bluuebunny/crossref_metadata_2025 huggingface dataset:
A short sequence, within the amino acid tandem repeat of a cancer‐associated mucin, contains immunodominant epitopes
Authors: Burchell Joy , Taylor‐Papadimitriou Joyce , Boshell Martina , Gendler Sandra , Duhig Trevor
Published: February 2007

The polymorphic epithelial mucin (PEM) appears to be the target molecule for many monoclonal antibodies (MAbs) which react with tumour‐associated and epithelium‐specific antigens. PEM contains a large domain made up of 20 aminoacid tandem repeats which are highly immunodominant as many of the antibodies reactive with this molecule recognize epitopes within this area. Using overlapping peptide octamers, we have precisely mapped the epitopes of 4 MAbs reactive with the tandem repeats including one, SM‐3, which shows enhanced tumour specificity. We report that the core of the SM‐3 epitope corresponds to the continuous amino acid sequence Pro‐Asp‐Thr‐Arg‐Pro. We also show that the epitopes recognized by 3 other antibodies, which show reactivity with normal and malignant tissues, map to within this area of the tandem repeat. However, none of these epitopes contain the proline found at the amino end of the SM‐3 determinant. These results are consistent with the idea that, in the cancer‐associated mucin, premature termination of the carbohydrate side‐chains results in the exposure of the SM‐3 epitope.
Regulation of cell turnover in the livers of tumour‐bearing rats: Occurrence of apoptosis
Authors: Tessitore Luciana , Valente Guido , Bonelli Gabriella , Costelli Paola , Baccino Francesco Maria
Published: February 2007

Growth of a highly‐deviated ascites hepatoma (Yoshida AH‐130) in rats caused initial hyperplastic enlargement of the liver, followed by progressive reduction to a size lower than that seen in controls. The time‐course of this biphasic change in liver weight roughly corresponded to the exponential and stationary phases of tumour growth. Histologically, scattered small foci of perilobular necrosis were observed during the hyperplastic phase and these were consistently associated with a moderate elevation of glutamate‐pyruvate transaminase (GPT) activity in the blood plasma. By contrast, signs of necrosis were absent and plasma GTP levels had returned to normal during the phase of hepatic involution, which was characterized by enhanced apoptosis, a type of single‐cell death known to be involved in the regulation of tissue size under both normal and pathological conditions. Biochemically, alterations in liver protein mass resulted from changed rates of tissue protein degradation. The apoptotic bodies could either be lost from the liver via blood, lymph and bile, or phagocytosed and degraded by adjacent cells. Disposal of the apoptotic bodies is likely to account, at least in part, for the enhanced rates of liver protein turnover that characterize hepatic involution.
Suppression of c‐myc mRNA expression by steroid hormones in HTLV‐I‐infected T‐cell line, KH‐2
Authors: Koizumi Tamio , Nakao Yoshinobu , Kawanishi Michiko , Maeda Sakan , Sugiyama Taketoshi , Fujita Takuo
Published: February 2007

The effects of l,25(OH)2D3 and dexamethasone on cellular proliferation and gene expression of the HTLV‐l‐infected T‐cell line, KH‐2, established from a patient with adult T‐cell leukemia, endemic in the south‐west Japanese islands and the Caribbean, were examined. KH‐2 cells are integrated by HTLV‐I proviral DNA and expressed mRNA for c‐myc, IL‐2 receptor a‐chain (IL‐2Rα), and T‐cell receptor β‐chain (TCRβ) while it did not express IL‐2 mRNA. l,25(OH)2D3 and dexamethasone did not suppress the mRNA levels of HTLV‐I, IL‐2Rα or TCRβ but reduced the c‐myc mRNA level. The reduction of c‐myc mRNA level was marked in l,25(OH)2D3‐treated cells but relatively weak in dexamethasone‐treated cells. This inhibitory effect of the steroid hormones correlated with the inhibition of KH‐2 cell proliferation.
Membrane fluidity affects tumor‐cell motility, invasion and lung‐colonizing potential
Authors: Taraboletti Giulia , Perin Lianna , Bottazzi Barbara , Mantovani Alberto , Giavazzi Raffaella , Salmona Mario
Published: February 2007

Membrane fluidity, determined by steady‐state fluorescence polarization measurements, was correlated with metastatic capacity of murine tumor‐cell lines. A correlation was observed in cell lines with different metastatic potential, and was confirmed when their lung‐colonizing ability was modulated by alteration of either the membrane lipid composition or the culture conditions. Two cellular functions, motility and basement membrane invasion, were affected by the membrane lipid composition, and might explain the role of membrane fluidity observed in cancer metastasis.
Biochemical and NMR studies on structure and release conditions of RNA‐containing vesicles shed by human colon adenocarcinoma cells
Authors: Ceccarini M. , Guidoni L. , Luciani A. M. , Mariutti G. , Rosi A. , Viti V.
Published: February 2007

Large amounts of particulate material, mostly lipid vesicles, are released by human colon adenocarcinoma HCT‐8R cells when they are packed at high density in saline solution. RNA is also present in the released structures. Vesicle shedding is displayed only by healthy and viable cells. The process, in our experimental conditions, lasts up to 40 min, and can be restored by supplementing cells with nutrients and oxygen. RNA and lipids give rise to IH and 3IP NMR signals. The process is somehow related to a thermotropic transition observed by means of IH NMR spectroscopy for peculiar lipid domains in the plasma membrane. Analysis of 3IP NMR spectra of the phosphodiester groups, upon pH variation, indicates strong interaction between RNA and proteins in an assembled structure. A constant amount of polyA+ RNA can be recovered from the vesicles. The electrophoretic pattern and in vitro protein synthesis indicate that mRNA can be isolated as a functionally active molecule with a major 5 Kb fraction.
Effects of cyclosporin a and verapamil on the intracellular daunorubicin accumulation in chinese hamster ovary cells with increasing levels of drug‐resistance
Authors: Silbermann M. H. , Boersma A. W. M. , Jamssen A. L. W. , Scheper R. J. , Herweijer H. , Nooter K.
Published: February 2007

Multidrug‐resistance (MDR) is characterized by the presence of a 170 kDa glycoprotein (P‐glycoprotein) in the plasma membrane. P‐glycoprotein is thought to act as an efflux pump, leading to reduced drug accumulation in MDR cells. This defect in drug accumulation can be overcome by membrane transport modulating agents (MTMAs). We determined the concentration of MTMA needed for maximal restoration of daunorubicin content in 4 Chinese hamster ovary cell lines with increasing levels of drug‐resistance using flow cytometry. Stimulation of daunorubicin accumulation occurred in a dose‐dependent manner. The required level of MTMA needed for maximal drug accumulation increased with the level of drug‐resistance. CHrA3 cells, which have a level of resistance comparable to clinical samples, needed relatively low concentrations of MTMA for maximal restoration of drug accumulation. This indicates that, in trials combining drugs and MTMAs, low dosages of MTMAs could be sufficient for optimal potentiation of cytotoxicity.
Cell fusion in tumor development and progression: Occurrence of cell fusion in primary methylcholanthrene‐induced tumorigenesis
Authors: Fortuna M. B. , Dewey M. J. , Furmanski P.
Published: February 2007

Definitive evidence for the occurrence of cell fusion in tumorigenesis was sought in methylcholanthrene‐induced sarcomas. This was approached by using allophenic mice generated from strains differing for electrophoretic variants of the ubiquitous, dimeric enzyme glucose phosphate isomerase, with fusion assessed by heterodimer formation. Eighty‐three carefully trimmed primary tumor samples (from 23 individual tumors in allophenic mice) were analyzed, as were 1,140 clones derived from them. In all primary tumor samples, zymograms exhibited one GPI homopolymeric band. Expression of a hybrid band (indicative of a fusion event) was not observed in these samples. However, 9 (0.8%) of the tumor clones demonstrated a distinct and reproducible hybrid band which was uniformly lost upon recloning. Our data suggest that cell fusion, although uncommon, occurs in the clonogenic cell fraction during primary MCA tumorigenesis and is followed rapidly by chromosome segregation.
A case‐control study of diet and breast cancer in Argentina
Authors: Iscovich José Mario , Iscovich Ruth B. , Howe Geoffrey , Shiboski Steve , Kaldor John M.
Published: February 2007

A case‐control study of breast cancer was carried out in La Plata, Argentina, where the incidence of the disease is comparable to the highest rates recorded worldwide. One hundred and fifty incident cases were identified through major hospitals. For each case, a hospital control, matched by age and hospital, and a neighbourhood control, matched by residential area and age, were also chosen. Cases and controls were interviewed to obtain information on past diet, as well as demographic and socio‐economic characteristics, reproductive and menstrual history and other potential breast‐cancer risk factors. The dietary information was obtained from questions on the consumption of specific food items and information on portion sizes from an earlier study was used to estimate intake of calories and selected nutrients. There was a substantial excess energy intake among cases as compared to both control groups, which was present across all 3 major macronutrients which contribute to total calories. Among the food groups, the consumption of eggs was a risk factor for breast cancer, and wholemilk products and green leafy vegetables were protective. After adjusting for the calorie difference in multivariate statistical analyses of nutrients, fibre and betacarotene consumption were weakly protective. The results are discussed with reference to possible methodological difficulties and previous studies of diet and breast cancer.
Some endocrine characteristics of early menarche, a risk factor for breast cancer, are preserved into adulthood
Authors: Apter D. , Reinilä M. , Vihko R.
Published: February 2007

Early menarche is a risk factor for breast cancer. In a longitudinal manner, we have investigated the endocrine features of girls with early menarche. This study extends our investigations to the third decade of life in a cohort of girls followed up for 13 years. The group studied comprised 44 women, 20‐31 years of age. Eleven women had had their menarche before 12.0 years, 14 women at 12.0‐12.9 years and 19 women at 13.0 years or more. The women who had had early menarche had higher serum oestradiol concentrations during the follicular phase of the menstrual cycle than the women who had had their menarche later. The serum oestradiol concentrations increased rapidly at the beginning of cycle in these “early menarche” women. If there is a threshold which serum oestradiol concentrations must exceed to increase the risk of breast cancer, then these women have more days at risk than other women. In addition, the serum SHBG (sexhormonebinding globulin) concentration was about 30% lower in the follicularphase specimens of the women who had had their menarche before 12.0 years compared with those who had had their menarche at 13.0 years. Our data therefore indicate that women with early menarche are subject to a high degree of oestrogen stimulation at least until approximately 30 years of age. Our findings may have important consequences for the design of intervention programs for breast cancer prevention.
IL‐1 and IL‐6 release by tumor‐associated macrophages from human ovarian carcinoma
Authors: Erroi Annalaura , Sironi Marina , Chiaffarino Francesca , Zhen‐Guo Chen , Mengozzi Manuela , Mantovani Alberto
Published: February 2007

Our study was designed to investigate the production of interleukin‐l (IL‐I) and IL‐6 in tumor‐associated macrophages (TAM) isolated from ascites (18 cases) or solid (7 cases) human ovarian carcinoma. These are pleiotropic monokines which, in addition to affecting proliferation and differentiation of lymphocytes, act on various targets, including vascular cells and liver, and may therefore be involved in the pathogenesis of certain manifestations of malignancy. IL‐I was measured by the thymocyte costimulator assay, under conditions in which IL‐6 was inactive, and, in 8 cases, by radioimmunoassay (RIA). IL‐6 was measured as hybridoma growth factor (HGF) on the 7TDI cell line. TAM did not release appreciable levels of IL‐I spontaneously and, upon LPS stimulation, were poor producers of this monokine compared to blood monocytes. In contrast, TAM supernatants contained a high level of HGF in the absence of deliberate stimulation, and exposure to LPS either did not affect or further augmented production of this monokine. HGF activity of TAM supernatants was completely blocked by anti‐IL‐6 antibodies, Ascites fluid from 8 ovariancarcinoma patients contained high levels of HGF activity, blocked by anti‐IL‐6 antibodies. Thus, TAM exhibit a dissociation in their capacity to release the functionally related monokines IL‐I and IL‐6. IL‐6 produced by TAM may account for the elevation of liverderived acutephase proteins associated with malignancy.
Activation and immortalization of leukaemic B cells by epstein‐barr virus
Authors: Walls E. V. , Doyle M. G. , Patel K. K. , Allday M. J. , Catovsky D. , Crawford D. H.
Published: February 2007

We have studied the responses of chronic leukaemic B cells to infection by Epstein‐Barr virus (EBV). Our results define one population of B lymphocytes, represented by prolymphocyte leukaemic (PLL) cells, which are highly susceptible to immortalization by EBV. Another B‐cell type, represented by chronic lymphocytic leukaemic (CLL) cells, can be readily infected by the virus but is resistant to immortalization. Comparative studies of viral and cellular related events early after infection in these 2 cell types reveal that both express the EB viral nuclear antigen (EBNA) complex, but the immortalization‐resistant CLL cells fail to express the latent membrane protein (LMP), which can be detected in PLL cells 48 hr after infection. Circularization of the linear viral genome could be detected at 7 days post infection in the PLL cells, but only in 2 out of 4 CLL cells tested. Both CLL and PLL cells show increased surface expression of CD23 and HLA‐DR molecules after infection but, whereas PLL cells show an increase in size, together with RNA and DNA synthesis indicative of cell cycle progression, CLL cells appear to be arrested in the G1/S phase of the cycle. The results suggest that the outcome of infection by EBV is determined by the nature of the target cell rather than by random virus‐related events. The correlation between the block in immortalization of CLL cells and their failure to express LMP suggests that expression of this protein is essential for in vitro immortalization of B cells. The failure to detect circularization in some EBV‐infected CLL cells suggests that this, as well as LMP expression, may be dependent on prior activation of the B cell by EBV, an event which may vary between the different CLL samples tested.
Adoptive immunotherapy is suppressed in C57BL/6J AND B6.C‐H‐2bm12 mice following recognition of congenic class II MHC antigen determinants
Authors: Evans Robert , Duffy Theodore M.
Published: February 2007

In previous reports, we have shown that adoptive transfer of tumor‐sensitized T (immune) cells to tumor‐bearing mice that have received a prior injection of cyclophosphamide (CY) results in the induction of permanent tumor regression in syngeneic strains. It has also been shown that adoptive immunotherapy results in an increased expression of class II MHC antigens (la) by macrophages at the tumor site and in the peritoneal cavity and is associated with expansion of CD4+ and CD8+ T cells at the site of tumor regression. In this report, we use the la mutant strain, B6.C‐H‐2bm12, and con‐genic C57BL/6J (B6) mice to determine the relative importance of la expression in regulating amplification of immune responses following adoptive immunotherapy and to test the hypothesis that recognition of congenic la determinants will result in the induction of suppressor mechanisms that down‐regulate active immunity. The data indicated that the adoptive transfer of immune congenic T cells (B6 immune cells into CY‐treated tumor‐bearing bml2 mice and vice‐versa) down‐regulated active immunity, while the transfer of syngeneic immune cells resulted in permanent tumor regression. By using radiation‐chimeric mice, it was shown that down‐regulation was associated with incompatibility of the transferred immune T cells and bone‐marrow‐derived cells (puta‐tively expressing the la haplotype of donor‐derived macrophages) and the appearance of long‐lived splenic suppressor cells. Suppression per se was shown to be induced in response to the la difference between the two strains and not in response to the MCA/76‐9 sarcoma, which appears to be one of the few tumors that can induce active immunity in both the syngeneic and congenic strains without obvious subsequent down‐regulation by suppression.
Medroxyprogesterone acetate, an anti‐cancer and anti‐angiogenic steroid, inhibits the plasminogen activator in bovine endothelial cells
Authors: Ashino‐Fuse Hiromi , Takano Yoshihito , Oikawa Tsutomu , Shimamura Mariko , Iwaguchi Takao
Published: February 2007

Medroxyprogesterone acetate (MPA) is an anti‐cancer drug for mammary carcinomas and an angiostatic steroid. The effects of MPA on the growth and plasminogen activator (PA) activity of bovine endothelial cells were investigated to elucidate the inhibitory mechanism observed in angiogenesis. MPA did not suppress the growth of capillary endothelial cells, even at high concentrations. On the other hand, in bovine endothelial cells of 3 types (adrenal cortical capillary, aortic and pulmonary artery endothelial cells), MPA inhibited extracellular and cell‐associated activity of PA, which might be a protease involved in the neovascular response. MPA also greatly inhibited the high level of PA induced by basic fibroblast growth factor (FGF). The same result was obtained when PA production was induced by 4β‐phorbol‐l2‐myri‐state‐13‐acetate (PMA) in endothelial cells. These findings suggest that one of the points of inhibitory action of MPA in the process of angiogenesis may be the suppression of PA activity, and that inhibition of this protease might be useful for reduction of tumorigenic or excessive angiogenesis in vivo.
Phenotypic and cytogenetic characterization of a cell line derived from primary prostatic carcinoma
Authors: Brothman Arthur R. , Lesho Lori J. , Somers Kenneth D. , Wright George L. , Merchant Donald J.
Published: February 2007

A new cell line, PPC‐1, has been established from a specimen obtained from a patient with a poorly differentiated adenocarcinoma of the prostate. This is the first line of its type derived from a primary prostatic tumor site. PPC‐1 cells have become immortalized in culture, exhibit transformation parameters including relaxed growth factor requirements and anchorage‐independent growth, and are highly tumorigenic in nude mice. Cytogenetic studies by G‐banding revealed a grossly abnormal karyotype, with a modal chromosome number of 84, multiple marker chromosomes including both homogeneously staining regions and double minutes and clonal loss of chromosomes 3, 5, 10, 15 and Y.
Clustering of discrete cell properties essential for tumorigenicity and metastasis. I. Studies of syrian hamster embryo fibroblasts spontaneously transformed in vitro
Authors: Deichman G. I. , Kluchareva T. E. , Matveeva V. A. , Kushlinsky N. E. , Bassalyk L. S. , Vendrov E. L.
Published: February 2007

The expression of two discrete cell properties related to the host natural effector mechanisms, i.e., resistance to damage by H202, a cytotoxic product of activated macrophages, and the ability to secrete PGE, which inhibits NK‐cell cytotoxicity, has been examined in parental Syrian hamster embryo cells spontaneously transformed in vitro (STHE strain) and in 18 in vivo selected sublines. In all cell variants, resistance to H202 and PGE‐releasing activity were either both expressed, or not expressed at all. Parental STHE cells and 5 variants selected in vivo, which were equally highly susceptible to H202‐induced damage, did not release any detectable amount of PGE upon contact with NK cells. In contrast, 13 other STHE variants selected in vivo and characterized by their resistance to H202, all released PGE upon contact with NK cells. Thus, these two biochemically unrelated cell phenotypic characteristics are likely to be either simultaneously selected in vivo, or united in cluster which pre‐exist or appear in rare cell variants of the parental cell population in the conditions of in vivo natural selection pressure.
Paradoxical effects of tumour necrosis factor in experimental ovarian cancer
Authors: Malik S. T. A. , Griffin D. B. , Fiers W. , Balkwill F. R.
Published: February 2007

Recombinant human tumour necrosis factor (rhTNF) had anti‐tumour activity against 2 of 3 human ovarian cancer xenografts growing intraperitonealy (i.p.) in nude mice, producing a moderate (2‐ to 3‐fold) increase in mouse survival time. rhTNF therapy caused a marked influx of polymorphonuclear neutrophils into the peritoneal cavity during the first few days of daily therapy. This was accompanied by a decrease in the number of peritoneal macrophages and lymphocytes. rhTNF also caused an increase in peripheral blood neutrophils. With continuation of daily therapy, the peritoneal neutrophil influx diminished, with restoration of the macrophage and lymphocyte populations. After 2 to 3 weeks there was a small but significant increase in peritoneal Thy 1.2 cells. In the peripheral blood, the neutrophilia was less marked than at the start of therapy. Mild myelosuppression was indicated by significant falls in haemoglobin and platelet counts. Within 24 hr of the start of therapy in the 2 responsive xenografts (HU and LA) tumour clumps in the peritoneum were surrounded by host inflammatory cells, and tumours fixed to the omentum were infiltrated by neutrophils and mononuclear cells. In both instances necrosis was evident by 4 to 7 days. The third xenograft (OS) grew although the rhTNF therapy induced the same inflammatory changes in the peritoneum. In contrast to its positive effect on the survival of tumour‐bearing mice, rhTNF promoted the adhesion of tumour cells to the peritoneum and their establishment as tumour nodules below the mesothelial surface. This phenomenon was seen in all 3 xenografts including the OS xenograft which did not respond in any other way to rhTNF therapy.
Modulation of growth, differentiation and glycoprotein synthesis by β‐ALL‐trans retinoic acid in a multicellular tumor spheroid model for squamous carcinoma of the head and neck
Authors: Sacks Peter G. , Oke Victor , Amos Brad , Vasey Tracey , Lotan Reuben
Published: February 2007

Cell line MDA 886Ln was established from a laryngeal lymph node metastasis. When grown as a multicellular tumor spheroid (MTS), it exhibits squamous differentiation. We studied the effects of ß‐all‐trans retinoic acid (RA) on the growth, differentiation and glycoprotein content of this MTS model for squamous carcinomas of the head and neck. The growth of MTSs was inhibited in a dose‐dependent manner by 10−6 to 10−10 M RA. Growth inhibition occurred between 3 and 5 days of RA treatment (10−6 M). Immunohistochemical and electrophoretic analyses revealed that RA suppressed the morphological markers of squamous differentiation (squames), involucrin expression, and keratin expression. Glycoprotein expression was examined by metabolic labelling using 3H‐glucosamine, in situ labelling of polyacrylamide gels with 125l‐labelled wheat‐germ agglutinin (WGA), localization of fluorescein isothionate‐WGA in frozen sections, and determination of sialyltransferase activity. Treatment using 10−6 M RA altered glycoprotein expression both biochemically and morphologically, and WGA was shown to bind preferentially to sialic acid residues. The sensitivity of this MTS model to RA treatment and its ability to be analyzed through morphological, immunohistochemical and biochemical techniques suggest that it will prove useful in studying the relationships between growth, differentiation and RA‐induced alterations in squamous carcinomas.
Effect of polarity and differentiation on antibody localization in multicellular tumour spheroid and xenograft models and its potential importance for in vivo IMMUNOTARGETING
Authors: Pervez S. , Kirkland S. C. , Epenetos A. A. , Mooi W. J. , Evans D. J. , Krausz T.
Published: February 2007

Two monoclonal antibodies (MAbs) AUAI and HMFGI recognize antigens located on different membrane domains of polarized epithelial cells. We have assessed the accessibility of these antigens in multicellular tumour spheroids produced in culture using a well‐polarized (HRA‐19) and a non‐polarized cell line (LoVo) of human large‐bowel carcinoma origin. Multicellular spheroids of HRA‐19 cells develop polarity, so that the membrane which is in contact with the culture medium (apical) becomes antigenically distinct from the membrane facing the centre of the spheroids (basolateral). This was confirmed by immunostaining sections of spheroids with 2 MAbs, AUAI and HMFG I. AUA I recognizes an antigen located exclusively on the basolateral membranes of polarized epithelial cells, and stained only internal membranes in spheroid sections. Conversely HMFG1, which recognizes an antigen located on the apical membranes, stained only the periphery of the spheroids. These 2 MAbs were then radiolabeled with 125l and incubated with live spheroids for 4 hr at 37°C. Autoradiography of spheroid sections showed a marked difference between the 2 MAbs. 125l‐HMFGI‐radioantibody localized exclusively on the spheroid surface in a pattern identical to the in vitro immunostaining pattern, while 125l‐AUAI radioanti‐body showed no binding in spite of the uniform presence of antigen on all tumour cells basolaterally. This appeared to be the result of the inaccessibility of basolateral antigenic sites in well‐polarized epithelial cells because of the tight junctions connecting these cells at their apicai surfaces. In contrast to the HRA‐19 cell line LoVo, spheroids do not develop polarity; as a result, when stained with AUAI, variable antigenic expression all over the cell surface was seen. Autoradiographs of these spheroids showed 125I‐AUAI binding with a penetration to a depth of about 1–3 cells, while HMFG I which shows no reactivity with this cell line in vitro, did not bind. This phenomenon was further investigated in xenografts of the HRA‐19 cell line. It was shown that in a well‐differentiated adenocarcinoma where the tumour cells forming acini are arranged in a polarized fashion, the luminal antigenic sites may be inaccessible to the injected MAb. The striking differences in binding of MAbs on polarized and unpolarized tumours indicate the importance of cell polarization and exact location of antigenic sites for in vivo immunotargeting.
Expression of tag‐72 in normal colon, transitional mucosa, and colon cancer
Authors: Xu Mai , Real Francisco X. , Welt Sidney , Schüssler Martina H. , Oettgen Herbert F. , Old Lloyd J.
Published: February 2007

Monoclonal antibody (MAb) B72.3 detects an epitope carried by high‐molecular‐weight mucins (tumor‐associated glycoprotein, TAG‐72) recently identified as sialyl‐Tn. B72.3 MAb has a restricted pattern of reactivity with normal tissues but it reacts with a high proportion of epithelial cancers. To determine the possible relationship between neoplastic transformation and reactivity with B72.3 MAb, we have analyzed samples of normal colon, colon cancer and transitional mucosa (mucosa adjacent to colorectal cancer) or reactive mucosa (mucosa adjacent to squamous carcinoma of the anal canal, or mucosa overlying lymphoma). B72.3 MAb reacted strongly with 21/21 specimens of transitional mucosa and with 17/21 specimens of adjacent colon cancer. Reactivity of B72.3 MAb with transitional mucosa was strong and homogeneous, whereas reactivity with cancer tissue was weaker and more heterogeneous. Reactive mucosa adjacent to squamous carcinoma or lymphoma was also reactive with B72.3 MAb. Our findings show that, in the colon, expression of TAG‐72 antigen occurs during the process of epithelial cell transformation but is also regulated by factors unrelated to the process of carcinogenesis.
EGF stimulates anchorage‐independent growth of a human bladder carcinoma cell line (KU1) with an amplified and over‐expressed EGF receptor gene
Authors: Ishikawa Jiro , Maeda Sakan , Sugiyama Taketoshi , Nishimura Ryuichiro , Mizoguchi Akira , Kamidono Sadao
Published: February 2007

Southern blot analysis of 6 human bladder carcinoma cell lines revealed amplification of the epidermal growth factor receptor (EGFR) gene in the KUI cell line. The amplification of the gene was about 4‐fold as compared with that of human placental DNA. Several restriction endonuclease digestions revealed that there was no gross rearrangement of the EGFR gene in KUI. Northern blot analysis showed normal 10 and 5.6 kb of EGFR gene‐related mRNA species. 125I‐EGF binding revealed 2 distinct EGF binding sites on KUI cells: high‐affinity sites 5.7 × 105 receptors per cell with I.I nm Kd and lowaffinity sites 2.3 × 106 receptors per cell with 7.4 nm Kd. The number of the EGFR was compatible with that of the A431 squamous carcinoma cell line which has an amplified, rearranged and over‐expressed EGFR gene. Solid‐phase immunoisolation analysis showed a single 170 kDa EGFR protein in KUI as well as in A431. Unlike other cell lines with amplified and over‐expressed EGFR gene, anchorage‐dependent growth of KUI was stimulated but not inhibited by EGF. Moreover, anchorage‐independent growth of KUI was stimulated by EGF.
Antioxidant enzyme activities in normal and transformed mouse liver cells
Authors: Sun Yi , Oberley Larry W. , Elwell James H. , Sierra‐Rivera Elaine
Published: February 2007

Copper‐ and zinc‐containing superoxide dismutase (Cu‐ZnSOD), manganese‐containing superoxide dismutase (MnSOD), catalase (CAT), glutathione peroxidase (GPX, both Se‐dependent and Se‐independent), and glutathione reductase (GR) were measured in normal, nitrosoguanidine‐transformed and SV40‐transformed mouse liver cells in culture, as well as in mouse liver homogenates. Enzyme activities were compared on the basis of 3 different endpoints: per mg protein, per mg DNA, and per 106 cells. Except for GR, activity of all the measured anti‐oxidant enzymes was much higher in vivo than in vitro. All of the anti‐oxidant enzyme activities were lower in general in the 2 transformed cell lines than in the in vitro normal cell line, except Cu‐ZnSOD, which showed little change. However, MnSOD was the only enzyme which showed lowered activity in both transformed cell lines, no matter what endpoint was used. This finding is in agreement with previous work showing lowered MnSOD activity in tumor cells.
Influence of animal host and tumor implantation site on radio‐antibody uptake in the GW‐39 human colonic cancer xenograft
Authors: Blumenthal R. D. , Sharkey R. M. , Kashi R. , Natale A. M. , Goldenberg D. M.
Published: February 2007

The magnitude and kinetics of tumor uptake of a monoclonal antibody (MAb) directed against carcinoembryonic antigen (CEA) in the GW‐39 human colorectal cancer xenograft differ according to the animal used (nude mouse or hamster) and the site of implantation of the tumor within the animal (cheek pouch, leg muscle, subcutaneous or liver). Several physiological factors have been evaluated in an attempt to explain these differences in radio‐antibody accumulation. The following observations have been made: (1) The animal host with the slower blood clearance of radio‐antibody and the higher non‐tumor tissue uptake has the higher tumor uptake; (2) the xenografts with a higher blood‐flow rate, vascular volume and/or vascular permeability have a higher specific radio‐antibody targeting; (3) the smaller, more viable tumors take up more radio‐antibody per gram than the larger tumors; and (4) tumors with higher specific antigen content accrete more radio‐antibody. These results are discussed in terms of the feasibility of clinical tumor imaging and therapy with radiolabeled antibodies.
Antigenic modulation and internalization of monoclonal antibody to human colonic carcinoma cells detected by enzyme‐linked immunosorbent assay
Authors: Yokota T. , Otsuji E. , Noguchi A. , Yamaguchi T. , Sawai K. , Takahashi T.
Published: February 2007

We studied antigenic modulation and internalization of monoclonal antibody (MAb) A7 using the enzyme‐linked immunosorbent assay (ELISA) and biotin‐labelled antibody‐staining techniques. Incubation of the colonic SW1116 cell line with an excess of MAb A7 induced modulation of the cell‐surface antigen. When the line was assayed by ELISA, a change in cellular reactivity with MAb A7 was seen after 1 hr. After 24 hr, the cellular reactivity showed a 52% decrease in absorbance. Modulation was inhibited by 0.1 % sodium azide and acetone fixation, suggesting that this is an energy‐dependent phenomenon. The internalization of biotinylated MAb A7 was examined. Internalized biotinylated MAb A7 was detected in cells fixed before labelling with avidin‐biotin peroxidase complex. It was observed that the amount of MAb A7 which remained associated with the cell surface had decreased since A7 was internalized.
A new gastric carcinoma cell line (LIM1839) derived from a young caucasian male
Authors: Whitehead Robert H. , Novak Ulrike , Thomas Robert J. , Lukeis Robyn E. , Walker Francesca E. , Jones Jennifer
Published: February 2007

We describe a new and unique gastric carcinoma cell line (LIM1839) derived from a young Caucasian male with rapidly progressing disease. The cell line grows with a pleomorphic morphology and has been in continuous culture for more than 3 years. The cells cannot be cloned in semi‐solid agar or grown in nude mice despite numerous attempts. The karyotype of the cultured cells is highly abnormal with a large number of structural and numerical changes. Some chromosomes are dicentric and this feature has persisted in this culture. The cells express one of the small‐intestinal dipeptidases, amino‐peptidase N, but do not express dipeptidyl peptidase IV or the disaccharidases, sucrase isomaltase or maltase glucoamylase. The cells express high levels of EGF receptors and of messenger RNA for insulin‐like growth factor II.
Transformation of normal human melanocytes and non‐malignant nevus cells by adenovirus 12‐SV40 hybrid virus
Authors: Jambrosic Jadranka , Mancianti Maria Laura , Ricciardi Robert , Sela Ben‐Ami , Koprowski Hilary , Herlyn Meenhard
Published: February 2007

Infection of normal human melanocyte and nevus cultures with an adenovirus 12‐Simian Virus 40 hybrid virus (Ad12‐SV40) produced transformed cells that expressed SV40‐T antigen. The Ad12‐SV40 cells exhibited rapid cell proliferation to high cell densities and efficient growth in soft agar, but none of 15 transformed melanocyte and nevus cultures formed tumors when injected s.c. or under the renal capsule into athymic nude mice. While the Ad12‐SV40‐transformed cells lost certain properties associated with the melanocytic phenotype, i.e., pigmentation, tyrosinase activity and melanosome content, the expression of melanoma‐associated antigens, including nerve growth factor receptor, p97 melanotransferrin, and chondroitin sulfate proteoglycan, remained stable. The transformed melanocytes acquired the ability to express HLA‐DR antigen, which is found on nevus and melanoma cells. Total ganglioside patterns in Ad12‐SV40‐transformed cells changed to reflect more advanced stages of tumor progression. Transformed melanocytes, like nevus and melanoma cells, showed increased GD3 content and transformed nevus cells increased GD2 which is a feature of malignant melanoma cells. Ad 12‐SV40‐transformed human melanocytes and nevus cells are useful tools for studying tumor progression under experimental conditions.
Further evaluation of the prognostic value of morphometric and flow cytometric parameters in breast‐cancer patients with long follow‐up
Authors: Uyterlinde Anne M. , Baak Jan P. A. , Schipper Nellie W. , Peterse Hans , Matze Erna , Meuer Chris J. L.
Published: February 2007

The added prognostic value of cellular DNA content compared with single and combined morphometric factors and classical parameters such as tumor size, nodal status, histologic grade and estrogen receptor (ER) content was investigated in 225 consecutive breast‐cancer patients with long follow‐up. Of all features investigated, the MPI (multivariate prognostic index) had the strongest prognostic value [Mantel‐Cox (MC) =48.2, p <0.00005]. The results further showed that neither age nor ER content had significant prognostic value, but the DNA index (DI) as a single parameter had (though weak) prognostic significance (MC =5.9, p =0.015); a similar result was obtained with the percentage of S‐phase cells (MC =6.1, p =0.013). The DI had (restricted) additional prognostic value to the morphometric features (MPI plus DI Mantel‐Cox 53.0, p <0.0001). The percentage of S‐phase cells had no additional prognostic value over the MPI. On the other hand, the additional value of the DI over tumor size and nodal status was much more impressive (MC =41.0 and 40.7), although it did not reach the prognostic significance of the MPI. Prediction of disease outcome with a linear combination of quantitative microscopical parameters of the primary tumor alone [MAI (mitotic activity index), DI and mean nuclear area] was very accurate, even without considering lymph‐node status (MC 30.8, p <0.0005). Grade had no additional value to the MPI at all (p =0.76). This could be especially important for lymph‐node‐negative patients in whom the prognostic value of the MPI and the MAI are confirmed.
Elevated frequency of a specific allele of the l‐MYC gene in male patients with bone and soft‐tissue sarcomas
Authors: Kato Mitsuo , Toguchida Junya , Honda Kazuo , Sasaki Masao S. , Ikenaga Mituo , Sugimoto Masayuki , Yamaguchi Toshikazu , Kotoura Yoshihiko , Yamamuro Takao , Ishizaki Kanji
Published: February 2007

Restriction fragment length polymorphisms (RFLPs) of 2 oncogenes, c‐Ha‐ras and L‐myc, have been analyzed in 101 patients with bone and soft‐tissue sarcoma and in 98 normal individuals. The c‐Ha‐ras gene was highly polymorphic both in sarcoma patients and in normal individuals. In contrast to our previous observation in breast cancer patients (Honda et al., 1988), no significant difference in allele frequencies between normal and sarcoma populations was observed. The L‐myc locus revealed 2‐allele polymorphism, allele L (10‐kb) and S (6.6‐kb), after digestion with Eco RI. The allele frequencies of L and S in sarcoma patients were 0.381 and 0.619, respectively, and those in normal individuals were 0.485 and 0.515, respectively. While the distributions of alleles in both populations fitted well with the Hardy‐Weinberg equilibrium, the frequency of the S allele was significantly higher in sarcoma patients than in normal individuals (p <0.05). When sarcoma patients were divided into male and female subpopulations, this difference was highly significant only in males (p <0.01) but not in females. Our results suggest that males carrying the S allele may be prone to develop sarcoma.
Isolation and characterization of a heterodimeric surface antigen on human melanoma cells and evidence that it is the 4f2 cell activation/proliferation molecule
Authors: Dixon Walter T. , Sikora Lydia K. J. , Demetrick Douglas J. , Martin Jerry L.
Published: February 2007

Murine monoclonal antibody (MAb) LS109 was one of a series of MAbs produced by hyperimmunization of mice with detergent extracts of pooled melanoma cell lines and metastatic melanoma patient tumors. ELISA screening of extracts of individual cultured melanoma cell lines and single patient tumors with MAb LS109 gave an interesting pattern of reactivity. The antibody was strongly positive with some of these extracts, yet negative or weakly positive with others. In addition, there was strong reactivity with a restricted set of normal necropsy tissues and certain non‐melanoma tumor extracts. Taken together, our data suggest that MAb LS109 recognizes a normal differentiation antigen which is perhaps aberrantly expressed or over‐produced during certain stages of melanoma tumor progression. The antigen recognized by LS109 is a heterodimeric surface glycoprotein molecule, consisting of an 89‐kDa “heavy” chain linked by disulfide bonds to an 83‐kDa “light” chain. Under non‐reducing SDS‐PAGE conditions, the intact dimer migrates with an M of approximately 140kDa. The 89‐kDa component appears to be heavily N‐glycosylated whereas the 38‐kDa component has little, if any, covalently attached carbohydrate. Our data show the biosynthesis, glycosylation and turnover of the LS109 antigen, as well as evidence of its surface localization. In addition, evidence is presented that the LS109 antigen is identical to the 4F2 cell activation/proliferation molecule previously described on a variety of normal and neoplastic cells.
Effect of the ebna‐2 gene on the surface antigen phenotype of transfected ebv‐negative B‐lymphoma lines
Authors: Åman Pierre , Rowe Martin , Kai Chieko , Finke JÜRgen , Rymo Lars , Klein Eva , Klein George
Published: February 2007

Two EBV‐negative B‐lymphoma cell lines with different phenotypes were transfected with the Epstein‐Barr virus EBNA‐2 gene. The effects on the expression of 8 B‐cell surface markers were analyzed by immunofluorescence methods. In one of the EBNA‐2 transfected cell lines, the expression of the CR2 receptor CD21 was induced and the expression of CD23 was enhanced. The results suggest that the EBNA‐2 gene is involved in the regulation of CD21 and CD23 in EBV‐carrying cells.
The effect of the E2 prostaglandin enprostil, and the somatostatin analogue sms 201 995, on the growth of a human gastric cell line, MKN45G
Authors: Watson Susan A. , Durrant Lindy G. , Morris David L.
Published: February 2007

The effect of enprostil and the somatostatin analogue SMS 201 995 on the growth of a clonal variant of the human gastric adenocarcinoma cell line, MKN45, was studied. The derived cell line grew twice as fast as MKN45 when grown as a xenograft line in nude mice. However, it did not respond trophically to gastrin either in vitro or in vivo (unlike MKN45) although it possessed the same number of gastrin receptors as the parental line. Gastrin production by the cell line during in vitro culture was twice that of MKN45; thus, the cell line was denoted MKN45G. When MKN45G was grown as xenografts in nude mice (n =10/group), enprostil (20 μg/kg/day) significantly inhibited tumour growth when administered continuously by an osmotic mini‐pump from day 1 to day 7 of a 20‐day experiment, and induced tumour regression when administered from day 7 to day 14. Enprostil reduced post‐prandial serum gastrin levels when administered from day 7 to day 14 and prevented gastrin release by MKN45 in vitro. SMS 201 995 at doses of 25 and 240 μg/kg/day induced tumour regression when administered from day 1 to day 7 and the former dose reduced post‐prandial serum gastrin levels at day 5. Gastrin release by MKN45G was not affected by SMS 201 995 in vitro, thus its effect may not be mediated directly via gastrin, requiring interaction between other hormones or growth factors in the in vivo situation.
Recurrent mutation of immunoglobulin and c‐myc genes and differential expression of cell surface antigens occur in variant cell lines derived from a burkitt lymphoma
Authors: Guy K. , Middleton P. G. , Bansal N. S. , Ross J. A. , Steel C. M.
Published: February 2007

The phenotypic and molecular genetic characteristics of 4 variant sublines of the Burkitt lymphoma cell line Namalwa have been examined. The sublines are DNA‐fingerprint‐identical and derived from a monoclonal tumour, as shown by a rearrangement of the T‐cell‐receptor β‐chain gene common to the 4 sublines. There is non‐co‐ordinate expression of MHC class‐1, MHC class‐II, surface immunoglobulin and a number of antigens recognized by CD MAbs on the different sublines. These different phenotypes of the cells are reminiscent of B cells arrested in varying states of cellular maturity. On Southern blots there are different patterns of restriction fragments hybridizing with Ig heavy‐ and light‐chain gene probes among the sublines, indicating that multiple rearrangements or mutations of 1g genes have occurred in the cells. Different patterns of hybridizing fragments among the sublines were also found by using c‐myc probes, implying the existence of different mutations of the c‐myc locus. The c‐myc mutation found in one of the sublines mapped to the 5′ flanking sequence and in another 3′ to the c‐myc locus. Using the J17BS8 probe, which detects a restriction fragment length polymorphism in the 3′ flanking region of the c‐myc gene, a 4‐fold variation in the gene copy number among the sublines was found and one of the sublines was shown to be hemizygous for c‐myc. Examination of DNA from early cultures of Namalwa cells showed that the alterations in Ig and c‐myc structure had occurred on prolonged culture of the cells.
EGF and TGF‐α, the ligands of hyperproduced EGFR in human esophageal carcinoma cells, act as autocrine growth factors
Authors: Yoshida Kazuhiro , Kyo Eikai , Tsuda Toshitaka , Tsujino Tetsuhiro , Ito Masanori , Niimoto Minoru , Tahara Elichi
Published: February 2007

In order to ascertain autocrine growth factors in esophageal carcinomas, we analysed expression of mRNAs and proteins for epidermal growth factor (EGF), transforming growth factor‐α (TGF‐α) and epidermal growth factor receptor (EGFR) in 6 esophageal carcinoma cell lines. Gene alterations were also examined. All of the esophageal carcinoma cell lines expressed mRNA for EGFR and TGF‐α genes. Interestingly, EGF mRNA of about 5.0 kb was also detected in TE‐1, TE‐2, and TE‐8 cells. Production of protein was also confirmed by binding assay and ELISA on 3 of the 6 cell lines. The cells had a relatively high number of EGFRs and produced TGF‐α and EGF protein at the same time. Furthermore, anti‐EGF (KEM‐10) and anti‐TGF‐α (WA‐3) monoclonal antibodies (MAbs) inhibited spontaneous uptake of tritiated thymidine (3H‐TdR) by TE‐1 cells which expressed EGF, TGF‐α and EGFR mRNA and protein. These results strongly suggest that EGF and/or TGF‐α produced by carcinoma cells function as autocrine growth factors for human esophageal carcinomas.
Oncofetal antigen in Xiphophorus detected by monoclonal antibodies directed against melanoma‐associated antigens
Authors: Claus Gert , Winkler Christoph , Lohmeyer JÜRgen , Anders Fritz , Schartl Manfred
Published: February 2007

Monoclonal antibodies (MAbs) directed against Xiphophorus melanoma cells were developed and tested by indirect immunofluorescence and immunoperoxidase staining for reactivity with a panel of 15 allogeneic tissues and 12 allogeneic cell lines. The reactivity of such MAbs was restricted to melanoma cells from tumor biopsies and melanoma‐derived cell lines. In addition, all embryonic cells of all histiotypes from developmental stages later than mid‐organogenesis and from corresponding short term in vitro cultures reacted with these MAbs. In contrast, normal tissues and organs from adult fish displayed no reactivity, thus implying that the melanomaassociated antigens detected by the MAbs described are oncofetal antigens.