bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fusion of rous‐sarcoma‐virus‐transformed rat cells to morphologically normal human or rat cells results in transcriptional suppression of the provirus that depends on its chromosomal integration site
Authors: Green A. R. , Poole C. J. , Povey S. M. , Rowe D. , Searle S. , Wyke J. A. 
Published: February 2007

AbstractThe fusion of a Rous sarcoma virus (RSV)‐transformed rat fibroblast clone to at least 2 different human cell types reproducibly produces phenotypically normal hybrids. Analysis of such hybrids reveals that proviral silence is the result of transcriptional down‐regulation, presumably by a trans‐acting human molecule. Furthermore, this phenomenon seems to be strongly influenced by the proviral chromosomal integration site and its imposition may entail a mechanism that is required only transiently.
Characterization of a new model of human prostatic cancer: The multicellular tumor spheroid
Authors: Donaldson Jonathan T. , Allan Tucker J. , Keane Thomas E. , Walther Philip J. , Webb Karen S. 
Published: February 2007

AbstractMulticellular tumor spheroids (MTS) provide a closer in vitro correlate to in vivo malignancy than do conventional monolayer cultures; while simulating many parameters of in vivo growth, MTS systems provide those perquisites (i. e., experimental control, economy, expediency) associated with in vitro evaluation of preclinical therapeutic strategies. For these reasons, we exploited the proclivity of the highly metastatic human prostatic carcinoma subline I‐LN‐PC3‐IA to spontaneously assume a spheroid morphology under routine culture conditions. I‐LN spheroids demonstrate salient features described in other spheroid systems and exhibit histologic characteristics of human prostate carcinoma. Cells encompassed in the I‐LN spheroid format demonstrated functional divergence from their monolayer counterparts with respect to immunoreactivity for prostatic acid phosphatase, positional dependence of prostate‐restricted p40 antigen expression, and chemotherapeutic drug response. This new in vitro‐in vivo transition model of human prostatic carcinoma should provide a valuable in vitro context to expediently evaluate in vivo correlates of oncolytic protocols on a malignancy that remains refractive to therapy.
A weakly tumorigenic phenotype with high mhc class‐i expression is associated with high metastatic potential after surgical removal of the primary murine fibrosarcoma
Authors: Pérez M. , Algarra I. , Ljunggren H. G. , Caballero A. , Mialdea M. J. , Gaforio J. J. , Klein G. , Kärre K. , Garrido F. 
Published: February 2007

AbstractWe have examined the metastatic capacity of different clones of a chemically induced fibrosarcoma GR9. These clones have previously been characterized for their H‐2 class‐I and class‐II phenotype, NK sensitivity and local tumor growth. Our present data show that clones which express low amounts of H‐2 class‐I antigens are poorly metastatic in a post‐surgical spontaneous metastasis assay, while those expressing high levels of class‐I antigens possess a high metastatic capacity. These results correlate inversely with local growth patterns of the clones. High metastatic capacity was associated with resistance to NK cells. In an experimental metastasis assay, based on intravenous administration of in vitro carried GR9 clones to syngeneic BALB/c mice, an opposite result to the post‐surgical assay was obtained. Gamma‐IFN treatment of B9 clones (H‐2‐deficient) enhanced H‐2 class‐I expression and diminished experimentally induced metastases. Metastatic colonies, from the spontaneous metastasis assay, obtained from different organs, showed changes in the ratio H‐2K/H‐2D. There was a tendency for downregulation of the expression of H‐2K molecules in H‐2‐positive clones and for up‐regulation of H‐2D expression in H‐2‐negative clones.
Immunofluorescence study of the action of navelbine, vincristine and vinblastine on mitotic and axonal microtubules
Authors: Binet Stéphane , Chaineau Eric , Fellous Arlette , Lataste Hedwige , Krikorian Anais , Couzinier Jean‐Pierre , Meininger Vincent 
Published: February 2007

AbstractAmong the various non‐naturally‐occurring Vinca alkaloid compounds, nor‐anhydro‐vinblastine (Navelbine, NVB) exhibits in preliminary clinical studies broader anti‐tumor activity and lower neurotoxicity than vinblastine (VBL) and vincristine (VCR). The action of these 3 Vinca alkaloids on axonal and mitotic microtubules has been studied experimentally in a specific model, the tectal plate anlage of mouse embryos at the earliest stages of neuronal differentiation. Post‐implantation embryos were cultured in toto in a medium containing increasing concentrations of drugs. Microtubules were stained using immunofluorescence with a tubulin‐specific polyclonal antibody in semi‐thin sections after embedding in highmolecular‐weight polyethylene glycol. All drugs induced depolymerization of mitotic interpolar microtubules and cell metaphase block at the same concentration. Increasing the concentrations led to progressive depolymerization of kinetochore microtubules. However, NVB was the only drug to induce complete microtubule depolymerization. The activity of the 3 compounds on axonal microtubules was identical: depolymerization of a labile pool of microtubules. This was observed at higher concentrations with NVB than with the 2 other Vinca alkaloids. Our results show that, in this model, NVB is as active on mitotic microtubules as VCR and VBL, and less active on axonal microtubules. None of the 3 drugs modified microtubule length but all appeared to induce disruption of the labile microtubule pool without altering the stable pool.
Impaired mitochondrial respiration and stimulated glycolysis by m‐iodobenzylguanidine (mibg)
Authors: Loesberg Cornelia , Rooij Henny Van , Nooijen Willem J. , Meijer Alfred J. , Smets Lou A. 
Published: February 2007

Abstractm‐lodobenzylguanidine (MIBG) is a functional analogue of the neurotransmitter norepinephrine. Radio‐iodinated 131I‐MIBG is used clinically as a tumor‐targeted radiopharmaceutical agent in the diagnosis and treatment of adrenergic tumors. Native MIBG has previously been demonstrated to be cytotoxic in cultured cells and to produce anti‐tumor responses in animals when non‐toxic schedules are used. In this study the effect of MIBG was investigated on isolated rat liver mitochondria and on various tumor cell lines (human neuroblastoma SK‐N‐SH, mouse neuroblastoma N1E115 and mouse lymphosarcoma S49). Results revealed that MIBG inhibits respiration of isolated liver mitochondria at complex I of the respiratory chain, without affecting F1 ATP‐ase. In cell lines, impairment of the mitochondrial respiration was evident from reduced oxygen consumption and decreased intracellular ATP levels. In response to this effect, the glycolytic flux was stimulated as shown by increased glucose consumption and lactic acid production. Cytotoxicity of MIBG was proportional to drug‐induced alterations in glucose metabolism.
Baboon anti‐idiotype antibodies mimic a carcinoembryonic antigen epitope
Authors: Losman Michele J. , Monestier Marc , Hansen Hans J. , Goldenberg David M. 
Published: February 2007

AbstractA baboon was immunized with NP‐4, a murine monoclonal antibody (MAb) to carcinoembryonic antigen (CEA). Antiidiotype antibodies were purified from the baboon serum by affinity chromatography on a NP‐4‐coupled matrix, followed by adsorption of the non‐specific antibodies on an irrelevant MAb. Baboon anti‐idiotype antibodies inhibited specifically the binding between NP‐4 and CEA. Mice immunized with baboon anti‐idiotype antibodies produced antibodies to the CEA epitope recognized by NP‐4. These results indicate that baboon anti‐idiotype antibodies functionally mimic a CEA epitope and that they can be suitable for idiotype therapy of human CEA‐producing carcinomas.
Human T‐cell leukemia virus type‐I‐infected T‐cell lines scarcely produce p56lck, whether or not they express lck MRNA
Authors: Oh‐hori Nobuhira , Koga Yasuhiro , Yoshida Hiroki , Morita Minoru , Kimura Genki , Nomoto Kikuo 
Published: February 2007

AbstractWe have previously reported that lck mRNA (a lymphocyte‐specific protein tyrosine kinase gene) is absent in human T‐cell leukemia virus type I (HTLV‐I)‐infected interleukin‐2(IL‐2)‐independent T‐cell lines, while HTLV‐I‐negative T‐cell lines and HTLV‐I‐positive IL‐2‐dependent ones express a large amount of lck mRNA. To further investigate the levels of lck expression, we prepared rabbit anti‐Lck antiserum directed against the synthetic oligopeptide of 32 amino acids corresponding to the carboxy terminus of this gene product, p56lck. Using this antiserum, we show that HTLV‐I‐positive T‐cell lines, whether they are IL‐2‐dependent or not, scarcely express p56lck. In other words, IL‐2‐dependent HTLV‐I‐positive T‐cell lines seldom produce p56lck In spite of high expression of lck mRNA. Absence of p56lck is suspected of playing an important role in malignant transformation of HTLV‐I‐infected T‐cells.
Metabolism of low‐density lipoprotein in differentiated and undifferentiated HT29 colon cancer cells
Authors: Viallard Viviane , Lacombe Christiane , Trocheris Véronique , Tabacik Christiane , Aliau Sigrid 
Published: February 2007

AbstractThe metabolism of human low‐density lipoproteins was studied in 2 subpopulations deriving from cells of HT29, a human colon carcinoma cell line. When grown on standard medium (25 mM glucose), about 95% of these cells are undifferentiated (G+ cells). From this heterogeneous population, a subpopulation with features of differentiated small‐intestinal cells was selected by glucose deprivation (G− cells). The characteristics of the LDL receptor were first investigated. The results showed that the binding of 125I‐LDL to G+ and G− cells performed at 4°C was saturable and specific. The Kdvalues were not statistically different in the 2 cell subpopulations. The Bmax of G+ cells was 55 ± 6 ng 125I‐LDL/mg cell protein and showed no changes whatever the phase of culture. In G− cells, the Bmax was higher during the exponential phase of culture and decreased in the post‐confluent phase (82 ± 5 versus 15 ± 6.8 ng 125I‐LDL/mg cell protein). Cellular degradation of 125I‐LDL was effective in both cell subpopulations but time‐course studies showed that, in post‐confluent G− cells, degradation was slowed as compared to G+ cells (4 hr vs. 2 hr to reach maximal degradation). The rate of LDL processing at 37°C was enhanced by pre‐incubation with FCS‐supplemented medium, suggesting the existence of a serum component which stimulates the total degradation of 125I‐LDL. Concerning regulation of the LDL receptor activity, we demonstrated that pre‐incubation of G+ cells with LDL induced 80% down‐regulation of receptor number in both phases of culture. This was also observed in G− cells during the exponential phase while only a 20% decrease of the receptor number was observed in post‐confluent G− cells. The LDL degradation of G+ cells resulted in an inhibition of the cholesterogenic activity by 30% and 60% depending on the phase of culture. In G− cells, LDL pre‐incubation inhibited cholesterol synthesis to the same extent (45%) in the exponential phase but did not affect the rate of cholesterol synthesis when cells were confluent. The defective regulatory role of LDL on receptor number and cholesterol synthesis suggests that, in the post‐confluent differentiated cells, cholesterol derived from LDL does not reach the regulatory pool. Taken together, our findings indicate the existence of functional LDL receptors in the HT29 cell line, either in the differentiated or in the undifferentiated form.
Role of cell cholesterol in modulating antineoplastic ether lipid uptake, membrane effects and cytotoxicity
Authors: Diomede Luisa , Bizzi Adalgisa , Magistrelli Armando , Modest Edward J. , Salmona Mario , Noseda Alessandro 
Published: February 2007

AbstractMernbrane‐interactive ether lipids (EL) exert toxic and antiproliferative effects on cancer cells in vitro. They appear to be selectively more toxic to cancer cells than to normal cells and thus they are ideal candidates for bone‐marrow purging procedures. However, no conclusive explanation has yet been provided for this property. We now present some data indicating that the cholesterol concentration in the incubation medium modulates EL toxicity against the HL60 leukemic cell line in vitro. Furthermore, model membranes richer in cholesterol take up EL more slowly, and cell cholesterol enrichment of HL60 cells counteracts EL biophysical membrane interaction, but not toxicity, in our experimental model. However, the K562 cell line, a leukemia line less sensitive to EL toxic action, has higher levels of cell cholesterol. Our data provide evidence to explain differences in sensitivity to EL among different cell types and contribute to the understanding of the mechanism of action of EL.
Incidence and determinants of skin cancer in a high‐risk australian population
Authors: Green Adèle , Battistutta Diana 
Published: February 2007

AbstractIn a Queensland community, we surveyed the incidence of basal‐cell carcinoma (BCC) and squamous‐cell carcinoma (SCC), and associated risk factors. In December, 1986, 2,095 residents were examined by dermatologists for skin cancer. Of these, 1,770 further participated in a follow‐up postal sur vey in December, 1987, regarding all skin cancers in the pre ceding 2 years, and 87 reported being treated for skin cancer in the 2‐year period between December 1985 and November 1987. The estimated annual incidence rates of non‐melanoma skin cancer in men and women aged 20‐69 years were 2,389/ 100,000 and 1,908/100,000 respectively, with an overall ratio of BCC cases to SCC cases of 4.5 to one. While both tumour types occurred more commonly in fair‐complexioned people, the risk associated with high sun exposure was greater for SCC than for BCC. Clinical signs of solar skin damage, espe cially the number of solar keratoses on the face, were the strongest predictors of both types of skin cancer.
Prenatal x‐ray exposure and childhood cancer in swedish twins
Authors: Rodvall Ylva , Pershagen Göran , Hrubec Zdenek , Ahlbom Anders , Pedersen Nancy L. , Boice John D. 
Published: February 2007

AbstractThe association between X‐ray exposure in utero and child hood cancer was studied in a case‐control study, nested in a national cohort of Swedish twin births. Records of the Swedish Twin Register for those born 1936‐1967 (n = 83,316) were linked to the Swedish Cancer Register (1958‐1983) and the Swedish Cause‐of‐Death Register (1952‐1983). Ninety‐five cases of childhood cancer before the age of 16 were identified. Two controls from the Twin Register were matched to each case by sex and year of birth. Maternal X‐rays during preg nancy were documented for 41% of the cases and 36% of the controls. The crude relative risk of any childhood cancer associated with any prenatal X‐ray was 1.2 (95% CI; 0.7‐2.1). For the cases 64% of the X‐rayed women had had abdominal X‐rays, the numbers for the controls were 57%. Fifty‐nine per cent of the X‐rayed women had had abdominal X‐rays, which were associated with a relative risk for all cancers of 1.4 (Cl; 0.8‐2.5), leukemias I.7(CI; 0.7‐4.1) and tumors of the central nervous system 1.5 (Cl; 0.5‐4.2). There was no apparent confounding by mother's age, drug use, obstetric complications, previous miscarriages, social class or length of pregnancy. The observed relative risks of cancer following prenatal X‐ray ex posure are consistent with previous studies, suggesting that the developing fetus may be more sensitive to the carcinogenic effects of ionizing radiation than are children irradiated post‐natally.
Oral contraceptives and risk of breast cancer
Authors: Paul Charlotte , Skegg D. C. G. , Spears G. F. S. 
Published: February 2007

AbstractA national population‐based case‐control study was conducted in New Zealand to assess the effects of hormonal contraception on breast‐cancer risk. A total of 891 women aged 25 to 54 with a first diagnosis of breast cancer, and 1864 control subjects, randomly selected from the electoral rolls, were interviewed. The relative risk of breast cancer for women who had ever used oral contraceptives was 1.0 (95% confidence interval 0.82‐1.3). There was no increase in risk with duration of use, even among women who had continued to use oral contraceptives for 14 or more years (relative risk = 1.1, 95% confidence interval 0.78‐1.7). The risk of breast cancer was not increased by use of oral contraceptives for long periods before the first pregnancy or by starting use at a young age. Parity, age at menarche, family history of breast cancer, or history of benign breast disease did not modify the effect of oral contraceptives on breast‐cancer risk. Relative risk estimates were slightly, although not significantly, increased during the first few years after starting oral contraception and in women under 35 years of age at diagnosis.
Influence of dietary fat on fecal mutagenicity in premenopausal women
Authors: Nair P. P. , Shami Samina , Sainz Eduardo , Menon Malini , Jerabek Lois B. , Yvonne Jones D. , Judd Joseph T. , Campbell William S. , Schiffman Mark H. , Taylor Philip R. , Schatzkin Arthur , Guidry Catherine , Brown Charles C. 
Published: February 2007

AbstractA dietary intervention study was conducted on 31 premenopausal women (age: 20‐40 years) to investigate the relationship between dietary fat and fecal mutagenicity. After a free‐living period (baseline) of one menstrual cycle, the subjects were placed on a high‐fat diet (40% calories from fat) for 4 menstrual cycles, followed by a low‐fat diet (20% calories from fat) for 4 menstrual cycles. One‐half of the subjects were randomly assigned throughout the study to a diet with a P:S ratio of 1.0 while the other half was assigned to one with a P:S ratio of 0.3; body weight by group remained constant. Threeday stool samples were collected at the mid‐follicular period during the free‐living phase and during the 4th menstrual cycle of each of the 2 controlled diet periods. Mutagenicity was assayed by the SOS chromotest. Reduction of dietary fat was accompanied by a significant decrease in fecal mutagenicity in both P:S groups. Combined values, i. e., both P:S groups, were 20.3 units for high‐fat diets vs. 8.78 for low‐fat diets.
Somatostatin receptor incidence and distribution in breast cancer using receptor autoradiography: Relationship to egf receptors
Authors: Reubi J. C. , Waser B. , Foekens J. A. , Klijn J. G. M. , Lamberts S. W. J. , Laissue J. 
Published: February 2007

AbstractSomatostatin receptors (SS‐R) were measured with in vitro receptor autoradiography using the SS analog 125I‐[Tyr3]‐SMS 201‐995 as radioligand in 342 breast‐tumor samples. In a group of 158 “small” tumor samples (mean section surface: 14 mm2 ± 0.4; mean ± SEM), 34 tumors (21%) were SS‐R positive. In a group of 72 “large” tumor samples (mean size: 180 mm2 ± 8; mean ± SEM), 33 tumors (46%) were SS‐R positive. In this second group, more than half of the tumors had a non‐homogeneous distribution of SS‐R, i. e., tumor regions within SS‐R positive tumors were SS‐R negative. In a group of 48 additional patients, we could show that primaries and their metastases, or double primaries from right and left breasts, or 2 primaries resected consecutively, could both occasionally be SS‐R positive. Finally, in 71 SS‐R‐positive primary tumors, 18 tumor samples were found to have simultaneously Epidermal Growth Factor receptors (EGF‐R); in 12 of these 18 cases, the 2 receptor types were not topographically overlapping. Whereas SS‐R were located on tumor tissue, EGF‐R were often seen on adjacent normal lobules and ducts. These results show that a subgroup of breast tumors contain SS‐R, in several cases non‐homogeneously distributed. Their location does not coincide with that of EGF‐R. Metastasis of SS‐R‐positive primaries may be SS‐R‐positive, as are sometimes second primaries. For evaluation of SS‐R incidence and distribution, autoradiography is of advantage, specially if it is performed on large tumor samples, since it allows precise identification of the tissue elements containing these receptors.
Are energy and energy‐providing nutrients related to exocrine carcinoma of the pancreas?
Authors: Bueno De Mesquita H. B. , Moerman C. J. , Runia S. , Maisonneuve P. 
Published: February 2007

AbstractDuring 1984‐88 a population‐based case‐control study was carried out in The Netherlands in collaboration with the International Agency for Research on Cancer in order to further explore the possible relationship between diet and exocrine pancreatic carcinoma. Past habitual dietary intake was assessed in 164 cases and 480 controls. This is the first series of population‐based studies of pancreas cancer to perform a comprehensive assessment of diet. The results of logistic regression analysis, controlled for age, gender and total cigarette consumption, suggested a positive association with past habitual intake of energy in directly interviewed patients (OR highest versus lowest quintile 3.35; 95% confidence interval 1.51‐7.18). No indication of an effect of Queteler index was found. When maximum‐weight‐ever‐achieved was used, non‐significantly reduced risks were observed for the upper 4 quintiles of “maximum” Quetelet index. After controlling for age, gender, response status and total cigarette consumption, a positive relationship with habitual past intake of total carbohydrates was observed (OR 2.40; 95% confidence interval 1.44‐3.99). The effect decreased considerably when the analysis was restricted to subjects who reported stable long‐term dietary intake. After controlling for age, gender, total cigarette consumption and response status, a significant, positive association between pancreatic cancer and past habitual intake of simple sugars was found (OR 1.95; 95% confidence interval 1.24‐3.07). Among those who reported stable longterm dietary intake, no effect was seen. The positive effect of simple sugars was present in males only (OR 2.15; 95% confidence interval 1.18‐3.93) and was smaller in men who reported long‐term stable dietary intake. Our findings suggest that the development of exocrine pancreatic carcinoma is positively related to past habitual intake of total energy, total carbohydrates and simple sugars, whereas no relationship with body‐mass index was observed.