bluuebunny/crossref_metadata_2025_split huggingface dataset:
Melanoma Differentiation Associated Gene-7/Interleukin-24 Promotes Tumor Cell-Specific Apoptosis through Both Secretory and Nonsecretory Pathways
Authors: Sauane Moira , Lebedeva Irina V. , Su Zao-zhong , Choo Heng-tong , Randolph Aaron , Valerie Kristoffer , Dent Paul , Gopalkrishnan Rahul V. , Fisher Paul B. 
Published: September 2005

Abstract
Melanoma differentiation associated gene-7/interleukin-24 (Mda-7/IL-24), a novel member of the IL-10 family of cytokines, uniquely displays cancer-specific apoptosis-inducing activity. Positive results in ongoing phase I/II clinical trials have strengthened the possibility of its utilization as a cancer gene therapeutic. Previous studies document that signaling events leading to Ad.mda-7-induced transformed cell apoptosis are tyrosine kinase-independent. These results suggest that mda-7/IL-24 cancer cell-specific activity could occur through mechanisms independent of binding to its currently recognized cognate receptors and might even occur independent of receptor function. An adenovirus vector expressing a nonsecreted version of MDA-7/IL-24 protein was generated via deletion of its signal peptide. This nonsecreted protein was as effective as wild-type secreted MDA-7/IL-24 in inducing apoptosis in prostate carcinoma cell lines and displayed transformed cell specificity and localization of MDA-7/IL-24 in the Golgi/endoplasmic reticulum compartments. Our results indicate that mda-7/IL-24-mediated apoptosis can be triggered through a combination of intracellular as well as secretory mechanisms and can occur efficiently in the absence of protein secretion.
Flavopiridol Induces p53 via Initial Inhibition of Mdm2 and p21 and, Independently of p53, Sensitizes Apoptosis-Reluctant Cells to Tumor Necrosis Factor
Authors: Demidenko Zoya N. , Blagosklonny Mikhail V. 
Published: September 2005

Abstract
Flavopiridol (FP) inhibits gene expression and causes apoptosis, and these effects cannot be explained by inhibition of cyclin-dependent kinases that govern cell cycle. The simple and established notion that FP is an inhibitor of transcription predicts its effects. Because Mdm-2 targets p53 for degradation, FP, as predicted, dramatically induced p53 by inhibiting Mdm-2. Once p53 was induced, restoration of transcription (by removal of FP) resulted in superinduction of p21 and Mdm-2. Similarly, low concentrations of FP (50 nm) induced p21 and Mdm-2 because of their initial down-regulation. A sustained decrease of Mdm-2/p21 expression and accumulation of p53 coincided with near-maximal cytotoxicity of FP at concentrations &gt;100 nm. Induction of p53 was a marker, not a cause, of cytotoxicity. FP caused rapid apoptosis (caspase-dependent cell death) in p53-null leukemia cells. In these cells, FP-induced apoptosis was converted to growth arrest by inhibitors of caspases. In apoptosis-reluctant A549 and PC3M cancer cells, FP inhibited cell proliferation but did not cause apoptosis. Like typical inhibitors of transcription, FP sensitized cells to apoptotic stimuli, allowing tumor necrosis factor to cause rapid and massive apoptosis in otherwise apoptosis-reluctant cells. We discuss that, as a reversible inhibitor of transcription, FP can be used clinically in novel rational drug combinations.
Complex Regulation of Signal Transducers and Activators of Transcription 3 Activation in Normal and Malignant Keratinocytes
Authors: Quadros Marlene R. D. , Peruzzi Francesca , Kari Csaba , Rodeck Ulrich 
Published: September 2005

Abstract
Previous work implicated activation of the signal transducer and activator of transcription (STAT)3 downstream of the epidermal growth factor receptor (EGFR) in the malignant phenotype of squamous carcinoma cells (SCC). Here, we show that EGFR-dependent STAT3 activation is restricted to malignant keratinocytes. Specifically, constitutive and epidermal growth factor-induced phosphorylation of STAT3 on Y705 was observed only in SCC but not in either immortalized (HaCaT) or normal keratinocyte strains. Furthermore, STAT3 activation as determined by DNA binding assays was restricted to SCC and dependent on EGFR activation. Forced expression of EGFR in immortalized keratinocytes (HaCaT cells) was associated with enhanced EGFR activation but not STAT3-Y705 phosphorylation. EGFR-dependent activation of mitogen-activated protein kinase (MAPK) kinase 1 negatively regulated STAT3-Y705 phosphorylation in normal and malignant keratinocytes. Together, these results underscore that EGFR activation is required but not sufficient for STAT3 activation to occur in malignant keratinocytes. They also highlight complex regulation of STAT3 phosphorylation through EGFR activation including negative regulation via the MAPK kinase/MAPK signaling pathway.
Position in Cell Cycle Controls the Sensitivity of Colon Cancer Cells to Nitric Oxide-Dependent Programmed Cell Death
Authors: Jarry Anne , Charrier Laetitia , Bou-Hanna Chantal , Devilder Marie-Claire , Crussaire Véronique , Denis Marc G. , Vallette Geneviève , Laboisse Christian L. 
Published: September 2005

Abstract
Mounting evidence suggests that the position in the cell cycle of cells exposed to an oxidative stress could determine their survival or apoptotic cell death. This study aimed at determining whether nitric oxide (NO)-induced cell death in colon cancer cells might depend on their position in the cell cycle, based on a clone of the cancer cell line HT29 exposed to an NO donor, in combination with the manipulation of the cell entry into the cell cycle. We show that PAPA NONOate (pNO), from 10−4 m to 10−3 m, exerted early and reversible cytostatic effects through ribonucleotide reductase inhibition, followed by late resumption of cell growth at 5 × 10−4 m pNO. In contrast, 10−3 m pNO led to late programmed cell death that was accounted for by the progression of cells into the cell cycle as shown by (a) the accumulation of apoptotic cells in the G2-M phase at 10−3 m pNO treatment; and (b) the prevention of cell death by inhibiting the entry of cells into the cell cycle. The entry of pNO-treated cells into the G2-M phase was associated with actin depolymerization and its S-glutathionylation in the same way as in control cells. However, the pNO treatment interfered with the build-up of a high reducing power, associated in control cells with a dramatic increase in reduced glutathione biosynthesis in the G2-M phase. This oxidative stress prevented the exit from the G2-M phase, which requires a high reducing power for actin deglutathionylation and its repolymerization. Finally, our demonstration that programmed cell death occurred through a caspase-independent pathway is in line with the context of a nitrosative/oxidative stress. In conclusion, this work, which deciphers the connection between the position of colonic cancer cells in the cell cycle and their sensitivity to NO-induced stress and their programmed cell death, could help optimize anticancer protocols based on NO-donating compounds.
Quantifying Transient Hypoxia in Human Tumor Xenografts by Flow Cytometry
Authors: Bennewith Kevin L. , Durand Ralph E. 
Published: September 2005

Abstract
Transient hypoxia is a poorly understood and potentially important factor that may limit tumor response to various forms of therapy. We assessed transient hypoxia on a global scale in two different human tumor xenografts by sequentially administering two hypoxia markers followed by quantification of hypoxic cells using flow cytometry. High levels of the first hypoxia marker (pimonidazole) were maintained in the circulation over an 8-hour period by multiple hourly injections, providing a “time-integrated” hypoxia measure showing an asymptotic increase in the total number of hypoxic cells. Subsequent administration of a second hypoxia marker (CCI-103F) showed that substantial numbers of the previously pimonidazole-labeled cells were no longer hypoxic during the circulation lifetime of the second marker. The overall fraction of tumor cells that demonstrated changes in hypoxic status with time increased with different kinetics and by different magnitudes in the two xenograft systems. Specifically, up to 20% of the cells in SiHa (human cervical squamous cell carcinoma) tumors and up to 8% of the cells in WiDr (human colon adenocarcinoma) tumors were intermittently hypoxic over an 8-hour period. Also, the tumor cells that demonstrated transient hypoxia were typically not adjacent to functional tumor blood vessels. Similar approaches could be used in the clinic to provide information on the duration of intermittent hypoxia episodes and the fraction of transiently hypoxic tumor cells, which would, in turn, have important implications for the strategic improvement of cancer therapy.
Molecular Profiling of Human Hepatocellular Carcinoma Defines Mutually Exclusive Interferon Regulation and Insulin-Like Growth Factor II Overexpression
Authors: Breuhahn Kai , Vreden Sebastian , Haddad Ramsi , Beckebaum Susanne , Stippel Dirk , Flemming Peer , Nussbaum Tanja , Caselmann Wolfgang H. , Haab Brian B. , Schirmacher Peter 
Published: September 2005

Abstract
Molecular subtyping of human hepatocellular carcinoma (HCC) with potential mechanistic and therapeutic impact has not been achieved thus far. We have analyzed the mRNA expression patterns of 43 different human HCC samples and 3 HCC cell lines in comparison with normal adult liver using high-density cDNA microarrays. Two main groups of HCC, designated group A (65%) and group B (35%), were distinguished based on clustering of the most highly varying genes. Group A HCCs were characterized by induction of a number of interferon (IFN)-regulated genes, whereas group B was characterized mainly by down-regulation of several apoptosis-relevant and IFN-regulated genes. The number of apoptotic tumor cells and tumor-infiltrating lymphocytes was significantly higher in tumors of group A as compared with those of group B. Based on the expression pattern, group B was further subdivided into two subgroups, designated subgroup B1 (6 of 43 tumors, 14%) and subgroup B2 (9 of 43 tumors, 21%). A prominent characteristic of subgroup B1 was high overexpression of insulin-like growth factor (IGF)-II. All tested HCC cell lines expressed equally high concentrations of IGF-II transcripts and co-segregated with group B1 in clustering. IGF-II overexpression and induction of IFN-related genes were mutually exclusive, even when analysis was extended to other cancer expression profile studies. Moreover, IFN-γ treatment substantially reduced IGF-II expression in HCC cells. In conclusion, cDNA microarray analyses provided subtyping of HCCs that is related to intratumor inflammation and tumor cell apoptosis. This profiling may be of mechanistic and therapeutic impact because IGF-II overexpression has been linked to reduced apoptosis and increased proliferation and may be accessible to therapeutic intervention.
Transduction of Soluble
Flt-1
Gene to Peritoneal Mesothelial Cells Can Effectively Suppress Peritoneal Metastasis of Gastric Cancer
Authors: Sako Akihiro , Kitayama Joji , Koyama Hiroyuki , Ueno Hikaru , Uchida Hiroaki , Hamada Hirofumi , Nagawa Hirokazu 
Published: September 2005

Abstract
The prognosis of gastric cancer with peritoneal metastasis has not improved. Despite many promising studies, gene therapy has limited clinical application because of the lack of suitable vector systems to enable selective gene transduction to tumor cells. The aim of this study was to clarify whether gene therapy targeted to peritoneal mesothelial cells (PMCs) can inhibit peritoneal dissemination of gastric cancer. In vitro experiments showed that adenovirus expressing LacZ infected human omental tissue-derived PMCs more efficiently than human gastric cancer cell lines MKN1 and MKN45. When adenovirus expressing LacZ was injected into the peritoneal cavity of nude mice, the expression was detected in the peritoneum for at least 4 weeks. Furthermore, when adenovirus expressing soluble Flt-1 (Ad-sFLT-1) was i.p. administered in vivo, a high level of sFlt-1 protein could be detected in peritoneal lavage for 8 weeks. When MKN45 cells were i.p. inoculated 3 days after adenoviral vector injection, Ad-sFLT-1 markedly reduced the number of metastatic nodules larger than 1 mm in diameter on the peritoneal surface, and significantly prolonged the survival of nude mice without any significant side effects. Thus, peritoneal dissemination was significantly suppressed by a single i.p. injection of Ad-sFlt-1. Anti-angiogenic gene therapy targeted to PMCs could be a novel and practical strategy against peritoneal dissemination of gastric cancer, because it does not require tumor-specific gene transfer.
Tetrandrine Induces Early G1 Arrest in Human Colon Carcinoma Cells by Down-Regulating the Activity and Inducing the Degradation of G1-S–Specific Cyclin-Dependent Kinases and by Inducing p53 and p21Cip1
Authors: Meng Ling-hua , Zhang Hongliang , Hayward Larry , Takemura Haruyuki , Shao Rong-Guang , Pommier Yves 
Published: September 2005

Abstract
Tetrandrine is an antitumor alkaloid isolated from the root of Stephania tetrandra. We find that micromolar concentrations of tetrandrine irreversibly inhibit the proliferation of human colon carcinoma cells in MTT and clonogenic assays by arresting cells in G1. Tetrandrine induces G1 arrest before the restriction point in nocodazole- and serum-starved synchronized HT29 cells, without affecting the G1-S transition in aphidicolin-synchronized cells. Tetrandrine-induced G1 arrest is followed by apoptosis as shown by fluorescence-activated cell sorting, terminal deoxynucleotidyl transferase–mediated nick end labeling, and annexin V staining assays. Tetrandrine-induced early G1 arrest is mediated by at least three different mechanisms. First, tetrandrine inhibits purified cyclin-dependent kinase 2 (CDK2)/cyclin E and CDK4 without affecting significantly CDK2/cyclin A, CDK1/cyclin B, and CDK6. Second, tetrandrine induces the proteasome-dependent degradation of CDK4, CDK6, cyclin D1, and E2F1. Third, tetrandrine increases the expression of p53 and p21Cip1 in wild-type p53 HCT116 cells. Collectively, these results show that tetrandrine arrests cells in G1 by convergent mechanisms, including down-regulation of E2F1 and up-regulation of p53/p21Cip1.
The
ADPRT V762A
Genetic Variant Contributes to Prostate Cancer Susceptibility and Deficient Enzyme Function
Authors: Lockett Kristin L. , Hall M. Craig , Xu Jianfeng , Zheng S. Lilly , Berwick Marianne , Chuang Shu-Chun , Clark Peter E. , Cramer Scott D. , Lohman Kurt , Hu Jennifer J. 
Published: September 2005

Abstract
The ADP-ribosyltransferase (ADPRT) gene encodes a zinc-finger DNA-binding protein, poly(ADP-ribose) polymerase-1 (PARP-1), that modifies various nuclear proteins by poly(ADP-ribosyl)ation and functions as a key enzyme in the base excision repair pathway. We have conducted two studies to test whether an amino acid substitution variant, ADPRT V762A (T2444C), is associated with prostate cancer (CaP) risk and decreased enzyme function. The first study used genomic DNA samples from an ongoing, clinic-based case-control study (488 cases and 524 controls) to show that a higher percentage of the CaP cases carried the ADPRT 762 AA genotype than controls (4% versus 2%). In Caucasians, the AA genotype was significantly associated with increased CaP risk [odds ratio (OR), 2.65; 95% confidence interval (CI), 1.08–6.49], and the VA genotype was associated with a slight but not significantly increased CaP risk (OR, 1.18; 95% CI, 0.85–1.64) using VV as the referent group after adjustment for age, benign prostatic hyperplasia, and family history. Furthermore, this association was stronger in younger (&lt;65) men (OR, 4.77; 95% CI, 1.01–22.44) than older (≥65) men (OR, 1.78; 95% CI, 0.55–5.82). The second study used freshly isolated peripheral lymphocytes from 354 cancer-free subjects to demonstrate that the ADPRT 762 A allele contributed to significantly lower adenosine diphosphate ribosyl transferase (ADPRT)/PARP-1 activities in response to H2O2 in a gene dosage-dependent manner (P &lt; 0.0001, test for linear trend). The PARP-1 activities (mean ± SD dpm/106 cells) were 18,554 ± 9,070 (n = 257), 14,847 ± 7,082 (n = 86), and 12,155 ± 6,334 (n = 11) for VV, VA, and AA genotypes, respectively. This study is the first to provide evidence that the ADPRT V762A-genetic variant contributes to CaP susceptibility and altered ADPRT/PARP-1 enzyme function in response to oxidative damage.
Hypoxia-Induced Vascular Endothelial Growth Factor Transcription and Protection from Apoptosis Are Dependent on α6β1 Integrin in Breast Carcinoma Cells
Authors: Chung Jun , Yoon Sangoh , Datta Kaustubh , Bachelder Robin E. , Mercurio Arthur M. 
Published: September 2005

Abstract
The α6β1 integrin has been implicated in breast carcinoma progression, but the mechanisms involved remain elusive. MDA-MB-435 cells engineered to be deficient in α6β1 expression form primary tumors that are highly apoptotic and unable to metastasize, although they exhibit no increased apoptosis in vitro under standard culture conditions. Based on the hypothesis that α6β1 is necessary for the survival of these cells in the tumor microenvironment, we report here that hypoxia protects these cells from apoptosis induced by serum deprivation and that hypoxia-mediated protection requires α6β1 expression. We investigated the influence of α6β1 on vascular endothelial growth factor (VEGF) expression because autocrine VEGF is necessary for the survival of serum-deprived cells in hypoxia. The results obtained indicate that α6β1 is necessary for VEGF expression because the ability of hypoxia to activate HIF-1 and to stimulate VEGF transcription in MDA-MB-435 cells is dependent on α6β1 expression by a mechanism that involves protein kinase C-α.
Identification of Genetic Variants in Base Excision Repair Pathway and Their Associations with Risk of Esophageal Squamous Cell Carcinoma
Authors: Hao Bingtao , Wang Haijian , Zhou Kaixin , Li Yi , Chen Xiaoping , Zhou Gangqiao , Zhu Yunping , Miao Xiaoping , Tan Wen , Wei Qingyi , Lin Dongxin , He Fuchu 
Published: September 2005

Abstract
The etiology of esophageal squamous cell carcinoma (ESCC) has been shown to be associated with genetic and certain environmental factors that produce DNA damage. Base excision repair (BER) genes are responsible for repair of DNA damage caused by reactive oxygen species and other electrophiles and therefore are good candidate susceptibility genes for ESCC. We first screened eight BER genes for new and potential functional polymorphisms by resequencing 27 DNA samples. We then identified and genotyped for important tagging single nucleotide polymorphisms (SNPs) in a case-control study of 419 patients with newly diagnosed esophageal cancer and 480 healthy controls by frequency matching on age and sex. The association between genotypes and ESCC risk was estimated by unconditional multivariate logistic regression analysis, and stepwise regression procedure was used for constructing the final logistic regression model. We identified 129 SNPs in the eight BER genes, including 18 SNPs that cause amino acid changes. In the final model, 4 SNPs, including 2 in the coding regions (ADPRT Val762Ala and MBD4 Glu346Lys) and others in noncoding regions (LIG3 A3704G and XRCC1 T-77C), remained as significant predictors for the risk of ESCC. The adjusted odd ratios were 1.25 [95% confidence interval (CI) 1.02–1.53] for the ADPRT 762Ala allele, 1.25 (95% CI 1.02–1.53) for the MBD4 346 Lys allele, 0.78 (95% CI 0.63–0.97) for the LIG3 3704G allele, and 1.38 (95% CI 1.01–1.89) for the XRCC1–77C allele. In addition, we observed a significant gene-gene interaction between XRCC1 Gln399Arg and ADPRT Val762Ala. The results suggest that the polymorphisms in five BER genes may be associated with the susceptibility to ESCC in a Chinese population.
Frontiers of Mutagenesis and DNA Repair
Authors: Kelley Mark R. , Tompkinson Alan E. , Williams Kandace J. , Drinkwater Norman R. , Fung Victor A. 
Published: September 2005

Abstract
The Chemical Pathology Study Section, Center for Scientific Review, NIH hosted a 1-day workshop in Ventura, California, in the winter of 2003. There were 32 invited participants including invited speakers. The workshop consisted of three sessions and focused on recent developments in our understanding of the molecular mechanisms of mutagenesis and DNA repair, namely, error-prone DNA polymerases, DNA repair models and DNA repair networks.
Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand
Authors: Ludwig Aaron T. , Moore Jill M. , Luo Yi , Chen Xiaohong , Saltsgaver Nicole A. , O’Donnell Michael A. , Griffith Thomas S. 
Published: September 2005

AbstractMycobacterium bovis Bacillus Calmette-Guérin (BCG) use in the treatment of bladder cancer was first reported in 1976, but the mechanism of the induced antitumor activity has still not been fully explained. BCG is a potent immunostimulant, normally producing a Th1 cytokine response, including IFN. Recent studies have shown CpG oligodeoxynucleotide induce tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) expression via IFN production. Given that Mycobacterial DNA contains high amounts of CpG motifs, we hypothesized that BCG’s antitumor properties are akin to CpG oligodeoxynucleotide, where the cytokine response to BCG induces TRAIL up-regulation. Using ELISA, urine IFN-γ, and TRAIL levels were initially undetectable in BCG therapy patients but were high after later induction treatments. More importantly, patients that responded to BCG therapy had significantly higher urine TRAIL levels, which killed bladder tumor cells in vitro versus nonresponders. Flow cytometry of fresh urine revealed TRAIL-expressing neutrophils. Given these data, we propose TRAIL plays a role in BCG-induced antitumor effects.
Increased Plasma Vascular Endothelial Growth Factor (VEGF) as a Surrogate Marker for Optimal Therapeutic Dosing of VEGF Receptor-2 Monoclonal Antibodies
Authors: Bocci Guido , Man Shan , Green Shane K. , Francia Giulio , Ebos John M. L. , du Manoir Jeanne M. , Weinerman Adina , Emmenegger Urban , Ma Li , Thorpe Philip , Davidoff Andrew , Huber James , Hicklin Daniel J. , Kerbel Robert S. 
Published: September 2005

Abstract
A major obstacle compromising the successful application of many of the new targeted anticancer drugs, including angiogenesis inhibitors, is the empiricism associated with determining an effective biological/therapeutic dose because many of these drugs express optimum therapeutic activity below the maximum tolerated dose, if such a dose can be defined. Hence, surrogate markers are needed to help determine optimal dosing. Here we describe such a molecular marker, increased plasma levels of vascular endothelial growth factor (VEGF), in normal or tumor-bearing mice that received injections of an anti-VEGF receptor (VEGFR)-2 monoclonal antibody, such as DC101. Rapid increases of mouse VEGF (e.g., within 24 hours) up to 1 order of magnitude were observed after single injections of DC101 in non–tumor-bearing severe combined immunodeficient or nude mice; similar increases in human plasma VEGF were detected in human tumor-bearing mice. RAFL-1, another anti-VEGFR-2 antibody, also caused a significant increase in plasma VEGF. In contrast, increases in mouse VEGF levels were not seen when small molecule VEGFR-2 inhibitors were tested in normal mice. Most importantly, the increases in plasma VEGF were induced in a dose-dependent manner, with the maximum values peaking when doses previously determined to be optimally therapeutic were used. Plasma VEGF should be considered as a possible surrogate pharmacodynamic marker for determining the optimal biological dose of antibody drugs that block VEGFR-2 (KDR) activity in a clinical setting.