bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1676: Cytotoxicity of fenretinide and its metabolite 4-oxo-4-HPR in malignant lymphoid cells can be dependent and independent of reactive oxygen species (ROS)
Authors: Cooper Jason P. , Reynolds Charles P. , Curley Robert W. , Kang Min H. 
Published: February 2011

Abstract
Fenretinide (4-HPR) is a cytotoxic retinoid that increases ROS and ceramides and has shown clinical activity against neuroblastoma and lymphoid malignancies. We compared the cytotoxicity, ROS generation, and sphingolipid synthesis of 4-oxo-4-HPR (a recently identified 4-HPR metabolite) with 4-HPR in malignant lymphoid cells. Cytotoxicity of 4-oxo-4-HPR and 4-HPR was measured in 14 malignant lymphoid cell lines using a DIMSCAN system. Median concentrations cytotoxic for 90% of cells (IC90) were 2.1 µM (range: 1.1 − 15.9) for 4-oxo-4-HPR and 4.4 µM (range: 0.7 − 29.2) for 4-HPR. In 2 of 3 cell lines tested, ROS generation (DCFDA by flow cytometry) was higher with 4-HPR vs. 4-oxo-4-HPR (table). Ascorbic acid (AA) abrogated ROS generation and significantly attenuated cytotoxicity of 4-oxo-4-HPR and 4-HPR in CCRF-CEM and COG-LL-317 cells. However, in GA-10 cells AA completely abrogated ROS generation, but not cytotoxicity, for both 4-oxo-4-HPR and 4-HPR. Intracellular sphingolipid (SL) changes, another suggested mechanism for 4-HPR cytotoxicity, were measured by tandem mass spectrometry in GA-10 cells at 48-hours, and both 4-oxo-4-HPR and 4-HPR treatment increased SL, with significantly higher (p &lt; 0.05) increases by 4-oxo-4-HPR. The fold increase/control for 4-oxo-4-HPR vs. 4-HPR: ceramides = 2.1 ± 0.13 vs. 1.3 ± 0.11; dihydroceramides = 87.6 ± 7.1 vs. 34.0 ± 5.1; sphingomyelins = 4.1 ± 0.14 vs. 2.4 ± 0.04). Thus, 4-oxo-4-HPR is similar in cytotoxicity to 4-HPR, less active in generating ROS, but more active in increasing SL. The cytotoxicity of both 4-HPR and 4-oxo-4-HPR in the GA-10 cell line is independent of ROS, providing a novel in vitro model for identifying the role of SL in the cytotoxicity of these agents.Table.Cytotoxicity and ROS generation for 4-HPR and 4-oxo-4-HPR, and cell survival after ROS abrogation. Cell Line (Histopathology)CCRF-CEM (T ALL)COG-LL-317 (T ALL)GA-10 (B Burkitt lymphoma)IC90 (µM)4-oxo-4-HPR1.32.41.54-HPR1.01.57.3 ROS Generation‡ (fold increase/control)4-oxo-4-HPR2.3 ± 0.03***1.6 ± 0.02***1.7 ± 0.04**4-HPR8.3 ± 0.36***5.3 ± 0.26***2.2 ± 0.29** ROS abrogation‡ (% inhibition from drug alone)4-oxo-4-HPR + AA55%***31%*100%*4-HPR + AA83%***91%***100%*** Cell Survival at 20 hours‡AA102.5% ± 12.6107.3% ± 14.986.8% ± 14.94-oxo-4-HPR12.9% ± 2.926.3%± 2.010.9% ± 6.84-oxo-4-HPR + AA22.9% ± 3.5***63.1% ± 8.6***9.1% ± 3.74-HPR1.2% ± 0.69.1% ± 2.011.9% ± 6.24-HPR + AA27.9% ± 6.8***91.2% ± 11.4***12.6% ± 3.1‡ Treatments: 10 µM 4-oxo-4-HPR, 10 µM 4-HPR, 200 µM AA; * P &lt; 0.05, ** P &lt; 0.01, *** P &lt; 0.001
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1676.
Abstract 1680: Characterization of olanzapine glucuronidation: Potential role of the UGT2B10 codon 67 SNP in olanzapine metabolism
Authors: Erickson Kathryn K. , Lazarus Philip 
Published: February 2011

Abstract
Olanzapine (OLZ) is an atypical antipsychotic with broad applications for cancer patients including treatment-resistant depression, psychiatric problems such as schizophrenia or bipolar disorder, and chemotherapy-induced nausea and vomiting. The half-life of OLZ varies widely between patients. The purpose of the present study was to determine the relative contribution of various UDP-glucuronosyltransferases (UGTs) that are known to metabolize OLZ and examine the role of functional UGT genetic variants as a potential determinant of OLZ metabolism.
OLZ glucuronides were identified by ultra-pressure liquid chromatography (UPLC) and the UGTs exhibiting activity against OLZ were determined using homogenates of UGT-over-expressing HEK293 cell lines. Kinetic analysis was performed for active wild-type and variant UGTs. The clinical and physiological relevance of polymorphic active UGTs was examined by studying OLZ metabolism in 114 human liver microsomes and characterizing their glucuronidation activity via UPLC. One-Way ANOVA using Tukey's family error rate was used for pairwise comparisons between cell lines. Student's 2-sample t-test was used to compare human liver microsome glucuronidation data.
UPLC analysis of cell line homogenate samples revealed three distinct glucuronidation products. We found that two UGT enzymes, UGT1A4 and UGT2B10, exhibit glucuronidation activity against OLZ. The enzymatic activity of UGT1A4 codon 24 and codon 48 variants against OLZ was significantly different from wild-type UGT1A4 (both p &lt; 0.05). In addition, the UGT2B1067Tyr variant exhibited no glucuronidation activity against OLZ. Human liver microsomes homozygous for the UGT2B1067Tyr variant exhibited an 82% reduction in glucuronidation activity against OLZ (p&lt;0.05).
These data demonstrate the significance of a previously unrecognized UGT (UGT2B10) in OLZ excretion and the potential importance of a functional SNP at codon 67 of the UGT2B10 gene in the wide variability observed in OLZ metabolism between individuals. This could have an important impact on overall patient response/toxicity to OLZ.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1680.
Abstract 1683: ATF4 down-regulation potentiates L-asparaginase activity in ovarian cancer cell lines
Authors: Lorenzi Philip L. , Llamas Jenny , Caplen Natasha J. , Weinstein John N. 
Published: February 2011

Abstract
The enzyme-drug L-asparaginase (L-ASP) has been used for four decades to treat acute lymphoblastic leukemia. However, its unique mechanism of action is still poorly understood, and its clinical efficacy has proven unpredictable. Those problems have prompted a continuing search for biomarkers that predict L-ASP response. We previously found that the expression of asparagine synthetase (ASNS) is strongly correlated with L-ASP activity in leukemia cell lines of the NCI-60 cell line panel. Unexpectedly, however, the correlation was also apparent in ovarian cancer lines, suggesting that L-ASP might be effective against a low-ASNS subset of ovarian cancers if salient characteristics of the cell lines reflect clinical ovarian tumors. Using siRNA to down-regulate ASNS by 5-fold produced a proportional ∼5-fold potentiation of L-ASP activity in some ovarian cancer lines (OVCAR-3 and OVCAR-4). Surprisingly, ASNS siRNAs yielded a striking &gt;500-fold potentiation in other ovarian lines (OVCAR-8 and OVCAR-8/ADR). Taken together, those findings suggest that the L-ASP/ASNS correlation is causal but also support the hypothesis that L-ASP activity is modulated by additional molecules or pathways. To address that hypothesis and to further elucidate the L-ASP mechanism of action, we have initiated genome-wide siRNA library screening. Preliminary screens in the OVCAR-8 cell line using a 418-gene apoptosis library, a custom 392-gene metabolic library, and the MTS assay as an endpoint yielded Z′ factors &gt;0.90, indicating a robust screen. RNAi-mediated down-regulation of apoptosis genes had little or no effect on L-ASP's anticancer activity. That was surprising because L-ASP has been reported to cause apoptosis through glutamine depletion. Knock-down of ATF4, a transcription factor involved in cell metabolism, did markedly potentiate L-ASP activity (&gt;500-fold). Furthermore, ATF4 knock-down markedly enhanced L-ASP anticancer activity toward the highly resistant cell line, OVCAR-4. These findings suggest that ATF4 is an important mediator of L-ASP resistance and provide rationale for investigation of ATF4 as a predictive biomarker of L-ASP effect.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1683.
Abstract 1688: Effect of Gefitinib on the reactions of mammalian type I and type II DNA topoisomerases
Authors: Topcu Zeki , Unlukurt Isa , Zencir Sevil 
Published: February 2011

Abstract
Developing small molecule inhibitors in anti-cancer drug research is an integral part of clinical oncology. Gefitinib (Iressa) is a promising small molecule inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase. It was shown to have the potential to improve the clinical effectiveness of EGFR-targeted therapies and gained a significant impact in treatment of non-small-cell lung cancer (NSCLC). Over the past years, several naturally occurring and synthetic compounds with anti-cancer activities were shown to exert their actions via interfering with normal DNA topoisomerase reactions. DNA topoisomerases are ubiquitous enzymes that regulate DNA topology by making transient breakages at nucleic acid backbone and rejoining of DNA strands. Topoisomerases carry out their reactions by two different mechanisms; Type I topoisomerases make a single-stranded break in a DNA duplex while type II topoisomerases create transient breaks in both strands of a duplex. In this study we aimed to examine the effects of Gefitinib on these enzymes to extend the evaluation of its biological activities by plasmid supercoil relaxation and kinetoplast decatenation assays for type I and type II topoisomerases, respectively. Our results are discussed in relation to the outcomes of Gefitinib reported in clinical trials, which together would contribute in identifying the mechanisms of Gefitinib-induced tumor cell-killing.
Key Words; Gefitinib; DNA topoisomerases; anti-cancer drugs
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1688.
Abstract 1689: Liquid chromatography-electrospray ionization-tandem mass spectrometry analysis for 7-carboxymethylguanine and 7-carboxyethylguanine in human liver DNA
Authors: Wang Mingyao , Cheng Guang , Chen Li , Villalta Peter W. , Hecht Stephen S. 
Published: February 2011

Abstract
The carcinogenic nitrosamines N-nitrososarcosine (NSAR) and 3-(methylnitrosamino)propionic acid (MNPA) have been detected in the diet, tobacco products, and human urine. Metabolic activation of NSAR by methyl hydroxylation would produce a DNA carboxymethylating agent while similar metabolism of MNPA would produce a carboxyethylating agent, each of which would be expected to react at the 7 position of guanine to give 7-carboxymethylguanine (7-CMG) and 7-carboxyethylguanine (7-CEG), respectively. Furthermore, acrylic acid, a major industrial product, environmental contaminant and likely endogenous metabolite, and β-propiolactone, are also known to react with DNA to give 7-CEG. We developed a liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS-SRM) method to quantify these adducts in human liver DNA. [15N5]7-CMG and [15N5]7-CEG were synthesized and used as internal standards. After addition of the internal standards, the DNA was hydrolyzed enzymatically and the hydrolysate was partially purified by solid-phase extraction. The fraction containing 7-CMG and 7-CEG was treated with acetyl chloride in methanol to convert them to the corresponding methyl esters. After re-purification by solid-phase extraction, the appropriate fraction was analyzed by LC-ESI-MS/MS-SRM for the transitions m/z 224[M + H]+ → m/z 164[(M + H) - C2H4O2]+ for 7-CMG and m/z 238[M + H]+ → m/z 152 [BH]+ for 7-CEG. Human liver DNA samples had clear peaks co-eluting with [15N5]7-CEG, but no peaks were observed at the retention time of 7-CMG. The on column detection limits were approximately 10 and 5 fmol, respectively, for the methyl esters of 7-CMG and 7-CEG. The detection limit for the methyl ester of 7-CEG in DNA (starting with 1 mg) was approximately 8 fmol. Known addition studies using 7-CEG and calf thymus DNA demonstrated that the method was accurate and precise. Artifactual formation of 7-CEG during DNA isolation and enzyme hydrolysis was excluded. The method was applied for the analysis of 27 human liver samples. 7-CEG, but not 7-CMG, was detected in each sample, mean ± S.D, 408 ± 375 fmol/µmol guanine (82 adducts per 109 nucleotides), range 17 − 1491 fmol/µmol guanine. This is the first report demonstrating the presence of 7-CEG in DNA from humans. While MNPA, β-propiolactone and acrylic acid are possible sources of this DNA adduct, we consider acrylic acid to be the most likely because of its ubiquitous occurrence and probable endogenous formation from the lipid peroxidation product acrolein.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1689.
Abstract 1690: Analysis of benzo[a]pyrene and phenanthrene tetraol enantiomers in human urine: Relevance to the bay region diol epoxide hypothesis of benzo[a]pyrene carcinogenesis and to biomarker studies
Authors: Hecht Stephen S. , Carmella Steven G. , Hochalter J. Bradley 
Published: February 2011

Abstract
One widely accepted metabolic activation pathway of the prototypic carcinogenic polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (BaP) proceeds through the bay region diol epoxide BaP-(7R,8S)-diol-(9S,10R)-epoxide. However, few studies have addressed the analysis of human urinary metabolites of BaP which result from this pathway. Phenanthrene (Phe) is structurally related to BaP, but human exposure to Phe is far greater and its metabolites can be readily detected in human urine. Thus, we have proposed that Phe metabolites can be biomarkers of PAH exposure and metabolic activation. Phe-tetraols in particular could be biomarkers of the diol epoxide pathway. While BaP-tetraols and Phe-tetraols have been previously quantified in human urine, no published studies have determined their enantiomeric composition. This is important because different enantiomers would result from the bay region diol epoxide and “reverse” diol epoxide pathways, the latter being associated with weak mutagenicity and carcinogenicity. We addressed this problem using chiral HPLC to separate the enantiomers of Phe-1,2,3,4-tetraol and BaP-7,8,9,10-tetraol. Urine samples from smokers were subjected to hydrolysis with β-glucuronidase and arylsulfatase followed by solid-phase extraction on a Strata-X polymeric sorbent cartridge and a Bond Elute phenylboronic acid cartridge, chiral HPLC on a Cyclobond II or Pirkle column, and quantitation by gas-chromatography-negative ion chemical ionization-tandem mass spectrometry-selected reaction monitoring analysis of the Phe-tetraols, as their tetra-trimethylsilyl ethers. The results demonstrated that &gt;96% of Phe-tetraol in smokers’ urine was Phe-(1S,2R,3S,4R)-tetraol, resulting from the “reverse” diol epoxide pathway, whereas less than 4% resulted from the bay region diol epoxide pathway of Phe metabolism. The corresponding (R,R)-stereochemistry of their precursor diols Phe-1,2-diol and Phe-3,4-diol was also confirmed. Urine from creosote workers with very high exposure to PAH was similarly analyzed for BaP-tetraol enantiomers. In contrast to the results of the Phe-tetraol analyses in smokers’ urine, &gt;75% of BaP-tetraol in these human urine samples was BaP-(7R,8S,9R,10S)-tetraol resulting from the bay region diol epoxide pathway of BaP metabolism. These results provide the first direct support based on human urinary metabolite analysis for the bay region diol epoxide pathway of BaP metabolism and demonstrate differences in BaP and Phe metabolism which may be important when considering Phe-tetraols as biomarkers of PAH metabolic activation.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1690.
Abstract 1691: Apoptotic and antitumor effects of rotenone in MCF-7 human breast cancer cells are mediated ROS through activating JNK and p38 MAPK signaling
Authors: Lin Jen-Kun , Deng Yea-Tzy , Huang Hsiu-Chen 
Published: February 2011

Abstract
Rotenone is a natural hydrophobic pesticide derived from the roots of Derris and Lonchorcarpus species. The pesticidal activity of rotenone is attributed to irreversible binding and inactivation of complex of the mitochondrial transport chain. This can block electron transport from complex to ubiquinone, resulting in a blockage of the oxidative phosphorylation process, and an increase of the reactive oxygen species (ROS). Rotenone has been shown to display anticancer activity through the induction of apoptosis in various cancer cells. However, the underlying mechanism is still not fully elucidated. In the present study, rotenone showed a strong growth inhibitory effect against human breast MCF-7 cells. DNA flow cytometric analysis, chromatin condensation and poly(ADP-ribose) polymerase (PARP) cleavage indicated rotenone actively induced apoptosis in MCF-7 cells. The anti-apoptotic protein BCl-2, was decreased, whereas the apoptotic protein, Bax, was increased in a time-dependent manner in rotenone-induced apoptosis. Moreover. The treatment of rotenone in MCF-7 cells caused the activation of c-jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPKs) and the inactivation of extracellular signal-regulated protein kinase1/2 (ERK1/2). The pharmacological inhibitor of JNK and p38 MAPK revealed significant protection against rotenone-induced apoptosis.
In summary, these results indicate rotenone may induce apoptosis through ROS and JNK/p38MAPK activation in MCF-7 cells. In conclusion, we examines the molecular mechanism involved in rotenone-induced apoptosis in human breast cancer MCF-7 cells. We have demonstrated a sequential events that rotenone-induced apoptosis in the cells through ROS generation, which serves as a pivotal upstream function in activating JNK and p38MAPKs, which leads to a decrease of BCl-2 and increase of Bax and finally to inducing apoptosis.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1691.
Abstract 1693: Assessment of Nrf2 luciferase reporter assay and heme oxygenase expression as models of oxidative stress in in vitro cultures of lung cells exposed to cigarette smoke condensate
Authors: Fields Wanda R. , Liedtke Wolfgang , Li Jinju , Bombick Betsy 
Published: February 2011

Abstract
The Nrf2 signaling pathway is an important regulator associated with oxidative stress, xenobiotic metabolism, DNA damage and anti-inflammatory response. A key responsive gene in the Nrf2 regulatory pathway is heme oxygense 1 (HO-1), a cytoprotective enzyme that serves in an antioxidant capacity. An imbalance in antioxidant capacity observed in animal models or individuals with specific Nrf2 and HO-1 polymorphisms has been associated with susceptibility to lung diseases. The objective of this study was to characterize the response of Nrf 2 promoter regulation and HO-1 expression following exposure to cigarette smoke in lung models for oxidative stress. Cigarette smoke condensate (CSC) was prepared from Kentucky 3R4F (K3R4F) reference cigarettes. Nrf2 promoter regulation and HO-1 expression were evaluated in lung cells exposed to K3R4F CSC (0 − 90μg total particulate matter/ml media). Nrf2 promoter regulation was evaluated in transiently-transfected Nrf2 luciferase reporter cells exposed to K3R4F CSC for 0.5, 1, 2, 6 or 24 hours followed by quantification of luciferase activity. HO-1 expression was assessed following exposure to the K3R4F CSC in normal human bronchial epithelial (NHBE) cells for 3, 6 or 24 hours using real-time quantitative RT/PCR and enzyme linked immunoassay (ELISA). Nrf2 reporter cells exhibited dose-dependent increases in promoter activation following CSC exposure. The maximum response was observed between 6 and 24 hours of exposure with 15-, 25-, and 40-fold increases across the exposure range. The specificity of the promoter response was confirmed with co- exposure of the inhibitor all-trans retinoic acid with CSC. The CSC-induced Nrf2 activation was reduced towards control levels in the presence of the inhibitor. CSC also induced dose- and time-dependent increases on HO-1 mRNA and protein levels in NHBE cells. The mRNA changes ranged from 10- to 70-fold with maximal responses observed between 3 and 6 hours. The dynamic range of HO-1 protein response was observed and reached a level of 11-fold increase by 60 μg/ml. Collectively, these responses are consistent with our previously reported study which identified oxidative stress responsive genes in NHBE cells exposed to repetitive applications of CSC. The data suggest that changes in the Nrf2 regulatory pathway may serve as an effective indicator of oxidative stress and the impact of tobacco products in in vitro lung cell culture models.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1693.