic effect of rituximab and other complement-fixing antitumor antibodies. [Cancer Res 2007;67(21):10556–63]
Suppression of PTEN Expression Is Essential for Antiapoptosis and Cellular Transformation by Oncogenic Ras
Authors: Vasudevan Krishna Murthi , Burikhanov Ravshan , Goswami Anindya , Rangnekar Vivek M. 
Published: November 2007

Abstract
Ras is one of the most commonly mutated oncogenes in the array of human cancers. The mechanism by which Ras induces cellular transformation is, however, not fully elucidated. We present here evidence that oncogenic Ras suppresses the expression of the tumor suppressor phosphatase and tensin homologue deleted from chromosome 10 (PTEN), and this action of oncogenic Ras is mediated by the Raf-mitogen-activated protein kinase/extracellular signal–regulated kinase (ERK) kinase (MEK)-ERK pathway via up-regulation of c-Jun. Jun+/+ cells undergo cellular transformation by oncogenic Ras, and restoration of wild-type PTEN, but not a phosphate-defective mutant of PTEN, induces apoptosis in these cells. Conversely, in Jun−/− cells, oncogenic Ras neither suppresses PTEN nor causes transformation, but rather it induces PTEN-dependent apoptosis. An apoptotic response to oncogenic Ras in Jun−/− cells can be prevented by suppressing PTEN expression. These findings imply that oncogenic Ras suppresses the apoptotic gene PTEN via the Raf-MEK-ERK-c-Jun pathway to induce antiapoptosis and cellular transformation. Together, our findings identify a novel molecular interface between the oncogenic and tumor suppressor pathways that regulates cellular transformation and survival. [Cancer Res 2007;67(21):10343–50]
A Cell Proliferation and Chromosomal Instability Signature in Anaplastic Thyroid Carcinoma
Authors: Salvatore Giuliana , Nappi Tito Claudio , Salerno Paolo , Jiang Yuan , Garbi Corrado , Ugolini Clara , Miccoli Paolo , Basolo Fulvio , Castellone Maria Domenica , Cirafici Anna Maria , Melillo Rosa Marina , Fusco Alfredo , Bittner Michael L. , Santoro Massimo 
Published: November 2007

Abstract
Here, we show that the anaplastic thyroid carcinoma (ATC) features the up-regulation of a set of genes involved in the control of cell cycle progression and chromosome segregation. This phenotype differentiates ATC from normal tissue and from well-differentiated papillary thyroid carcinoma. Transcriptional promoters of the ATC up-regulated genes are characterized by a modular organization featuring binding sites for E2F and NF-Y transcription factors and cell cycle–dependent element (CDE)/cell cycle gene homology region (CHR) cis-regulatory elements. Two protein kinases involved in cell cycle regulation, namely, Polo-like kinase 1 (PLK1) and T cell tyrosine kinase (TTK), are part of the gene set that is up-regulated in ATC. Adoptive overexpression of p53, p21 (CIP1/WAF1), and E2F4 down-regulated transcription from the PLK1 and TTK promoters in ATC cells, suggesting that these genes might be under the negative control of tumor suppressors of the p53 and pRB families. ATC, but not normal thyroid, cells depended on PLK1 for survival. RNAi-mediated PLK1 knockdown caused cell cycle arrest associated with 4N DNA content and massive mitotic cell death. Thus, thyroid cell anaplastic transformation is accompanied by the overexpression of a cell proliferation/genetic instability-related gene cluster that includes PLK1 kinase, which is a potential molecular target for ATC treatment. [Cancer Res 2007;67(21):10148–57]
Androgen Induction of the Androgen Receptor Coactivator Four and a Half LIM Domain Protein-2: Evidence for a Role for Serum Response Factor in Prostate Cancer
Authors: Heemers Hannelore V. , Regan Kevin M. , Dehm Scott M. , Tindall Donald J. 
Published: November 2007

Abstract
Androgen receptor (AR) activity is critical for prostate cancer progression. Overexpression of several AR-associated coactivators has been shown to be essential for AR activation during disease progression. The stimuli and signaling pathways leading to overexpression of these coregulators, however, remain largely elusive. Here, we investigated whether androgen signaling, which demarcates critical transitions during prostate cancer disease progression, can affect coregulator expression. We found that expression of four and a half LIM domain protein-2 (FHL2), a key AR coactivator that is overexpressed in prostate cancer and associates with a poor prognosis, is induced strongly by androgens. Androgen induction of this coactivator established a feed-forward mechanism that robustly activated the AR. Stimulation of FHL2 after androgen exposure was time- and dose-dependent and relied on the presence of a functional AR. Androgen induction of FHL2 depended on active transcription of the FHL2 gene, mediated by action of serum response factor (SRF) on its proximal promoter. Loss of SRF, a transcription factor that preferentially regulates the expression of genes involved in mitogenic response and cytoskeletal organization, hampered prostate cancer cell proliferation. These results suggest a novel indirect mechanism of androgen action on FHL2 expression and provide evidence that SRF is an important determinant of AR action in prostate cancer cells. [Cancer Res 2007;67(21):10592–9]
A Novel Ovarian Xenografting Model to Characterize the Impact of Chemotherapy Agents on Human Primordial Follicle Reserve
Authors: Oktem Ozgur , Oktay Kutluk 
Published: November 2007

Abstract
Many chemotherapeutic agents, especially of the alkylating family, alter fertility in premenopausal females. However, it is not practically possible to quantify and characterize the impact of cancer drugs on ovarian reserve in a clinical setting. Thus, our specific aim was to develop a xenograft model to characterize the in vivo impact of chemotherapy agents on human ovary. Ovarian pieces from 24 weeks old abortuses were xenografted s.c. to severe combined immunodeficient mice (n = 52). Animals received either a single dose of 200 mg/kg of cyclophosphamide or the vehicle. Grafts were recovered from the control and treated mice 12 to 72 h after the cyclophosphamide injection and serially sectioned for primordial follicle counts. Apoptosis was assessed with terminal nucleotidyl transferase–mediated nick end labeling (TUNEL) assay. Platelet/endothelial cell adhesion molecule 1 (PECAM-1) staining, as well as intra-vital fluorescein-conjugated lectin and Evans blue labeling were done to assess microvasculature by confocal microscopy. Although there was 12% reduction in primordial follicle density by 12 h following treatment (P &gt; 0.05), the follicle loss increased significantly at 24 h (53%, P &lt; 0.01) and peaked at 48 h (93%, P &lt; 0.0001). TUNEL staining peaked at 12 h, earlier than the diminishment in follicle numbers, and decreased thereafter. Xenograft vascularization pattern was similar to non-xenografted tissue, indicating appropriate in vivo drug delivery. The impact of cyclophosphamide on primordial follicle reserve in our human ovarian xenograft model is consistent with the clinical gonadotoxicity of this drug. Human ovarian xenografting is a promising model to characterize the gonadotoxic effects of current and emerging cancer drugs without a need for lengthy clinical studies. [Cancer Res 2007;67(21):10159–62]