bluuebunny/crossref_metadata_2025 huggingface dataset:
Overexpression of 5-Lipoxygenase in Rat and Human Esophageal Adenocarcinoma and Inhibitory Effects of Zileuton and Celecoxib on Carcinogenesis
Authors: Chen Xiaoxin , Wang Su , Wu Nan , Sood Sandeep , Wang Peng , Jin Zhe , Beer David G. , Giordano Thomas J. , Lin Yong , Shih Wei-chung J. , Lubet Ronald A. , Yang Chung S.
Published: September 2005

Purpose: Aberrant arachidonic acid (AA) metabolism, especially through the cyclooxygenase (Cox) and 5-lipoxygenase (5-Lox) pathways, has been suggested to play an important role in the development of esophageal adenocarcinoma (EAC). The purpose of this study was to investigate the expression of 5-Lox in EAC of a rat model and in human samples as well as the chemopreventive effects of zileuton (a specific 5-Lox inhibitor) and celecoxib (a specific Cox2 inhibitor) in the rat EAC model.

Experimental Design: 5-Lox expression in EAC of a rat esophagogastroduodenal anastomosis model and of humans was examined with immunohistochemistry. A chemoprevention study was designed to test whether zileuton and celecoxib could suppress aberrant AA metabolism and esophageal adenocarcinogenesis.

Results: With immunohistochemistry, we found that 5-Lox was overexpressed during esophageal adenocarcinogenesis in our rat model and in humans. In the chemoprevention study, EAC incidence was reduced in a dose-dependent manner from 68.8% (11 of 16) to 44.4% (8 of 18; P > 0.05) and 31.3% (5 of 16; P < 0.05) by 500 and 1,000 ppm zileuton, respectively, and to 33.3% (7 of 21; P < 0.05) and 20% (3 of 15; P < 0.05) by 500 and 1,000 ppm celecoxib, respectively. With isobolographic analysis, zileuton and celecoxib, both at a dose of 500 ppm, had an additive effect by reducing the tumor incidence to 16.7% (3 of 18, P < 0.01). Leukotriene B4 and prostaglandin E2 levels in the esophageal tissues were also significantly reduced by zileuton and celecoxib.

Conclusions: This study clearly demonstrated that 5-Lox and Cox2 play important roles in the development of EAC. Both zileuton and celecoxib had inhibitory effects on esophageal adenocarcinogenesis through inhibition on their respective enzymes of AA metabolism.
Treatment of Neuroblastoma Meningeal Carcinomatosis with Intrathecal Application of α-Emitting Atomic Nanogenerators Targeting Disialo-Ganglioside GD2
Authors: Miederer Matthias , McDevitt Michael R. , Borchardt Paul , Bergman Ira , Kramer Kim , Cheung Nai-Kong V. , Scheinberg David A.
Published: September 2005

Labeling of specific antibodies with bifunctional chelated Actinium-225 (225Ac; an α generator) allows the formation of new, highly potent and selective α-emitting anticancer drugs. We synthesized and evaluated a radioimmunoconjugate based on 3F8, an IgG3 antibody that specifically binds to ganglioside GD2, which is overexpressed by many neuroectodermal tumors including neuroblastoma. The 225Ac-1,4,7,10-tetra-azacylododecane (DOTA)-3F8 construct was evaluated for radiochemical purity and sterility, immunoreactivity, cytotoxicity in vitro, induction of apoptosis on GD2-positive cells, as well as for pharmacological biodistribution and metabolism of the 225Ac generator and its daughters in a nude mouse xenograft model of neuroblastoma. The 225Ac-3F8 showed an IC50 of 3 Bq/ml (80 pCi/ml) on the neuroblastoma cell line, NMB7, in vitro. Apoptosis of these cells was not observed. Biodistribution in mice showed specific targeting of a subcutaneous tumor; there was redistribution of the 225Ac daughter nuclides mainly from blood to kidneys and to small intestine. Toxicity was examined in cynomolgus monkeys. Monkeys injected with 1 to 3 doses of intrathecal 225Ac-3F8 radioimmunoconjugate (80 to 150 kBq/kg total dose) did not show signs of toxicity based on blood chemistry, complete blood counts, or by clinical evaluations. Therapeutic efficacy of intrathecal 225Ac-3F8 was studied in a nude rat xenograft model of meningeal carcinomatosis. The 225Ac-3F8 treatment improved survival 2-fold from 16 to 34 days (P = 0.01). In conclusion, in vivo α generators targeted by 3F8 warrant additional study as a possible new approach to the treatment of carcinomatous meningitis.
A Selective c-Met Inhibitor Blocks an Autocrine Hepatocyte Growth Factor Growth Loop in ANBL-6 Cells and Prevents Migration and Adhesion of Myeloma Cells
Authors: Hov Håkon , Holt Randi Utne , Rø Torstein Baade , Fagerli Unn-Merete , Hjorth-Hansen Henrik , Baykov Vadim , Christensen James G. , Waage Anders , Sundan Anders , Børset Magne
Published: September 2005

Purpose: We wanted to examine the role of the hepatocyte growth factor (HGF) receptor c-Met in multiple myeloma by applying a novel selective small molecule tyrosine kinase inhibitor, PHA-665752, directed against the receptor.

Experimental Design: Four biological sequels of HGF related to multiple myeloma were studied: (1) proliferation of myeloma cells, (2) secretion of interleukin-11 from osteogenic cells, (3) migration of myeloma cells, and (4) adhesion of myeloma cells to fibronectin. We also examined effects of the c-Met inhibitor on intracellular signaling pathways in myeloma cells.

Results: PHA-665752 effectively blocked the biological responses to HGF in all assays, with 50% inhibition at 5 to 15 nmol/L concentration and complete inhibition at around 100 nmol/L. PHA-665752 inhibited phosphorylation of several tyrosine residues in c-Met (Tyr1003, Tyr1230/1234/1235, and Tyr1349), blocked HGF-mediated activation of Akt and p44/42 mitogen-activated protein kinase, and prevented the adaptor molecule Gab1 from complexing with c-Met. In the HGF-producing myeloma cell line ANBL-6, PHA-665752 revealed an autocrine HGF–c-Met–mediated growth loop. The inhibitor also blocked proliferation of purified primary myeloma cells, suggesting that autocrine HGF–c-Met–driven growth loops are important for progression of multiple myeloma.

Conclusions: Collectively, these findings support the role of c-Met and HGF in the proliferation, migration, and adhesion of myeloma cells and identify c-Met kinase as a therapeutic target for treatment of patients with multiple myeloma.
The Spermatozoa Protein, SLLP1, Is a Novel Cancer–Testis Antigen in Hematologic Malignancies
Authors: Wang Zhiqing , Zhang Yana , Mandal Arabinda , Zhang Jian , Giles Francis J. , Herr John C. , Lim Seah H.
Published: September 2005

Purpose: Neoplastic cells often aberrantly express normal testicular proteins. Because these proteins have a very restricted normal tissue expression, they may be suitable targets for immunotherapy. SLLP1 is an intra-acrosomal, nonbacteriolytic, c lysozyme–like protein recently isolated from human spermatozoa. In this study, we determined whether SLLP1 is a novel cancer–testis antigen in hematologic malignancies

Experimental Design: SLLP1 expression in hematologic tumor cells and normal tissues was determined using a combination of reverse transcription-PCR, real-time PCR, and Western blot analysis. The presence of antibodies against SLLP1 was determined by ELISA analysis.

Results: SLLP1 was aberrantly expressed in the tumor cells from 2 of 9 acute myeloid leukemia, 3 of 11 chronic lymphocytic leukemia, 4 of 14 chronic myeloid leukemia, and 6 of 17 multiple myeloma. In contrast, they were not detected in corresponding specimens from any healthy donors. SLLP1 exhibited a very restricted normal tissue expression, being found only in testis/spermatozoa. SLLP1 was expressed in some tumor cells at a level of >25%. High titer IgG antibodies against SLLP1 were also detected in the sera of some of these patients.

Conclusions: SLLP1 is a novel cancer–testis antigen in hematologic malignancies and is capable of eliciting B-cell immune responses in vivo in cancer-bearing individuals. Our results, therefore, support SLLP1 as a protein target appropriate for additional in vitro study to define its suitability for immunotherapy.
Flavopiridol Blocks Integrin-Mediated Survival in Dormant Breast Cancer Cells
Authors: Najmi Saltanat , Korah Reju , Chandra Rachna , Abdellatif Maha , Wieder Robert
Published: September 2005

Purpose: Breast cancer micrometastases in the bone marrow are resistant to chemotherapy. They can remain dormant for years before some begin to proliferate. We seek to understand survival mechanisms and develop targeted approaches to eliminating these cells.

Experimental Design: In an in vitro model of dormancy, basic fibroblast growth factor 2 (FGF-2), abundant in the bone marrow, inhibits the growth of well-differentiated cells in the 2- to 10-cell stage and up-regulates integrin α5β1. Through this integrin, cells bind fibronectin, spread out, and acquire a survival advantage, partly through activation of the phosphatidylinositol 3-kinase/Akt pathway. We investigated the effects of Taxotere, flavopiridol, and mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase and p38 inhibitors on survival of dormant clones and that of flavopiridol on expression of integrins, adhesion strength, and phosphorylation of Akt, ERK 1/2, and p38.

Results: Dormant MCF-7 and T-47D cell clones were resistant to Taxotere concentrations 10-fold higher than needed to eliminate growing clones but were almost completely eradicated by 200 nmol/L flavopiridol. Flavopiridol caused a decrease in FGF-2–induced expression of integrins, including α5 and β1, and decreased FGF-2–induced specific adhesion to fibronectin. It diminished Akt phosphorylation, but reexpression of active Akt was not sufficient to reverse dormant clone inhibition. Flavopiridol did not affect phosphorylation of ERK 1/2 and p38 but diminished total protein levels. Chemical inhibition of these pathways partially abrogated dormant clone survival.

Conclusions: Flavopiridol has pleiotropic effects on key targets involved with survival of dormant breast cancer cells and may represent a useful approach to eliminating cells dependent on multiple signal pathways for survival.
Accurate Discrimination of Barrett's Esophagus and Esophageal Adenocarcinoma Using a Quantitative Three-Tiered Algorithm and Multimarker Real-time Reverse Transcription-PCR
Authors: Mitas Michael , Almeida Jonas S. , Mikhitarian Kaidi , Gillanders William E. , Lewin David N. , Spyropoulos Demetri D. , Hoover Loretta , Graham Amanda , Glenn Tammy , King Peter , Cole David J. , Hawes Robert , Reed Carolyn E. , Hoffman Brenda J.
Published: September 2005

Esophageal adenocarcinoma (EA) is increasing faster than any other cancer in the U.S. In this report, we first show that EA can be distinguished from normal esophagus (NE) and esophageal squamous cell carcinoma by plotting expression values for EpCam, TFF1, and SBEM in three-dimensional Euclidean space. For monitoring progression of Barrett's esophagus (BE) to EA, we developed a highly sensitive assay for limited quantities of tissue whereby 50 ng of RNA are first converted to cDNA using 16 gene-specific primers. Using a set of training tissues, we developed a novel quantitative three-tiered algorithm that allows for accurate (overall accuracy = 61/63, 97%) discrimination of BE versus EA tissues using only three genes. The gene used in the first tier of the algorithm is TSPAN: samples not diagnosed as BE or EA by TSPAN in the first tier are then subjected to a second-tier analysis using ECGF1, followed by a third-tier analysis using SPARC. Addition of TFF1 and SBEM to the first tier (i.e., a five-gene marker panel) increases the overall accuracy of the assay to 98% (62/63) and results in mean molecular diagnostic scores (± SD) that are significantly different between EA and BE samples (3.19 ± 1.07 versus −2.74 ± 1.73, respectively). Our results suggest that relatively few genes can be used to monitor progression of BE to EA.
Overexpression of the Aldo-Keto Reductase Family Protein AKR1B10 Is Highly Correlated with Smokers' Non–Small Cell Lung Carcinomas
Authors: Fukumoto Shin-ichi , Yamauchi Naoko , Moriguchi Hisashi , Hippo Yoshitaka , Watanabe Akira , Shibahara Junji , Taniguchi Hirokazu , Ishikawa Shumpei , Ito Hirotaka , Yamamoto Shogo , Iwanari Hiroko , Hironaka Mitsugu , Ishikawa Yuichi , Niki Toshiro , Sohara Yasunori , Kodama Tatsuhiko , Nishimura Masaharu , Fukayama Masashi , Dosaka-Akita Hirotoshi , Aburatani Hiroyuki
Published: September 2005

Purpose: Squamous cell carcinoma (SCC) and adenocarcinoma of the lung are currently subject to similar treatment regimens despite distinct differences in histology and epidemiology. The aim of this study is to identify a molecular target with diagnostic and therapeutic values for SCC.

Experimental Design: Genes specifically up-regulated in SCC were explored through microarray analysis of 5 SCCs, 5 adenocarcinomas, 10 small cell lung carcinomas, 27 normal tissues, and 40 cancer cell lines. Clinical usefulness of these genes was subsequently examined mainly by immunohistochemical analysis.

Results: Seven genes, including aldo-keto reductase family 1, member B10 (AKR1B10), were identified as SCC-specific genes. AKR1B10 was further examined by immunohistochemical analysis of 101 non–small cell lung carcinomas (NSCLC) and its overexpression was observed in 27 of 32 (84.4%) SCCs and 19 of 65 (29.2%) adenocarcinomas. Multiple regression analysis showed that smoking was an independent variable responsible for AKR1B10 overexpression in NSCLCs (P < 0.01) and adenocarcinomas (P < 0.01). AKR1B10 staining was occasionally observed even in squamous metaplasia, a precancerous lesion of SCC.

Conclusion: AKR1B10 was overexpressed in most cases with SCC, which is closely associated with smoking, and many adenocarcinoma cases of smokers. These results suggest that AKR1B10 is a potential diagnostic marker specific to smokers' NSCLCs and might be involved in tobacco-related carcinogenesis.
Lack of Telomerase Activity in Lung Carcinoids Is Dependent on Human Telomerase Reverse Transcriptase Transcription and Alternative Splicing and Is Associated with Long Telomeres
Authors: Zaffaroni Nadia , Villa Raffaella , Pastorino Ugo , Cirincione Rosalia , Incarbone Matteo , Alloisio Marco , Curto Maria , Pilotti Silvana , Daidone Maria Grazia
Published: September 2005

Purpose: Preliminary evidence indicates that telomerase activity is significantly less expressed in typical carcinoids than in large cell neuroendocrine carcinomas or in small cell lung cancers. Knowledge of the mechanisms by which telomerase is differentially regulated in neuroendocrine lung tumors is important for a better understanding of the pathogenesis of these malignancies.

Experimental Design: We investigated telomerase activity in 86 neuroendocrine lung tumors and correlated the enzyme activity with the expression of the enzyme subunits [human RNA component (hTR), human telomerase reverse transcriptase (hTERT), and alternatively spliced hTERT variants], with the telomere-associated protein human protection of telomere-1, and with the telomere length pattern.

Results: A significantly (P = 0.0001) lower frequency of telomerase-positive cases was found in typical carcinoids (14%) than in large cell neuroendocrine carcinomas (87%) and small cell lung cancers (92%). hTR was constitutively expressed in all carcinoids. Telomerase-negative carcinoids were characterized by the absence of any hTERT transcript, only displayed the β− alternatively spliced variant, or concomitantly expressed the α+β+ full-length message with different combinations of alternatively spliced variants. However, in these tumors, a more abundant level of alternatively spliced transcripts than that of the α+β+ full-length transcript was generally found. No significant difference was observed in human protection of telomere-1 expression between telomerase-negative and telomerase-positive carcinoids. Telomeres were significantly (P < 0.05) longer in telomerase-negative carcinoids than in telomerase-positive carcinoids (median value, 9.15 versus 4.47 kb). However, alternative lengthening of telomeres, as shown by associated promyelocytic leukemia bodies, was not observed in these tumors.

Conclusions: Our results indicate that telomerase is repressed in most lung carcinoids and that hTERT transcription and alternative splicing play a role in such a negative regulation. Moreover, the absence of any telomerase maintenance mechanism may contribute to the favorable prognosis of this malignancy.
Stratification of Intermediate-Risk Endometrial Cancer Patients into Groups at High Risk or Low Risk for Recurrence Based on Tumor Gene Expression Profiles
Authors: Ferguson Sarah E. , Olshen Adam B. , Viale Agnès , Barakat Richard R. , Boyd Jeff
Published: September 2005

Purpose: Endometrial cancers classified as “intermediate risk” based on clinical and/or pathologic features are associated with a 15% to 20% risk of recurrence. Here, we test whether global gene expression profiling can distinguish intermediate-risk tumors into high-risk and low-risk subgroups.

Experimental Design: Tumor specimens were obtained from 75 intermediate-risk endometrial cancer patients, 13 who had recurred and 62 who had not recurred with a median follow-up of 24 months. Gene expression profiles were obtained using the Affymetrix U133A GeneChip oligonucleotide microarray. The genes most associated with risk of recurrence were used to create a risk score using a leave-one-out cross-validation method and the univariate Cox proportional hazards regression model. Time to recurrence curves for the high-risk and low-risk subgroups were estimated using the Kaplan-Meier method, and the difference in time to recurrence between these two subgroups was tested using the log-rank test.

Results: There was a significant difference in time to recurrence between high-risk and low-risk patients using risk scores as defined above (P = 0.04). The estimated hazard ratio (95% confidence interval) was 3.07 (1.00-9.43).

Conclusions: Patients with intermediate-risk endometrial cancers identified as high-risk for recurrence according to a gene expression–based risk score have a significantly increased risk for recurrence compared with those classified as low risk. These findings suggest that gene expression profiling can potentially contribute to the clinical classification and management of intermediate-risk endometrial cancers.
Regulation of Fibroblast Growth Factor-2 Activity by Human Ovarian Cancer Tumor Endothelium
Authors: Whitworth Melissa K. , Backen Alison C. , Clamp Andrew R. , Wilson Godfrey , McVey Rhona , Friedl Andreas , Rapraeger Alan C. , David Guido , McGown Alan , Slade Richard J. , Gallagher John T. , Jayson Gordon C.
Published: September 2005

Fibroblast growth factor-2 (FGF-2) is a potent angiogenic cytokine that is dependent on heparan sulfate for its biological activity. We have investigated the relationship among heparan sulfate, FGF-2, and the signal-transducing receptors in human, advanced-stage, serous ovarian adenocarcinoma. Using a unique molecular probe, FR1c-Ap, which consisted of a soluble FGF receptor 1 isoform lllc covalently linked to an alkaline phosphatase moiety, the distribution of heparan sulfate that had the ability to support the formation of a heparan sulfate/FGF-2/FGFR1 isoform IIIc alkaline phosphatase heparan sulfate construct complex was determined. This may be taken as a surrogate marker for the distribution of biologically active heparan sulfate and was distributed predominantly in endothelial cells and stroma but was absent from adenocarcinoma cells. In situ hybridization revealed the expression of FGFR1 mRNA in the endothelium and reverse transcription-PCR confirmed the presence of FGFR1 isoform IIIc but not isoform IIIb. The presence of FGF-2 around tumor endothelium was detected through immunohistochemistry. Double-staining techniques showed that heparan sulfate was found predominantly at the basal aspect of the endothelium and suggested that syndecan-3 might function as one of the proteoglycans involved in FGF-2 signaling in the endothelium. The data suggest that the entire extracellular signaling apparatus, consisting of FGF-2, biologically active heparan sulfate, and FGFRs capable of responding to FGF-2, is present in ovarian cancer endothelium, thereby highlighting the cytokine and its cognate receptor as potential targets for the antiangiogenic treatment of this disease.
A Phase I Study of α-Galactosylceramide (KRN7000)–Pulsed Dendritic Cells in Patients with Advanced and Recurrent Non–Small Cell Lung Cancer
Authors: Ishikawa Aki , Motohashi Shinichiro , Ishikawa Eiichi , Fuchida Hiroki , Higashino Kazuko , Otsuji Mizuto , Iizasa Toshihiko , Nakayama Toshinori , Taniguchi Masaru , Fujisawa Takehiko
Published: September 2005

Purpose: Human Vα24 natural killer T (NKT) cells bearing an invariant Vα24JαQ antigen receptor, the counterpart of murine Vα14 NKT cells, are activated by a specific ligand, α-galactosylceramide (αGalCer, KRN7000), in a CD1d-dependent manner. I.v. administration of αGalCer-pulsed dendritic cells (DC) induces significant activation and expansion of Vα14 NKT cells in the lung and resulting potent antitumor activities in mouse tumor metastatic models. We did a phase I dose escalation study with αGalCer-pulsed DCs in lung cancer patients.

Experimental Design: Patients with advanced non–small cell lung cancer or recurrent lung cancer received i.v. injections of αGalCer-pulsed DCs (level 1: 5 × 107/m2; level 2: 2.5 × 108/m2; and level 3: 1 × 109/m2) to test the safety, feasibility, and clinical response. Immunomonitoring was also done in all completed cases.

Results: Eleven patients were enrolled in this study. No severe adverse events were observed during this study in any patient. After the first and second injection of αGalCer-pulsed DCs, dramatic increase in peripheral blood Vα24 NKT cells was observed in one case and significant responses were seen in two cases receiving the level 3 dose. No patient was found to meet the criteria for partial or complete responses, whereas two cases in the level 3 group remained unchanged for more than a year with good quality of life.

Conclusions: In this clinical trial, αGalCer-pulsed DC administration was well tolerated and could be safely done even in patients with advanced disease.
SMAD4 as a Prognostic Marker in Colorectal Cancer
Authors: Alazzouzi Hafid , Alhopuro Pia , Salovaara Reijo , Sammalkorpi Heli , Järvinen Heikki , Mecklin Jukka-Pekka , Hemminki Akeseli , Schwartz Simo , Aaltonen Lauri A. , Arango Diego
Published: September 2005

More than 50% of patients with Dukes C colorectal cancer have disease recurrence and die within 5 years after surgical removal of their primary tumor. It is currently not possible to distinguish patients with good and bad prognosis. SMAD4 is an important tumor suppressor gene that mediates transforming growth factor-β superfamily signaling and is located in chromosome 18q21, a region with frequent genetic losses in these tumors. Allelic imbalance in 18q has been linked to poor prognosis in a subset of colorectal cancer patients. Therefore, we generated a tissue microarray containing triplicate tumor samples from 86 Dukes C patients and used immunohistochemistry to assess the relative expression level of SMAD4 and its value as a prognostic marker. In addition, SMAD4 was screened for mutations and two polymorphic microsatellite markers were used to assess the presence of allelic imbalance in these tumors. Patients with tumors expressing high SMAD4 levels had significantly better overall (P < 0.025) and disease-free (P < 0.013) survival than patients with low levels. This identifies SMAD4 as a prognostic marker for Dukes C colorectal cancer. Although all tumors with absent SMAD4 staining showed allelic imbalance in 18q21, tumors with 18q21 allelic imbalance as a group showed no difference in SMAD4 levels compared with tumors without allelic imbalance, suggesting that additional mechanisms of SMAD4 down-regulation exist. In addition, although SMAD4 mutations were found in five tumors, they were not associated with shorter survival. In conclusion, the level of expression of SMAD4 was found to be a more sensitive marker than 18q21 allelic imbalance and SMAD4 mutations, which were of no prognostic significance for these patients.
Evasion of a Single-Step, Chemotherapy-Induced Senescence in Breast Cancer Cells: Implications for Treatment Response
Authors: Elmore Lynne W. , Di Xu , Dumur Catherine , Holt Shawn E. , Gewirtz David A.
Published: September 2005

Purpose: The purpose of this study is to define the mechanistic basis for recovery of proliferative capacity in breast tumor cells after chemotherapy. Here, we test the hypothesis that evasion of senescence confers resistance to chemotherapeutic drugs and ionizing radiation.

Experimental Design: MCF-7 cells were treated with a single, clinically relevant dose (0.75-1.0 μmol/L) of Adriamycin. Two weeks following induction of senescence, clonal outgrowths were expanded and characterized in terms of senescence-associated β-galactosidase activity, gene expression profiles (Affymetrix U95 probe sets, Affymetrix, Santa Clara, CA) with confirmatory Western analyses, and telomerase activity following a second drug treatment. Levels of intracellular Adriamycin, as well as cross-resistance to other therapeutic agents, were also determined to define the resistance phenotype.

Results: A senescence-resistant (SR) clone (clone 2) was identified that was largely refractory to both Adriamycin-induced and γ-irradiation–induced senescence. Clone 2 continued to proliferate and maintain high levels of telomerase activity following a second drug treatment, when treated parental cells expressed very low levels of telomerase and many positive cell cycle regulators. SR clone 2 also expressed substantially more cdc-2 than parental cells and undetectable levels of MDR1, showed an intact p53 checkpoint and only a modestly lower level of intracellular drug accumulation, while exhibiting cross-resistance to other topoisomerase inhibitors.

Conclusions: SR clone 2 is intrinsically resistant to DNA damage–induced senescence perhaps through an ability to prevent down-regulation of cdc-2. Telomerase is a marker of proliferative recovery for breast cancer cells after chemotherapy exposure. Evasion or escape from a single-step, drug-induced senescence may represent a unique and previously unrecognized drug-resistance phenotype.
Caspase Regulation in Non–Small Cell Lung Cancer and its Potential for Therapeutic Exploitation
Authors: Fennell Dean A.
Published: September 2005

Metastatic non–small cell lung cancer (NSCLC, stages IIIB/IV) is one of the most common and rapidly lethal causes of cancer related mortality worldwide. Efficacy of chemotherapy, the mainstay of treatment, is limited due to resistance in the vast majority of patients. NSCLC cells exhibit intrinsic apoptosis resistance. Understanding the molecular basis of this phenotype is critical, if therapy is to move beyond the therapeutic plateau that has been reached with conventional chemotherapy. Caspases occupy a pivotal position in the final common pathway of apoptosis. Increasing evidence suggests that these proteases are constitutively inhibited in NSCLC. This review discusses current knowledge relating to caspase regulation in NSCLC and highlights novel strategies for reversing the apoptosis resistant phenotype, with potential to accelerate development of effective therapy.
Severe Drug Toxicity Associated with a Single-Nucleotide Polymorphism of the Cytidine Deaminase Gene in a Japanese Cancer Patient Treated with Gemcitabine plus Cisplatin
Authors: Yonemori Kan , Ueno Hideki , Okusaka Takuji , Yamamoto Noboru , Ikeda Masafumi , Saijo Nagahiro , Yoshida Teruhiko , Ishii Hiroshi , Furuse Junji , Sugiyama Emiko , Kim Su-Ryang , Kikura-Hanajiri Ruri , Hasegawa Ryuichi , Saito Yoshiro , Ozawa Shogo , Kaniwa Nahoko , Sawada Jun-ichi
Published: September 2005

Purpose: We investigated single-nucleotide polymorphisms of the cytidine deaminase gene (CDA), which encodes an enzyme that metabolizes gemcitabine, to clarify the relationship between the single-nucleotide polymorphism 208G>A and the pharmacokinetics and toxicity of gemcitabine in cancer patients treated with gemcitabine plus cisplatin.

Experimental Design: Six Japanese cancer patients treated with gemcitabine plus cisplatin were examined. Plasma gemcitabine and its metabolite 2′,2′-difluorodeoxyuridine were measured using an high-performance liquid chromatography method, and the CDA genotypes were determined with DNA sequencing.

Results: One patient, a 45-year-old man with pancreatic carcinoma, showed severe hematologic and nonhematologic toxicities during the first course of chemotherapy with gemcitabine and cisplatin. The area under the concentration-time curve value of gemcitabine in this patient (54.54 μg hour/mL) was five times higher than the average value for five other patients (10.88 μg hour/mL) treated with gemcitabine plus cisplatin. The area under the concentration-time curve of 2′,2′-difluorodeoxyuridine in this patient (41.58 μg hour/mL) was less than the half of the average value of the five patients (106.13 μg hour/mL). This patient was found to be homozygous for 208A (Thr70) in the CDA gene, whereas the other patients were homozygous for 208G (Ala70).

Conclusion: Homozygous 208G>A alteration in CDA might have caused the severe drug toxicity experienced by a Japanese cancer patient treated with gemcitabine plus cisplatin.
In vivo Generation of Angiostatin Isoforms by Administration of a Plasminogen Activator and a Free Sulfhydryl Donor: A Phase I Study of an Angiostatic Cocktail of Tissue Plasminogen Activator and Mesna
Authors: Soff Gerald A. , Wang Hao , Cundiff Deborah L. , Jiang Keyi , Martone Brenda , Rademaker Alfred W. , Doll Jennifer A. , Kuzel Timothy M.
Published: September 2005

Purpose: Angiostatin4.5 (AS4.5), the endogenous human angiostatin, is derived from plasminogen in a two-step process. A plasminogen activator converts plasminogen to plasmin, then plasmin undergoes autoproteolysis to AS4.5. A free sulfhydryl donor can mediate plasmin autoproteolysis. To translate this process to human cancer therapy, we conducted a phase I trial of administration of a tissue plasminogen activator (tPA) with a free sulfhydryl donor (mesna).

Patients and Methods: Fifteen patients with advanced solid tumors were treated. The dose of tPA was escalated (cohorts; 1, 2, 3, 5, and 7.5 mg/h for 6 hours). Mesna was administered as a 240 mg/m2 bolus followed by an infusion of 50 mg/h, concurrent with tPA. Both tPA and mesna were administered 3 consecutive days every 14 days.

Results: No dose-limiting toxicity was observed. Two AS4.5 isoforms were generated, Lys-AS4.5 and Glu-AS4.5. Mean baseline Lys-AS4.5 level was 20.4 nmol/L (SE, 2.9). In the 5 mg/h tPA cohort, Lys-AS4.5 levels increased by an average of 143% or 24 nmol/L (SE, 4.9) above baseline. Glu-AS4.5 (Mr ∼ 62,000) was also generated (additional 77 amino acids at amino terminus compared with Lys-AS4.5). Glu-AS4.5 level at baseline was undetectable in four of five patients in the 5 mg/h tPA cohort, but at end of infusion, was ∼67 nmol/L (SE, 20). Two patients in the 5 mg/h tPA cohort experienced decreases in tumor markers with treatment, although no clinical objective responses were observed.

Conclusion: This study shows that in vivo generation of AS4.5 is safe in humans and may provide a practical approach to achieve antiangiogenic therapy.
Anti-Flt1 Peptide, a Vascular Endothelial Growth Factor Receptor 1–Specific Hexapeptide, Inhibits Tumor Growth and Metastasis
Authors: Bae Dong-Goo , Kim Tae-Dong , Li Ge , Yoon Wan-Hee , Chae Chi-Bom
Published: September 2005

Purpose: The purpose of this study was to develop antagonists specific for the vascular endothelial growth factor receptor 1 (VEGFR1) and to investigate the effects of the antagonists on the VEGF-induced endothelial cell functions and tumor progression.

Experimental Design: Hexapeptides that inhibit binding of VEGFR1 and VEGF were identified through screening of synthetic peptide library. A selected peptide, anti-Flt1, was investigated for binding specificity with various receptors and ligand peptides. Effects of the peptide on proliferation, cell migration, and fibrin gel–based angiogenesis of endothelial cells were also investigated. The activity of anti-Flt1, in vivo, was evaluated for inhibition of tumor growth and metastasis in VEGF-secreting cancer cell–implanted mice by s.c. injections of the peptide.

Results: Here, we report on a short peptide that binds to VEGFR1 and prevents binding of VEGF. A hexapeptide, anti-Flt1 (Gly-Asn-Gln-Trp-Phe-Ile or GNQWFI), was identified from peptide libraries. The anti-Flt1 peptide shows specificity toward binding to VEGFR1 and it inhibits binding of VEGF, placental growth factor (PlGF), and VEGF/PlGF heterodimer to VEGFR1. This peptide does not inhibit the proliferation of endothelial cells induced by VEGF and VEGF/PlGF heterodimer but it effectively blocks VEGF-induced migration of endothelial cells and their capacity to form capillary-like structures on fibrin gel–based in vitro angiogenesis system. Furthermore, growth and metastasis of VEGF-secreting tumor cells were also significantly inhibited by s.c. injections of anti-Flt1 peptide in nude mice. Accordingly, VEGF-induced migration and capillary formation are mediated through VEGFR1, and these processes may play an important role in the growth and metastasis of VEGF-secreting tumors.

Conclusions: We show that a peptide (anti-Flt1) specific for VEGFR1 inhibits growth and metastasis of tumor that secretes VEGF. The effects on endothelial cell functions, in vitro, indicate that the anticancer activity of anti-Flt1 peptide with reduced blood vessel density could also be due to the blocking of VEGFR1-mediated endothelial cell migration and tube formation. Although the effects of anti-Flt1 peptide still remain to be further characterized, the receptor 1–specific peptide antagonist, anti-Flt1, has potential as a therapeutic agent for various angiogenesis-related diseases, especially cancer.
In vivo Effects of the Human Type I Insulin-Like Growth Factor Receptor Antibody A12 on Androgen-Dependent and Androgen-Independent Xenograft Human Prostate Tumors
Authors: Wu Jennifer D. , Odman Austin , Higgins Lily M. , Haugk Kathy , Vessella Robert , Ludwig Dale L. , Plymate Stephen R.
Published: September 2005

Purpose: The type I insulin-like growth factor receptor (IGF-IR) and its ligands have been shown to play a critical role in prostate carcinoma development, growth, and metastasis. Targeting the IGF-IR may be a potential treatment for prostate cancer. A fully human monoclonal antibody, A12, specific to IGF-IR, has shown potent antitumor effects in breast, colon, and pancreatic cancers in vitro and in vivo. In this study, we tested the in vivo effects of A12 on androgen-dependent and androgen-independent prostate tumor growth.

Experimental Design: Androgen-dependent LuCaP 35 and androgen-independent LuCaP 35V prostate tumors were implanted s.c. into intact and castrated severe combined immunodeficient mice, respectively. When tumor volume reached about 150 to 200 mm3, A12 was injected at 40 mg/kg body weight thrice a week for up to 5 weeks.

Results: We find that A12 significantly inhibits growth of androgen-dependent LuCaP 35 and androgen-independent LuCaP 35V prostate xenografts, however, by different mechanisms. In LuCaP 35 xenografts, A12 treatment induces tumor cell apoptosis or G1 cycle arrest. In LuCaP 35V xenografts, A12 treatment induces tumor cell G2-M cycle arrest. Moreover, we find that blocking the function of IGF-IR down-regulates androgen-regulated gene expression in androgen-independent LuCaP 35V tumor cells.

Conclusions: Our findings suggest that A12 is a therapeutic candidate for both androgen-dependent and androgen-independent prostate cancer. Our findings also suggest an IGF-IR–dependent activity of the androgen receptor in androgen-independent prostate cancer cells.
Green Tea Extract Modulates Actin Remodeling via Rho Activity in an In vitro Multistep Carcinogenic Model
Authors: Lu Qing-Yi , Jin Yu-Sheng , Pantuck Allan , Zhang Zuo-Feng , Heber David , Belldegrun Arie , Brooks Mai , Figlin Robert , Rao JianYu
Published: September 2005

Alteration of actin polymerization and loss of actin filaments is a marker of cellular dedifferentiation and early malignant transformation. To study this phenomenon, an in vitro human urothelial model consisting of two cell lines, HUC-PC and MC-T11, were incorporated into the study design. These two cell lines have different malignant transformation potential. The effect of green tea extract (GTE), a potential anticancer agent, on actin remodeling was investigated. Upon exposure to the carcinogen 4-aminobiphenyl (4-ABP), the untransformed HUC-PC undergoes malignant transformation whereas the transformed MC-T11 progresses from noninvasive to invasive tumor. GTE induces actin polymerization in MC-T11 cells in a dose-responsive manner, but this effect is less obvious in the untransformed, more differentiated HUC-PC cells, which natively have higher actin polymerization status. In contrast, GTE antagonizes carcinogen 4-ABP induced actin depolymerization and stress fiber disruption in HUC-PC cells. In MC-T11 cells, GTE inhibits 4-ABP induced motility by increasing cell adhesion and focal adhesion complex formation. The effect of GTE on actin remodeling seems to be mediated by the stimulation of small GTP-binding protein Rho activity, because C3 exoenzyme, a specific inhibitor for Rho, blocks GTE-mediated Rho activation and stress fiber formation in MC-T11 cells. This study shows that GTE exerts an effect on cytoskeletal actin remodeling and provides further support for the use of GTE as a chemopreventive agent.
Endocrine Effects of Tamoxifen Plus Exemestane in Postmenopausal Women with Breast Cancer
Authors: Love Richard R. , Hutson Paul R. , Havighurst Thomas C. , Cleary James F.
Published: September 2005

Purpose: In some specific circumstances, combined hormonal therapies for breast cancer seem to be more effective than single maneuvers. In two laboratory mammary cancer models, the combination of the aromatase inactivator exemestane plus tamoxifen gives a higher response rate than is found with either agent alone.

To evaluate the endocrine effects of the combination of exemestane and tamoxifen, we studied 33 postmenopausal women disease-free following primary treatments for breast cancer who were taking tamoxifen for at least 3 months.

Design: After observation for symptoms on tamoxifen for 4 weeks, blood samples were taken and patients were begun additionally on exemestane 25 mg p.o. qd. Eight weeks later, blood samples were again taken, and exemestane was discontinued.

Results: A decrease in alkaline phosphatase was found with exemestane treatment (P = 0.06), whereas no change in osteocalcin level was observed. A decrease in high-density lipoprotein cholesterol level was found (P = 0.0025), whereas total cholesterol, low-density lipoprotein cholesterol and triglyceride levels showed no changes with exemestane treatment. Estradiol, estrone, and estrone sulfate levels decreased to immeasurable or very low levels with exemestane treatment (all P < 0.001). No significant changes in frequencies of common drug-associated side effects, such as vasomotor symptoms or weight change, were found.

Conclusions: Based on the absence of adverse endocrine effects with the addition of exemestane to tamoxifen therapy observed in this study, further clinical evaluation of the efficacy of this combination is warranted.
Association of NCOA3 Polymorphisms with Breast Cancer Risk
Authors: Burwinkel Barbara , Wirtenberger Michael , Klaes Rüdiger , Schmutzler Rita K. , Grzybowska Ewa , Försti Asta , Frank Bernd , Bermejo Justo Lorenzo , Bugert Peter , Wappenschmidt Barbara , Butkiewicz Dorota , Pamula Jolanta , Pekala Wioletta , Zientek Helena , Mielzynska Danuta , Siwinska Ewa , Bartram Claus R. , Hemminki Kari
Published: September 2005

The nuclear receptor coactivator 3 (NCOA3, also known as AIB1) is a coactivator of nuclear receptors like the estrogen receptor. NCOA3 is overexpressed in ∼60% of primary human breast tumors, and high levels of NCOA3 expression are associated with tamoxifen resistance and worse survival rate. In contrast, NCOA3 deficiency suppresses v-Ha-ras–induced breast cancer initiation and progression in mice. Here, we analyzed the influence of NCOA3 coding single nucleotide polymorphisms on breast cancer risk by performing a case-control study using a German and a Polish study population and identified an association between NCOA3 polymorphisms and breast cancer. A joint analysis of the German and the Polish study population revealed a significant protective effect for the 1758G>C (Q586H) and 2880A>G (T960T) variants. In addition, haplotype analysis showed a protective effect of the 1758C-2880A and 1758G-2880G haplotypes (odds ratio 0.79; 95% confidence interval, 0.67-0.93; P = 0.004). Because of the impact of NCOA3 in antiestrogen therapy resistance, these polymorphisms might also influence therapy outcome in breast cancer.
B7-H4 Is Highly Expressed in Ductal and Lobular Breast Cancer
Authors: Tringler Barbara , Zhuo Shaoqiu , Pilkington Glenn , Torkko Kathleen C. , Singh Meenakshi , Lucia M. Scott , Heinz David E. , Papkoff Jackie , Shroyer Kenneth R.
Published: September 2005

Purpose: This study was designed to investigate the expression of B7-H4 protein, a member of the B7 family that is involved in the regulation of antigen-specific immune responses, in normal breast and in primary and metastatic breast carcinomas.

Experimental Design: Archival formalin-fixed tissue blocks from breast cancers and normal somatic tissues were evaluated for B7-H4 expression by immunohistochemistry with manual and automated image analysis. The proportion of B7-H4-positive cells and the intensity of B7-H4 staining were compared with histologic type, grade, stage, hormone receptor status, and HER-2/neu status.

Results: B7-H4 was detected in 165 of 173 (95.4%) primary breast cancers and in 240 of 246 (97.6%) metastatic breast cancers. B7-H4 staining intensity was greater in invasive ductal carcinomas [24.61 relative units (RU)] and in invasive lobular carcinomas (15.23 RU) than in normal breast epithelium (4.30 RU, P = 0.0003). Increased staining intensity was associated with negative progesterone receptor status (P = 0.014) and history of neoadjuvant chemotherapy (P = 0.004), and the proportion of B7-H4-positive cells was associated with negative progesterone receptor (P = 0.001) and negative HER-2/neu (P = 0.024) status. However, there was no statistically significant relationship between the proportion of B7-H4-positive cells or staining intensity and grade, stage, or other clinicopathologic variables. Low levels of B7-H4 expression were also detected in epithelial cells of the female genital tract, lung, pancreas, and kidney, but B7-H4 was generally absent in most other normal somatic tissues.

Conclusions: The nearly ubiquitous expression of B7-H4 in breast cancer, independent of tumor grade or stage, suggests a critical role for this protein in breast cancer biology.
Shc Family Expression in Neuroblastoma: High Expression of shcC Is Associated with a Poor Prognosis in Advanced Neuroblastoma
Authors: Terui Elena , Matsunaga Tadashi , Yoshida Hideo , Kouchi Katsunori , Kuroda Hiroaki , Hishiki Tomoro , Saito Takeshi , Yamada Shin-ichi , Shirasawa Hiroshi , Ohnuma Naomi
Published: September 2005

The biological features and prognosis of neuroblastoma, a neural crest-derived pediatric tumor, are closely associated with expression of the Trk receptor. Because the Shc family proteins (ShcA, ShcB, and ShcC) are adaptors for various receptors, including Trk receptors, and are regulators of neuronal cell development, we speculated that they may play a role in neuroblastoma. Therefore, in this study, we used semiquantitative reverse transcription-PCR to examine the expression of these three genes in 15 neuroblastoma cell lines, an all-trans-retinoic acid–treated neuroblastoma cell line, and 52 tumor samples. In neuroblastoma cell lines and tumor samples, shcA was ubiquitously and highly expressed. Little expression of shcA was observed. Also, shcB was hardly expressed in neuroblastoma cell lines, but its expression in RT-BM-1 cells was enhanced after all-trans-retinoic acid–induced differentiation, and it was highly expressed in low-stage tumors (P = 0.0095). This suggests that ShcB participates in cellular differentiation and may correlate with a favorable prognosis in neuroblastoma. Finally, the expression of shcC was observed in most of the neuroblastoma cell lines and in some stage 4 patients. Patients with a high expression of shcC had a very poor prognosis (P < 0.0001) and amplification of MYCN, and all died within 31 months after diagnosis. Therefore, ShcC seems to be associated with an aggressive tumor phenotype, perhaps by enhancing TrkB signals. Our results suggest that the expressions of shcB and shcC are important biological factors in neuroblastoma and are useful prognostic indicators.
Cleavage of L1 in Exosomes and Apoptotic Membrane Vesicles Released from Ovarian Carcinoma Cells
Authors: Gutwein Paul , Stoeck Alexander , Riedle Svenja , Gast Daniela , Runz Steffen , Condon Thomas P. , Marmé Alexander , Phong Minh-Chau , Linderkamp Otwin , Skorokhod Alexander , Altevogt Peter
Published: September 2005

Purpose: The L1 adhesion molecule (CD171) is overexpressed in human ovarian and endometrial carcinomas and is associated with bad prognosis. Although expressed as a transmembrane molecule, L1 is released from carcinoma cells in a soluble form. Soluble L1 is present in serum and ascites of ovarian carcinoma patients. We investigated the mode of L1 cleavage and the function of soluble L1.

Experimental Design: We used ovarian carcinoma cell lines and ascites from ovarian carcinoma patients to analyze soluble L1 and L1 cleavage by Western blot analysis and ELISA.

Results: We find that in ovarian carcinoma cells the constitutive cleavage of L1 proceeds in secretory vesicles. We show that apoptotic stimuli like C2-ceramide, staurosporine, UV irradiation, and hypoxic conditions enhance L1-vesicle release resulting in elevated levels of soluble L1. Constitutive cleavage of L1 is mediated by a disintegrin and metalloproteinase 10, but under apoptotic conditions multiple metalloproteinases are involved. L1 cleavage occurs in two types of vesicles with distinct density features: constitutively released vesicles with similarity to exosomes and apoptotic vesicles. Both types of L1-containing vesicles are present in the ascites fluids of ovarian carcinoma patients. Soluble L1 from ascites is a potent inducer of cell migration and can trigger extracellular signal-regulated kinase phosphorylation.

Conclusions: We suggest that tumor-derived vesicles may be an important source for soluble L1 that could regulate tumor cell function in an autocrine/paracrine fashion.