bluuebunny/crossref_metadata_2025 huggingface dataset:
Alterations of Choline Phospholipid Metabolism in Ovarian Tumor Progression
Authors: Iorio Egidio , Mezzanzanica Delia , Alberti Paola , Spadaro Francesca , Ramoni Carlo , D'Ascenzo Sandra , Millimaggi Danilo , Pavan Antonio , Dolo Vincenza , Canevari Silvana , Podo Franca
Published: October 2005

Recent characterization of abnormal phosphatidylcholine metabolism in tumor cells by nuclear magnetic resonance (NMR) has identified novel fingerprints of tumor progression that are potentially useful as clinical diagnostic indicators. In the present study, we analyzed the concentrations of phosphatidylcholine metabolites, activities of phosphocholine-producing enzymes, and uptake of [methyl-14C]choline in human epithelial ovarian carcinoma cell lines (EOC) compared with normal or immortalized ovary epithelial cells (EONT). Quantification of phosphatidylcholine metabolites contributing to the 1H NMR total choline resonance (3.20-3.24 ppm) revealed intracellular [phosphocholine] and [total choline] of 2.3 ± 0.9 and 5.2 ± 2.4 nmol/106 cells, respectively, with a glycerophosphocholine/phosphocholine ratio of 0.95 ± 0.93 in EONT cells; average [phosphocholine] was 3- to 8-fold higher in EOC cells (P < 0.0001), becoming the predominant phosphatidylcholine metabolite, whereas average glycerophosphocholine/phosphocholine values decreased significantly to ≤0.2. Two-dimensional {phosphocholine/total choline, [total choline]} and {glycerophosphocholine/total choline, [total choline]} maps allowed separate clustering of EOC from EONT cells (P < 0.0001, 95% confidence limits). Rates of choline kinase activity in EOC cells were 12- to 24-fold higher (P < 0.03) than those in EONT cells (basal rate, 0.5 ± 0.1 nmol/106 cells/h), accounting for a consistently elevated (5- to 15-fold) [methyl-14C]choline uptake after 1-hour incubation (P < 0.0001). The overall activity of phosphatidylcholine-specific phospholipase C and phospholipase D was also higher (∼5-fold) in EOC cells, suggesting that both biosynthetic and catabolic pathways of the phosphatidylcholine cycle likely contribute to phosphocholine accumulation. Evidence of abnormal phosphatidylcholine metabolism might have implications in EOC biology and might provide an avenue to the development of noninvasive clinical tools for EOC diagnosis and treatment follow-up.
Host Lymphodepletion Augments T Cell Adoptive Immunotherapy through Enhanced Intratumoral Proliferation of Effector Cells
Authors: Wang Li-Xin , Shu Suyu , Plautz Gregory E.
Published: October 2005

T-cell adoptive immunotherapy for stringent murine tumor models, such as intracranial, s.c., or advanced pulmonary metastases, routinely uses lymphodepletive conditioning regimens before T-cell transfer, like recent clinical protocols. In this study, we examined whether host lymphodepletion is an obligatory component of curative T-cell therapy; we also examined the mechanism by which it augments therapy. Mice bearing intracranial, s.c., or 10-day pulmonary metastases of MCA 205 received total body irradiation conditioning or were nonirradiated before i.v. transfer of tumor-reactive T cells. Total body irradiation was not required for immunologically specific curative therapy and induction of memory provided that a 3- to 12-fold higher T-cell dose was administered. The mechanism involved enhanced intratumoral proliferation of T-effector cells in total body irradiation–conditioned recipients. In this tumor model, intratumoral Treg cells were not detected; consequently, intratumoral T-effector cells produced identical amounts of IFN-γ upon ex vivo antigen stimulation irrespective of total body irradiation conditioning. Thus, host lymphodepletion augments T-cell immunotherapy through enhanced antigen-driven proliferation of T-effector cells, but curative therapy can be achieved in nonconditioned hosts by escalation of T-cell dose. These data provide a rationale for dose escalation of T-effector cells in situations where single or repeated lymphodepletion regimens are contraindicated.
The p270 (ARID1A/SMARCF1) Subunit of Mammalian SWI/SNF-Related Complexes Is Essential for Normal Cell Cycle Arrest
Authors: Nagl Norman G. , Patsialou Antonia , Haines Dale S. , Dallas Peter B. , Beck George R. , Moran Elizabeth
Published: October 2005

Mammalian SWI/SNF-related complexes are ATPase-powered nucleosome remodeling assemblies crucial for proper development and tissue-specific gene expression. The ATPase activity of the complexes is also critical for tumor suppression. The complexes contain seven or more noncatalytic subunits; only one of which, hSNF5/Ini1/BAF47, has been individually identified as a tumor suppressor thus far. The noncatalytic subunits include p270/ARID1A, which is of particular interest because tissue array analysis corroborated by screening of tumor cell lines indicates that p270 may be deficient in as many as 30% of renal carcinomas and 10% of breast carcinomas. The complexes can also include an alternative ARID1B subunit, which is closely related to p270, but the product of an independent gene. The respective importance of p270 and ARID1B in the control of cell proliferation was explored here using a short interfering RNA approach and a cell system that permits analysis of differentiation-associated cell cycle arrest. The p270-depleted cells fail to undergo normal cell cycle arrest on induction, as evidenced by continued synthesis of DNA. These lines fail to show other characteristics typical of arrested cells, including up-regulation of p21 and down-regulation of cyclins. The requirement for p270 is evident separately in both the up-regulation of p21 and the down-regulation of E2F-responsive products. In contrast, the ARID1B-depleted lines behaved like the parental cells in these assays. Thus, p270-containing complexes are functionally distinct from ARID1B-containing complexes. These results provide a direct biological basis to support the implication from tumor tissue screens that deficiency of p270 plays a causative role in carcinogenesis.
Roscovitine Is an Effective Inducer of Apoptosis of Ewing's Sarcoma Family Tumor CellsIn vitroandIn vivo
Authors: Tirado Oscar M. , Mateo-Lozano Silvia , Notario Vicente
Published: October 2005

The Ewing's sarcoma family of tumors (ESFT) comprises several well-characterized malignant neoplasms with particularly aggressive behavior. Despite recent progress in the use of multimodal therapeutic approaches and aggressive local control measures, a substantial proportion of patients die because of disease progression. Furthermore, this outcome has not changed significantly over the last 15 to 20 years. Consequently, new, more effective therapeutic options are sorely needed for the treatment of ESFT. Because ESFT cells overexpress several cyclin-dependent kinases (CDK), we explored the efficacy against ESFT of roscovitine, a CDK inhibitor shown to be surprisingly safe for humans in clinical trials of their anticancer activity. Results showed that ESFT cell lines are uniformly sensitive to roscovitine. In addition to exerting comparatively minor cell cycle effects, roscovitine treatment concomitantly caused the up-regulation of the expression of the proapoptotic protein BAX and the down-regulation of both survivin and XIAP, thus resulting in caspase-dependent apoptosis. Furthermore, in vivo experiments showed that s.c. growth of ESFT xenografts was also significantly slowed by i.p. injection of roscovitine. These results strongly suggest that roscovitine may be an effective therapeutic agent against ESFT and recommend its evaluation against ESFT in clinical trials and its inclusion in future treatment protocols.
A Tumorigenic Subpopulation with Stem Cell Properties in Melanomas
Authors: Fang Dong , Nguyen Thiennga K. , Leishear Kim , Finko Rena , Kulp Angela N. , Hotz Susan , Van Belle Patricia A. , Xu Xiaowei , Elder David E. , Herlyn Meenhard
Published: October 2005

Recent studies suggest that cancer can arise from a cancer stem cell (CSC), a tumor-initiating cell that has properties similar to those of stem cells. CSCs have been identified in several malignancies, including those of blood, brain, and breast. Here, we test whether stem cell–like populations exist in human melanomas. In ∼20% of the metastatic melanomas cultured in growth medium suitable for human embryonic stem cells, we found a subpopulation of cells propagating as nonadherent spheres, whereas in standard medium, adherent monolayer cultures were established. Individual cells from melanoma spheres (melanoma spheroid cells) could differentiate under appropriate conditions into multiple cell lineages, such as melanocytic, adipocytic, osteocytic, and chondrocytic lineages, which recapitulates the plasticity of neural crest stem cells. Multipotent melanoma spheroid cells persisted after serial cloning in vitro and transplantation in vivo, indicating their ability to self-renew. Furthermore, they were more tumorigenic than adherent cells when grafted to mice. We identified similar multipotent spheroid cells in melanoma cell lines and found that the stem cell population was enriched in a CD20+ fraction of melanoma cells. Based on these findings, we propose that melanomas can contain a subpopulation of stem cells that contribute to heterogeneity and tumorigenesis. Targeting this population may lead to effective treatments for melanomas.
Chronic Inflammation Promotes Retinoblastoma Protein Hyperphosphorylation and E2F1 Activation
Authors: Ying Lei , Marino Jillian , Hussain S. Perwez , Khan Mohammed A. , You Shaojin , Hofseth Anne B. , Trivers Glennwood E. , Dixon Dan A. , Harris Curtis C. , Hofseth Lorne J.
Published: October 2005

Chronic inflammation contributes to tumorigenesis. The retinoblastoma protein (pRb), in its hyperphosphorylated form, releases E2 promoter binding factor-1 (E2F1), which drives cell proliferation. Here, we show that pRb is hyperphosphorylated in both mouse and human colitis. In turn, pRb hyperphosphorylation is associated with release of E2F1 from pRb, resulting in the activation of E2F1 target molecules involved in proliferation and apoptosis. These observations provide insight into the in vivo mechanisms associated with chronic colon inflammation and increased colon cancer risk.
The Role ofP53andMDM2Polymorphisms in the Risk of Esophageal Squamous Cell Carcinoma
Authors: Hong Yuan , Miao Xiaoping , Zhang Xuemei , Ding Fang , Luo Aiping , Guo Yongli , Tan Wen , Liu Zhihua , Lin Dongxin
Published: October 2005

The tumor suppressor P53 pathway plays a crucial role in preventing carcinogenesis and genetic variations of this pathway may be associated with cancer susceptibility. We tested this hypothesis by examining the contribution of functional polymorphisms in P53 and MDM2 to risk of esophageal squamous cell carcinoma (ESCC). DNA from 758 ESCC patients and 1,420 controls were genotyped for P53 codon 72Arg>Pro and MDM2 309T>G polymorphisms. Odds ratios (OR) and 95% confidence intervals (CI) of ESCC were estimated by logistic regression. We observed an increased risk of ESCC associated with the P53 Pro/Pro (OR, 1.83; 95% CI, 1.43-2.35; P < 0.001) or MDM2 GG (OR, 1.49; 95% CI, 1.16-1.91; P = 0.002) genotype, compared with the P53 Arg/Arg or MDM2 TT genotype, respectively. Interaction between these P53 and MDM2 polymorphisms increased risk of ESCC in a multiplicative manner, with the OR being 3.10 (95% CI, 2.07-4.69) for subjects carrying both P53 Pro/Pro and MDM2 GG genotypes. Significant interactions were observed between these polymorphisms and smoking, with risk being the highest (OR, 5.29; 95% CI, 2.91-9.61) in smokers having both P53 Pro/Pro and MDM2 GG genotypes. The MDM2 GG genotype was also associated with risk of developing poorly differentiated and advanced ESCC compared with the GT or TT genotype (OR for high-grade and stages III-IV versus low-grade and stages I-II = 1.60; 95% CI, 1.00-2.64; P = 0.049). The P53 and MDM2 polymorphisms may be genetic determinants for the development of ESCC.
Cancer Mortality among Men Occupationally Exposed to Dichlorodiphenyltrichloroethane
Authors: Cocco Pierluigi , Fadda Domenica , Billai Beatrice , D'Atri Mario , Melis Massimo , Blair Aaron
Published: October 2005

Several studies have evaluated cancer risk associated with occupational and environmental exposure to dichlorodiphenyltrichloroethane (DDT). Results are mixed. To further inquire into human carcinogenicity of DDT, we conducted a mortality follow-up study of 4,552 male workers, exposed to DDT during antimalarial operations in Sardinia, Italy, conducted in 1946 to 1950. Detailed information on DDT use during the operations provided the opportunity to develop individual estimates of average and cumulative exposure. Mortality of the cohort was first compared with that of the Sardinian population. Overall mortality in the cohort was about as expected, but there was a deficit for death from cardiovascular disease and a slight excess for nonmalignant respiratory diseases and lymphatic cancer among the unexposed subcohort. For internal comparisons, we used Poisson regression analysis to calculate relative risks of selected malignant and nonmalignant diseases with the unexposed subcohort as the reference. Cancer mortality was decreased among DDT-exposed workers, mainly due to a reduction in lung cancer deaths. Birth outside from the study area was a strong predictor of mortality from leukemia. Mortality from stomach cancer increased up to 2-fold in the highest quartile of cumulative exposure (relative risk, 2.0; 95% confidence interval, 0.9-4.4), but no exposure-response trend was observed. Risks of liver cancer, pancreatic cancer, and leukemia were not elevated among DDT-exposed workers. No effect of latency on risk estimates was observed over the 45 years of follow-up and within selected time windows. Adjusting risks by possible exposure to chlordane in the second part of the antimalarial operations did not change the results. In conclusion, we found little evidence for a link between occupational exposure to DDT and mortality from any of the cancers previously suggested to be associated.
N-(4-Hydroxyphenyl)Retinamide Inhibits Invasion, Suppresses Osteoclastogenesis, and Potentiates Apoptosis through Down-regulation of IκBα Kinase and Nuclear Factor-κB–Regulated Gene Products
Authors: Shishodia Shishir , Gutierrez Angelica M. , Lotan Reuben , Aggarwal Bharat B.
Published: October 2005

N-(4-hydroxyphenyl) retinamide [4-HPR], a synthetic retinoid, has been shown to inhibit tumor cell growth, invasion, and metastasis by a mechanism that is not fully understood. Because the nuclear factor-κB (NF-κB) has also been shown to regulate proliferation, invasion, and metastasis of tumor cells, we postulated that 4-HPR modulates the activity of NF-κB. To test this postulate, we examined the effect of this retinoid on NF-κB and NF-κB–regulated gene products. We found that 4-HPR potentiated the apoptosis induced by tumor necrosis factor (TNF) and chemotherapeutic agents, suppressed TNF-induced invasion, and inhibited RANKL-induced osteoclastogenesis, all of which are known to require NF-κB activation. We found that 4-HPR suppressed both inducible and constitutive NF-κB activation without interfering with the direct DNA binding of NF-κB. 4-HPR was found to be synergistic with Velcade, a proteasome inhibitor. Further studies showed that 4-HPR blocked the phosphorylation and degradation of IκBα through the inhibition of activation of IκBα kinase (IKK), and this led to suppression of the phosphorylation and nuclear translocation of p65. 4-HPR also inhibited TNF-induced Akt activation linked with IKK activation. NF-κB–dependent reporter gene expression was also suppressed by 4-HPR, as was NF-κB reporter activity induced by TNFR1, TRADD, TRAF2, NIK, and IKK but not that induced by p65 transfection. The expression of NF-κB–regulated gene products involved in antiapoptosis (IAP1, Bfl-1/A1, Bcl-2, cFLIP, and TRAF1), proliferation (cyclin D1 and c-Myc), and angiogenesis (vascular endothelial growth factor, cyclooxygenase-2, and matrix metalloproteinase-9) were also down-regulated by 4-HPR. This correlated with potentiation of apoptosis induced by TNF and chemotherapeutic agents.
RUNX3 Inactivation by Point Mutations and Aberrant DNA Methylation in Bladder Tumors
Authors: Kim Wun-Jae , Kim Eun-Jung , Jeong Pildu , Quan Changyi , Kim Jiyeon , Li Qing-Lin , Yang Jeong-Ook , Ito Yoshiaki , Bae Suk-Chul
Published: October 2005

RUNX3 is inactivated at high frequency in many tumors. However, in most cases, inactivation is caused by silencing of the gene due to promoter hypermethylation. Because epigenetic silencing is known to affect many major tumor suppressor genes in cancer cells, it is not clear whether RUNX3 is primarily responsible for the induction of carcinogenesis in these cases, except for the gastric cancer cases that we reported previously. We investigated genetic and epigenetic alterations of RUNX3 in 124 bladder tumor cases and seven bladder tumor–derived cell lines. Here we show that RUNX3 is inactivated by aberrant DNA methylation in 73% (90 of 124) of primary bladder tumor specimens and 86% (six of seven) of bladder tumor cell lines. In contrast, the promoter regions of 20 normal bladder mucosae were unmethylated. Importantly, one patient bore missense mutations, each of which resulted in amino acid substitutions in the highly conserved Runt domain. The mutations abolished the DNA-binding ability of RUNX3. A second patient had a single nucleotide deletion within the Runt domain coding region that resulted in truncation of the protein. RUNX3 methylation was a significant risk factor for bladder tumor development, superficial bladder tumor recurrence, and subsequent tumor progression. These results strongly suggest that inactivation of RUNX3 may contribute to bladder tumor development and that promoter methylation and silencing of RUNX3 could be useful prognostic markers for both bladder tumor recurrence and progression.
Celecoxib and NS-398 Enhance Photodynamic Therapy by Increasing In vitro Apoptosis and Decreasing In vivo Inflammatory and Angiogenic Factors
Authors: Ferrario Angela , Fisher Anita M. , Rucker Natalie , Gomer Charles J.
Published: October 2005

Photodynamic therapy (PDT) elicits both apoptotic and necrotic responses within treated tumors and produces microvascular injury leading to inflammation and hypoxia. PDT also induces expression of angiogenic and survival molecules including vascular endothelial growth factor, cyclooxygenase-2 (COX-2), and matrix metalloproteinases. Adjunctive administration of inhibitors to these molecules improves PDT responsiveness. In the current study, we examined how the combination of PDT and COX-2 inhibitors improve treatment responsiveness. Photofrin-mediated PDT combined with either celecoxib or NS-398 increased cytotoxicity and apoptosis in mouse BA mammary carcinoma cells. Immunoblot analysis of protein extracts from PDT-treated cells also showed poly(ADP-ribose) polymerase cleavage and Bcl-2 degradation, which were further enhanced following combined therapy. Tumor-bearing mice treated with PDT and either celecoxib or NS-398 exhibited significant improvement in long-term tumor-free survival when compared with PDT or COX-2 inhibitor treatments alone. The combined procedures did not increase in vivo tumor-associated apoptosis. Administration of celecoxib or NS-398 attenuated tissue levels of prostaglandin E2 and vascular endothelial growth factor induced by PDT in treated tumors and also decreased the expression of proinflammatory mediators interleukin-1β and tumor necrosis factor-α. Increased tumor levels of the antiinflammatory cytokine, interleukin 10, were also observed following combined treatment. This study documents for the first time that adjunctive use of celecoxib enhances PDT-mediated tumoricidal action in an in vivo tumor model. Our results also show that administration of COX-2 inhibitors enhance in vitro photosensitization by increasing apoptosis and improve in vivo PDT responsiveness by decreasing expression of angiogenic and inflammatory molecules.
Gene Expression Profiling of Human Sarcomas: Insights into Sarcoma Biology
Authors: Baird Kristin , Davis Sean , Antonescu Cristina R. , Harper Ursula L. , Walker Robert L. , Chen Yidong , Glatfelter Arthur A. , Duray Paul H. , Meltzer Paul S.
Published: October 2005

Sarcomas are a biologically complex group of tumors of mesenchymal origin. By using gene expression microarray analysis, we aimed to find clues into the cellular differentiation and oncogenic pathways active in these tumors as well as potential biomarkers and therapeutic targets. We examined 181 tumors representing 16 classes of human bone and soft tissue sarcomas on a 12,601-feature cDNA microarray. Remarkably, 2,766 probes differentially expressed across this sample set clearly delineated the various tumor classes. Several genes of potential biological and therapeutic interest were associated with each sarcoma type, including specific tyrosine kinases, transcription factors, and homeobox genes. We also identified subgroups of tumors within the liposarcomas, leiomyosarcomas, and malignant fibrous histiocytomas. We found significant gene ontology correlates for each tumor group and identified similarity to normal tissues by Gene Set Enrichment Analysis. Mutation analysis done on 275 tumor samples revealed that the high expression of epidermal growth factor receptor (EGFR) in certain tumors was not associated with gene mutations. Finally, to further the investigation of human sarcoma biology, we have created an online, publicly available, searchable database housing the data from the gene expression profiles of these tumors (http://watson.nhgri.nih.gov/sarcoma), allowing the user to interactively explore this data set in depth.
Wnt-5a Protein Expression in Primary Dukes B Colon Cancers Identifies a Subgroup of Patients with Good Prognosis
Authors: Dejmek Janna , Dejmek Annika , Säfholm Annette , Sjölander Anita , Andersson Tommy
Published: October 2005

Oncogenic Wnt/β-catenin signaling occurs in a majority of colorectal cancers. In contrast, very little is known about the role of the nontransforming Wnt protein family member Wnt-5a in those tumors. In the most common of the three colon cancer stages, Dukes B or lymph node–negative, the outcome is the hardest to predict. We searched for a predictive marker in this group and observed loss of or reduced Wnt-5a expression in 50% of Dukes B tumors. Such Wnt-5a negativity was a strong predictor of adverse outcome, with a relative risk of death of 3.007 (95% confidence interval, 1.336-6.769; P = 0.008) after 5 years in Wnt-5a-negative patients. Furthermore, the median survival time after diagnosis was 109.1 months for patients with Wnt-5a-positive primary tumors but only 58 months for those with Wnt-5a-negative primary tumors. To find a possible biological explanation for these results, we studied the invasive and poorly differentiated human colon cancer cell line, SW480, which does not express Wnt-5a protein and the Wnt-5a-expressing and moderately differentiated Caco2 colon cancer cell line. We found that the addition of recombinant/purified Wnt-5a significantly reduced the migratory capacity of SW480 cells. By comparison, equivalent treatment did not significantly alter migration in the Wnt-5a-expressing Caco2 colon cancer cell line. These findings indicate that the expression of Wnt-5a in primary Dukes B colon cancer tissue constitutes a good prognostic marker for longer survival, which can be explained by the ability of Wnt-5a to impair tumor cell migration and thus reduce invasiveness and metastasis.
Meeting Report: NCI Think Tanks in Cancer Biology
Authors: Sogn John A. , Anton-Culver Hoda , Singer Dinah S.
Published: October 2005

Over the past year and a half, the Division of Cancer Biology of NCI has been assessing the state of cancer biology, with the goal of developing a research agenda for the near future that would accelerate progress in cancer research. Our goal was to identify emerging concepts and promising opportunities for investigation across nine scientific areas with unusual promise for rapid progress. A series of meetings called Think Tanks was convened, each involving a panel of 15-25 experts. In all, over 160 leaders in cancer research and related fields discussed the current state of science in their disciplines, projected its trajectory and recommended what NCI could or should do to facilitate progress. In addition to emphasizing the importance of continued support for investigator-initiated research, the Think Tanks permitted identification of a number of overarching themes. Critical among them was the need to support the development of integrative cancer biology and to encourage studies of the tumor microenvironment by establishing an infrastructure for interactive research. There was also consensus about the importance of comparative studies of normal and tumor states, and development of mechanisms for supporting collaborative, interdisciplinary research and training.
Hyperplastic Gastric Tumors with Spasmolytic Polypeptide–Expressing Metaplasia Caused by Tumor Necrosis Factor-α–Dependent Inflammation in Cyclooxygenase-2/Microsomal Prostaglandin E Synthase-1 Transgenic Mice
Authors: Oshima Masanobu , Oshima Hiroko , Matsunaga Akihiro , Taketo Makoto Mark
Published: October 2005

We showed recently that Helicobacter infection induces expression of cyclooxygenase-2 and microsomal prostaglandin E synthase-1 in the mouse stomach, and that transgenic mice expressing both cyclooxygenase-2 and microsomal prostaglandin E synthase-1 (K19-C2mE mice) develop hyperplastic gastric tumors with inflammatory histopathology. To investigate possible roles of proinflammatory cytokines and acquired immunity in the gastric hyperplasia of K19-C2mE mice, we introduced knockout mutations for tumor necrosis factor-α (TNF-α; Tnf), interleukin-1 receptor-α chain (Il1r1), and Rag2 genes, respectively. Among the compound mutants, only the Tnf (−/−) K19-C2mE mice showed significant suppression of hyperplastic tumors with reduced cell proliferation. In contrast, tumorigenesis remained unaffected in either compound mutants of K19-C2mE containing Il1r1 or Rag2 mutation, indicating that neither interleukin-1β signaling nor T cell/B cell response was required for the development of hyperplastic tumors. Importantly, spasmolytic polypeptide/trefoil factor 2–expressing metaplasia (SPEM) in the K19-C2mE stomach was also suppressed in the Tnf (−/−) K19-C2mE mice, indicating that TNF-α–dependent inflammation is responsible for SPEM development. Because gastric metaplasia to the SPEM lineage is considered as a preneoplastic lesion of gastric cancer, it is possible that inhibition of TNF-α–dependent inflammation, together with eradication of Helicobacter, can be an effective prevention strategy for gastric cancer.
Association between Acquired Uniparental Disomy and Homozygous Gene Mutation in Acute Myeloid Leukemias
Authors: Fitzgibbon Jude , Smith Lan-Lan , Raghavan Manoj , Smith Matthew L. , Debernardi Silvana , Skoulakis Spyros , Lillington Debra , Lister T. Andrew , Young Bryan D.
Published: October 2005

Genome-wide single nucleotide polymorphism analysis has revealed large-scale cryptic regions of acquired homozygosity in the form of segmental uniparental disomy in ∼20% of acute myeloid leukemias. We have investigated whether such regions, which are the consequence of mitotic recombination, contain homozygous mutations in genes known to be mutational targets in leukemia. In 7 of 13 cases with uniparental disomy, we identified concurrent homozygous mutations at four distinct loci (WT1, FLT3, CEBPA, and RUNX1). This implies that mutation precedes mitotic recombination which acts as a “second hit” responsible for removal of the remaining wild-type allele, as has recently been shown for the JAK2 gene in myeloproliferative disorders.
Anti–Prostate Stem Cell Antigen Monoclonal Antibody 1G8 Induces Cell Death In vitro and Inhibits Tumor Growth In vivo via a Fc-Independent Mechanism
Authors: Gu Zhennan , Yamashiro Joyce , Kono Evelyn , Reiter Robert E.
Published: October 2005

Prostate stem cell antigen (PSCA), a 123–amino acid cell surface glycoprotein, is highly expressed in both local and metastatic prostate cancers as well as in a large proportion of bladder and pancreatic cancers. PSCA overexpression correlates with a high risk of recurrence after primary therapy for prostate cancer. We have reported previously that anti-PSCA monoclonal antibody (mAb) 1G8 inhibits tumor growth, prevents metastasis, and prolongs the survival of mice inoculated with human prostate cancer cell lines and xenografts. The current study was undertaken to elucidate the mechanism of action of anti-PSCA antibody therapy. In particular, we asked whether antitumor activity resulted from recruitment of an immune response or a direct effect on the tumor cell itself. In vitro assays show that both intact 1G8 and F(ab′)2 fragments of 1G8 induce prostate cancer cell death. The anti-PSCA antibody-induced cell death is caspase independent and requires antigen cross-linking. These results were confirmed in in vivo models in which both 1G8 and F(ab′)2 fragments were able to inhibit prostate tumor formation and growth equally. These results suggest that the anti-PSCA mAb 1G8 acts by a direct, Fc-independent mechanism to inhibit prostate tumor growth both in vitro and in vivo.
p27kip1 in Intestinal Tumorigenesis and Chemoprevention in the Mouse
Authors: Yang WanCai , Bancroft Laura , Liang Jiao , Zhuang Min , Augenlicht Leonard H.
Published: October 2005

Targeted inactivation of p27kip1 was sufficient for intestinal tumor formation in mice, but this was strictly a function of diet: tumors formed in p27+/− or p27−/− mice fed control AIN-76A diet and were increased by a western-style diet but did not develop in mice fed standard chow diet. When crossed with the Apc1638N+/− mouse, Apc+/−,p27+/− or Apc+/−,p27−/− mice not only formed twice as many tumors than the sum of the tumors from mutation at either locus alone, but on AIN76A diet also developed intestinal intussusception, a tumor-associated pathology in patients leading to intestinal blockage that has not been reported for intestinal cancer in mouse models. Moreover, the frequency of intussusception was increased when the compound mutant mice were maintained on the western diet, leading to early death. Despite this more aggressive tumor phenotype generated by inactivation of p27 than by inactivation of another cyclin-dependent kinase inhibitor, p21WAF1/cip1, the nonsteroidal anti-inflammatory drug sulindac was still effective in inhibiting intestinal tumor formation in Apc+/−,p27+/− or Apc+/−,p27−/− mice, which contrasts with the abrogation of the effects of sulindac in Apc+/−,p21+/− or Apc+/−,p21−/− mice, indicating that p27 is not necessary for tumor inhibition by sulindac. Furthermore, tumor inhibition by sulindac was linked to the induction of p21 expression by the drug, regardless of p27 status, leading to suppression of cell proliferation and promotion of cell differentiation and apoptosis in the intestinal mucosa.
Sleep Duration and Breast Cancer: A Prospective Cohort Study
Authors: Verkasalo Pia K. , Lillberg Kirsi , Stevens Richard G. , Hublin Christer , Partinen Markku , Koskenvuo Markku , Kaprio Jaakko
Published: October 2005

Breast cancer incidence has increased during recent decades for reasons that are only partly understood. Prevalence of sleeping difficulties and sleepiness has increased, whereas sleeping duration per night has decreased. We hypothesized that there is an inverse association between sleep duration and breast cancer risk, possibly due to greater overall melatonin production in longer sleepers. This population-based study includes information from women born in Finland before 1958. Sleep duration, other sleep variables, and breast cancer risk factors were assessed by self-administered questionnaires given in 1975 and in 1981. Breast cancer incidence data for 1976 to 1996 was obtained from the Finnish Cancer Registry. Hazard ratios (HR) and 95% confidence intervals (CI) were obtained from Cox proportional hazards models adjusting for potential confounders. Altogether, 242 cases of breast cancer occurred over the study period among the 12,222 women with sleep duration data in 1975. For these women, the HRs for breast cancer in the short (≤6 hours), average (7-8 hours), and long sleep (≥9 hours) duration groups were 0.85 (CI, 0.54-1.34), 1.0 (referent), and 0.69 (CI, 0.45-1.06), respectively. Analysis restricted to the 7,396 women (146 cases) whose sleep duration in 1975 and 1981 were in the same duration group (stable sleepers) yielded HRs of 1.10 (CI, 0.59-2.05), 1.0, and 0.28 (CI, 0.09-0.88), with a decreasing trend (P = 0.03). This study provides some support for a decreased risk of breast cancer in long sleepers.
Ku86 Modulates DNA Topoisomerase I–Mediated Radiosensitization, but not Cytotoxicity, in Mammalian Cells
Authors: Shih Shyh-Jen , Erbele Tara , Chen Allan Y.
Published: October 2005

Ku86 is an integral component of the nonhomologous end-joining (NHEJ) pathway of cellular double-strand break repair. In the current study, we investigated the role of Ku86 in DNA topoisomerase I–mediated radiosensitization induced by camptothecin in mammalian cells. Interestingly, as examined by clonogenic survival assay, a 30-minute camptothecin treatment induced significantly higher levels of radiosensitization in the Ku86-deficient Chinese hamster ovary xrs-6 cells than in the hamster Ku86-complemented xrs-6+hamKu86 cells, albeit exhibiting similar drug toxicity in these two cell lines. To confirm these findings, similar studies were conducted in two pairs of transfectant sublines established from the Ku86-deficient Chinese hamster lung fibroblast XR-V15B cells. Compared with the vector-alone sublines, radiation resistance was restored in the human Ku86-complemented sublines without alteration of cell cycle distributions. Again, significantly higher levels of camptothecin-induced radiosensitization were observed in the vector-alone sublines than in the Ku86-complemented XR-V15B sublines. In contrast, camptothecin treatments, ranging from 0.5 to 24 hours, induced similar cytotoxicities in both vector-alone and Ku86-complemented sublines. Because neither the DNA-damaging etoposide and cisplatin nor the tubulin-binder vinblastine induced enhanced levels of radiosensitization in the Ku86-deficient cells, Ku86 seems to uniquely affect topoisomerase I–mediated radiosensitization induced by camptothecin. Furthermore, cotreatment with DNA replication inhibitor aphidicolin abolished both camptothecin-induced cytotoxicity and radiosensitization in the vector-alone, as well as the Ku86-complemented subline cells, indicating both events are initiated by replication-dependent topoisomerase I–mediated DNA damages. Taken together, our data show a novel role of Ku86 in modulating topoisomerase I–mediated radiosensitization, but not cytotoxicity, in mammalian cells.
Molecular Portraits and 70-Gene Prognosis Signature Are Preserved throughout the Metastatic Process of Breast Cancer
Authors: Weigelt Britta , Hu Zhiyuan , He Xiaping , Livasy Chad , Carey Lisa A. , Ewend Matthew G. , Glas Annuska M. , Perou Charles M. , van't Veer Laura J.
Published: October 2005

Microarray analysis has been shown to improve risk stratification of breast cancer. Breast tumors analyzed by hierarchical clustering of expression patterns of “intrinsic” genes have been reported to subdivide into at least four molecular subtypes that are associated with distinct patient outcomes. Using a supervised method, a 70-gene expression profile has been identified that predicts the later appearance or absence of clinical metastasis in young breast cancer patients. Here, we show that distant metastases display both the same molecular breast cancer subtype as well as the 70-gene prognosis signature as their primary tumors. Our results suggest that the capacity to metastasize is an inherent feature of most breast cancers. Furthermore, our data imply that poor prognosis breast carcinomas classified either by the intrinsic gene set or the 70 prognosis genes represent distinct disease entities that seem sustained throughout the metastatic process.
Cytochrome P4501A1 and Glutathione S Transferase Gene Polymorphisms in Patients with Aplastic Anemia in India
Authors: Poonkuzhali B. , Shaji R.V. , Salamun D.E. , George B. , Srivastava A. , Chandy M.
Published: October 2005

The etiology of acquired aplastic anemia (AA) in most patients remains unclear. It is believed that patients with a reduced ability to detoxify environmental toxins are at increased risk of developing AA. Cytochrome P450 (CYP450) and glutathione S transferase (GST) are the major phase I and phase II xenobiotic-metabolizing enzymes. We analyzed the impact of the polymorphisms in CYP4501A1 and GSTM1 and GSTT1 genes on the susceptibility and disease severity in 200 patients with AA and compared the frequency with the normal population. There was a significantly increased frequency of the CYP1A1m4 allele in AA patients compared with normal controls (odds ratio = 3.01; 95% confidence interval 1.76–5.17; p = 0.00001). None of the other CYP1A1 genotypes or the GST genotypes were significantly different between AA patients and controls. Altered metabolism of benzo(a)pyrene due to the polymorphism in the CYP1A1 gene might be an etiologic factor in the increased incidence of AA in these patients. The CYP1A1m4 allele may play a role in determining the risk of AA in India.
Apoptosis in Thalassemia major Reduced by a Butyrate Derivative
Authors: El-Beshlawy A. , Seoud H. , Ibrahim A. , Youssry I. , Gabre H. , Isma’eel H. , Aoun E. , Taher A.
Published: October 2005

Background and Objectives: In cases of β-thalassemia major, apoptosis appears to be greatly enhanced in the early-stage erythroid precursors in the bone marrow leading to ineffective erythropoiesis. L-Carnitine is found to strongly reduce apoptosis in different diseases. We investigated the effect of oral L-carnitine therapy on apoptosis in thalassemia major patients. Methods: Eighteen thalassemia major patients with a mean age of 12.2 ± 6.6 years were included. Detection of apoptosis was done by photometric enzyme immunoassay (ELISA) and agarose gel electrophoresis before and after 6 months of oral therapy with L-carnitine (50 mg/kg/day). Results: A significant decrease of apoptosis frequency in the erythroid precursors in the bone marrow of studied cases was noted after therapy. The quantity of nucleosomes measured by ELISA dropped from 3.65 ± 1.338 to 1.60 ± 0.65 after therapy (p = 0.005). A positive ladder pattern reflecting apoptosis on agarose gel electrophoresis was detected in 88.9% of cases prior to treatment versus 16.7% after therapy (p = 0.006). Patients also had a significant decrease in the frequency of transfusions and increase in the pre-transfusion hemoglobin levels after therapy. Conclusion:L-Carnitine seems to be a good modulator of apoptotic processes in thalassemic patients leading to a decreased frequency of programmed erythroblast death and general improvement of the disease condition.
CD56-Positive Acute Lymphoblastic Leukemia
Authors: Matano Sadaya , Terahata Shintaro , Nakamura Shigeo , Kobayashi Kazumi , Sugimoto Tatshuho
Published: October 2005

We report a patient with lung cancer who developed CD56-positive acute lymphoblastic leukemia. He was referred to our hospital for thrombocytopenia. Atypical cells were found in the blood and the bone marrow. These cells were immunophenotypically positive for CD3ε, CD56, and terminal deoxynucleotidyl transferase, and negative for surface CD3, CD4, CD19, CD33, and myeloperoxidase. A small proportion of leukemic cells express CD13. There were no rearrangements of T-cell receptor (TCR)-β, TCR-γ, or immunoglobulin heavy chain. No Epstein-Barr virus was detected. Systemic examination did not detect any tumors other than pulmonary adenocarcinoma, and the patient was diagnosed as having acute natural killer (NK) cell leukemia. Chemotherapy was effective, and he achieved complete remission. The course of the disease was complicated by a lung abscess, and the patient died 3 months after the diagnosis. We considered that the diagnosis was blastic NK cell lymphoma/leukemia subtype. However, it actually was myeloid/NK cell precursor leukemia subtype that weakly expressed CD13.
Comparative Effect of Fish Oil Feeding and Other Dietary Fatty Acids on Plasma Lipoproteins, Biliary Lipids, and Hepatic Expression of Proteins Involved in Reverse Cholesterol Transport in the Rat
Authors: Morgado Nora , Rigotti Attilio , Valenzuela Alfonso
Published: October 2005

Background: While elevated plasma high-density lipoprotein (HDL) levels has been associated to a reduction in cardiovascular risk, dietary fish oils rich in omega–3 polyunsaturated fatty acids (PUFAs) may protect against this disease. The protective effect of HDL is associated to its participation in the reverse cholesterol transport pathway. On the other hand, omega–3 PUFAs decrease plasma HDL levels compared to other fatty acids, which may suggest an effect on reverse cholesterol transport. Aim: In this work, the effect of dietary fish oil on the fatty acid composition of hepatic membranes, plasma lipoprotein cholesterol profile, biliary lipids, and the expression of proteins involved in reverse cholesterol transport, was compared to other dietary oils having a different degree of fatty acid unsaturation. Methods: Male rats were fed a semi synthetic diet containing fish oil (omega–3), sunflower oil (omega–6), olive oil (omega–9) or coconut oil (saturated). Hepatic membrane fatty acid composition, plasma cholesterol levels, lipoprotein cholesterol profile, biliary lipids, hepatic mRNA levels for lecithin cholesterol acyltransferase, hepatic lipase, apo E, and apo A-I, and hepatic protein levels of the scavenger receptor class B type I, caveolin-1, and the ATP binding cassette transporter A1 were analyzed. Plasma apo A-I and apo E protein levels were also evaluated. Results: Compared to the other diets, omega–3 PUFAs significantly changed omega–3/omega–6 fatty acid ratio of hepatic membranes, caused a reduction of plasma total and HDL cholesterol, and selectively increased biliary cholesterol secretion. No modification in the expression levels of lecithin cholesterol acyltransferase, hepatic lipase, apo A-I and apo E mRNA was observed. Hepatic scavenger receptor class B type I, caveolin-1, and the ATP binding cassette transporter A1 protein levels were also not affected. Plasma apo A-I, but not apo E, was reduced. Conclusions: These results show that dietary omega–3 PUFAs reduce plasma HDL cholesterol and increase biliary cholesterol without concomitant modifications in the expression of key genes and proteins involved in reverse cholesterol transport. These findings suggest that functional changes in the activity of these proteins as consequence of the incorporation of omega-3 PUFAs into hepatic membranes and plasma lipoproteins may underlie the effect of fish oil feeding on plasma and hepatic cholesterol metabolism in the rat.
Failure of a Short-Term Antibiotic Therapy for Human Brucellosis Using Ciprofloxacin
Authors: Al Dahouk Sascha , Hagen Ralf M. , Nöckler Karsten , Tomaso Herbert , Wittig Martina , Scholz Holger C. , Vergnaud Gilles , Neubauer Heinrich
Published: October 2005

Background: Human brucellosis is characterized byfocal complications, chronic courses, and therapeutic failures. Methods: In a relapsed case of brucellosis after short-term antibiotic therapy using doxycycline and ciprofloxacin two Brucella strains were isolated, before and after treatment.In vitro susceptibilities of both isolates were determined by E tests® including a great variety of antibiotics. In a killing rate experiment the bactericidal activities of doxycycline, streptomycin, rifampin and ciprofloxacin as single agents and in combinations were determined. Results: Lowest MIC values were measured for doxycycline and ciprofloxacin. MICs did not change under therapy. Streptomycin alone exhibited the most effective killing within 6 h, whereas the other single agents did not show bactericidal activity. Doxycycline plus ciprofloxacin was the most active combination in vitro. Conclusion: Routine susceptibility testing of Brucellae is not obligatory as most of the ‘traditional’ anti-Brucella antibiotics are active in vitro and bactericidal efficacy may differ in vivo.
Effects of Mupirocin at Subinhibitory Concentrations on Biofilm Formation in Pseudomonas aeruginosa
Authors: Ishikawa Jinko , Horii Toshinobu
Published: October 2005

Background: Subinhibitory concentrations of mupirocin can suppress flagellar formation in Pseudomonas aeruginosa. In this study, we evaluated the effect of mupirocin on biofilm formation in P. aeruginosa. Methods:P. aeruginosa PAO-1 (MIC, >1,024 µg/ml for mupirocin) was used. Viable bacteria adhering or forming biofilm on a Cell Desk were counted and observed by scanning electron microscopy. Results: With or without continuous exposure to 256 µg/ml of mupirocin, counts of adherent and/or biofilm-forming bacteria showed no difference until day 10. Whereas biofilm formation with glycocalyx was observed on day 6–10 without mupirocin, mupirocin reduced biofilm formation and glycocalyx production for 10 days. Conclusions: Subinhibitory concentrations of mupirocin can reduce biofilm formation in vitro in P. aeruginosa.
Serial Cytokine Profiles in Shunt-Related Ventriculitis Treated with Intraventricular Vancomycin
Authors: Laborada Gary , Cruz Florencia , Nesin Mirjana
Published: October 2005

Background: A 1-month-old premature infant developed persistent shunt-related methicillin-resistant Staphylococcus aureus ventriculitis that was not responsive to parenteral therapy with vancomycin plus gentamicin (or rifampin). Methods: The infant was treated by intraventricular administration of vancomycin (5 days: 10 mg/day). In addition to standard testing of the cerebrospinal fluid (CSF), tumor necrosis factor alpha, interleukin-8 and interleukin-6 were serially measured. Results: Sterilization of the CSF was followed by a decline in the number of WBC and proinflammatory cytokines in the CSF. Conclusion: Intraventricular administration of antibiotics may be considered if ventriculitis is refractory to systemic antimicrobial therapy. Serial measurements of inflammatory cytokines in the CSF may provide an additional diagnostic tool to monitor the outcome of therapy.
Pharmacokinetics of Fluconazole in the Cerebrospinal Fluid of Children with Hydrocephalus
Authors: Bafeltowska J.J. , Buszman E.
Published: October 2005

Background: The aim of this study was to examine the pharmacokinetics of fluconazole in the CSF of children with hydrocephalus during CNS infection treatment after intravenous and/or intraventricular drug administration. Direct fluconazole administration into the ventricular CSF of patients to treat serious CNS infections is an aggressive therapy, and data on the pharmacokinetics of fluconazole in CSF are limited. Methods: A method of fluconazole quantification in CSF by solid-phase extraction (SPE)-high-performance liquid chromatography (HPLC) was developed to conduct pharmacokinetic studies. The population of patients included 2 children with hydrocephalus. Fluconazole was administered intravenously at average multiple doses of 12.5 mg/kg/24 h and intraventricularly at doses of 4, 5 and 7.5 mg/24 h, and 7.5 and 10 mg/12 h. The CSF samples were taken 2–24 h after administration of fluconazole. The concentrations of fluconazole in CSF specimens were assessed, and after pharmacokinetic studies the fluconazole dosage was modified. Results: The method of fluconazole determination in CSF using the SPE-HPLC method is specific, precise and accurate. After intravenous fluconazole administration, the concentration of this antifungal drug was not detected in the ventricular CSF. The pharmacokinetic parameters determined after intraventricular fluconazole administration were: steady-state peak CSF fluconazole concentration (19.54 ± 5.63 mg/l); trough CSF fluconazole concentration (0.0–0.3 mg/l); elimination rate constant (0.4654 ± 0.2097 h–1), and half-life (1.84 ± 0.93 h). Conclusions: The authors developed a method to determine fluconazole in CSF by SPE-HPLC. After intravenous fluconazole administration, the drug was not detected in the examined CSF samples. The intraventricular multidose pharmacokinetic data suggest the necessity of fluconazole monitoring in children with hydrocephalus during the treatment of shunt infection.