bluuebunny/crossref_metadata_2025 huggingface dataset:
Fractional allelic imbalance in human breast cancer increases with tetraploidization and chromosome loss
Authors: Cornelisse Cees J. , Kuipers‐Dijkshoorn Nel , van Vliet Margreethe , Hermans Jo , Devilee Peter
Published: February 2007

We have previously reported a complete allelotype study of 86 primary breast carcinomas, in which each non‐acrocentric chromosome arm was studied with at least one polymorphic DNA‐marker for the presence of allelic imbalance (Al, allelic loss or allelic gain) in the tumor. Here we report the statistical analysis of this data set, investigating the relationships between Al, DNA aneuploidy and several clinico‐pathological parameters of tumor progression. Al on 13 different chromosome arms, including 3p, 11 p, and 17p, correlated significantly with the total number of Al events at other sites, suggesting that they are progression‐related events. Al at 1q and 16q did not show such a correlation and may thus represent earlier events. Mean fractional allelic imbalance (FAI) was significantly higher in flow cytometrically aneuploid tumors than in diploid tumors (0.27 vs. 0.17, p = 0.007), and was highest in hypotetraploid tumors (0.37). This suggests that tetraploidization followed by chromosome segregation may underlie the development of Al at multiple sites. No correlation was found between mean FAI and clinico‐pathological variables such as lymph‐node involvement, stage, age, estrogen‐receptor content and development of distant metastases, although there was a noticeable trend towards impaired survival for those patients with a higher‐than‐median FAI value.
Patients with cervical cancer produce an antibody response to an HSV‐inducible tumour‐specific cell polypeptide
Authors: MacNab Joan C. M. , Nelson J. S. , Daw S. , Hewitt R. E. P. , Lucasson J.‐F. , Shirodaria P. V.
Published: February 2007

Anti‐sera raised against HSV‐2‐infected cells (Wl) and the sera of animals bearing tumours (TBS) to HSV‐2 transformed cells contain antibodies to a set of tumour‐specific cell‐coded polypeptides. The specificity of these polypeptides for tumour cells is monitored by the ability of [35S]‐L‐methionine labelled proteins to be immunoprecipitated by these anti‐sera, in contrast to control cells from which the polypeptides are not precipitated. The polypeptides which share an epitope and are co‐precipitated are of MWs 90, 000 (a doublet), 40, 000 and 32,000. The upper 90,000‐MW polypeptide (U90) is induced by HSV‐2 infection. This communication deals with the 40,000‐MW polypeptide which was shown to be immunoprecipitated by TBS and a monoclonal antibody (MAb) raised to the DNA‐binding proteins of HSV‐2‐infected cells. Immunological and biochemical studies reveal that the 40,000‐MW protein which is immunoprecipitated comprises more than one polypeptide, and that the proteins may need to interact to produce the peptide pattern specific for the tumour form of the immunoprecipitated 40, 000‐MW protein. Wl antisera and TBS both recognise antigens specific for tumour cells in sections of cervical‐carcinoma tissue. Sera from patients with cancer of the cervix contain antibodies to a cell‐coded polypeptide of MW 40, 000, which by peptide analysis is indistinguishable from the 40, 000‐MW polypeptide induced by HSV‐2 infection and immunoprecipitated by Wl and TBS.
SDZ PSC 833, A non‐immunosuppressive cyclosporine: Its potency in overcoming P‐glycoprotein‐mediated multidrug resistance of murine leukemia
Authors: Keller Roland P. , Altermatt Hans J. , Nooter Kees , Poschmann Guenter , Laissue Jean A. , Bollinger Pietro , Hiestand Peter C.
Published: February 2007

Cyclosporin A (CsA, Sandimmune) is known to reverse P‐glycoprotein(P‐gp 170)‐mediated multidrug resistance as efficiently as other prototype compounds of resistance modifiers. The immunosuppressive activity and nephrotoxicity of CsA, however, may limit its clinical use. PSC‐833, a new cyclosporine, exerts a similar resistance‐modifying activity but lacks toxicity or immunosuppressive activity. We have tested its potency in vitro and in vivo on the L1210 leukemia cell line transfected with a full‐length cDNA copy of the human mdr I gene, which showed a stable 30‐fold resistance towards adriamycin as compared to the parental cell line. In vitro growth of the transfected cell was unchanged. In vivo growth was less aggressive; the survival time of inoculated mice was prolonged. In vitro, PSC‐833 was at least as potent as CsA or verapamil in reversing multidrug resistance. In vivo, the drug‐resistant L1210 leukemia was completely unresponsive to i.v. monotherapy with adriamycin at its maximum tolerated dose (MTD). PSC‐833 enhanced the activity and toxicity of adriamycin. The MTD of adriamycin was about 3 times lower than when given alone. On this basis, the MTD of i.v. adriamycin in combination with oral PSC‐833 successfully overcame refractoriness to treatment. Survival times of the mice were considerably prolonged and even some cures of leukemic mice occurred.
Analysis of tyrosine kinase mRNAs including four FGF receptor mRNAs expressed in MCF‐7 breast‐cancer cells
Authors: Lehtola Laura , Partanen Juha , Sistonen Lea , Korhonen Jaana , Wärri Anni , Härkzönen Pirkko , Clarke Robert , Alitalo Kari
Published: February 2007

The MCF‐7 cell line is a hormone‐responsive human breast‐cancer cell line, which has been extensively used in studies of estrogen regulation of cell growth. These studies have indicated that the growth stimulation of the MCF‐7 cells by estrogens may be effected by an autocrine mechanism involving several growth factors, such as EGF, TGFα and IGF‐I and their receptors. We have amplified and cloned tyrosine‐kinase‐related sequences from the MCF‐7 cell mRNA using the polymerase chain reaction and characterized the partial cDNAs obtained by nucleic acid sequencing. Nine tyrosine kinase cDNAs and one serine/threonine kinase cDNA were identified among the amplified sequences. Four different tyrosine kinase genes encoding receptors for fibroblast growth factors (FGFs) were found to be expressed by the MCF‐7 cells. In addition, differences were observed in the expression of these members of FGF receptor family in different breast‐cancer cells. A putative tyrosine‐kinase receptor and a novel serine/threonine kinase were preferentially expressed in estrogen‐responsive tumor cell lines. However, no estrogen‐dependent regulation of any of the novel tyrosine‐kinase receptor mRNAs was found in any of the cell lines including the MCF‐7 or ZR‐75‐1 cells, where the expression of the neu proto‐oncogene mRNA was decreased during estrogen treatment. The expression of several FGF receptors by breast‐cancer cells suggests that FGFs may be involved in their growth regulation and tumorigenesis.
Short‐term assays for detection of conditional cancerogens I. Construction of DR‐CAT Raji cells and some of their characteristics as tester cells
Authors: Polack Axel , Laux Gerhard , Hergenhahn Manfred , Kloz Ulrich , Roeser Helmut , Hecker Erich , Bornkamm Georg W.
Published: February 2007

A number of agents including the tumor promoter 12‐0‐tetradecanoyl‐phorbol‐13‐acetate (TPA) can induce an abortive virus cycle in the EBV‐non‐producer Burkitt's‐lymphoma line Raji. Two distant regions, DL and DR, of the EBV genome with almost complete homology carry strong promoters which are induced in an abortive or lytic cycle and additionally function as lytic origins of viral DNA replication. To set up a system in which the activity of EBV‐inducing agents can be measured in a quantitative and reproducible fashion, we generated a cell line which carries multiple copies of a DR‐promoter chloramphenicol‐acetyltransferase (CAT) construct on an episomal vector. CAT activity is low in untreated cells, but high upon treatment of the cells with various EBV‐inducing agents. Combinations of different agents can produce an over‐additive effect. The Raji‐DR‐CAT cell line may provide a simple quantitative and reproducible test system for EBV‐inducing agents, especially for tumor promoters which activate protein kinases C.
The desmoplastic response: Induction of collagen synthesis by melanoma cells in vitro
Authors: Fearns Colleen , Dowdle Eugene B.
Published: February 2007

When cells from the human malignant melanoma cell line, UCT‐Mel 7, were injected into athymic nude mice, tumours developed that were intensely infiltrated with fibrous tissue. In an attempt to reproduce this desmoplastic response in vitro, we co‐cultured fibroblasts with UCT‐Mel‐7 cells, and observed a 2‐fold increase in the rate of fibroblast collagen synthesis. This was associated with an increase in the amount of collagen mRNA present in co‐cultured fibroblasts. The stimulation was both dose‐ and time‐dependent, with maximal stimulation at a melanoma cell:fibroblast ratio of 1:1. Analysis of the kinetics of proline incorporation into collagen showed that co‐culture affected the maximal rate of proline incorporation; no effect was observed on the concentration of proline required for 50% maximal collagen synthesis. The induction of fibroblast collagen synthesis showed an absolute requirement for close proximity between the fibroblasts and the melanoma cells. No soluble fibrogenic factor released by melanoma was detected.
Enhancement by vaso‐active intestinal peptide of gastric carcinogenesis induced by N‐methyl‐N'‐nitro‐N‐nitrosoguanidine in rats
Authors: Iishi Hiroyasu , Tatsuta Masaharu , Baba Miyako , Okuda Shigeru , Taniguchi Haruo
Published: February 2007

The effects of vaso‐active intestinal peptide (VIP) on gastric carcinogenesis induced by N‐methyl‐N'‐nitro‐N‐nitrosoguanidine (MNNG) were investigated in Wistar rats given VIP every other day for 27 weeks after oral administration of MNNG for 25 weeks. In week 52, administration of VIP caused a significant increase in the incidence of gastric cancers, but did not influence their histological appearance. VIP significantly increased the labeling indices of the antral mucosa. Our findings indicate that VIP enhances gastric carcinogenesis, and that this effect may be related to its effect in increasing cell proliferation of the antral epithelial cells.
Relationship between sensitivity to natural killer cells and MHC class‐I antigen expression in colon carcinoma cell lines
Authors: Blottière Hervé M. , Zennadi Rahima , Burg Cedric , Douillard Jean‐Yves , Meflah Khaled , Pendu Jacques Le
Published: February 2007

The sensitivity of colorectal tumors to NK‐cell‐mediated cytotoxicity and their expression of major histocompatibility complex (MHC) class‐I antigens were studied in an attempt to determine whether such antigens play a role in the susceptibility of colorectal tumors to NK‐cell lysis. In a rat colon‐carcinoma model, 2 clones differing in their sensitivity to NK‐cell‐mediated cytotoxicity were tested for class‐I expression; it was seen that the more sensitive cells (REGb) expressed less class‐I products than did the resistant cells (PROb). However, when MHC class‐I antigen expression was increased by IFN‐γ treatment, no change in NK‐cell lysis was found with the PROb cells, while an increase in cytotoxicity was obtained with the REGb cells. After in vivo or in vitro selection of NK‐resistant REGb cells, we observed in the selected cells an important decrease in RT‐I class‐I antigen expression. Fifteen different human colorectal cell lines were also studied for HLA class‐I expression and NK‐cell susceptibility, and no quantitative correlation between these 2 features was seen. However, cell lines which were deficient in HLA class‐I antigens were more sensitive than class‐I‐positive cells.
N‐ras gene mutations in acute myeloid leukemia: Accurate detection by solid‐phase minisequencing
Authors: Syvänen Ann‐Christine , Söderlund Hans , Laaksonen Eveliina , Bengtström Marina , Turunen Minna , Palotie Aarno
Published: February 2007

Mutations in the N‐ras gene are found in one‐third of patients with acute myeloid leukemia. The N‐ras mutations could serve as markers for residual cells, if a highly sensitive method for detecting the mutations was available. We applied a new method, solid‐phase minisequencing, to analyze bone‐marrow cells from 16 patients with acute myeloid leukemia for mutations in codon 12, 13 and 61 of the N‐ras gene. In the solid‐phase minisequencing technique the mutations are identified by a primer extension reaction, in which a single labelled nucleoside triphosphate is incorporated into an immobilized DNA fragment previously amplified by the polymerase chain reaction. We identified N‐ras mutations in 5 of the patients (30%). In one patient, we observed 2 mutations that were shown to be located in different alleles. With the solid‐phase minisequencing method, we were able to determine the proportion of mutated cells in the samples. We found that in 4 of the samples only a fraction (7–64%) of the blasts carried an N‐ras mutation, and in one sample practically all blast cells were mutated. The method was highly sensitive, allowing us to identify N‐ras mutations even when the sample consisted of 99.7% normal cells and only 0.3% mutated blasts.
Visualization of the plasmin receptor on carcinoma cells
Authors: Correc P. , Zhang S. , Komano O. , Laurent M. , Burtin P.
Published: February 2007

In order to visualize the receptor for plasmin and plasminogen present on human carcinoma cells, SWI116 and MCF7‐MF cells were incubated with biotinylated plasminogen or plasmin and fluoresceinated streptavidin, and counterstained with propidium iodide. It was first demonstrated that biotinylation did not alter the binding properties of plasminogen and plasmin, provided that the biotinylation rate was around 2. Specific staining of tumor cells was obtained using these reagents. Images with green fluorescence were clearly visible as grains or contours at the surface of tumor cells. The localization of fluorescent grains was analyzed more precisely using confocal microscopy. The percentage of stained cells varied from one experiment to another between 10 and 60%. In no experiment were all the cells observed to be positive. Mitotic cells were more frequently stained than non‐mitotic cells, suggesting a relationship between the presence of plasmin receptors and cell proliferation. This was confirmed by the use of Ki67 monoclonal antibody (MAb), as B‐Pg‐binding tumor cells generally had their nucleus stained by this antibody. Other images indicated staining of the extracellular matrix. Finally, 2 rat tumor‐cell sub‐lines of colonic origin (DHD K12 Pro‐b and Reg‐b) were shown to bind human biotinylated plasminogen, confirming the strong interspecies reactivity of plasmin receptors.
Androgen regulation of prolactin‐receptor gene expression in MCF‐7 and MDA‐MB‐453 human breast cancer cells
Authors: Ormandy Christopher J. , Clarke Christine L. , Kelly Paul A. , Sutherland Robert L.
Published: February 2007

Lactogenic hormones which bind to the PRLR are likely to be growth‐stimulatory in human breast‐cancer cells. Oestrogen and progesterone control cellular expression of the PRLR; however, elevated androgen levels in some breast‐cancer patients raised the possibility that androgens may also influence breast‐cancer sensitivity to lactogenic hormones. This study investigated whether androgens could affect expression of the PRLR in the MCF‐7 breast‐cancer cell line. PRLR binding activity was increased approximately 2‐fold by treatment for 24 hr with 10 nM RI881, TEST, DHT, MPA and ORG 2058. Northern analysis indicated that DHT also increased the level of PRLR mRNA. The antiprogesterone, RU 38486, displaced tritiated ORG 2058 binding but not tritiated DHT binding to MCF‐7 cells; it completely antagonized ORG 2058 and partially antagonized RI881 induction of the PRLR, but had no effect on induction by DHT. The anti‐androgen, RU 23908, displaced tritiated DHT binding but not tritiated ORG 2058 binding, and antagonized DHT and RI881 induction of PRLR but not induction of the PRLR by ORG 2058. These data indicated that ORG 2058 acting via the PR and DHT acting via the AR were able to induce PRLR expression in MCF‐7 cells. In MDA‐MB‐453 cells, which express the AR but not the ER or PR, DHT and RI881 increased PRLR binding to 150% of control values at 0.1 nM. ORG 2058 was ineffective, demonstrating androgen induction of PRLR in the absence of PR and ER. These data indicate that PRLR can be regulated by androgens in MCF‐7 and MDA‐MB‐453 human breast‐cancer cells.
Detection of simian T‐lymphotropic virus type I using the polymerase chain reaction
Authors: Dezzutti Charlene S. , Lazo Aristides , Yee Joanne Y. , Blakeslee James R. , Mathes Lawrence E. , Brown Bobby G. , Lairmore Michael D.
Published: February 2007

To develop the polymerase chain reaction (PCR) for the detection of simian T‐lymphotropic virus type I (STLV‐I) infection, cell lines or peripheral‐blood mononuclear cells (PBMC) from 2 non‐human primate species [African green monkeys (AGM), Cercopithecus aethiops; baboon, Papio cynocephalus] were evaluated for their STLV‐I status using oligonucleotide primer pairs and probes specific for the tax and pol gene regions of the closely related human T‐lymphotropic virus type I (HTLV‐I). These PCR results were compared with serologic (Western blot assay) and viral culture (p24‐antigen capture assay) data. PCR products for both gene regions were detected in established baboon, Japanese macaque and rhesus macaque STLV‐I‐producing cell lines. STLV‐1 tax and pol products were also detected in PBMC from 4 of 4 infected AGM and 4 of 4 infected baboons, each of which were also Western‐blot‐positive and p24‐antigen‐capture‐positive. Of the remaining AGM (n = 7) and baboon (n = 1) which were PCR‐negative, each was also Western‐blot‐negative and p24‐antigen‐capture‐negative. Two seronegative and virus‐culture‐negative AGM were classified as PCR indeterminate with weak reactivity using tax primers. These primer pairs failed to amplify DNA from uninfected human PBMC, an uninfected human lymphoid cell line, a simian immunodeficiency virus macaque (SIVmac251)‐infected cell line and a simian‐retrovirus‐type‐D(SRV‐D)‐infected cell line. HTLV‐II‐pol‐specific primer pairs failed to amplify DNA from STLV‐I‐infected cell lines and PBMC from STLV‐I‐infected monkeys. Further, HTLV‐I pol and tax primer pairs successfully amplified RNA from HTLV‐I‐ and STLV‐I‐infected cell lines by reverse transcriptase (RT)‐PCR. We have demonstrated excellent specificity in the detection of STLV‐I by PCR using these HTLV‐I‐derived primers and probes. Additionally, our data suggest that the tax and pol gene regions are conserved between HTLV‐I and STLV‐I strains found among these diverse species of non‐human primates.
Correlation of growth of tumours in NC‐cell‐depleted mice with NC‐ and NK‐cell‐mediated lysis in vitro
Authors: Smart Y. Cheng , Farrelly Margaret L. , Burton Robert C.
Published: February 2007

The anti‐tumour surveillance activity of natural cytotoxic (NC) cells was studied in vivo using the transplantable tumours WEHI‐164 fibrosarcoma, MPC‐11 plasmacytoma, WEHI‐7 T‐lymphoma, B16 melanoma and EL‐4 thymoma in syngeneic and semi‐allogeneic mice. Experimentally, mice were treated with the anti‐NC‐1.1 monoclonal antibody (MAb) 1C4 to abrogate splenic NC activity. This was followed by s.c. inoculation of MTD100 doses of the tumours. Comparison of the diameters of the tumours in the anti‐NC‐1.1 ‐treated mice with control mice using non‐parametric statistics showed significantly faster growth of WEHI‐164 (p < 0.01), MPC‐11 (p < 0.05) and WEHI‐7 (p < 0.05) when the mean tumour diameters were < 15mm in the anti‐NC‐1.1 ‐treated mice. Significantly faster growth was also observed in anti‐NC‐1.1 ‐treated mice with the B16 tumour (p < 0.05), but at a later stage of growth, when the tumour diameter was > 15 mm. In vitro, WEHI‐164, MPC‐11 and WEHI‐7 were shown to be predominantly sensitive to lysis by mouse splenic NC cells, while B16 was predominantly lysed by splenic natural‐killer (NK) cells. Anti‐NC‐1.1 treatment of mice did not affect the growth of EL‐4 in vivo and in vitro experiments with anti‐NK‐1.1 and anti‐NC‐1.1 MAb indicated that this tumour was lysed by sub‐sets of NK and NC cells distinct from those which lysed the other tumours. We conclude that, in mice at least, NC cells have an in vivo role in controlling the growth of some transplantable tumours, and this correlates with the in vitro NC cell lysis of these same tumours.
c‐myc over‐expression in human primary ovarian tumours: Its relevance to tumour progression
Authors: Tashiro Hironori , Miyazaki Kohji , Okamura Hitoshi , Iwai Akio , Fukumoto Manabu
Published: February 2007

Expression of the c‐myc gene was analyzed in 56 human primary ovarian cancer tissues, including 51 common epithelial and 5 non‐epithelial tumours to determine molecular events in the carcinogenic process in ovaries. Over‐expression of the c‐myc gene was found in 37.3% of all ovarian tumour tissues, and in 63.5% of serous adenocarcinoma tissues. Significant over‐expression of the c‐myc gene at Stage III compared with other stages, and one remarkable case of over‐expression in a serous tumour of low malignant potential suggest that c‐myc expression is temporarily activated at some stage(s) during tumorigenesis of ovarian cancer, especially of serous tumours.
Recombinant interferon α‐2A combined with prednisone in metastatic renal‐cell carcinoma: Treatment results, serum interferon levels and the development of antibodies
Authors: Fosså Sophie D. , Lehne Gustav , Gunderson Ragnhild , Hielmaas Unni , Holdener Eduard E.
Published: February 2007

Five partial responses were seen in 23 patients with metastatic renal‐cell carcinoma (MRCC) receiving interferon‐α 2a (IFN) + prednisone (P). Four of 24 subsequent patients responded to IFN + P (combined response rate 19%). The median response duration was 8 months (3 to 30 months). The one‐year survival for all eligible patients was 52%. Eight of 26 evaluable patients developed antibodies detected by an enzyme immunoassay. In 2 patients, high levels of neutralizing antibodies were also found, together with particularly low IFN levels. In one patient the development of neutralizing antibodies coincided with the loss of initial response. The treatment was well tolerated by most patients. Premature discontinuation of treatment was necessary in only 2 patients. In MRCC, combination treatment with IFN + P is as effective as IFN monotherapy (response rate 19%), with significantly reduced subjective toxicity. The clinical relevance of the development of antibodies against IFN requires further investigation.
The content of urokinase‐type plasminogen activator antigen as a prognostic factor in urinary bladder cancer
Authors: Hasui Yoshihiro , Marutsuka Kousuke , Suzumiya Junji , Kitada Shinichiro , Osada Yukio , Sumiyoshi Akinobu
Published: February 2007

Urokinase‐type plasminogen activator (u‐PA) is thought to be implicated in cancer invasion and metastasis. The aim of this study was to determine whether the u‐PA content of cancer tissue is a prognostic factor in bladder cancer. Tissue samples from 46 patients with bladder cancer were assessed for u‐PA antigen by a highly sensitive enzyme immunoassay. The relationships between the u‐PA level in extracts of bladder cancer and the survival rates of the bladder‐cancer patients were examined. Patients with a high u‐PA level (8 ng/mg of protein and more) showed a statistically significantly higher rate of survival than those with a low u‐PA level (p < 0.005). The u‐PA antigen level in cancer tissue was significantly lower in low‐graded and non‐invasive cancers than in others (p < 0.01).
Dietary determinants of lung‐cancer risk: Results from a case‐control study in Yunnan province, China
Authors: Swanson C. A. , Mao B. L. , Li J. Y. , Lubin J. H. , Yao S. X. , Wang J. Z. , Cai S. K. , Hou Y. , Luo Q. S. , Blot W. J.
Published: February 2007

The relation between diet and lung cancer was studied among male residents of a mining community in Yunnan Province. After obtaining food frequency data from subjects or proxies, we compared diets of 428 cases, aged 35–74 years, and 1,011 age‐matched controls. Cases tended to consume slightly more rice, but less protein‐rich foods (i.e., bean curd, meat, eggs) and vegetables than did controls. The relative risks of lung cancer across increasing quartiles of meat (i.e., pork) consumption, for example, were 1.00, 0.67, 0.72 and 0.46 (p for trend <0.01). The relative risks of lung cancer across increasing quartiles of consumption of dark‐green, leafy vegetables were 1.00, 0.62, 0.52 and 0.41 (p for trend <0.01). Although specific dietary constituent(s) responsible for the protective effect of vegetable consumption could not be identified, carotenoids other than β‐carotene, or compounds in cruciferous or Allium vegetables, are possibilities.
Serum oncoproteins and growth factors in asbestosis and silicosis patients
Authors: Brandt‐Rauf Paul W. , Smith Steven , Hemminki Kari , Koskinen Heikki , Vainio Harri , Niman Henry , Ford Jean
Published: February 2007

Levels of 9 different oncoproteins and growth factors were assayed by immunoblotting with monoclonal antibodies in 91 serum samples collected between March 1983 and August 1987 from 46 pneumoconiosis patients (36 asbestosis, 10 silicosis) at high risk for the development of cancer. Follow‐up of these patients through June 1991 showed that 18 had developed cancer (11 lung, 2 pleural mesothelioma, 2 transitional‐cell carcinomas of the urinary bladder, 1 osteosarcoma, 1 non‐Hodgkin's lymphoma, 1 adenocarcinoma of the gallbladder). Increased serum levels of ras oncogene‐related protein (p21) were found in 7 of the 18 patients who developed cancer (5 lung, 2 pleural mesothelioma) versus 2 of the 28 patients without cancer, a statistically significant difference (p = 0.012). In addition, 6 of the 7 p21‐positive cancer cases had positive serum samples prior to clinical diagnosis of disease (average = 16.3 months, range = 3–26 months prior to diagnosis), suggesting that elevated serum p21 levels may be a useful marker for earlier detection in a significant percentage of respiratory malignancies. Finally, elevated serum levels of PDGF‐related protein were detected significantly more frequently in advanced pneumoconiosis cases (ILO radiographic classification of 2/1 or greater) than in less advanced cases (80% vs. 41.9%; p = 0.016), and there was a tendency for these PDGF‐positive patients to have progression of their disease (68.2% vs. 41.7%; p = 0.065), suggesting that elevated serum PDGF levels may be a marker for the development of severe and progressive pneumoconioses.
Probing daunorubicin accumulation defects in non‐P‐glycoprotein expressing multidrug‐resistant cell lines using digitonin
Authors: Versantvoort C. H. M. , Broxterman H. J. , Feller N. , Dekker H. , Kuiper C. M. , Lankelma J.
Published: February 2007

Multi drug resistance (MDR) in tumor cells is frequently associated with reduced cellular cytostatic drug accumulation, caused by the drug efflux protein, P‐glycoprotein (Pgp). The action of Pgp in tumor cells can be detected by measuring the increase of daunorubicin accumulation upon blocking Pgp with drugs such as verapamil. A number of MDR cell lines have been described, characterized by decreased drug accumulation without Pgp being present. For such non‐Pgp MDR cells no gene probes or functional assays are available to study this phenotype in clinical tumor specimens. We have worked out a method which enables the detection of drug‐transport‐related decreases in cellular daunorubicin accumulations without the need for the use of specific Pgp blockers. The cells used were SW‐1573‐, GLC4‐ and HT1080‐sensitive cell lines, which accumulated (corrected for DNA content) 272%, 1,288% and 203% more daunorubicin than the non‐Pgp MDR sub lines SW‐1573/2RI20, GLC4/ADR and HTI080/DR4. When the plasma membranes of these MDR lines were permeabilized with 20 μM digitonin an increase to 282%, 1,260% and 239% of 14C‐daunorubicin control accumulation was measured (at pH = 7.35). The intracellular pH measured with BCECF was the same in parent and corresponding MDR cells, excluding the role of pH differences in the measured effects. This method provides a tool allowing the detection of cellular mechanisms (including Pgp) which are related to active outward transport of daunorubicin.
Isolation of cDNA clones corresponding to genes differentially expressed in two colon‐carcinoma cell lines differing by their tumorigenicity
Authors: Denis Marc G. , Chadeneau Corinne , Lustenberger Patrick , Mevel Bernard Le , Meflah Khaled
Published: February 2007

In an effort to isolate genes involved in the progression of colonic cells leading to a carcinoma, we used as a model 2 rat colon‐carcinoma cell lines selected from the same tumor, differing by their tumorigenicity. When soluble, Triton‐X‐100 extracted, or cytoskeletal proteins from the progressive PROb cells and the regressive REGb cells were analyzed by SDS‐PAGE, minor differences were seen. Furthermore, mRNA‐cDNA hybridization analyses showed extensive homology between the 2 mRNA populations. Thus, the homology between the 2 clones is high at both the protein and the mRNA levels. A PROb cDNA library was hybridized with 32P‐cDNA synthesized from PROb or REGb mRNA. The clones giving a stronger signal when hybridized with the homologous PROb probe were isolated. The specificity of each clone was confirmed by RNA blotting. Most of the positive clones showed a 2‐ to 3‐fold higher expression in PROb cells when compared with REGb cells. One clone (J 13) corresponded to an mRNA 7‐ to 10‐fold more abundant in PROb cells, and was further studied. No gene amplification was detected by Southern blot analysis, indicating that the difference in mRNA content was most likely due to an increased transcription of this gene in PROb cells. Sequencing of the cDNA showed high homology with the rat ferritin light sub‐unit. Over‐expression of ferritin in PROb cells as compared with REGb cells was confirmed at the protein level using specific antibodies.
An autocrine mitogenic activity produced by a pleural human mesothelioma cell line
Authors: Lauber Béatrice , Leuthold Margrit , Schmitter Doris , Cano‐Santos Josefina , Waibel Robert , Stahel Rolf A.
Published: February 2007

The pleural human mesothelioma cell line ZL5 established in our laboratory exhibits an unusual phenotype with adherent and floating cells. ZL5 cells grow in a chemically defined medium (ACL3*) and can be maintained over 3 weeks in protein‐free basal medium alone (RPMI). Basal medium conditioned by ZL5 cells possesses a mitogenic activity with an autocrine effect, as measured by cell counting and by a 3H‐thymidine incorporation assay. Moreover, the conditioned medium affects the DNA synthesis of a variety of other lung‐derived cells. The active principle of medium conditioned by ZL5 cells is not identical to the defined growth‐factors EGF, PDGF, and TGF‐β, known to stimulate the growth of normal human mesothelial cells: treatment with these factors does not mimic the effect of conditioned medium on ZL5 cells. Our observations suggest that the mesothelioma cell line ZL5 produces an unknown autocrine mitogen.
Regulation of human colon‐carcinoma cell adhesion to extracellular matrix by transforming growth factor β1
Authors: Chakrabarty Subhas
Published: February 2007

The regulatory effect of transforming growth factor β1 (TGF‐β1) on the adhesion of human colon‐carcinoma cells to the extracellular matrix (ECM) was investigated. ECMs used in this study included tissue‐culture wells coated with fibronectin, laminin, collagen and BSA, as well as plastic wells. Three phenotypically different human colon‐carcinoma cell lines (Moser, HCT116, and KM 12SM) were used. The Moser cell line is moderately differentiated and, in terms of the diversity of responses elicited by TGF‐β1, is the human colon‐carcinoma cell line most responsive to TCP‐β1 as reported to date. By comparison, the undifferentiated HCT116 and the highly meta‐ static KM 12SM cells are unresponsive to this growth factor. We showed that TGF‐β1 regulated the adhesion responses of all 3 cell lines. However, the response profiles as well as the endogenous adhesive properties of each cell line were quite different from those of the others. Endogenous Arg‐Gly‐Asp(RGD)‐related receptors were present on the HCT 116 but not on the other cells. The observed regulatory effect of TGF‐β1 was contingent on the cell line, the type of ECM, and the growth‐factor treatment protocol used. When cells were treated with TGF‐PI for 16 hr prior to exposure to ECM in a 4‐hr adhesion assay, a significant increase in adhesion to fibronectin and collagen was observed for the Moser cells. For the identical experimental protocol, the KM 12SM cells responded by increas‐ ing adhesion to fibronectin, while the HCT 116 cells responded by decreasing adhesion to collagen. Kinetic analyses of TGF‐p I treatment showed that increased adhesion response to laminin was induced in the Moser cells after 2 hr of growth‐factor treatment. This response declined rapidly upon further exposure of the cells to TGF‐β1. Simultaneous exposure of cells to both TGF‐β1 and ECM negated the adhesion responses described above. The up‐modulation of adhesion to fibronectin, laminin and collagen by TGF‐β1 was mediated through RGD‐related integrin receptors. RGD‐containing peptides effectively blocked the enhanced adhesion responses induced by TGF‐β1.
Risk factors for tumors of the brain and meninges: Results from the Adelaide adult brain tumor study
Authors: Ryan Philip , Lee Marjorie W. , North J. Brian , McMichael Anthony J.
Published: February 2007

A population‐based case‐control study of incident primary brain tumors in adults was carried out in Adelaide, Australia in the period 1987 through 1990. It included 110 subjects with newly diagnosed primary glioma, 60 subjects with meningioma and 417 controls selected from the Australian Electoral Roll and frequency‐matched to cases for age (within 2 years), sex and postal code. Some interesting new associations were found: (I) an increased risk of glioma in women who reported working with cathode‐ray tubes (relative risk = 4.1, 95% confidence interval: 1.3–13.2); (2) a decreased risk of glioma in those with a history of allergic diseases (relative risk = 0.5, 95% confidence interval: 0.3–0.9); and (3) an increased risk of meningioma in those exposed to passive smoking from a spouse, especially amongst females (relative risk = 2.7, 95% confidence interval: 1.2–6.1). A pooled analysis of the multi‐center group of studies to which the present study belongs should allow more confident claims concerning risk factors for brain tumors.
Antibodies to human herpes virus‐6 and clinical course in patients with Hodgkin's disease
Authors: Levine Paul H. , Ebbesen Peter , Ablashi Dharam V. , Carl Saxinger W. , Nordentoft Axel , Connelly Roger R.
Published: February 2007

Serial serum samples from 37 patients with Hodgkin's disease (HD) and 39 healthy controls were studied for antibodies to human herpes virus‐6 (HHV‐6) using ELISA and indirect immunofluorescent antibody (IFA) tests and to the Epstein‐Barr virus (EBV) using a radio‐complement fixation assay. Antibodies to HHV‐6 in the pre‐treatment sera from the HD patients were not significantly different from those of controls, but significant changes in titers related to clinical course were noted among the HD patients. HHV‐6 IFA titers increased significantly in the course of follow‐up in patients who relapsed and decreased significantly over time in patients who did not. These serologic studies support tissue‐based investigations indicating that EBV plays a greater etiologic role in HD than HHV‐6, although HHV‐6 serology may be of prognostic value or may assist in identifying individuals with immunologic abnormalities. The identification of diverse HHV‐6 antibody patterns using different assays may reflect the presence of a number of antibodies with varying implications, similar to those identified for EBV.
Descriptive epidemiology of male breast cancer in Europe
Authors: La Vecchia Carlo , Levi Fabio , Lucchini Franca
Published: February 2007

Trends in death certification rates from male breast cancer over the period 1955–89 were analysed for 25 European countries (excluding the Soviet Union and a few small countries) on the basis of official data from the World Health Organization database. In the late 1980's, about 550–600 deaths per year from male breast cancer were certified in these countries. The variation was relatively limited, most age‐standardized (world standard) rates being within the range of 1.5 to 3.0 per million. The highest rates were in France, Hungary, Austria and Scotland. No clear pattern of trend was observed over the last few decades, but mortality rates in the late 1980's tended to be, for most countries, lower than those registered 3 decades earlier. Comparison was possible for 18 countries, and for 11 (including the largest ones, i.e. France, Germany, Italy and England and Wales), male breast cancer rates in 1985–89 were lower than in 1955–59. The pattern was similar when only truncated (from 35 to 64 years) mortality rates were considered and, for the largest countries, upon accurate inspection of age‐specific rates. In conclusion, therefore, this overview of male breast cancer trends in Europe precludes any generalized increase in mortality from the disease over recent decades and, hence, weighs against the introduction and presence of any important new cause of this rare disease.
Heterologous regulation of inositol lipid hydrolysis in human breast cancer cells by oestradiol 17β, bombesin and fluoroaluminate
Authors: Schrey M. P. , Furlong M. M. , Holt J. R. , Patel K. V.
Published: February 2007

Inositol lipid turnover has been implicated in the action of oestradiol 17β and bombesin‐related peptides on the human breast cancer cell line MCF‐7. In the present study, in addition to measuring inositol lipid turnover as indicated by inositol monophosphate (IP) accumulation, we have also monitored the effect of oestradiol on the incorporation of both 3H‐inositol and 14C‐glycerol into MCF‐7 cell phospholipids. Pre‐treatment of MCF‐7 cells with oestradiol (10 nM) for 48 hr stimulated a 4.3‐fold increase in IP production. This was similarly accompanied by a 3.4‐fold increase in the incorporation of 3H‐inositol into total phosphoinositides and a 40% increase in cell growth. The oestrogen antagonist LY117018 completely attenuated these effects. Oestradiol also stimulated 14C‐glycerol incorporation into phosphatidyl inositol, ‐choline and ‐ethanolamine by 97%, 82% and 99%, respectively. IP production in response to bombesin was potentiated by oestradiol in a dose‐dependent fashion. Fluoroaluminate (AIF4−) stimulated a dose‐dependent increase in IP production and oestradiol pre‐treatment increased the sensitivity of this IP response to AIF4−. Medroxyprogesterone acetate inhibited bombesin‐stimulated IP production but had no effect on the response to AIF4−. Our data suggest that the oestrogenic action on basal IP production in MCF‐7 cells may reflect an effect on inositol lipid synthesis rather than turnover. However, the potentiation by oestradiol of both bombesin‐ and AIF4−‐stimulated inositol lipid hydrolysis suggests the operation of a post‐receptor regulatory mechanism(s) which is independent of the inositol lipid pool size.
Comparison of 131I‐labelled anti‐episialin 139H2 with cisplatin, cyclophosphamide or external‐beam radiation for anti‐tumor efficacy in human ovarian cancer xenografts
Authors: Molthoff Carla F. M. , Pinedo Herbert M. , Schlüper Hennie M. M. , Rutgers Derk H. , Boven Epie
Published: February 2007

Three human ovarian cancer xenografts of different origin and grown s.c. in nude mice as well‐established tumors were studied for their sensitivity to cisplatin (CDDP), cyclophosphamide (CTX), 131I‐labelled anti‐episialin monoclonal antibody (MAb) 139H2, or external‐beam radiotherapy. The maximum tolerated dose of CDDP given weekly i.v. × 2 induced a tumor growth inhibition (GI) of 77.5% and 85.1% of the serous xenografts Ov.Ri(C) and OVCAR‐3, respectively. The mucinous xenograft Ov.Pe was relatively resistant to CDDP. The maximum tolerated dose of CTX, given i.p. × 2 with a 2‐week interval, induced a GI between 52.9% and 59.7% for each of the 3 xenografts. Radioimmunotherapy with 500–750 μCi 131I‐specific MAb 139H2, administered i.v. × 2 with a 2‐week interval, was more effective than CDDP or CTX. The 500 μCi 131I‐MAb 139H2 schedule induced 100% GI in Ov.Ri(C) xenografts and all tumors were cured. The same schedule was slightly less effective in OVCAR‐3 xenografts, but complete tumor regressions could still be obtained. Ov.Pe xenografts were least sensitive to radioimmunotherapy. The 2 injections of 500 μ‐Ci 131I‐control MAb gave only transient growth inhibition of OVCAR‐3 and Ov.Pe tumors, but gave complete regressions of Ov.Ri(C) xenografts. Biodistribution using tracer doses of 131I‐MAb 139H2 and 125I‐control MAb showed different degrees of specificity for MAb 139H2 in the 3 xenografts. Radiation doses absorbed in Ov.Ri(C), OVCAR‐3 and Ov.Pe xenografts per 10 μCi injected dose were 30, 41 and 29 cGy respectively. Treatment with 10 Gy external‐beam radiation suggested that the effects of radioimmunotherapy in each tumor line were related to the intrinsic radiosensitivity of the xenografts.
Visualization of oxidative processes at the cellular level during neutrophil‐mediated cytotoxicity against a human hepatoma cell line, HCC‐M
Authors: Saito Hidetsugu , Fukumura Dai , Kurose Iwao , Suematsu Makoto , Tada Shinichiro , Kagawa Tatehiro , Miura Soichiro , Morizane Toshio , Tsuchiya Masaharu
Published: February 2007

Human neutrophil‐mediated oxidative processes against a human hepatoma cell line, HCC‐M, was visualized at the cellular level by using a silicon‐intensified target camera and subsequently processing with a computer‐assisted digital‐imaging processor. Neutrophils were activated by a streptococcal preparation, OK‐432. A hydroperoxide‐sensitive tracer, dichlorofluorescin diacetate, was loaded in HCC‐M and temporal and spatial changes of lipid peroxides in this cell after addition of stimulated neutrophils were analyzed. The luminol‐dependent chemiluminescence activity of neutrophils was significantly enhanced and continued for at least 2 hr by stimulation with OK‐432, and its activity was shown to be accumulated at the site where a neutrophil attached with HCC‐M. The intensity of dichlorofluorescein fluorescence in HCC‐M rapidly increased after adding stimulated neutrophils, and their reaction was significantly attenuated by superoxide dismutase. The number of non‐viable cells was increased as the dichlorofluorescein fluorescence increased. It is suggested that oxidative stress may play an important role in neutrophil‐mediated tumor‐cell damage.
Intestinal brush‐border‐associated enzymes: Co‐ordinated expression in colorectal cancer
Authors: Real Francisco X. , Xu Mai , RosaVilá M. , de Bolós Carme
Published: February 2007

The brush border of normal small‐intestine epithelial cells is rich in enzymes that are involved in the digestive process. Such molecules can be used as markers to analyze cell lineages and differentiation properties of colorectal cancers. Monoclonal antibodies detecting dipeptidyl peptidase‐IV, aminopeptidase N, endopeptidase F, sucrase‐isomaltase, alkaline phosphatase, maltase‐glucoamylase and lactase have been used to analyze the phenotype of colorectal cancers, adjacent mucosa and histologically normal distant mucosa. The avidin‐biotin peroxidase complex method was used. Expression of dipeptidyl peptidase‐IV, aminopeptidase N, sucrase‐isomaltase and alkaline phosphatase was common in non‐neoplastic mucosa adjacent to, and distant from, the tumor; in contrast, endopeptidase F, maltase‐glucoamylase and lactase were rarely expressed in normal distant mucosa and more frequently expressed in mucosa adjacent to the tumor. Dipeptidyl peptidase‐IV, aminopeptidase N, endopeptidase F, sucrase‐isomaltase and alkaline phosphatase were frequently expressed in colorectal cancers, whereas maltase‐glucoamylase and lactase were rarely expressed. Two general patterns of antibody reactivity were observed: diffuse cytoplasmic and apical; apical reactivity was generally associated with more differentiated tumors. A logistic predictive regression model indicated that enzyme expression in colorectal cancers followed a coordinate pattern, but was unrelated to the location of the tumor, Dukes stage or differentiation grade. In conclusion, expression of brush‐border‐associated enzymes occurs frequently in colorectal cancers and is regulated in a co‐ordinated manner. These markers can be used for the phenotypic sub‐classification of colorectal cancers.
Clinical pharmacokinetic study of tiazofurin administered as a 1‐hour infusion
Authors: Jayaram Hiremagalur N. , Lapis Erzsebet , Tricot Guido , Kneebone Patricia , Paulik Edith , Zhen Weining , Engeler George P. , Hoffman Ronald , Weber George
Published: February 2007

Tiazofurin, 2‐β‐d‐ribofuranosylthiazole‐4‐carboxamide, is cytotoxic to murine and human tumor cells. In earlier Phase‐I/‐II trials performed in other centers in patients with solid tumors, the drug was given mainly as a 10‐min bolus or as a continuous i.v. infusion for 5 days. These protocols were associated with serious side effects, including neurotoxicity, pleuropericarditis, and occasional myelosuppression. In our study, 26 patients with end‐stage leukemia were treated with tiazofurin with I‐hr daily i.v. infusions, resulting in lower incidence and less severity of side effects. In this group, 7 attained complete remission and 7 showed hematologic responses. Out of 12 evaluable patients with myeloid blast crisis of chronic granulocytic leukemia, 10 (83%) responded to therapy, with 6 attaining complete response. We present pharmacokinetic parameters of our clinical study and examine some of the reasons for the lower toxicity found in our trials. In leukemic patients during and after infusion at doses of 1,100, 2,200 and 3,300 mg/m2 tiazofurin peak plasma concentrations were 245, 441 and 736 μM, respectively, values one‐half of those calculated from other reports with a 10‐min bolus administration. In our I ‐hr infusion method, biphasic pharmacokinetics were noted with αt1/2 and βt1/2 of 0.5 and 6.2 hr, and tiazofurin was eliminated at a faster rate than in previous trials with continuous infusion. The area under the curve with our I ‐hr infusion was 52% of that reported for the same dose given by continuous infusion. Our I ‐hr infusion method and prompt and effective treatment of side effects enabled us to administer higher doses and larger total amounts of tiazofurin in longer treatment cycles than in any previous trials elsewhere. Tiazofurin therapy using I ‐hr infusion may be feasible for other carefully selected types of malignancies.