bluuebunny/crossref_metadata_2025 huggingface dataset:
Monoclonal antibody to human T‐cell leukemia virus P19 defines polypeptide antigen in human choriocarcinoma cells and syncytiotrophoblasts of first‐trimester placentas
Authors: Suni Jukka , Närvänen Ale , Wahlström Torsten , Lehtovirta Pentti , Vaheri Antti
Published: February 2007

In previous studies we detected retrovirus RD114 p30‐related antigen in human placental syncytiotrophoblasts and antibodies in cord blood sera. We now report that a monoclonal IgG antibody specific for the p19 protein of human T‐cell leukemia virus (HTLV) reacts with human syncytiotrophoblastic antigen. When used in the immunoperoxidase tissue‐staining procedure, the monoclonal antibody reacted with the syncytiotrophoblastic cells in sections of all early placentas (<15 weeks of gestation), blighted ova and benign (hydatidiform mole) or malignant placental tumors (destructive mole, choriocarcinoma). In all cases the reactivity was mainly confined to the cytoplasm of the cells with syncytiotrophoblastic morphology. Normal embryonal or adult tissues tested were negative. In immunoblotting of cultured choriocarcinoma cells, anti‐HTLV p19 detected a single polypeptide at mol.wt 28,000 from proteins separated by electrophoresis.
The prognostic significance of two epithelial membrane antigens expressed by human mammary carcinomas
Authors: Wilkinson M. J. S. , Howell A. , Harris M. , Taylor‐Papadimitriou J. , Swindell R. , Sellwood R. A.
Published: February 2007

As many patients with mammary carcinoma are now treated by conservative forms of surgery, there is a need for prognostic information obtainable from the primary tumour alone. One possible source is the antigenic profile of tumour cells. Using an indirect immunoperoxidase technique, we stained histological sections of the primary tumour from 175 patients with each of two monoclonal antibodies (HMFG‐1, HMFG‐2), raised against milk fat globule membrane antigens known to be preserved in formalin‐fixed tissues. Sections were assessed by light microscopy as to both the overall distribution of antigen expressed and its site in tumour cells. The findings were related to relapse‐free survival by life‐table analysis. The median duration of follow‐up was 36 months. Two patterns of staining with antibody HMFG‐1 gave information of prognostic significance but staining with HMFG‐2 was without significance. Complete absence of staining with HMFG‐1 in 13 patients was associated with an extremely poor prognosis and 10 (77%) of these patients developed metastases within 18 months of follow‐up (p<0.001). Extracellular staining (ECS) in 22 patients, however, was associated with a favourable prognosis. As assessed by a semi‐quantitative method, only one patient (5%) demonstrating a high level of ECS developed metastases (p<0,004). These two patterns were analysed for a relationship to other prognostic indicators. Absence of staining was independent of histological grade, tumour size, axillary lymph node status and menopausal status. ECS was associated with low histological grade although this relationship was not absolute. In addition to their use in diagnosis, we conclude that monoclonal antibodies such as HMFG‐1 may be useful as prognostic indicators.
Increased incidence of mouse mammary tumor virus‐related antigen in tunisian patients with breast cancer
Authors: Levine P. H. , Mesa‐Tejada R. , Keydar I. , Tabbane F. , Spiefelman S. , Mourali N.
Published: February 2007

Biopsies obtained from 74 Tunisian women with breast cancer (33 cases), benign breast disease (17 cases), and cervical cancer (24 cases) were assayed for the presence of an antigen cross‐reacting with gp52 of the mouse mammary tumor virus (MMTV) in order to determine the frequency and possible prognostic significance of this antigen in a form of rapidly progressing breast cancer designated poussée évolutive or PEV. Antigen was detected in 23/33 breast carcinomas (70%) but in none of the 41 control specimens. An evaluation of reactivity according to tumor aggressiveness and survival could be performed in retrospect on 29 of the breast cancer patients with a follow‐up of up to 11 years. The frequency of gp52‐related antigen was similar in the patients with the most aggressive form of PEV with inflammatory signs (8/12 or 67% positive) and those breast cancer patients without PEV (12/17 or 71% positive). Within each of the two groups, PEV+and PEV O, no correlation was observed between the presence or absence of antigen and the disease‐free interval or survival. We conclude that the identification of gp52‐related antigens in the breast cancer biopsies from North African women has implications different from these observed in other populations. While thus far not indicative of disease aggressiveness and prognosis, the higher frequency of detectable antigen in comparison to biopsies obtained from patients born in the United States and Europe may have relevance to the etiology and pathogenesis of this disease.
Studies on chemical carcinogen enhancement of epstein‐barr virus induced transformation of human neonatal and adult peripheral blood lymphocytes
Authors: Henderson Earl E. , Fronko Gerald
Published: February 2007

The effects of a wide range of selected chemical carcinogens on the frequency of Epstein‐Barr virus (EBV)‐induced transformation have been investigated. The carcinogens tested included direct‐acting chemicals and chemicals requiring either activation via reactions with nucleophiles, or cell‐mediated enzyme activation. Treatment with some but not all chemicals suspected of being carcinogens resulted in enhanced EBV‐induced transformation of neonatal or adult peripheral blood lymphocytes (PBLs). The temporal relationship between carcinogen exposure and EBV infection could dramatically influence the results of the chemical carcinogen‐cellular interaction as measured by the cells' ability to subsequently undergo morphologic transformation. This relationship was particularly evident when cells were treated with alkylating agents such as dimethylsulfonate (DMS) or N‐methyl‐N′‐nitro‐N‐nitro‐soguanidine (MNNG). Beginning at 24h, and at later times following EBV‐infection, cellular transformation became more resistant to the cytotoxic effects of DMS and, in contrast, more sensitive to the cytotoxic effects of MNNG. These diametrically opposed results clearly demonstrate the ability of EBV infection to alter the response of lymphocytes to chemical carcinogens as measured by transformation. The lymphoblastoid cell lines (LCLs) established from carcinogen‐treated PBLs had increased cloning efficiency. Furthermore, using radiolabelled, molecularly cloned subgenomic fragments of EBV DNA and DNA‐DNA hybridization, we have been able to detect an increased number of EBV genome equivalents in whole‐cell and high‐molecular‐weight cellular DNA extracted from LCLs established from MNNG as well as DMS‐treated PBLs. We propose that carcinogen enhancement of EBV‐induced transformation is an example of a two‐step mechanism of oncogenic transformation in primary human lymphoid cells. The possible significance of these findings in relation to potential development of lymphomas following EBV exposure will be discussed.
Sensitivity of cultured human pancreatic carcinoma cells to dihydroxyanthracenedione
Authors: Fountzilas George , Gratzner Howard , Lim Lori O. , Yunis Adel A.
Published: February 2007

We tested the effectiveness of dihydroxyanthracenedione (DHAD) on cell growth of two human pancreatic carcinoma cell lines MlA PaCa‐2 and PANC‐1. At the level of ID50, the drug was almost equally effective against both cell lines. When the time exposure of MIA PaCa‐2 cells to the drug was increased from 1 h to continuous exposure for 5 days, the ID50 was decreased about three‐fold only (1.4 × 10−8 M and 4 × 10−9 M respectively). At the level of ID50 also the difference between 6 h exposure and continuous exposure for 5 days was minimal. In equimolar concentrations and with 1 h exposure, DHAD was more effective against MIA PaCa‐2 cells than other chemotherapeutic agents including adriamycin, mitomycin‐C, 5‐FU, vincristine, vindesine, vinblastine, VP‐16–213, bleomycin, cis‐platinum, asparaginase and acivicin. In concentrations of 5 × 10−7 M, DHAD caused about 40% inhibition of 14C‐thymidine incorporation of MIA PaCa‐2 cells. Treatment of MIA PaCa‐2 cells with the ID50 of DHAD for 1 h caused retardation of cellular traverse, with the major effect appearing to be in G2+M phase of the cycle. From these data DHAD appears to be a potent drug against human pancreatic carcinoma in vitro.
A scoring system for wilms' tumour: Pathological study of the second medical research council (MRC) trial
Authors: Marsden H. B. , Lawler W. , Carr T. , Kumar S.
Published: February 2007

The second MRC nephroblastoma trial was devised to determine whether more intensive chemotherapy in the early stages and multiple chemotherapy in the poorer prognosis groups would give improved results. As a separate study the pathological and clinical aspects were assessed to see whether information may be obtained concerning the behaviour of individual tumours of the 159 cases included, 142 were regarded as nephroblastoma. Significant features were the age of the patient, clinical stage at diagnosis, tubular status of the neoplasm and the presence or absence of anaplasia. A scoring system has been devised to take account of these factors.
Effects of indomethacin on the growth of cultured mammary tumors
Authors: Fulton Amy M.
Published: February 2007

We have studied the relative prostaglandin E (PGE)' synthesizing abilities of a number of mammary tumor liners cultured in vitro. These lines differ in a number of biologic characteristics including tumorigenicity, immunogenicity and metastatic potential. They also synthesize different levels of PGE and these levels are in the same relative order seen in sit The metastatic tumor lines 4526 and 410.4 synthesize more PGE than does the non‐metastatic tumor line 410. Syntheticactivity of all lines decreases with time in culture. Relative synthetic capacity is not correseen with the slowest wowing (68H) and fastest growing (4526) cell lines. lndomethacin is able to inhibit the synthesis of PGE in vitro in a dose‐dependent manner and the presence of indomethacin in of cell division.
Further characterization of marek's disease virus‐infected lymphocytes. I. In vivo infection
Authors: Calnek B. W. , Schat K. A. , Ross L. J. N. , Shek W. R. , Chen C‐L. H.
Published: February 2007

Previous reports from this laboratory identified bursa‐derived lymphocytes (B cells) and non‐B cells as the predominant cell types respectively involved in the early cytolytic and subsequent latent infection of chickens with Marek's disease virus (MDV). It was not known whether these differences were qualitative or quantitative or if the method for detection of latent infection (viral antigen production after 48 h of in vitro cultivation) was sensitive enough. To further define the cells involved in the various phases of MDV infection, we used monoclonal antibodies which specifically react with B cells, or T cells, or la‐antigen‐bearing cells. Dual fluorescence tests to detect surface markers and viral internal antigen (VIA) were conducted with infected spleen cell freshly collected from MDV‐infected chickens or after in vitro cultivation of those cells. The same antibodies were also used for a rosetting procedure to yield fractions enriched or depleted of T cells, B cells or la‐bearing cells. These were examined directly for viral DNA by in situ hybridization or dot blot DNA hybridization and for VIA cultivation. We learned that infected T cells also comprise part of the early cytolytic phase of MDV infection but constitute a minority population (approximately 2–3%) compared to B cells (83–92%) at 3 or 4 days post infection. Latently infected cells were definitively identified as mostly la‐bearing T cells, although a few (2–4%) were B cells. Prior to in vitro cultivation, latently infected cells apparently had insufficient viral DNA for detection by in situ hybridization, but the more sensitive dot blot procedure revealed viral DNA in fractions later found positive by VIA expression after in vitro cultivation. Viral DNA replication in latently infected cells apparently had occured after 48 h cultivation because in situ hybridization detected infected cells at that time. Treatment of cell cultures with iodo‐deoxyuridine, 12‐O‐tetradecanoyl phorbol‐13‐acetate or n‐butyrate failed to increase the number of spleen cells which expressed VIA.
Immuno‐selection In vivo of H‐2D phenotypic variants from a metastatic clone of sarcoma cells results in cell lines of altered metastatic competence
Authors: Katzav S. , Segal S. , Feldman M.
Published: February 2007

To find out whether manipulation of H‐2 expression on metastatic cells could alter their metastatic properties, we immunoselected in vivo H‐2 antigen variants from a metastatic clone of the T10 sarcoma [originating in a (C57BL/6 XC3H.eB)F1 mouse] and tested their metastatic capacity. The unselected metastatic cells (IE7) were previously found to express H‐2Db and H‐2Dk antigens, but they did not express the H‐2K antigens of either parental haplotype. Transplantation of IE7 cells into C57BL/6J irradiated mice resulted in loss of H‐2Dk expression and a reduction in H‐2Db antigen density. Further transplantation of these cells into non‐irradiated C57BL/6J mice led to a total loss of H‐2 expression. The cells concomitantly lost their metastatic potency. Immunoselection of IE7 cells in C3H.eB irradiated and non‐irradiated mice resulted in cells which were H‐2Dk‐positive but H‐2Db‐negative. Cells of these selected variants not only retained their metastatic potential, but in fact were far more metastatic than the unselected IE7 cells. Thus, changes in H‐2 expression on tumor cells may alter their metastatic potential. In the case of T10 cells, H‐2Dk expression seems to be directly involved in their metastatic capacitiy.
Preparation and properties of a mouse monoclonal antibody (W14A) to human chorionic gonadotropin
Authors: Searle F. , Partridge C. S. , Kardana A. , Green A. J. , Buckley R. G. , Begent R. H. J. , Rawlins G. A.
Published: February 2007

A mouse monoclonal antibody, W14A, has been prepared which reacts with intact human chorionic gonadotropin and its beta‐subunit, showing less than 2% cross‐reactivity towards the alpha‐subunit and 0.5% cross‐reactivity towards the beta‐subunit of luteinizing hormone. The reagent is suitable for the radioimmunolocalization of choriocarcinoma and trophoblastic teratoma in humans. A preliminary radioimmunoassay has been developed.
Age and cohort effects in primary liver cancer
Authors: Stevens Richard G. , Merkle Elle J. , Lustbader Edward D.
Published: February 2007

Primary liver cancer incidence data from 30 populations reported in Cancer Incidence in Five Continents were analyzed. After adjustment for time trends, log incidence increases linearly with log age. Liver cancer risk increases more rapidly with age than that of colon cancer, stomach cancer, or lung cancer in non‐smokers; it increases less rapidly than that of prostatic cancer or of lung cancer in smokers. Over the past 20 years, most populations have been found to have increasing age‐adjusted liver cancer incidence. There is no correlation between change in rates and magnitude of rates. Male rates are higher than female rates and the ratio of the two tends to be higher in high‐risk areas.
Triplication of one chromosome no. 15 with an altered C‐myc containing ecori fragment and elimination of the normal homologue in a T‐cell lymphoma line of akr origin (TIKAUT)
Authors: Wirschubsky Zvi , Wiener Francis , Spira Jack , Sümegi Janos , Klein George
Published: February 2007

An ouabain‐ and thioguanine‐resistant subline (TIKAUT) of spontaneous AKR lymphoma, TKA, was trisomic for chromosome 15 and contained a single 33 kb EcoRI fragment, containing the oncogene c‐myc. The original TKA lymphoma and derived in vitro line contained the same 33 kb fragment, as well as a normal 22 kb fragment. It has been concluded that the original 15‐trisomic TKA tumor has duplicated a 15‐chromosome that contained the changed fragment, while maintaining the normal fragment as well. Subsequently, in the derived TIKAUT line, the changed chromosome duplicated again, giving rise to three copies, and the normal homologue was eliminated altogether. This confirms our earlier somatic hybrid study showing that the duplicated 15‐chromosome of a T‐cell leukemia confers an advantage on the cell that favors tumorigenicity, whereas the normal homologue exerts a counteracting influence. Therefore, in the course of tumor progression, the changed chromosome tends to be amplified, whereas its normal homologue tends to be eliminated.
The inhibitory effects of horse anti‐rat AFP antiserum on the uptake of 2‐deoxy‐D‐glucose by AFP‐producing rat hepatoma cells
Authors: Ohkawa Kiyoshi , Tsukada Yutaka , Hibi Nozomu , Hirai Hidematsu
Published: February 2007

The inhibitory effect of horse antiserum against rat alpha‐fetoprotein (AFP) on the uptake of 2‐deoxy‐D‐glucose (2dG) by the AFP‐producing rat ascites hepatoma AH66 cells was studied. AH66 cells cultured in medium containing 20% heat‐inactivated antiserum had a 1.5‐fold lower rate of sugar uptake than did AH66 cells which were cultured in medium containing 20% heat inactivated normal horse serum. The inhibition of 2dG uptake by antiserum was dependent on both the concentration and the exposure time of antiserum. Preincubation of AH66 tumor cells for 2 and 6 h with antiserum prior to the measurement of 2dG uptake resulted in a 70.1% and 58.2% decrease in 2dG uptake compared to control cells. Antiserum did not inhibit the rate of phosphorylation of 2dG by tumor cells. Kinetic constants for the uptake of 2dG in both AH66 cells treated with antiserum to AFP and in control cells were calculated from Lineweaver‐Burk plots. The Km remained constant at approximately 1.2 mM, but the Vmax was twice as small for the cells treated with antiserum as for the control cells (571 vs 923 nanomoles/2 × 10s cells/min). These studies suggest that the inhibition of 2dG uptake by treatment with antiserum was the result of a decrease in the number of transport sites, or a decrease in the amount of carrier protein for the sugar which was present on the surface of the plasma membrane of the AH66 cells.
Glycoconjugates of murine tumor lines with different metastatic capacities. I. Differences in fucose utilization and in glycoprotein patterns
Authors: Schwartz Reinhard , Schirrmacher Volker , Mühlradt Peter F.
Published: February 2007

Since various experimental findings point towards an important role of cell surface carbohydrates ‐ in particular sialic acid ‐ in cancer metastasis, the rationale of this study was to look for possible differences in carbohydrate metabolism and glycoprotein expression in well‐defined related tumor lines of different metastatic capacity. The tumor lines analyzed were L5178Y E (=Eb), a low‐metastasizing, methylcholanthrene‐induced lymphoma of a DBA/2 mouse, and L5178Y ES(=ESb), a spontaneous high‐metastatic variant thereof. A non‐related, highly metastasizing tumor, MDAY‐D2, and ConA‐stimulated spleen cells were included in the study. These cell lines were compared for incorporation rates of various labelled carbohydrates and for glycoprotein patterns in SDS‐polyacry‐lamide gels. Marked differences were observed in the incorporation of 3H‐fucose, while the incorporation of 3H‐glactose and 3H‐mannose was similar inthe different cell lines studied. Only the metastatic variant ESb incorporated 3H‐fucose at a rate similar to that of ConA‐stimulated T‐cell blasts. Eb cells did not incorporate 3H‐fucose while MDAY‐D2 had a significantly lower 3H‐fucose incorporation rate. Separation and purification of the intracellular products of 3H‐fucose by gel filtration and high‐voltage electrophoresis revealed in Eb cells a block in the synthesis of fucosylated glycoproteins at the step of the fucose‐I‐P‐guanylyttransferase. No apparent defect in the fucose pathway was detectable in MDAY‐D2 cells. An Eb → ESb shifted cell line regained the ability to incorporate 3H‐fucose. All tumors displayed unique glycoprotein patterns in SDS‐PAGE. Labelling with 3H‐mannose revealed the most distinct bands, while labelling with 3H‐galactose gave fewer and broader bands. Although clonal instability of metastasizing tumor variants has been frequently reported, subclones of Eb and ESb showed characteristics similar to those of the original cell lines with regard to metastatic capacity, fucose metabolism and glycoprotein expression. These results will be discussed in relation to differences in fucose metabolism and in surface expression of fucose as observed in other tumor systems consisting of high‐ and low‐metastatic lines.
Characterization of the fbr‐murine osteosarcoma virus complex: FBR‐MuSV encodes a fos‐derived oncogene
Authors: Michiels L. , Maisin J. R. , Pedersen F. S. , Merregaert J.
Published: February 2007

The FBR murine osteosarcoma virus complex, isolated from a radiation‐induced osteosarcoma of an X/Gf mouse causes the rapid appearance of osteosarcomas in newborn mice and transforms fibroblasts in vitro. The two components of the FBR‐viral complex have been isolated separately in tissue culture: FBR‐MuLV by end‐point dilution and FBR‐MuSV by the establishment of mouse [FBR‐NP117 (NIH 3T3)] and rat non‐producer cell lines [FBR‐NP415 (REF)]. The host range and RNase TI fingerprint analysis of FBR‐MuLV demonstrated a pattern closely related to, but distinguishable from, Akv‐MuLV. Transformed cells from both mice and rats contain a rescuable FBR‐MuSV genome. These pseudotypes produce foci in tissue culture and induce osteosarcomas in susceptible mouse strains. An FBR‐MuSV (FBR‐MuLV) cDNA probe detects a 5.2 kb Hindlll and a 9.5 kb EcoRI FBR‐MuSV‐specific fragment in FBR‐MuSV‐transformed non‐producer rat cells. The same fragments hybridized with a fos specific probe, demonstrating that FBR‐provirus contains a c‐fos‐derived onc‐gene.
Evidence for a transforming growth factor(S) in the serum‐free conditioned medium of SV40‐transformed 3T3 fibroblasts
Authors: Pirozzi Suzanne , Young Delano V.
Published: February 2007

Unlike untransformed 3T3 fibroblasts, Simian Virus 40‐transformed 3T3 cells (SV3T3) do not require the presence of exogenous polypeptide mitogens in order to become competent for the initiation of DNA synthesis. As an explanation for this state of perpetual competence, growth activity for 3T3 cells was found in the serum‐free conditioned medium of SV3T3 cells. This activity, which is abolished by incubation with pepsin, but withstands to a fair degree denaturants (8 M urea and 4 M guanidinium HCI) and a reducing agent (65 mM dithioerythritol), enhances the growth of Swiss and BALB/c 3T3 cells in 1% (v/v) calf serum medium and ensures the complete survival of Swiss 3T3 cells for several days in the total absence of serum. The growth activity appears to be derived from the SV3T3 cells, since it is not found in the non‐conditioned medium (and the insulin and transferrin components of this serum‐free medium have only weak growth activity alone) and the chances of it being due to residual serum growth factors are slight because of the method of growing the cells and the collection of the conditioned medium. Moreover, in a separate experiment to test the possible involvement of cell attachment factors, rat fibronectin was found not to affect 3T3 growth in the standard growth assay. The conditioned medium growth activity apparently has the biological capabilities of transforming growth factors. After concentration by ammonium sulfate precipitation, it can stimulate DNA synthesis in confluent, quiescent Swiss 3T3 cells, in both the absence and presence of 10% depleted calf serum. It also permits the growth of large colonies of Swiss 3T3 cells in soft agar. As part of a preliminary characterization of the conditioned medium growth activity, gel filtration in 0.15 M NaCl, 0.001 M HCl resolves the activity into high (mol. wt. ≥ 100,000) and low (mol. wt. 5,000–6,000) molecular weight factors. Since re‐chromatography of the nigh molecular weight factor, which may still be in an aggregated form, does not generate the smaller, the latter is not a dissociation product of the former. The precise relationship of these SV3T3‐conditioned medium growth factors to other growth factors, including known transforming growth factors, has not yet been determined.
Hormone‐dependent enhancement of neoplastic phenotype expression by MuMTV‐infected heterologous cells, and MuMTV‐induced cellular antigens
Authors: Kryukova I. N. , Litvinov S. V.
Published: February 2007

A new property, i.e. acquisition of insulin (insulin + dexa‐methasone)‐mediated enhancement of anchorage independence by heterologous MuMTV‐infected cells, is described. Hormone‐mediated anchorage‐independent growth enhancement in MuMTV‐infected cells is followed by expression of a cell‐surface antigen, recognized by allogeneic (C3H→AKR) anti‐Thy 1.2 antigen serum. The absorption test and the use of monoclonal antibody to the Thy 1.2 antigen showed that hormone‐dependent antigen on the cell surfaces of experimentally and naturally MTV‐infected cells was different from the Thy 1.2 antigen itself. Utilization of anti‐p53 ( protein of transformation ) monoclonal antibody enabled us to identify this cell membrane antigen as p53.
Modifying influences of betel quid ingredients on B(a)P‐induced carcinogenesis in the buccal pouch of hamster
Authors: Rao A. Ramesha
Published: February 2007

The present study evaluates the incidence of tumors in hamster buccal pouches following short‐term (10 days) and long‐term (6 months) topical exposures to graded doses of benzo(a)pyrene, B(a)P (25 μg, 50 μg and 100 μg per pouch either daily for 10 days or thrice weekly for 6 months) alone or in combination with extract of tobacco (1 mg/pouch, twice daily), betel nut (1 mg/pouch, twice daily) or betel leaf (5 mg/pouch, twice daily). Given alone, the three doses of B(a)P respectively yielded, 6 months after the last treatment, 4%, 8.7% and 16.7% tumors in the short‐term study, and 20%, 35% and 61% tumors in the long‐term study. Short‐term treatments with individual ingredients of betel quid did not produce any tumors while long‐term treatments produced tumors only with tobacco (17.6%) and betel nut (10.5%). When B(a)P and betel quid ingredients were painted concomitantly for 10 days, there was, depending upon the dose of B(a)P, complete or partial suppression of tumor production. But when B(a)P‐plus‐tobacco or B(a)P‐plus‐betel nut treatments were given for 6 months, there was a considerable increase in tumor incidence. Betel leaf extract, in both short‐term and long‐term studies, expressed its inhibitory influence on B(a)P‐induced tumorigensis.
Plasminogen activators, activation inhibitors and alpha2‐macroglobulin produced by cultured normal and malignant human cells
Authors: Saksela Olli , Vaheri Antti , Schleuning Wolf‐Dieter , Mignatti Paolo , Barlati Sergio
Published: February 2007

In the present paper we have characterized the plasminogen activators (PA) synthesized by 25 different human cell lines. Technically easy methods were adopted for concentration and immunological characterization of the activators even in the presence of PA inhibitors. Most cell lines produced u‐PA (mol. wt 55,000), melanoma and HeLa cells t‐PA (mol. wt 66,000) and two carcinoma cell lines and normal skin fibroblasts produced no detectable PA. The classical 125I‐fibrin method was compared to a caseinolytic assay and some of the discrepancies between results obtained with the two methods were shown to be due to cell‐derived NaDodSO4‐sensitive proteinase inhibitors in culture media. Additionally, synthesis and uptake by the cells of the wide‐spectrum proteinase inhibitor alpha‐2‐macroglobulin (alpha2M) were studied by radioimmunoassay and immunofluorescence. No production of alpha2M could be measured in any of the malignant cell lines. In normal cells no correlation existed between the production of alpha2M and the observed inhibition of PA activity, which indicates that other proteinase inhibitors are produced by the cells.
Preparation and characterization of monoclonal antibodies against placental alkaline phosphatase and other human trophoblast‐associated determinants
Authors: Travers Paul , Bodmer Walter
Published: February 2007

We have prepared monoclonal antibodies by immunizing BALB/c mice with purified human term placental plasma membranes. The antibodies were selected to show predominant specificity for trophoblast and trophoblast derivatives. Four of these antibodies have been found to recognize the placenta‐specific isozyme of alkaline phosphatase (EC 3.1.3.1), and to cross‐react with the closely related testis form of this enzyme. One antibody recognized transferrin, a serum protein with an abundant placental receptor. The specificities of the other antibodies, whose target antigens are unknown, are described. Their reactivity with some human tumour‐derived epithelial cell lines suggests that they may provide useful markers of human trophectoderm differentiation, as well as for properties selected for during tumour progression.
The ability of normal mouse cells to reduce the malignant potential of transformed mouse bladder epithelial cells depends on their somatic origin
Authors: Cowell John K. , Franks L. M.
Published: February 2007

Somatic cell hybrids have been made between a transformed mouse bladder carcinoma cell line and normal mouse bladder epithelium and mesenchyme. In the epithelial tumour/mesenchyme hybrids the malignant phenotype was expressed dominantly whereas in the carcinoma/normal epithelium hybrids the malignant potential was greatly reduced. In both cases the dominant in vitro and in vivo phenotype was that of the normal parental cells. All hybrid tumours were first palpable after 4–7 days, demonstrating that the tumours had not arisen as a result of in vivo selection of a sub‐population of tumorigenic cells. Chromosome analysis showed that the carcinoma/normal epithelium hybrids were all in the hypertetraploid range but the large variation in the karyotypic profile of each hybrid made it impossible to implicate any specific chromosomes in the control of expression of the malignant phenotype. During normal development in bladder epithelium, terminal differentiation is associated with tetraploid formation by cell fusion. The reduction in malignancy of the carcinoma/normal epithelium hybrids may perhaps be due to the expression of genes associated with normal terminal differentiation after cell fusion and tetraploid formation. This is also supported by the more differentiated phenotype of the hybrid tumours. Of the 10 mesenchyme/epithelium hybrids analysed cytotogenetically, four were in the hypertetraploid range from which little meaningful data could be obtained about specific chromosome losses. Chromosome analysis of the cells from the near‐tetraploid hybrids showed only minor differences from what might have been expected from the input of the two parents; these differences appeared to be due to random chromosome loss. The maximum number of chromosomes lost from any of the hybrids was five, although one, two or three was more usual. The only consistent chromosome loss was of a single copy of chromosome 4, which in two of the hybrids represented the only chromosome change. The possibility that this loss might facilitate re‐expression of the malignant phenotype is discussed.
Influence of 12‐o‐tetradecanoylphorbol‐13‐acetate (TPA) on the susceptibility of K562 to natural cytotoxicity: Evidence for clonal variation in differentiation‐induced changes of lytic sensitivity
Authors: Kimber Ian , Moore Michael , Harrison Christine J.
Published: February 2007

The effect of 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) on the sensitivity to NK cell‐mediated lysis of two cloned populations of K562 which exhibit marked and stable differences in their susceptibility to natural cytotoxicity has been examined. Culture in medium supplemented with TPA concentrations of 1 ng/ml or more invariably caused a decrease in the susceptibility of the sensitive clone E10/P2, whereas treatment of the relatively resistant clone F9/P2 with TPA under identical conditions caused a significant increase in susceptibility to natural cytotoxicity. In both cases the change in susceptibility occurred within 1 day of culture in TPA and was rapidly reversible following removal of the inducing agent. The changes in resistance to natural cytotoxicity induced by TPA were independent of variations in osmotic fragility and were not attributable to alterations in NK cell binding capacity as determined by cold competition analysis. In contrast to the effect of TPA, exposure of E10/P2 and F9/P2 to interferon (IFN) caused a reduction in sensitivity to natural cytotoxicity of both populations which was associated with a decreased capacity to compete for lysis of labelled target cells. These data suggest that the effects of differentiating agents on target susceptibility to NK cell lysis are variable and that responses to TPA are clonally distributed within cell populations.
Prevalence of possible adult t‐cell leukemia virus‐carriers among volunteer blood donors in Japan: A nation‐wide study
Authors: Maeda Yoshiaki , Furukawa Michiyo , Takehara Yuhei , Yoshimura Keiji , Miyamoto Kanji , Matsuura Takao , Morishima Yasuo , Tajima Kazuo , Okochi Kazuo , Hinuma Yorio
Published: February 2007

A nation‐wide survey of carriers of adult T‐cell leukemia virus (ATLV) detected as anti‐ATLA (ATLV‐associated antigens) in volunteer blood donors was made in Japan. A total of 200 sera from donors between 40 and 64 years of age, collected in each of 64 blood centers located in eight districts, were tested for anti‐ATLA by an indirect immunofluorescence test. The highest rate (8%) of seropositive donors was found in Kyushu and lower rates of 0.3 to 1.2% in other districts. However, the positive rate varied considerably in different localities even within districts with a high or low seropositive incidence. Further studies of all the donors (16 to 64 years old) in eight centers in Kyushu demonstrated two facts: (1) that the frequency of seropositive donors increased with age, and (2) that four centers in this district showed distinctly high incidences of seropositive donors, while the other four centers showed low incidences. The seropositive rate among all donors was estimated to be about 3% in Kyushu and 0.08 to 0.3% in all other districts.
Immunohistochemical localization of Y hapten and the structurally related H type‐2 blood‐group antigen on large‐bowel tumours and normal adult tissues
Authors: Brown A. , Ellis I. O. , Embleton M. J. , Baldwin R. W. , Turner D. R. , Hardcastle J. D.
Published: February 2007

The monoclonal antibody C14/1/46/10 which defines the Y hapten carbohydrate antigen (Brown et a., 1983) was shown, by the indirect immunoperoxidase technique, to stain tissue sections of 96% of colo‐rectal adenocar‐cinomas and 100% of colo‐rectal adenomas. In contrast, a monoclonal antibody defining the related H type‐2 blood‐group antigen was found to stain 86% of adenocarcinomas and 32% of adenomas. In adenocarcinomas the percentage of cells stained for both antigens was, on average, greater in group O than in group A patients. In adenomas a focal pattern of expression was observed, for both Y hapten and H type‐2 antigen, that was characteristic of group A but not group O adenocarcinomas. In the normal mucosa of the distal colon, whilst H type‐2 antigen was absent, Y hapten was found in the immature cells of the crypt bases. A comparison of the cellular phenotypes present in adenocarcinomas, adenomas and normal mucosa of the distal colon supports the adenoma‐carcinoma sequence hypothesis for the genesis of colo‐rectal carcinomas. In normal adult tissues Y hapten was predominantly found on epithelial cells whilst nervous tissues, muscles and connective tissues were negative. The expression of Y hapten in several positive tissues was dependent upon secretor status. A comparison of the expression of Y hapten and H type 2 antigen on normal adult tissues revealed that all of the permutations of expression of these two structually related antigens were possible.
Preparation of four daunomycin‐monoclonal antibody 79IT/36 conjugates with anti‐tumour activity
Authors: Gallego J. , Price M. R. , Baldwin R. W.
Published: February 2007

As an approach to developing more specific anti‐tumour therapeutic agents, daunomycin has been covalently linked to the human tumour localizing, murine monoclonal antibody 79IT/36. Four procedures for coupling drug to antibody were investigated. The sugar amino group of daunomycin was modified by reaction with succinic anhydride or cis aconitic anhydride and these derivatives were linked to antibody, a carbodiimide reagent being used to produce stable peptide bonding. Alternatively, 14‐bromo daunomycin was linked directly to antibody or antibody containing free thiol groups introduced by means of the heterobifunctional reagent SPDP [N‐succinimidyl‐3 (2‐py‐ridyldithio) propionate] thus producing a thioether linkage. Each of the conjugates, with drug‐antibody ratios of 3 to 4:1, retained a proportion of drug activity although the succinic anhydride derivative was the least cytotoxic. The three other conjugates specifically bound to tumour cells expressing the 79IT/36 antibody defined antigen. In shorterm assays in which tumour cells were briefly exposed to conjugates and then washed to remove non‐bound conjugate, it was determined that the conjugate with the cis aconityl linkage displayed the greatest selective cytotoxicity against tumour cells reactive with the 79IT/36 antibody. These studies illustrate the feasibility of preparing chemically defined drug‐antibody conjugates retaining cytotoxicity and selectivity of action against tumour cells.
Abnormal properties of skin fibroblasts from patients with breast cancer
Authors: Azzarone B. , Mareel M. , Billard C. , Scemama P. , Chaponnier C. , Macieira‐Coelho A.
Published: February 2007

The growth properties of fibroblasts from the thoracic skin of patients with mammary cancers were compared to those of fibroblastic cultures from patients with benign lesions or having undergone surgery for non‐neoplastic diseases. As expected, an inverse correlation was found between the doubling potential of fibroblasts in vitro and the donor's age for cells from patients with benign lesions; however no correlation, was found with cultures from cancer patients. Moreover, the latter group responded in an abnormal way to three biological parameters: anchorage dependence, colony formation on monolayers of normal human epithelial cells and saturation densities in overcrowded culture conditions. Skin fibroblasts from one patient with a benign lesion, whose mother had developed a breast cancer, displayed all the abnormal growth properties. Periodic controls of this patient resulted in the early detection of a carcinoma 3 years after the first operation for a benign microcystic lesion. Finally, we found that multiple subcultivations in overcrowded culture conditions cause the selection of a fibroblastic cell subset with greater growth potential which, in the cell strain tested, could invade foreigh tissus in vitro.
Selective effects of insulin and hydrocortisone on colony formation and chemosensitivity of human tumors in soft agar
Authors: Kern David H. , Chien Fu‐Wen , Morton Donald L.
Published: February 2007

Because low plating efficiencies of most human cancers severely limit the number of successful chemosensitivity tests that can be performed, we studied the growth‐enhancing effects of insulin and hydrocortisone on a variety of solid tumors. Colony formation in soft agar was significantly increased in 23/49 (47%) tumors treated with 3 U/ml insulin, whereas fewer colonies were observed in 7 (14%). These effects were highly selective for tumor type. Colony growth for ovarian, lung, and colon carcinomas increased by 123%, 37% and 28%, respectively. In contrast, insulin inhibited the growth of melanoma, kidney, and breast tumors. Hydrocortisone at 0.05 μg/ml increased colony numbers in 23/45 (51%) tumors, while in 7 (16%) colony numbers were decreased. Growth of ovarian, lung, breast, and kidney carcinomas was increased by 136%, 126%, 78% and 69%, respectively, whereas melanomas, sarcomas, and colon tumors were inhibited by hydrocortisone. In vitro chemosensitivities were relatively unchanged by the hormones. In 168 (134 paired) drug/tumor tests, sensitivity to standard antineoplastic drugs in the presence or absence of hormones was concordant 82% of the time (correlation coefficient, 0.71). However, in 20 tests (15%), significant enhancement of chemosensitivity was observed. We concluded that cloning efficiencies of many common human tumor types can be improved with hormones, and that these growth‐enhancing effects are selective for tumor type.
Inhibition of tumour‐induced angiogenesis by systemically administered protamine sulphate
Authors: Majewski Slsawomir , Kamińki Marek J. , Szmurlo Andrzej , Kamińska Grazyna , Malejczyk Jacek
Published: February 2007

Systemic administration of protamine sulphate significantly decreased the intensity of angiogenesis induced in X‐ray immunosuppressed (BALB/c × DBA/2W) F1 mice by either HEp‐2 (human larynx carcinoma) cells or semisyngeneic splenocytes injected intradermally. In vitro experiments have shown that protamine sulphate markedly decreases the proliferation of human endothelial cells as assessed by 3H‐TdR incorporation assay. In contrast, the proliferation of HEp‐2 cells was not affected, and only slight inhibition of normal human fibroblasts could be demonstrated. Heparin abolished the inhibitory effect of protamine sulphate, both in vivo and in vitro. These results suggest that the observed inhibitory effect of protamine sulphate on angiogenesis in vivo may be at least partially due to the interaction of this compound with endothelial cells.
A rat yolk‐sac antigen defined by monoclonal antibodies
Authors: van Hove L. , Sobis H. , Lu Y. L. , Vandeputte M.
Published: February 2007

The distribution of a rat yolk‐sac antigen (Rat YSA‐1) as defined by a monoclonal antibody raised against rat yolksac carcinoma cells is described. The antigen is present on rat yolk‐sac carcinomas, on visceral yolk‐sac endoderm and on embryonal endoderm of 9‐day‐old embryos. It is not present on a variety of rat tumors other than yolk‐sac carcinomas and not detectable on pre‐implantation embryos, inner cell mass and fetal endoderm. Rat YSA‐1 differs from alpha‐fetoprotein and Forssman antigen and is species‐specific. In adult rats the only cells displaying this antigen are the spermatozoa and certain cells of the spermatogenic lineage.
Analysis of a human osteogenic sarcoma antigen and its expression on various human tumour cell lines
Authors: Campbell D. G. , Price M. R. , Baldwin R. W.
Published: February 2007

The murine monoclonal antibody 79IT/36 cross‐reacts with cells other than the immunizing osteogenic sarcoma cell line 79IT, upon which the 79IT/36‐defined epitope is expressed on a protein of apparent molecular weight 72,000. An investigation was performed to determine whether the epitope occurred on similar molecules on other cell lines. Radiolabelled immunoprecipitates, prepared with the 79IT/36 antibody, from three osteogenic sarcoma cell lines (2 OS, 788T and 278T), the prostate carcinoma EB33 and the colon carcinoma HcLo each contained a protein with a molecular weight of 72,000 as the major constituent, together with, in some cases, material of lower molecular weight. This heterogeneity was shown by neuraminidase treatment of the immune precipitates to be due to variations in sialic acid content of the antigens since, in five of the six cell lines tested, such treatment produced homogeneous material of apparent molecular weight 55,000. Chymotrypsin treatment of the immune precipitates produced in each instance a major polyypeptide of molecular weight 47,000 which displayed no microheterogeneity. Immunoadsorbent‐purified antigen from 79IT cells was shown to bind strongly to Sepharose‐wheat‐germ agglutinin and less to Sepharose‐concanavalin A, confirming the glycoprotein nature of this antigen. These studies demonstrate that molecules expressing the 79IT/36‐defined epitopes on different tumour cell lines are glycoproteins which display heterogeneity with respect to apparent molecular weight that is attributable to varying degrees of sialylation. No apparent differences were detected in the polypeptide “backbone” of these antigenic molecules.
The isolation and characterization of colorectal epithelial cell lines at different stages in malignant transformation from familial polyposis coli patients
Authors: Paraskeva Christos , Buckle Brenda G. , Sheer Denise , Wigley Caroline B.
Published: February 2007

The genetic disease familial polyposis coli (hereditary adenomatosis of the colon and rectum) provides an excellent model for the study of tumour progression in the large bowel. We have isolated and characterized four epithelial cell lines from colorectal tumours from polyposis coli patients. These cell lines are grown on collagen‐coated Petri dishes in the presence of mouse 3T3 feeder cells in medium containing 20% foetal bovine serum. Of these cell lines three were isolated from premalignant adenomas and one from an adenocarcinoma. All four lines have a characteristic cuboidal epithelial morphology, and their epithelial origin was confirmed by positive staining with a monoclonal antibody which reacts specifically with the keratin filaments of simple epithelia. The adenoma‐derived lines display ultrastructural features characteristic of colonic epithelium including desmosomes, microvilli and mucin droplets. One of the adenoma‐derived cell lines, designated PC/AA, has retained differentiated functions in culture, namely mucin production, after 21 in vitro passages. PC/AA has a karyotype of 46, XY with no detectable chromosome rearrangements. The adenoma‐derived lines could be passaged from clumps of cells but not from single cells even in the presence of 3T3 feeder cells. The carcinoma‐derived line, designated PC/JW, could however grow from single cells in the presence of a feeder layer. The one premalignant adenoma‐derived line tested so far, PC/AA, did not produce tumours in athymic nude mice. In contrast, the carcinoma‐derived line, PC/JW was tumorigenic in athymic nude mice. PC/JW produced moderately welldifferentiated tumours which were histologically similar to the adenocarcinoma from which the cell line was isolated. PC/JW has a near‐diploid chromosome number with an isochromosome (I q), an isochromosome (14q) and an (Xp; 17q) translocation. Unidentified marker chromosomes were present in a few cells. The features at present which distinguish the carcinoma‐derived line from the adenomaderived lines are tumorigenicity, growth from single cells and chromosomal abnormalities. The isolation and characterization of differentiating human epithelial cell lines at different stages in malignant transformation provide an opportunity to examine the cellular and molecular mechanisms controlling tumour progression in the large intestine, and to obtain an insight into the multistep process of human epithelial carcinogenesis.