bluuebunny/crossref_metadata_2025 huggingface dataset:
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

Multicellular 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

We 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

Among 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

m‐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

A 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

We 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

The 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

Mernbrane‐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

In 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

The 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

A 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

A 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

Somatostatin 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

During 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.
Ca 72‐4 radioimmunoassay in the diagnosis of malignant effusions. Comparison of various tumor markers
Authors: Ferroni P. , Szpak C. , Greiner J. W. , Simpson J. F. , Guadagni F. , Johnston W. W. , Colcher D.
Published: February 2007

We evaluated the utility of the CA 72‐4, CEA, CA 125, CA 19‐9 and CA 15‐3 radioimmunoassays for the detection of tumor‐associated antigens (TAAs) in effusions of malignant vs. benign origin. Fluids were obtained from 51 patients with adenocarcinomas, 27 with non‐epithelial malignancies, and 68 with benign disorders. The CA 72‐4 radioimmunoassay (cut‐off value 8.5 U/ml) detected the TAG‐72 antigen in 51% of adenocarcinoma patients′ effusions, while only 1 of 68 benign specimens had an elevated TAG‐72 level. Similarly, CEA levels above 5 ng/ml were found in 55% of the fluids from patients with adenocarcinoma and 3.2% of effusions from patients with benign disease. CA 19‐9 (cut‐off value 37 U/ml) exhibited a lower degree of sensitivity, with positive values in 23.5% of the effusions due to adenocarcinomas and in 4.5% of the effusions due to benign disease. At a cut‐off value of 29 U/ml, CA 15‐3 was positive in 49% of fluids from patients with adenocarcinoma and in 3.0% of the benign fluids. The CA 125 RIA failed to show any specificity using the established cut‐off value of 35 U/ml, with approximately 80% of all the effusions giving positive results. The specificity of the assay was increased by using a cut‐off value of 3000 U/ml, but with a substantial loss in sensitivity (23.5%). Using a combination of the CA 72‐4 and CEA RIAs the sensitivity for malignant effusions was increased to 73.5%. No additional improvement in the overall sensitivity was observed when using the CA 72‐4 assay in combination with assays for the other markers, except in the case of I effusion. We conclude that the CA 72‐4 RIA, possibly in combination with other assays such as CEA, may be useful in distinguishing between adenocarcinomatous and benign effusions.
Icam ‐ melanoma cells are relatively resistant to cd3‐mediated t‐cell lysis
Authors: Braakman Eric , Goedegebuure Peter S. , Vreugdenhil Rea J. , Segal David M. , Shaw Stephen , Bolhuis Reinder L. H.
Published: February 2007

The primary activation pathway of T cells is via the T‐cell receptor (TCR)/CD3 complex, which is functionally interrelated with various accessory molecules. We examined the contribution of the lymphocyte‐function‐associated antigenI/intercellular adhesion molecule I (LFA‐I/ICAM‐I) interaction to CD3/TCR‐mediated lysis by cytotoxic T lymphocytes (CTL). We used ICAM‐I‐or+ tumor cell lines as target cells and anti‐CD3‐ or anti‐LFA‐I containing hetero‐cross‐linked monoclonal antibody (MAb) to bridge CTL and target cells and simultaneously to activate CTL. The ICAM‐I‐ melanoma‐derived cell line lgR39 was relatively resistant to CD3‐mediated lysis by both TCRαβ+ and TCRγdL+ CTL, when compared with ICAM‐I+ cell lines. Induction of ICAM‐I on the membrane of lgR39 cells by tumor necrosis factor (TNF) rendered these cells more susceptible to CD3‐mediated lysis. Anti‐ICAM‐I MAb inhibited this TNF‐enhanced susceptibility to lysis, directly demonstrating that the induction of ICAM‐I was critical in the TNF‐induced increase in susceptibility to lysis of lgR39 cells. CTL formed less efficient conjugates with the ICAM‐I‐ cells as compared to ICAM‐I+ cells. Both spontaneous and CD3‐induced conjugate formation as well as CD3‐mediated lysis of ICAM‐I‐ tumor cells by CTL were enhanced by the addition of anti‐LFA‐I containing heterocross‐linked MAb, thereby mimicking the LFA‐I/ICAM‐I interaction between CTL and target cells. Soluble anti‐CD18 MAb inhibited CD3‐mediated lysis of ICAM‐I‐ target cells by CTL without affecting their conjugate formation. Anti‐LFA‐I MAb added after conjugate formation still inhibited lysis of both ICAM‐I+or‐ tumor cells. Taken together, these findings suggest that the LFA‐I/ICAM‐I interaction co‐activates CD3/TCR‐mediated lysis by CTL through both an enhanced CTL‐target cell binding and the delivery of post‐conjugate costimulatory signals.
Analysis of cell‐surface sugar receptor expression by neoglycoenzyme binding and adhesion to plastic‐immobilized neoglycoproteins for related weakly and strongly metastatic cell lines of murine tumor model systems
Authors: Gabius Sigrun , Schirrmacher Volker , Franz Holger , Joshi Shantaram S. , Gabius Hans‐Joachim
Published: February 2007

Recognition of the carbohydrate part of cellular glycoconjugates by cell‐surface sugar receptors may contribute to interactions, essential to the establishment of metastases. Comparison of the properties of strongly metastatic variants to their related, less metastatic counterparts offers a generally accepted approach to the discovery of metastasisassociated characteristics. The chemically induced murine lymphoma line Eb and its spontaneously arising variant ESb with increased potential for lung and liver colonization, the virally induced lymphosarcoma cell line RAW 117‐P and its in vivo selected variant H 10 with increased potential for liver colonization, and the B16‐FI melanoma line and its in vivo selected variant F 10 with increased potential for lung colonization, were chosen. A panel of 12 types of chemically glycosylated E. coli β‐galactosidase, exposing the pivotal carbohydrate residues for specific carbohydrate‐dependent cell binding, was employed to study the expression of respective cellsurface sugar receptors on these cell lines. Specific binding occurred in a non‐uniform manner for the individual probes. Systematic measurements at a non‐saturating ligand concentration revealed quantitative differences between the 2 cell lines of each system. However, there were no consistent changes associated with the metastatic phenotype. A similar result was obtained employing Scatchard analyses for quantitative evaluation of binding characteristics in several cases. Surface receptor expression was responsive to chemical induction of differentiation in the lymphosarcoma model. Analyses of sugar‐inhibitable cell adhesion to neoglycoproteincoated plastic wells for the lymphoma and lymphosarcoma cells revealed that the presence of cell‐surface sugar receptors, even at similar densities to those defined by neoglycoenzyme binding, will not necessarily translate into an identical adhesive response. Several carbohydrates, especially N‐acetyl‐D‐galactosamine, can differentially affect this interaction at a non‐toxic concentration in both model systems.
Degradation of immobilized soluble elastin by tumor cells in culture: Quantitation by elisa
Authors: Caenazzo C. , Spina M. , Onisto M. , Fastelli G. , Gotte L. , Agostini C. , Semenzato G. , Garbisa S.
Published: February 2007

A new, sensitive assay based on the enzyme‐linked immunosorbent assay has been developed for measuring elastolytic activity produced by invasive and/or metastatic tumor cells in culture. Elastin peptides, obtained by treating the insoluble protein with either oxalic acid, KOH, or chymotrypsin, are adsorbed onto the surface of cell culture microtiter plastic wells, and incubated with dilution of standard proteinases or viable normal or tumor cells. The total amount of immobilized elastin peptides is revealed by the mean of specific antibodies, and detected by a microplate reader, while dose‐ and time‐dependent reduction of bound antibodies after incubation with proteases or cells is taken as a measure of elastin degradation. Adsorbed elastin has been found to be available as a substrate for purified enzymes, as well as for living melanoma cells (A2058 and B 16‐B16), c‐Ha‐ras transformed rat embryo fibroblasts, and human pulmonary macrophages, as demonstrated by the release into the culture medium of lower molecular weight digestion products. No degradation was achieved by BALB/3T3 and rat embryo control fibroblasts, and no inhibition was produced by the presence of fetal calf serum which, on the contrary, potentiated the degradation by active cells. This new method, revealing degradation of only a few nanograms of soluble elastin peptides, can be used for studying the importance in tissue invasion and metastasis of elastolytic proteinases produced by cells in culture.
Influence of cigarette smoking on the levels of DNA adducts in human bronchial epithelium and white blood cells
Authors: Phillips David H. , Schoket Bemadette , Hewer Alan , Bailey Eric , Kostic Szilárd , Vincze István
Published: February 2007

The presence of carcinogen‐DNA adducts in human tissues is evidence of exposure to carcinogens and may be an indicator of cancer risk. DNA was isolated from non‐tumorous bronchial tissue of 37 cigarette smokers, 8 former smokers and 8 non‐smokers and analyzed for the presence of aromatic and/or hydrophobic DNA adducts in the32P‐post‐labelling assay. Adducts were detected as bands of radioactive material when 5′‐32P‐labelled deoxyribonucleoside 3′, 5′‐bisphosphates were chromatographed on polyethyleneimine‐cellulose tic plates, and the patterns indicated the formation of adducts by a large number of compounds. Adduct levels detected in DNA from non‐smokers, former smokers and current smokers were 3.45 ± 1.62, 3.93 ± 1.92 and 5.53 ± 2.13 adducts/108nucleotides, respectively. The differences in adduct levels be tween smokers and former and non‐smokers were statistically significant (p< 0.01); and among the smokers, significant correlations were found between adduct levels and both daily cigarette consumption and total cigarette consumption (daily consumption × number of years smoked). DNA was also isolated from the peripheral‐blood leukocytes of 31 heavy smokers (>20 cigarettes/day) and 20 non‐smokers and analyzed by32P‐post‐labelling. Adduct levels in the smokers' samples were not significantly different from levels in the nonsmokers' samples (2.53 ± 1.31 and 2.12 ± 1.44 adducts/108nucleotides, respectively). Thus, evidence for carcinogen exposure was found in human bronchial epithelium, a target tissue for tobacco‐induced tumour formation, but not in peripheral‐blood cells, indicating possible limitations in the use of the latter as a surrogate, non‐target tissue source of DNA for monitoring human exposure to inhaled carcinogens.
Asbestos exposure and histologic cell types of lung cancer in surgical and autopsy series
Authors: Mollo F. , Piolatto G. , Bellis D. , Andrion A. , Delsedime L. , Bernardi P. , Pira E. , Ardissone F.
Published: February 2007

A case‐control study was carried out on 411 surgical and 106 autopsy histological tissue samples of lung cancer in men, in order to investigate the relationships between asbestos expo sure and cell type of pulmonary carcinoma. Both occupational history (obtained by interviews of surgical patients or of the next‐of‐kin for deceased subjects) and lung asbestos body con tent (determined by optical count after hypochlorite diges tion and membrane filtration of lung tissues) were considered as asbestos exposure indicators. No significant relationships were found in the surgical series after adjustment for smok ing. The autopsy series showed a trend towards an association between lung adenocarcinoma and asbestos exposure indicators and a markedly higher agreement between the 2 kinds of indicators than that observed in the surgical series.
High frequency of Epstein‐Barr virus genome detection in Hodgkin's disease of HIV‐positive patients
Authors: Uccini Stefania , Monardo Francesca , Stoppacciaro Antonella , Gradilone Angela , Aglianò Anna M. , Faggioni Alberto , Manzari Vittorio , Vago Luca , Cosianzi Giulio , Ruco Luigi P. , Baroni Carlo D.
Published: February 2007

Lymph nodes obtained from 7 HIV‐positive and 20 HIV‐negative patients with Hodgkin's disease were examined for the presence of Epstein‐Barr virus antigens and genome. EBV antigens were observed in only 2 out of 20 HIV‐negative patients, whereas lymph nodes of HIV‐positive patients did not reveal evidence of EBV antigens. By In situ hybridization and Southern blot analysis, EBV genome was found in 5 out of 7 HIV‐positive patients; the EBV genome was detected in the nucleus of Reed‐Sternberg and Hodgkin's cells. EBV DNA was observed by in situ hybridization and Southern blot analysis in only out of 20 HIV‐negative patients with Hodgkin's disease. In both groups, Reed‐Sternberg and Hodgkin's cells were neg ative for C3d EBV receptor. Our results show a statistically significant increased expression of EBV DNA in HIV‐positive patients with Hodgkin's disease, as compared with HIV‐negative patients with HD.
Expression and production of tenascin in benign and malignant lesions of melanocyte lineage
Authors: Natali Pier Giorgio , Nicotra Maria Rita , Bartolazzi Armando , Mottolese Marcella , Coscia Nadia , Bigotti Aldo , Zardi Luciano
Published: February 2007

The distribution of the extracellular matrix (ECM) glycoprotein tenascin (TN) has been evaluated immunohistochemically in benign and malignant lesions of the melanocytic lineage. Results of our study show that TN is detectable in a variety of benign and malignant lesions. In primary melanomas, TN displays a heterogeneous distribution, and a higher degree of expression of this glycoprotein is seen in lesions of greater dermal invasiveness. TN expression does not correlate with that of other ECM glycoproteins such as fibronectin. In vivo and in vitro experiments have also demonstrated that melanoma cells are capable of producing and releasing TN in the extracellular milieu.
Geographic association of Helicobacter pylori antibody prevalence and gastric cancer mortality in rural China
Authors: Forman D. , Sitas F. , Newell D. G. , Stacey A. R. , Boreham J. , Peto R. , Campbell T. C. , Li J. , Chen J.
Published: February 2007

To examine the geographic association between Helicobacter pylori infection and gastric cancer, we have assessed the prevalence of IgG antibodies to H. pylori in plasma samples taken in 1983 from 1882 men, aged 35‐64 years, in 46 rural counties of the People's Republic of China. The gastric cancer mortality rates in these counties in 1973‐75 varied from 3 per 1,000 (cumulative rate, 0‐64 years) to 69 per 1, 000. while the proportions of the population positive for H. pylori antibodies (based on an average of about 41 men per county) varied from 28% to 96%. After correction for the limited number of blood samples per county, the estimated correlation between H. pyori antibody prevalence and gastric cancer mortality was 40% (p = 0.02). No other type of cancer showed a significant association with H. pylori.
F11C antigen: A membrane marker able to distinguish two regressive and progressive variants from a rat colon adenocarcinoma
Authors: Caignard Anne , Genne Philippe , Olsson Nils‐Olivier , Oriol Rafael , Martin François
Published: February 2007

Cell variants that differ in their tumorigenicity and immunogenicity have been isolated from a BDIX rat colon adenocarcinoma cell line, DHD/K12. One variant, PRO, and the clones derived from it, are poorly immunogenic and induce progressive and metastatic tumors; the other one, REG, and its clones, are highly immunogenic and induce regressive tumors. When looking for a membrane marker distinguishing between PRO and REG lines, we obtained monoclonal hybridomas by immunizing BALB/c mice with PROb or REGb cell clones. Hybridoma FI IC, producing an IgM monoclonal antibody (MAb) was able to distinguish between the cell variants on membrane immunofluorescence. All REGb cells strongly express FI IC membrane antigen. On PROb cells, FI IC antigen expression is weak, as demonstrated by cytofluorimetric analysis, and limited to a fraction of the cell population. The FI IC membrane antigen is highly specific for the DHD/K12 cell line and the variants derived from it, but is not expressed on cells dissociated from the DHD transplanted tumor, from which DHD/K12 was established, suggesting that FI IC antigen emerged during cell culture. Fluorescence absorption on synthetic oligosaccharides demonstrated that FI IC antibody cross‐reacts with A type 3, A type 4 and A type 5 chain blood group tetrasaccharides.
Modulation of cellular gene expression in B lymphoma cells following in vitro infection by Epstein‐Barr virus (EBV)
Authors: Calender Alain , Cordier Martine , Billaud Marc , Lenoir Gilbert M.
Published: February 2007

In vitro infection of EBV‐negative lymphoma cell lines with immortalizing strains of Epstein‐Barr virus induces the cellsurface expression of B‐cell markers, such as the EBV receptor/CR2 (CD21) and the CD23 antigen. The non‐immortalizing EBV variant, P3HRI, which carries a deletion encompassing the EBV nuclear antigen 2 (EBNA2) gene, fails to induce any such expression. We show here that the EBV‐mediated up‐regulation of cell‐surface expression of these molecules is associated with an increased level of the specific steady‐state RNA corresponding to these 2 genes. These results suggest that the role of EBNA2 in B‐cell growth and immortalization may be related to its role in transactivation of cellular genes. In order to identify other cellular genes whose expression may be modulated by EBV, we analyzed the level of transcription of a set of genes possibly involved in Burkitt's lymphoma pathogenesis. The level of the c‐myc oncogene transcript was not significantly affected by in vitro EBV infection. The c‐fgr oncogene, thought to be specifically activated in EBV‐infected cells, was found to be expressed in some EBV‐negative lymphoma cells and also to be activated by both non‐immortalizing and immortalizing strains of EBV. The expression of vimentin, the major 56‐kDa polypeptide of mesenchymal cell intermediate filaments, was altered by all EBV isolates, in either a negative or a positive way, depending on the cell line. Expression of lymphocyte‐function‐associated antigens, LFA‐I α/β (CDI la/18) and LFA‐3 (CD58), involved in intercellular adhesion and the T‐cytotoxic pathway, were differentially regulated by EBV; a crucial observation was the activation by immortalizing EBV isolates of LFA‐1 β chain (CD18) and of LFA‐3 (CD58). The EBV‐ and possibly EBNA2‐associated modulation of cellular genes, such as CR2 (CD21), CD23 and LFAs, probably represents key events for EBV‐induced B‐cell proliferation, and also for in vivo immune control of EBV‐infected B cells.
A single dose‐response effect of aflatoxin B1 on rapid liver cancer induction in two strains of rats
Authors: Angsubhakorn Subhkij , Get‐Ngern Panisa , Miyamoto Makoto , Bhamarapravati Natth
Published: February 2007

To investigate rapid liver cancer induction in rats by aflatoxin B1 (AFB1), different single oral doses of AFB1 were given to 3 groups of I‐year‐old Buffalo and Wistar rats. The animals were treated once and all survivors were killed 6 weeks later. Control animals received an equal volume of solvent (DMSO), and both groups of animals were maintained under identical conditions throughout the period of experiment. The survival rates were 40% with low and medium doses in AFB1‐treated Buffalo and Wistar rats, and 0% in the high‐dose Buffalo rats. Slight ante‐mortem elevations in serum concentrations of glutamic pyruvic transaminase (SGOT) and glutamic oxaloacetic transaminase (SGPT) were indicative of the persistent damage effect of AFB1 at week 6. Total protein and albumin concentrations were not altered. The percent incidence of altered cell foci (areas) and neoplastic nodules was higher in Wistar than in Buffalo rats given a similar low dose. Various stages of well differentiated hepatocellular carcinomas (0.1‐0.2 cm in diameter) developed in 3 of 8 Wistar rats. It thus appears that Wistar rats are more susceptible to hepatocarcinogenesis following a single oral dose of AFB1 than Buffalo rats.
Relationships among tumor responsiveness, cell sensitivity, doxorubicin cellular pharmacokinetics and drug‐induced DNA alterations in two human small‐cell lung cancer xenografts
Authors: Pratesi G. , Capranico G. , Binaschi M. , De Isabella P. , Pilotti S. , Supino R. , Zunino F.
Published: February 2007

In an attempt to understand the underlying cellular/biochemical factors of sensitivity/resistance in human small‐cell lung cancer (SCLC), 2 SCLC tumor lines were compared with respect to tumor responsiveness to drug treatment, cell sensitivity, cellular doxorubicin accumulation, and DNA topoisomerase‐II‐mediated DNA cleavage. The tumor lines growing in nude mice with simillar growth characteristics (doubling time around 10 days) were selected since one (POCI tumor) was found to be hypersensitive and the other (POSG tumor) resistant to doxorubicin treatment. The pattern of anti‐tumor, drug response of the doxorubicin‐resistant tumor was atypical (i. e., non‐adherent to the well‐characterized multi‐drug‐resistant phenotype), since it responded to vincristine. The markedly different in vivo tumor response reflected the intrinsic cellular sensitivity to doxorubicin. No correlation was found between cellular drug accumulation and doxorubicin sensitivity following in vitro exposure to the drug. In agreement with this observation, the expression of mdr‐I gene was undetectable in these tumors. Thus, in the POSG tumor, resistance to doxorubicin occurred without expression of the P‐glycoprotein and reduction of cellular drug accumulation. In contrast, the extent of DNA cleavage produced by doxorubicin was markedly higher in the doxorubicin‐hypersensitive than in the doxorubicin‐resistant tumor. These results, taken together with previous observations in SCLC cell lines, support the important role of DNA topoisomerase‐mediated effects in the sensitivity of SCLC to doxorubicin.
Generation and characterization of monoclonal antibodies against multiple epitopes on the C‐terminal half of envelope gp46 of human T‐cell leukemia virus type‐I (HTLV‐I)
Authors: Tanaka Yuetsu , Yasumoto Masazumi , Nyunoya Hiroshi , Ogura Tsutomu , Kikuchi Masayoshi , Shimotohno Kunitada , Shiraki Hiroshi , Kuroda Naotaka , Shida Hisatoshi , Tozawa Hideki
Published: February 2007

In order to study the antigenicity of envelope 46 kDa glycoprotein (gp46) of human T‐cell leukemia virus type‐l (HTLV‐I), we have generated monoclonal anti‐gp46 antibodies (MAbs), REY‐7, REY‐11, REY‐16, REY‐30, MET‐2 and MET‐3 from rats and mice. Immunoblot and immunofluorescence assays showed that these MAbs recognize gp46 and its related antigens, and specifically stained HTLV‐I‐bearing cells. All MAbs reacted with a recombinant gp46 antigen, NI47, expressing the 147 amino acids in the C‐terminal half of gp46. By using various synthetic peptides corresponding to the gp46 sequence, epitopes recognized by REY‐7 and MET‐3, REY‐11 and RE Y‐16, and REY‐30 were mapped to regions corresponding to the amino acids 175‐199, 253‐282 and 288‐312, respectively. MET‐2 did not react with any of the peptides used. These results indicate that the present MAbs are directed against at least 4 distinct epitopes expressed on the C‐terminal half of gp46. The binding of these MAbs to gp46 was specifically inhibited by sera from HTLV‐I‐infected individuals, but none of these MAbs inhibited the cell fusion activity of HTLV‐I.
Resistance to a non‐immunogenic tumor, induced by Corynebacterium parvum or Listeria monocytogenes, is abrogated by anti‐interferonγ
Authors: Keller Robert , Keist Ruth , Leist Thomas P. , Van Der Meide Peter H.
Published: February 2007

The complex processes that determine the outcome of the interaction of tumor and host were explored in the operationally simple and reproducible rat D‐12 ascites tumor model. Animals exhibit weak spontaneous resistance against this tumor that is not augmented by repeated inoculation, by various routes, of irradiated syngeneic D‐12 tumor cells, but considerably enhanced after local administration of heatkilled Corynebacterium parvum (CP) or Listeria monocytogenes (LM) organisms. Inoculation of conventional or monoclonal anti‐rat IFNγ antibodies into the same compartment did not affect spontaneous tumor resistance, but largely abrogated the tumor‐protective effect triggered by CP or LM. Our findings support the concept that IFNγ, produced by T cells in the course of the specific immune response raised against immunogenic micro‐organisms, is able to enhance and to maintain local tumor resistance and thus to strengthen the capacity of the host to cope with a non‐immunogenic tumor.
Mapping of linear epitopes of human papillomavirus type 16: The E1, E2, E4, E5, E6 and E7 open reading frames
Authors: Dillner Joakim
Published: February 2007

Certain types of human papillomavirus (HPV), especially HPV type 16, are associated with proliferative lesions of the cervix uteri that can progress to malignancy. In order to map the linear epitopes of the HPV‐encoded proteins, we have synthesized the predicted amino acid sequences of the open reading frames (ORFs) in the early region of HPV 16, as a set of 94 synthetic 20‐residue peptides overlapping each other with 5 amino acids. The peptides were tested for reactivity with IgA, IgG and IgM antibodies in the sera of 30 patients with HPV 16‐carrying cervical neoplasia. The E1 ORF had only low immunoreactivity, but several relatively minor epitopes were identified in the carboxyterminal part. The E2 ORF was found to contain several epitopes that were highly immunoreactive with a majority (up to 87%) of the cervical cancer patients' sera. The E4 ORF had one major, regularly IgA‐ and IgG‐reactive epitope, whereas the E5 and E6 ORFs had only a few minor epitopes. The E7 ORF had several epitopes that were highly immunoreactive, but only with a minority of patients' sera. The 10 most immunoreactive peptides were also analyzed for immunoreactivity with 60 control sera, of which 22 were derived from patients with parotid gland tumors and 38 were derived from healthy volunteers. Most of the peptides were also immunoreactive with the control sera. However, the IgA antibodies, and to some extent the IgG antibodies, were found at much lower levels among the controls.