bluuebunny/crossref_metadata_2025 huggingface dataset:
Fibroblast‐mediated differentiation in human breast carcinoma cells (MCF‐7) grown as nodules IN VITRO
Authors: Brouty‐Boyé Danièle , Mainguené Claire , Magnien Véronique , Israel Lucien , Beaupain Rene
Published: February 2007

The growth of cells in 3‐dimensional form as nodules in vitro facilitates studies of in vivo cellular interactions. Taking advantage of this technique, human breast carcinoma cells (MCF‐7) were co‐cultured with stromal fibroblasts isolated from either normal or tumorous breast tissue to study the influence of such fibroblasts on tumor‐cell growth and differentiation. Ten days after co‐culture of carcinoma cells with fibroblasts from normal tissue at a 1:10 ratio, the size of nodules began to increase and stabilize by day 30 while the fibroblast number decreased and finally disappeared. Concurrently, the carcinoma cells underwent a progressive redifferentiation process which histologically resulted in the appearance of highly developed papillar and tubular structures after 2 months in culture. The production of mucins was further evidence that these cells had undergone differentiation. By contrast, when MCF‐7 cells were grown alone or with fibroblasts isolated from a breast carcinoma, the nodules continued to exhibit their characteristic histodedifferentiation properties and did not grow. The re‐establishment of a normal epithelial state of differentiation in MCF‐7 carcinoma nodules indicates that the phenotypic characteristics of tumor cells are reversible and are influenced or controlled by the stromal environment by which these tumor cells are surrounded or in contact with. Overall, our results open the possibility of exploiting the effects that connective tissue cells have on tumor‐cell differentiation for use in prevention and treatment of cancer.
Response of four human ovarian carcinoma cell lines to ALL‐TRANS retinoic acid: Relationship with induction of differentiation and retinoic acid receptor expression
Authors: Caliaro M. J. , Marmouget C. , Guichard S. , Mazars Ph. , Valette A. , Moisand A. , Bugat R. , Jozan S.
Published: February 2007

The response of 4 human ovarian carcinoma cell lines to retinoic acid was found to be related to the histological type and degree of differentiation of these tumor cells. The 2 serous cell lines NIHOVCAR3 and OVCCR1 were the most sensitive to the antiproliferative effect of RA. This inhibition was associated with morphological and biological changes that were indicative of differentiation. The undifferentiated IGROV1 cell line was not affected by RA. Since the effects of RA are thought to be mediated by nuclear retinoic acid receptors (RARs), the expression of RARs in human ovarian cancer cells was studied. RARα was detected as mRNA species of 3.1 and 2.6 kb in all 4 cell lines. RARβ was not detected in any of the cell lines, while RARγ (3 kb) was expressed in all of the ovarian cancer cells but at a very low level in the RA‐resistant IGROV1 cells.
Radiation leukemogenesis: Quantitative relationship between pre‐leukemic cells in the thymus and lymphoma induction
Authors: Kotler M. , Ruchlemer R. , Avni O. , Yefenof E.
Published: February 2007

Fractionated irradiation of C57BL/6 mice induces a population of pre‐leukemic (PL) cells that progress into mature thymic lymphomas after a latency of 4 to 6 months. Transfer of graded numbers of thymocytes from an irradiated mouse into recipient mice indicated that PL cells first appear in the thymus 6 weeks after irradiation. The initial proportion of the thymic PL cells is ≥10−5 and their frequency continuously increases with time, reaching ≥ 10−3 10 weeks after irradiation. The PL cell population that emerges early during the pre‐malignant latency consists of pleioclonal T lymphocytes. However, within 4 weeks a dominant PL clone can be detected which becomes the progenitor of a clonal fymphoma 9 to 15 weeks later. These results suggest that radiation leukemogenesis involves continuous accumulation of pleioclonal PL cells in the thymus, one of which is then selected for further maturation into frank lymphoma.
Effect of dibutyryl cyclic amp on morphologic features and marker production of human cervical argyrophil small‐cell carcinoma cell line
Authors: Shimizu Hiromu , Sawada Masumi , Tohyama Masaya , Takemura Koichi , Akedo Hitoshi , Ichimura Hiroshi , Ueda Gaiko , Tanizawa Osamu
Published: February 2007

The effect of dibutyryl cyclic AMP (dB‐cAMP) on the morphologic features and marker production of a human cervical argyrophil small‐cell carcinoma (ASCC) cell line was examined. Following 1–5 days' exposure to 5 mM dB‐cAMP, morphologic differentiation as defined by the expression of cytoplasmic processes (stellate cells) was observed. The number of stellate cells depended on the dose of dB‐cAMP and incubation time. Shortly after removal of dB‐cAMP from the culture medium, the treated cells returned to their original spherical shape. dB‐cAMP caused a reduction in the growth rate of cells which recovered after removal of the agent. The morphological changes appeared not to be the result of growth inhibition by dB‐cAMP, because the cells maintained in a serum‐free medium did not show any change in shape. Electron microscopic study revealed the development of intracytoplasmic microtubules, microfilaments, and an increase in the number of neurosecretory granules in the treated cells. The levels of neuron‐specific enolase, serotonin and gastrin in treated cells were significantly higher than those in untreated controls. These findings indicate that a reversible differentiation of cultured ASCC cells into neuroendocrine cells occurs in a growth medium containing dB‐cAMP.
Expression of tumour necrosis factor (TNFα) and its receptors in benign and malignant breast tissue
Authors: Miles D. W. , Happerfield L. C. , Naylor M. S. , Bobrow L. G. , Rubens R. D. , Balkwwill F. R.
Published: February 2007

As well as having anti‐tumour activity in animal models, TNFα has been implicated in the promotion of tumour invasion and metastasis. Expression and localization of TNFα mRNA and protein has been investigated in a series of benign and malignant breast tissues. TNFα mRNA was expressed in a minority of cells (≤0.5%) in 4/11 cases of benign breast tissue and in a higher proportion of invasive carcinomas (43/49 cases). Expression of TNFα mRNA was focal and confined to the tumour stroma. The presence of TNFα protein was confirmed by immunohistochemistry and again was predominantly stromal. Expression of mRNA and protein localized to infiltrating macrophages defined by the antibody EBM/11 in adjacent sections and using 2‐colour immunofluoresence. Although the average number of macrophages per high‐power field did not vary among invasive carcinomas of different histological type or grade, the number of cells expressing TNFα increased with increasing tumour grade. Immunodetectabfe p75 TNF receptor and to a lesser extent p55 receptor was present on cells of the mononuclear infiltrate and on the endothelium of invasive carcinomas, but not on the tumour cells themselves.
Analysis of cytomorphologically abnormal cervical scrapes for the presence of 27 mucosotropic human papillomavirus genotypes, using polymerase chain reaction
Authors: Husman Ana‐Maria De Roda , Walboomers Jan M. M. , Meijer Chris J. L. M. , Risse Ellen K. J. , Schipper Marguérite E. I. , Helmerhorst Theo M. , Bleker Otto P. , Delius Hajo , Van Den Brule Adriaan J. C. , Snijders Peter J. F.
Published: February 2007

The aim of this study was to investigate the distribution of 27 mucosotropic human papillomavirus (HPV) genotypes (HPV 6, 11, 13, 16, 18, 30, 31, 32, 33, 35, 39,4 0, 42, 43, 44, 45, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61 and 66) in cytomorphologically abnormal cervical scrapes (Pap IIIa‐Pap IV; n = 1, 373) using the polymerase chain reaction (PCR) method on crude cell suspensions. The scrapes were analyzed for the presence of HPV DNA by HPV general‐primer‐mediated PCR (GP‐PCR), which allows the detection of a broad spectrum of HPV types at the subpicogram level. Subsequently, 2 HPV typing procedures based on either type‐specific PCR (for HPV 6, 11, 16, 18, 31 and 33) or characterization of GP‐PCR products by hybridization (for HPV 13, 30, 32, 35, 39, 40, 42, 43, 44, 45, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61 and 66) were applied. Increasing total HPV prevalence was found with increasing severity of dysplasia from 71% in Pap IIIa to 100% in Pap IV scrapes (carcinoma in situ). The scrapes which were positive by type‐specific PCR included 47% cases of Pap IIIa, 71% cases of Pap IIIb and 90% cases of Pap IV. Moreover, 12% of Pap IIIa scrapes, 6% of Pap IIIb scrapes and 8% of Pap IV scrapes revealed positivity for one or more of the remaining HPV types, as determined by successive hybridizations of the GP‐PCR products. Taking the typing data together, we noted that the level of HPV heterogeneity decreased from 22 different HPV types (HPV 6, 11, 16, 18, 31, 33, 35, 39, 40, 42, 43, 44, 45, 51, 52, 54, 55, 56, 58, 59, 61 and 66) detected in the group of Pap IIIa scrapes to 13 (HPV 6, 11, 16, 18, 31, 33, 35, 45, 51, 52, 58, 59 and 61) and 10 HPV genotypes (HPV 6, 16, 18, 31, 33,45, 51, 52, 54 and 58) in the Pap IIIb and Pap IV classes, respectively. An increasing prevalence rate from Pap IIIa to Pap IV was found for HPV 16, 18, 31, 33, 45 and 54. The prevalence rate of identified HPV genotypes increased from 59% in Pap IIIa to 98% in Pap IV, indicating that almost all high‐risk HPV genotypes related to cervical cancer in The Netherlands have been characterized.
Reproductive history and gastric cancer among post‐menopausal women
Authors: Palli Domenico , Cipriani Francesco , Decarli Adriano , Galli Monica , Saieva Calogero , Fraumeni Joseph F. , Blot William J. , Buiatti Eva
Published: February 2007

A total of 339 post‐menopausal women with gastric cancer (GC) and 515 population controls were interviewed in a multi‐center study in Italy for information on reproductive history, dietary habits and other socio‐demographic variables. After adjusting for these factors, GC risk was significantly higher among women reporting menopause below age 45, while no effect was shown for age at menarche, parity, age at first livebirth, and number of abortions. When age at menopause was considered together with age at menarche for an index of fertility years, GC risk showed a significant inverse relation to duration of fertility. These results suggest a protective role for endocrine or other factors related to late age at menopause or to length of fertility. These findings may be relevant to explain the fact that rates of GC reported among females are lower than among males around the world, and suggest the need for further research into hormonal and other related risk factors.
Increased mutagen sensitivity in head‐and‐neck squamous‐cell carcinoma patients, particularly those with multiple primary tumors
Authors: Cloos Jacqueline , Braakhuis Boudewijn J. M. , Steen Ivar , Copper Marcel P. , De Vries Nico , Nauta Jos J. P. , Snow Gordon B.
Published: February 2007

Mutagen sensitivity is a constitutional factor which may be used to identify head‐and‐neck squamous‐cell carcinoma (HNSCC) patients at high risk for the development of multiple primary tumors (MPT). In this retrospective study, mutagen sensitivity was measured in HNSCC patients with a single primary tumor (SPT), HNSCC patients who have already developed MPT and control subjects with no tumor history. In vitro, lymphocytes were challenged with bleomycin and chromosomal damage was quantified by scoring chromatid breaks of 100 cells. A significant difference in the mean number of breaks per cell (b/c) was found between SPT patients and controls. Patients with MPT showed a significantly higher mean b/c value than SPT patients. This increase in mutagen sensitivity in HNSCC patients was not related to well‐known cancer risk factors such as age, or life‐style factors such as smoking and alcohol drinking habits. In addition, tumor site but not tumor stage was found to be related to mutagen sensitivity. On the basis of our findings, we propose that mutagen sensitivity is not an independent risk factor but a constitutional factor which reflects the way in which genotoxic compounds are dealt with and is thereby directly related to cancer risk.
Expression of cytokine/growth factors and their receptors in human melanoma and melanocytes
Authors: Mattei Stefano , Colombo Mario P. , Melani Cecilia , Silvani Anna , Parmiani Giorgio , Herlyn Meenhard
Published: February 2007

Human tumors can constitutively express cytokines and growth factors, but the extent of this expression has not been investigated. Using 44 different probes to cytokines, growth factors, and their receptors, we tested 21 melanoma and 5 melanocyte cultures for RNA transcript expression by reverse transcriptase‐polymerase chain reaction. With 30 amplification cycles, expression of the cytokines interleukin (IL)‐1β, IL‐6, leukemia inhibitory factor (LIF), IL‐7, groα, IL‐8 and the p35 chain of IL‐12 was detected in more than 60% of melanomas. Concomitant receptors for IL‐6 and IL‐7 were also detected. IL‐1α, IL‐5, Rantes, IL‐10, interferon (IFN)‐β, tumor‐necrosis factor (TNF)‐α, G‐colony‐stimulating factor (CSF) and GM‐CSF were expressed at lower levels. Melanocytes showed greatly reduced cytokine RNA transcripts, and only groα was consistently detected. No expression of IL‐2, IL‐3, IL‐4, IL‐9, the p40 chain of IL‐12, IFN‐α or IFN‐γ RNA transcripts was detected in melanomas or melanocytes. The growth factors expressed by melanomas and, after further signal amplification, by melanocytes were transforming growth factor (TGF)‐α, epidermal growth factor (EGF), TGF‐β, endothelial‐cell growth factor (ECGF), basic‐fibroblast growth factor (bFGF), nerve growth factor (NGF) and steel. The receptors EGFR, FGFR, NGFRp70 and c‐kit were also expressed by melanomas and melanocytes. These results point to new possible autocrine and paracrine pathways in melanoma biology.
Expression and function of the insulin‐like growth factor I system in human non‐small‐cell lung cancer and normal lung cell lines
Authors: Favoni Roberto E. , De Cupis Alessandra , Ravera Federica , Cantoni Claudia , Pirani Paolo , Ardizzoni Andrea , Noonan Douglas , Biassoni Roberto
Published: February 2007

In order to analyze the presence and the function of the “insulin‐like growth factor 1 (IGF‐1) system” in human non‐small‐cell lung cancer (N‐SCLC) we tested 5 cell lines of different histological sub‐types: A549, Ca‐Lu‐6, SK‐Lu‐1 (adenocarcinoma); Ca‐Lu‐1, SK‐Mes‐1 (squamous carcinoma) and one normal fibroblast‐like fetal lung cell line (IMR‐90) for expression of the IGF‐1 peptide and its RNA transcribed from the IGF‐1 gene; IGF‐binding proteins (IGF‐BP); IGF‐1 receptor (IGF‐1‐R) and its mRNA. In addition, we examined the capacity of exogenous human recombinant IGF‐1 to enhance the in vitro cell proliferation. In medium conditioned from cell cultures, we detected immunoreactive IGF‐1 material by radioimmunoassay. Western ligand blot and affinity labelling demonstrated the presence of several molecular species of IGF‐BPs (IGF‐BP‐4, −1, −2, −3) as well. Northern blot analysis of polyA+ RNA from all cell lines examined revealed the presence of IGF‐1 and IGF‐1‐R mRNA. Moreover, binding studies on cultured cell lines showed one class of high‐affinity, operative type‐1 IGF cell‐surface binding sites. Finally, by thymidine uptake and colorimetric metabolic MTT assays, we found that most neoplastic cell lines react mitogenically to IGF‐1 and that its physiological effect is abolished by an anti‐IGF‐1‐receptor antibody. These data indicate the importance of the IGF‐1 system in N‐SCLC growth. Furthermore, they suggest that this mitogenic complex should be appraised as a possible target for anti‐neoplastic drugs, antibodies or growth‐factor analogues offering potential new approaches to therapy.
Influence of fibroblasts on the invasion and migration of highly or weakly metastatic b16 melanoma cells
Authors: Saiki Ikuo , Murataxd Jun , Yoneda Junya , Kobayashi Hideo , Azuma Ichiro
Published: February 2007

We have examined the influence of fibroblasts on the invasive and migratory potential of highly metastatic melanoma B16‐BL6 and weakly metastatic B16‐FI cells in vitro. Co‐culture of B16‐BL6 cells with a fibroblast monolayer without cellular contact in a Transwell chamber more effectively induced tumor‐cell invasion into Matrigel basement membrane than co‐culture of B16‐FI cells with a fibroblast monolayer. The activity was closely correlated with the chemotactic migration of tumor cells toward the fibroblast monolayer. We also found that the conditioned medium (CM) from the co‐culture of fibroblasts with B16‐BL6 cells without cellular contact, i.e., CM (B16‐BL6/fibroblast), rather than from co‐culture with B16‐FI cells, could potentially promote the migration of tumor cells of both types. Tumor cells did not chemotactically migrate to the CM (B16‐BL6), CM (B16‐FI) or CM (fibroblast). Antibodies against TGF‐β1 or FN almost completely abolished the chemotactic migration of B16‐BL6 cells to the CM (B16‐BL6/fibroblast) or CM (TGF‐β1 ‐treated fibroblast) when these antibodies were c‐incubated with fibroblasts and either B16‐BL6 or TGF‐β1. In contrast, the anti‐EGF antibody did not show any inhibitory effects. Analysis of amounts of TGF‐β1 or FN in various CM using ELISA plates, and using their specific antibodies, revealed that the concentration of TGF‐β1 in the CM (B16‐BL6) was slightly higher than in the CM (B16‐FI), and the amount of FN in the CM (B16‐BL6/fibroblast) was twice as high as in the CM (B16‐FI /fibroblast). These results suggest that TGF‐β1 released from B16‐BL6 cells can stimulate fibroblasts to produce FN; consequently, the tumor cells were able to chemotactically migrate toward the released FN, and the differences in invasive and migratory activities towards fibroblasts in B16‐BL6 and B16‐FI cells may in part be due to the amounts of TGF‐β1 from tumor cells and of FN from TGF‐β1 ‐stimulated fibroblasts.
γ‐glutamyltranspeptidase expression regulates the growth‐inhibitory activity of the anti‐tumor prodrug γ‐L‐glutaminyl‐4‐hydroxy‐3‐iodobenzene
Authors: Prezioso Joseph A. , Hughey Rebecca P. , Wang Nu , Damodaran Kalyani M. , Bloomer William D.
Published: February 2007

γ‐L‐glutaminyl‐4‐hydroxy‐3‐iodobenzene (I‐GHB), a novel iodinated analog of γ‐L‐glutaminyl‐4‐hydrpxybenzene (GHB), demonstrates greater anti‐tumor activity in human and in murine melanoma cell lines. These phenolic amides are substrates for γ‐glutamyltranspeptidase (GGTP; E.G. 2.3.2.2), a cell‐membrane‐associated ecto‐enzyme which is elevated in a number of tumor systems. We now present data to show that the growth‐inhibitory activity of I‐GHB and GHB may be mediated via GGTP‐catalyzed reactions. The growth‐inhibitory activity of I‐GHB and GHB in pigmented B16‐BL6 melanoma cells was blocked significantly by rabbit anti‐rat GGTP polyclonal antibodies. The combination of L‐serine and sodium borate, a specific transition‐state inhibitor of GGTP, as well as acivicin, a glutamine antagonist and irreversible GGTP inhibitor, inhibited the killing of BL6 cells by GHB and I‐GHB. To further define the role of GGTP expression in the regulation of phenolic amide cytotoxicity, GGTP‐negative Chinese hamster ovary cells (CHO‐KI) were transfected with a functional rat renal cDNA representing the full‐length GGTP transcript. I‐GHB and GHB were significantly more cytotoxic in GGTP cDNA transfected Chinese hamster ovary (CHO‐KI‐GGTP) cells than in non‐transfected CHO‐KI cells. The combination of L‐serine and sodium borate blocked the cytotoxic activity of these pro‐drugs and also inhibited GGTP‐catalyzed formation of polymerized products from these phenolic amides in intact BL6 melanoma and CHO‐KI‐GGTP cells. Furthermore, melanin formation from GHB was not observed in non‐transfected CHO‐KI cells lacking GGTP expression. The combined data strongly suggest that GGTP‐catalyzed hydrolysis of the anti‐tumor pro‐drugs I‐GHB and GHB to 4‐aminophenols mediates the expression of antitumor activity.
Enhancement of interstitial photodynamic therapy by mitomycin C and EO9 in a mouse tumour model
Authors: Baas P. , Michielsen C. , Oppelaar H. , Van Zandwijk N. , Stewart F. A.
Published: February 2007

The tumoricidal effect of interstitial photodynamic therapy (IPDT) using Photofrin was found to increase when combined with the bioreductive alkylating agent mitomycin C (MMC) and, to a lesser extent, with the indoloquinone EO9. When MMC was given prior to IPDT of RIFI tumours, the light dose required for a given regrowth time or for 50% cure was reduced by a factor of 2 compared with IPDT alone. MMC given immediately after illumination did not increase the effects of IPDT, although MMC plus illumination without photosensitizer produced a significant increase in regrowth time compared with MMC or light alone. Combination of IPDT with EO9, given directly before illumination, only marginally increased the tumour regrowth times at non‐toxic doses. These results demonstrate that combining IPDT with MMC greatly improves the tumour response. Factors such as PDT‐induced hypoxia, pH changes, temperature in‐creases and production of toxic reactive oxygen species by both drugs may play a role in the enhanced MMC cvtotoxicity.
Characterization of a species of non‐specific cross‐reacting antigen (NCA) exressed by human monocytic cell lines: Structure and expression during cell differentiation
Authors: Kuroki Motomu , Yamanaka Takahiko , Matsuo Yoshino , Ohtani Takeshi , Matsuo Yoshinobu , Minowada Jun , Misumi Yoshio , Oikawa Shinzo , Nakazato Hiroshi , Matsuoka Yuji
Published: February 2007

It has been documented that human monocytes/macro‐phages are reactive with antibodies directed to carcinoembryonic antigen (CEA) and non‐specific cross‐reacting antigens (NCAs), a group of glycoproteins antigenically cross‐reactive with CEA, yet the molecules responsible for this antigenic activity have not been fully clarified. In the present study, among 7 myelomonocytic cell lines tested, 2 monoblastoid lines, U‐937 and THP‐I, were found to express NCA‐50/90, a glycosyl‐phosphatidylinositol‐anchored cell‐adhesion molecule chiefly expressed on granulocytes. The 2 cell lines showed a reaction pattern with 5 distinct anti‐CEA and anti‐NCA monoclonal antibodies, similar to that of CHO transfectants expressing recombinant NCA‐50/90. Immunoprecipitation and SDS‐PAGE analyses identified glycoproteins of about 95 and 55 kDa in U‐937 and THP‐1 cells, respectively. Deglycosylation of the 2 antigens with N‐glycanase gave the same apparent molecular mass of about 45,000, which was also the same as that of the deglycosylated form of the recombinant NCA‐50/90. Upon Northern‐blot analysis, only one band of approximately 2.5 kb was detected in both cell lines with a cDNA probe for NCA‐50/ 90, which has a broad specificity to the CEA gene family members. cDNA cloning demonstrated that the 2.5‐kb clones encode the peptide of NCA‐50/90. The expression of NCA‐50/90 by U‐937 and THP‐1 was down‐regulated at both the protein and mRNA levels during cell differentiation from monoblastoid to monocyte/macrophage‐like cells induced by stimulation with phorbol 12‐myristate 13‐acetate. Our observations suggest that NCA‐50/90 is a differentiation antigen of cells of the monocyte/macrophage lineage as well as of the granulocyte lineage.
Comparison between the effect of butyric acid and its prodrug pivaloyloxymethylbutyrate on histones hyperacetylation in an HL‐60 leukemic cell line
Authors: Aviram Adina , Zimrah Yael , Shaklai Mali , Nudelman Abraham , Rephaeli Ada
Published: February 2007

A butyric acid pro‐drug, pivaloyioxymethyl butyrate, AN‐9, developed in our laboratory, was previously shown to act as a differentiation‐inducing and an anti‐cancer agent. In this study we have shown that both AN‐9 and butyric acid caused a transient hyperacetylation of histones, which returned to basal levels after 6 and 12 hr, respectively. This activity precedes the induction of differentiation elicited by both agents. AN‐9 induced acetylation of histones at a concentration one order of magnitude lower than butyric acid. Pre‐treatment of the cells with esterase(s) inhibitors diminished the ability of AN‐9 to inhibit proliferation and induce differentiation. The above suggests that the intracellular release of butyric acid fragment, from the pro‐drug, is catalyzed by cellular esterase(s).
Tobacco, alcohol and the risk of gastric cancer. A population‐based case‐control study in Sweden
Authors: Hansson Lars‐Erik , Baron John , Nyrén Olof , Bergström Reinhold , Wolk Alicja , Adami Hans‐Olov
Published: February 2007

Previous studies have provided conflicting information on the role of tobacco and alcohol in gastric carcinogenesis. A population‐based case‐control study with 338 histologically confirmed gastric‐cancer cases and 679 control subjects was conducted. Information relating to life‐time tobacco consumption, alcohol intake and diet during adolescence and 20 years before interview, and to socio‐economic conditions was obtained through face‐to‐face interviews. Current cigarette smokers were found to have a greater risk than non‐users of tobacco. The duration of cigarette or pipe smoking was positively associated with gastric‐cancer risk. There was significant interaction between tobacco use and fruit consumption. High fruit intake was more protective among users of tobacco than among non‐users, and the risk estimates associated with cigarette smoking were higher among those with low fruit consumption than among frequent fruit‐eaters. Likewise, though to a lesser extent, vegetable intake interacted with tobacco use. Snuff dipping and alcohol intake was not associated with gastric‐cancer risk. However, high alcohol intake tended to increase the risk associated with tobacco use. This study adds further support to the role of tobacco smoking in gastric carcinogenesis, and demonstrates that high intake of fruits and vegetables may be particularly beneficial in smokers. © Wiley‐Liss, Inc.
Non‐involvement ofrasmutations in flat colorectal adenomas and carcinomas
Authors: Fujimori Takahiro , Satonaka Kazuhiro , Yamamura‐Idei Yuka , Nagasako Kou , Maeda Sakan
Published: February 2007

Ras gene mutations occur relatively early during colorectal tumor development and have been observed in 40‐50% of malignant colorectal tumors. Advances in endoscopic techniques have made it possible to detect small, flat colorectal tumors that could not be detected by standard examinations. To determine whether ras gene mutations are also involved in the genesis of small, flat colorectal tumors, we examined ras point mutations in 34 cases of small polypoid or flat elevated colorectal tumors (32 adenomas, 2 carcinomas) and in 26 cases of small, flat colorectal tumors (13 adenomas, 13 carcinomas) by means of the polymerase chain reaction (PCR) and dot‐blot hybridization. Ras gene point mutations were observed in 16 of the 34 tumors of the former type (47%), but in none of the 26 tumors of the latter type, even though the grade of dysplasia was severe in the flat tumors. Our results suggest that different genetic pathways for tumor progression may exist for polypoid and for flat colorectal carcinomas. © Wiley‐Liss, Inc.
Micro‐encapsulation of MDCK‐ras‐e cells prevents loss of E‐cadherin invasion‐suppressor function in vivo
Authors: Vandenbossche Geert M. R. , De Bruyne Georges K. , Bruyneel Erik A. , Clemminck Guy , Vleminckx Kris , van Roy Frans M. , Mareel Marc M.
Published: February 2007

The invasion‐suppressor molecule E‐cadherin mediates Cal2+‐dependent cell aggregation and prevents invasion. E‐cadherin‐positive Madin‐Darby canine kidney (MDCK) cells that were non‐invasive in vitro formed, upon i.p. injection, tumors that were invasive. Differentiated tubular tumor areas showed an intense immuno‐signal for E‐cadherin at intercellular contacts, whereas undefferentiated structures did not. Cell lines derived from such tumors turned out to be invasive in vitro and showed decreased Ca2+‐dependent cell aggregation but no change in E‐cadherin immunopositivitv. This combination of phenotypes indicated a loss of the E‐cadherin invasion‐suppressor function‐Mi cro‐en capsulation of i.p.‐injected cells prevented the loss of the E‐cadherin invasion‐suppressor function. We concluded that this loss in vivo was dependent upon immediate contacts between tumor cells and host cells or upon host factors that could not cross the capsule membrane. © Wiley‐Liss, Inc.
Molecular cloning and expression of a cDNA encoding a protein detected by the ki antibody from an ovarian carcinoma (OVCAR‐3) cell line
Authors: Chang Kai , Pastan Ira
Published: February 2007

MAb Kl recognizes a cell‐surface glycoprotein (MW ∼40 kDa) present in ovarian carcinomas, malignant mesotheliomas, squamous‐cell carcinomas and normal mesothelial cells. In this study, expression screening was used to isolate cDNA clones encoding an antigen recognized by MAb 0Kl from a cDNA library made from a human ovarian carcinoma cell line (OVCAR‐3). Subsequently, other clones were isolated by DNA hybridization using a cDNA probe derived from one of the initial clones. The sequence of all the clones was similar. The longest cDNA contains 2,444 base pairs, and encodes a polypeptide of 263 amino acids with a calculated molecular weight of 30,511 daltons. The nudeotide sequence and deduced ami no‐acid sequence of the protein show no homology to other sequences in current data bases. In vitro translation of RNA transcripts from the cDNA inserts yielded polypeptides of 29 and 30 kDa. Similar‐sized proteins were obtained upon expression of the cDNA in Escherich'm coti, and these proteins were reactive with MAb Kl. The protein(s) expressed in E. coli were purified and used to make rabbit or mouse anttsera. These antisera reacted strongly with a soluble cytosolk protein in OVCAR‐3 cells, but not with the membrane‐bound antigen. Soluble cytosolk proteins of a similar size, recognized with MAb Kl, were found in OVCAR‐3 and N87 (gastric cancer) cells but not in 10 other cancer cell lines. These data indicate that the cloned cDNA encodes a cytosolk protein that reacted with MAb Kl. This soluble protein is expressed only in cells containing the CAKI surface glvcoprotein, suggesting that the 2 proteins could be structurally related. © Wiley‐Liss, Inc.
Comparison of retinoic acid and phorbol myristate acetate as inducers of monocytic differentiation
Authors: Matikainln Sampsa , Hurme Mikko
Published: February 2007

Several human myeloid leukemia cell lines growing in vitro can be induced to differentiate to more mature monocyteJ. macrophage‐like cells by treatment with protein kinase C‐activating phorbol esters, such as PMA. In addition to PMA, cells of the THP‐I myeloid leukemia cell line acquire macro‐phage‐like characteristics after treatment with all‐trans retinoic acid (RA). To analyze the signal transduction mechanisms induced by RA, we first compared the effects of PMA and RA on the expression of genes which are known to be regulated during monocytic differentiation. Both RA and PMA effectively down‐regulated c‐myc expression, while c‐myb expression decreased only after PMA treatment. Expression of the β2‐integrin genes. CDIIa and CDIIb, was clearly increased after both of these treatments. Their effects on the src‐family tyrosine kinase genes were different: hck expression was similarly induced by these agents but lyn expression was stronger and more rapid after RA treatment. RA also enhanced lyn mRNA production rapidly in HL‐60, indicating that the activation of lyn gene expression is common in monocytic and granulocytic maturation of myeloid leukemia cells. To examine whether the AP‐1 enhancer activity is involved in RA‐induced monocytic differentiation, THP‐1 cells were transiently transfected with a chloramphenicol acetyi transferase (CAT)‐reporter gene containing S copies of the AP‐1 binding sites. In contrast to PMA, RA did not induce any CAT activity in these cells, thus suggesting that the RA‐induced changes in the expression of those genes described above were not dependent on the AP‐1 enhancer activity. © Wiley‐Liss, Inc.
The protein kinase C inhibitor CGP 41251, a staurosporine derivative with antitumor activity, reverses multidrug resistance
Authors: Utz Irene , Hofer Susanne , Regenass Urs , Hilbe Wolfgang , Thaler Josef , Grunicke Hans , Hofmann Johann
Published: February 2007

Multidrug resistance (MDR) is frequently associated with overexpression of a 170‐kDa P‐glycoprotein (Pgp). Data suggest altered protein kinase C (PKC) activity in cells expressing the multidrug‐resistant phenotype. The staurosporine derivative CCP A1251, an experimental anticancer drug, has been shown to exert selectivity for inhibition of protein kinase C activity and to exhibit antitumor activity in Wtro and in vivo. Here we show that CGP A1251 is also able to reverse MDR. After treatment of the mult id rug‐resistant human lymphoblastoid cell line CCRF‐VCR1000 with 500 nM Adriamydn, cell proliferation was reduced to 81% of untreated controls. A combination of 500 nM Adriamydn with a non‐toxic concentration of 150 nM CGP 41251 (IC50 for inhibition of cell proliferation 420 nM CGP 41251) inhibits cell proliferation of CCRF‐VCR1000 cells to 29% of untreated controls. In sensitive CCRF‐CEM cells no enhancement of Adriamycin‐induced cytotoxicity was observed upon addition of 150 nM CGP 41251. Strong synergism of the inhibition of cell proliferation was also observed after concomitant treatment of KB‐851 I cells with CGP 41251 and Vinblas‐tine or Adriamydn. Drug‐sensitive KB‐31 cells could not be further sensitized to Adriamycin or Vinblastine with CGP 41251 doses above 100 nM. Pretreatment with 50‐1000 nM CGP 41251 for 30 min led to a dose‐dependent increase in the intracellular accumulation of rhodamine 123, a substrate of P‐glycoprotein. Treatment of multidrug‐resistant CCRF‐VCR1000 cells with CGP 41251 for 10 min was sufficient to inhibit the efflux of rhodamine 123. Preincubation with CGP 41251 for 12 or 24 hr did not alter multidrug resistance gene (mdrl)‐mRNA levels. CGP 41251, a drug with antitumor efficacy in experimental systems, might offer an attractive combination partner for the treatment of tumors expressing the MDR phenotype. © Wiley‐Liss, Inc.
Pancreatic cancer in europe: Ki‐ras gene mutation pattern shows geographical differences
Authors: Scakpa Aldo , Capelli Paola , Villanueva Alberto , Zamboni Giuseppe , Lluì Felix , Accolla Roberto , Mariuzzi Gianmario , Capellà Gabriel
Published: February 2007

Seventy‐seven pancreatic ado no carcinomas (60 Spanish and 17 Italian) were tested for Ki‐ras gene mutations by analysis of polymerase chain reaction amplified sequences. Mutations involving codon 12 (GGT; gly) were detected in 16 Italian and 46 Spanish cases (80.5%in total). All Italian mutations involved the second base and were G to A transitions (GAT; asp) in 8 cases and G to T transversiorrs (GTT; val) in the remaining 8. Forty‐two Spanish mutations were characterized. Thirty‐eight were at the second and 4 at the first base: asp in 24 cancers, val in 14, arg (CGT) in 2 and cvs (TGT) in 2. Previous European studies and our present data show that 149 of the 186 pancreatic cancers harbored a codon 12 Ki‐ras mutation (80%), the large majority affecting the second base (73%), with a transitions/trans versions ratio of 1.3:1. However, the mutational pattern of cancers of the different European countries shows remarkable differences, both in the site of the mutation (first or second base) and in the ratio of transitions over transversions. Moreover, a significant subgroup of pancreatic carcinomas do not harbor Ki‐ras mutations. The classification of pancreatic cancers, according to the presence or absence, and type of Ki‐ras mutation, may be of importance in epidemiological studies. A critical reappraisal of existing epidemiological data, through a retrospective genotypic study using paraffin‐embedded cancer samples, may reveal significant correlations with specific genotoxic agents. © 1994 Wiley‐Liss, Inc.
Arachidonic acid metabolism in benign and malignant prostatic tissue in vitro: Effects of fatty acids and cyclooxygenase inhibitors
Authors: Chaudry Aziz A. , Wahle K. W. J. , McClinton S. , Moffat L. E. F.
Published: February 2007

Concentrations of fatty acids (FA) in prostatic tissue of patients with either benign or malignant prostatic disease have previously been shown to be significantly different. In particular, there was a significant reduction in arachidonic acid (AA, C20:4n‐6) and docosapentaenoic acid (DPA, C22:5n‐6) concentrations in malignant prostatic tissue (PCa) phospholipids (PL). It was suggested that the decreased AA concentration in PCa may be due to its increased metabolism via the cyclooxygenase (CO) and/or lipoxygenase (LO) pathways to produce eicosanoids such as prostaglandins (PGs) and/or leucotrienes (LTs) rather than an impairment in desaturase activity in situ. The eicosanoid production in benign prostatic tissue (BPH) and PCa was determined using [3H]AA. The only eicosanoid produced in significant amounts by either tissue was PGE2 and PCa converted radiolabelled AA to PGE2 at an almost 10‐fold higher rate than BPH. PGE2 production from [3H]AA by PCa was investigated in the presence of oleic acid (OA, C18:In‐9), eicosapentaenoic acid (EPA, C20:5n‐3), docosahexaenoic acid (DHA, C22:6n‐3), dihomo‐gamma‐linolenic acid (DGLA, C20:3n‐6), eicosatetraynoic acid (FTYA) and ketoprofen (KPN) respectively. OA was found to be the most effective inhibitor of PGE2 production by PCa compared with DHA. EPA, ETYA and KPN, while DGLA was the least effective. Diacyiglycerol (DAG) formation from labelled AA by PCa was about 4‐fold greater than in BPH. Such high levels of DAG may be a means of promoting tumorigenesis through activation of protein kinase C as found with phorbol esters which can be regarded as DAG analogues. © 1994 Wiley‐Liss, Inc.
The anti‐tumor arotinoid RO 40‐8757 protects bone marrow from the toxic effects of 5‐fluorouracil
Authors: Eliason James F. , Inoue Tomoaki , Kubota Akiko , Horii Ikuo , Hartmann Diethelm
Published: February 2007

Combination therapy with 5‐Fluorouracil (5‐FU) and the arotinoid Ro 40‐8757 (mofarotene) of established chemically induced mammary tumors in rats was examined. The cytotoxic drug was administered weekly and Ro 40‐8757 was given daily. The dose of Ro 40‐8757 used in this study did not have an effect on tumor burden but, in combination with 5‐FU, significantly enhanced the reduction in tumor burden and tumor number. In order to determine if Ro 40‐8757 had a protective effect on 5‐FU‐treated animals, several studies were performed with non‐tumor‐bearing mice. The 5‐FU was given once a week for 3 weeks at a dose that was lethal only after the third administration. When this treatment was combined with Ro 40‐8757 given 5 times/week, approximately 50% of the mice survived. Examination of the progenitor cell contents of femura and spleens of treated mice indicated that the protective effect of Ro 40‐8757 was manifested at the primitive hemopoietic progenitor cell level. Studies with murine bone marrow cells and human breast‐cancer cell lines in vitro demonstrated that there was no interaction between the 2 drugs at the cellular level, indicating that the arotinoid does not enhance the ability of cells to metabolize 5‐FU. This protective effect of the arotinoid makes it a useful potential partner for combination therapy with 5‐FU. © 1994 Wiley‐Liss, Inc.
Characterization of monoclonal antibody PAM4 reactive with a pancreatic cancer mucin
Authors: Gold David V. , Lew Karen , Maliniak Richard , Hernandez Marisol , Cardillo Thomas
Published: February 2007

A monoclonal antibody (MAb), PAM4, having reactivity with pancreatic carcinoma has been developed. PAM4 is an IgG, immunoglobulin produced by immunization of mice with mucin purified from the xenografted RIPI human pancreatic carcinoma. An immunohistochemical study of normal adult tissues showed the PAM4 reactive epitope to be restricted to the gastrointestinal tract and absent from normal pancreas. In neoplastic tissue, PAM4 was reactive with 85% of the pancreatic carcinomas, approximately half of the colon cancers and none of the breast, ovarian, prostate, renal and liver cancers. PAM4 was, in general, non‐reactive with pancreatitis specimens whereas CAI 9.9 and DUPAN2 were strongly reactive with each one. Treatment of the mucin antigen by heating, reduction of disulfide bonds, or protease digestion abolished immunoreactivity with PAM4. Treatment of the mucin by neuraminidase or period ate oxidation reduced immunoreactivity but did not completely abolish it. Our data are consistent with the proposal that the PAM4 epitope is a conformation ally dependent peptide epitope and that certain carbohydrate structures are necessary in order to maintain the correct peptide conformation. The high specificity and intense reactivity of PAM4 with pancreatic carcinoma tissue suggests that the antibody may prove useful for in vitro diagnostic assays as well as in vivo targeting of diagnostic and therapeutic agents. © 1994 Wiley‐Liss, Inc.
Acquisition of immunogenicity by AKR leukemic cells following DNA‐mediated gene transfer is associated with the reduction of constitutive reactive superoxide radicals
Authors: Qua Kwok Y. , Lim Siew P. , Oei Audrey A. , Sabapathy Tr. Kanaga , Hui Kam M.
Published: February 2007

We have employed the DNA‐mediated gene transfer method to introduce the allogeneic major‐histocompatibility‐complex(MHC)‐class‐1 gene H‐2Kb into the K36.16 tumor cells, H‐2k, in order to generate tumor‐specific immunity. The acquisition of immunogenicity by the H‐2Kb‐transformed clones following gene transfer is associated with the reduction of constitutive reactive superoxide radicals. When the levels of cellular superoxide for the H‐2Kb‐positive immunogenic clones were determined, they were significantly lower (30 to 60%) than that of the parental K36.16 tumor cells. This reduction of superoxide in the H‐2Kb‐transformed cells was associated with a significant increase in the level of Cu‐Zn superoxide dismutase (SOD) and GPX I, together with a reduction in the DNA‐binding form of the NF‐kB transcription factor. The K36.16 parental tumor cells were also found to be relatively more resistant to the cytotoxic effects of hydrogen peroxide in vitro. To further support the role of superoxide anion radicals in tumorigenesis, in vivo depletion of glutathione promoted the tumorigenicity of the H‐2Kb‐transformed clones in (AKR/J X C57BL/6/J) F1 mice, whereas SOD was able to reduce their tumorigenicity. In addition, the presence of R‐sulfoxine (BSO) in spleen‐cell cultures in vitro abolished the ability of the immune lymphocytes to develop into tumor‐specific cytotoxic T lymphocytes (CTL). These observations support the concept that oxidative processes in tumor cells may have a strong influence on the host response against tumors. © 1994 Wiley‐Liss, Inc.
The epstein‐barr virus latent membrane protein‐1 (LMP1) induces interleukin‐10 production in burkitt lymphoma lines
Authors: Nakagomi Hiroshi , Dolcetti Riccardo , Bejarano Maria Teresa , Pisa Pavel , Kiessling Rolf , Masucci Maria G.
Published: February 2007

Human interleukin‐10 (h‐IL‐10) is a pleiotropic cytokine with stimulatory activity on B‐Iymphocytes. Recent evidence indicates that infection with Epstein‐Barr virus (EBV) induces h‐IL‐10 production in B‐cells and that this cytokine may contribute to EBV‐induced B‐cell transformation. It is not known whether h‐IL‐10 induction by EBV correlates with distinct phenotypic features of the infected cells or with the expression of particular viral genes. We have approached these questions by investigating the expression of h‐IL‐10 mRNA in a panel of B‐cell lines including: in vitro EBV‐transformed lymphoblastoid cell lines (LCLs), EBV‐carrying Burkitt lymphoma (BL) lines, EBV‐negative BL lines and their sublines infected with different EBV strains, or transfected with the transformation‐associated viral gene. h‐IL‐10 mRNA was detected by reverse‐transcriptase‐assisted (RT)‐PCR in a subset of EBV‐negative BLs and in all FBV‐positive BL lines and LCLs investigated except Daudi. This cell line carries an EBV nuclear antigen (EBNA)‐2 gene‐defective virus strain. h‐IL‐10 mRNA was induced by conversion of 3 EBV‐negative and h‐IL‐10‐negative BL lines (BL41, BL47 and BL49) with the transforming, B95.8‐derived EBV strain. P3HR‐1 virus convertants that do not express the viral EBNA‐2 and the EBV latent membrane protein (LMP)‐1, and fail to progress towards a LCL‐like cell phenotype, showed no evidence of h‐IL‐10 up‐regulation. Expression of LMP1 was sufficient to induce h‐IL‐10 mRNA in transfected sublines of the EBV‐negative DG75 and BL41 cell lines, whereas expression of EBNA1, 2, 5 or 6 had no effect. h‐IL‐10 was detected in the culture supernatants of the LMP1 transfectants by specific ELISA assays. The present findings confirm the role of LMP1 in the transactivation of a wide variety of cellular genes which may be involved in EBV‐induced B‐cell transformation. © 1994 Wiley‐Liss, Inc.
Strong uptake of 111in‐pentetreotide by an MIBG‐negative, xenografted neuroblastoma
Authors: Manil L. , Perdereau B. , Barbaroux C. , Buixy F.
Published: February 2007

We investigated the distribution of 111In‐pentetreotide (Octreoscan, Mallinckrodt) in nude mice xenografted with a human neuroblastoma cell line (SKLAN, derived from the LAN I line). These cells develop into solid tumours in nude mice and can be grafted repeatedly in grafts of 108 cells. Animals were sequentially explored by scintigraphy 2, 4, 24 and 48 hr after i.v. injection of 2.5‐4 MBq of the tracer and killed at various times up to 46 hr. 111In‐pentetreotide was rapidly and strongly taken up by all tumours, with a tumour/muscle (T/M) ratio on resected samples of 20.0 ± 5.7 at 2 hr, 23.7 ± 3.0 at 4 hr, 75.6 ± 12.6 at 24 hr and 78.7 ± 12.4 at 48 hr, for tumours ranging from 0.5 to 8 g. Scintigraphy results were quantitatively in agreement Pre‐injection of a 15‐20 times larger quantity of unlabelled octreotide s.c. reduced the tumour uptake by a factor of 2. For comparison, nude mice xenografted with the same cell line were also studied with 123I‐MIBG (4 MBq). At 24 hr, the T/M ratio was 0.62 ± 0.18. Two other cell lines (glioblastoma ROM and small‐cell lung carcinoma SC41) which were similarly tested with 111In‐pentetreotide (2.5‐4 MBq) gave T/M ratios at 24 hr of 4.8 ± 2.8 and 38.4 ± 21.8, respectively. Pentetreotide seems to have a high affinity for this MIBG‐negative neuroblastoma cell line, which exhibited a clearly higher tumour uptake than the 2 other lines. This work provides new experimental arguments in favour of the particular interest of somatostatin analogues in neuroblastoma and confirms our first clinical results. © 1994 Wiley‐Liss, Inc.
Cd4+ T cells recovered from a mixed immune lymphocyte‐tumor cell culture induce thymidine incorporation by naive rat lymphocytes in response to tumor cells
Authors: Reisser Danièle , Martin François
Published: February 2007

Spleen cells from tumor‐immune rats incorporate thymidine when co‐cultured for 4 days with syngeneic cancer cells. Non‐adherent cells, recovered from a 7‐day mixed culture with cancer cells, had lost their capacity for incorporating thymidine when exposed again to the same tumor cells; however, in these conditions, the non‐adherent cells induce thymidine incorporation by fresh naive spleen cells. This response is restricted to tumor lines which originate from the same tumor as the cells used for immunization and is due to memory and/or activated CD45RC‐CD4+ T cells. Our results indicate that tumor‐specific T cells maintain their capacity to respond to tumor antigens, even after an extended culture time with tumor cells. In another study, in the same conditions, spleen cells from normal or tumor‐bearing rats did not evoke significant responses. © 1994 Wiley‐Liss, Inc.