bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential immunoreactivity and ca2+ ‐dependent degradation of vimentin in human fibroblasts and fibrosarcoma cells
Authors: Virtanen Ismo , Närvänen Outi , Lehto Veli‐Pekka
Published: February 2007

Immunostaining of normal human fibroblasts with a monoclonal antibody (MAb) (V22AC 12) revealed typical cytoplasmic arrays of vimentin filaments in both mitotic and interphase cells. In human A8387 fibrosarcoma cells and SV40‐virus‐transformed human fibroblasts, the same antibody showed positivity only in mitotic cells and in interphase cells only after treatment of the fixed cells with alkaline phosphatase. Upon immunoblotting with the MAb, an Mr 57,000 vimentin polypeptide was seen in normal fibroblasts. In fibrosarcoma cells the same polypeptide was revealed by this antibody only after treatment with alkaline phosphatase. The Mr 57,000 vimentin polypeptide was a major cytoskeletal protein in both fibroblasts and fibrosarcoma cells. Inclusion of Ca2+ into the cytoskeleton extraction medium brought about a somewhat increased degradation of vimentin in fibroblasts. In fibrosarcoma cells, such treatment caused a quantitative disappearance of the Mr 57,000 protein with a concomitant appearance of 3 distinct, low‐molecular‐weight degradation products in the detergent‐soluble fraction. Another Ca2+‐induced change in the polypeptide profile of fibrosarcoma cells was the disappearance of the Mr 240,000 non‐erythroid α‐spectrin and the concomitant appearance of a prominent Mr 140,000 degradation product. Inclusion of proteolysis inhibitors in the Ca2+‐supplemented extraction medium inhibited degradation of both vimentin and α‐spectrin polypeptides. The results suggest differences in the composition of the cytoskeletons of normal fibroblasts and fibrosarcoma cells, manifested in the differential Ca2+‐susceptibility of vimentin and non‐erythroid α‐spectrin. Results with MAb V22AC12 suggest that differential phosphorylation of vimentin could account for at least part of this difference.
Skin papillomas and other neoplasms induced by murine sarcoma viruses in mid‐gestation‐infected mice
Authors: Rossi Lorenzo , Barbieri Ottavia , Capurro Gloria , Aiello Cinzia , Ruzzon Tiziana , Muratore Olimpio
Published: February 2007

During extensive investigations on the effects of oncogenic retroviruses in developing rodents, the ability of MSV to mount a neoplastic response in CD‐I Swiss mouse embryos was determined. By infecting the animals directly in utero at selected stages of post‐implantation development, we detected a peculiar reaction of the embryonal tissues to certain MSVs: when mice were exposed to KiMSV at mid‐gestation, the newborn developed characteristic tumors, in addition to mesenchymal cell sarcomas, not induced in fetuses and neonates. These included pulmonary alveologenic tumors and skin papillomas and were seen in mice infected on days 8 and 10 of pregnancy, roughly corresponding to 15 and 35 somites, respectively. To determine the specificity of these events, other 8‐ and 10day‐old embryos were infected with retroviruses of the same or different families. HaMSV and MoMSV also induced mesenchymomas and a low incidence of skin papillomas (10% and 15% compared to 40% in the KiMSV group) but not pulmonary tumors. In contrast, FBRMSV was inactive in this respect and only osteogenlc sarcomas were detected in the offspring. Infecting the embryos on day 7 of pregnancy produced no tumors. Later infections (in 15‐day‐old fetuses and neonates) mainly induced mesenchymal sarcomas. No congenital malformations were detected in the embryos exposed to MSV during organogenesis, although some abortions and resorptions were seen.
Phorbol‐ester‐induced stable changes in the regulation of DNA synthesis and intracellular pH are accompanied by altered expression of protein kinase C in the monoblastoid cell line U‐937
Authors: Forsbeck Klas , Nilsson Kenneth , Nygren Peter , Larsson Rolf , Gylfe Erik , Skoglund Göran , Ingelman‐Sundberg Magnus
Published: February 2007

12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐induced changes in cytoplasmic PH, cytoplasmic Ca2+‐concentration, rate of DNA synthesis, and concentration and activity of protein kinase C (PKC) were studied in human monoblastoid cell lines. The cell line U‐937 GTB was compared to the subline U937 RES (adapted to growth in the presence of 10−9M TPA) and another subline U‐937 RESREV (U‐937 RES grown in TPA‐free medium) established in order to analyze the stability of the TPA‐induced differences. TPA induced half maximal inhibition of DNA synthesis in the wild‐type U‐937 GTB cell line at 10−9M, whereas 10 times higher concentrations of phorbol ester were needed for a corresponding inhibition of the U‐937 RES and U‐937 RESREV lines. Furthermore, the U‐937 RES cells exhibited a decreased sensitivity to TPA, and the U‐937 RESREV cells did not respond at all to this agent with regard to cytoplasmic alkalinization by an intracellular mechanism independent of Na+/H+ exchange. A Na+‐dependent system for extrusion of protons, which was activated by the Ca2+ ionophore ionomycin, was also severely depressed as a result of TPA‐adaptation. The concentration of PKC, measured by immunoblotting, was reduced by 34 and 24% in U‐937 RES and U‐937 RESREV cells, respectively, as compared to the wild‐type U‐937 GTB line. The corresponding reductions in PKC activity were 32 and 54% when histone III‐S was used as substrate. The data suggest that adaptation to growth in the presence of TPA results in stable modifications of several parameters, which are assumed to be involved in the regulation of proliferation and differentiation. Furthermore, the data from the U‐937 RESREV cells question a causal relationship between cytoplasmic alkalinization and control of proliferation.
Effects of the thiazolidinedione derivative CGP 19984 on growth and endocrine function of the Mtt‐W10 transplantable mammosmatotoropic pituitary tumor in female rats
Authors: Sylvester Paul W. , Utz Paul J. , Ip Margot M.
Published: February 2007

The thiazolidinedione derivative CGP 19984 has previously been shown to suppress the growth of hormone‐dependent mammary and prostatic tumors, primarily by reducing gonadotropin and subsequently gonadal steroid secretion. The present study examines the effects of CGP 19984 on the growth and hormone secretion of the autonomous, but estrogen‐responsive, MtT‐W10 mammosomatotropic transplantable rat pituitary tumor. Intact tumor‐bearing Wistar/Furth female rats were administered vehicle or 25, 100, or 250 mg/ kg CGP 19984 p. o. 5 × week for 4 weeks. CGP 19984 was found to significantly reduce MtT‐W 10 tumor growth and weight and reduce prolactin and growth hormone (GH) secretion in a dose‐responsive manner. A similar study in ovariectomized rats also showed that CGP 19984 treatment suppressed MtT‐W 10 pituitary tumor growth, weight and hormone secretion in a dose‐responsive manner, suggesting a direct inhibitory action of this drug on the tumor. In a third study, bromocryptine (CB‐154; 5 mg/kg) and CGP 19984 (50 mg/kg) were both found to be effective in suppressing growth of the MtT‐W 10 tumor in intact female rats. However, rats treated with CGP 19984 alone had reduced serum and tumor GH and prolactin concentrations, while rats treated with CB‐ 154 alone had reduced serum and tumor prolactin, but no change in GH concentrations. These results suggest that CGP 19984 effectively inhibits growth and hormone secretion of the autonomous MtT‐W 10 pituitary tumor by apparently suppressing both somatotropic and lactotropic cell populations within the tumor. Furthermore, these findings indicate that CGP 19984 may be an effective alternative to CB‐154 in the clinical treatment of prolactin‐producing adenomas, as well as other types of pituitary adenomas.
Effects of sodium cyclamate and sodium saccharin on focus induction in explant cultures of rat bladder
Authors: Nicholson Linda J. , Jani Harsha
Published: February 2007

The tumour‐promoting activities of sodium cyclamate and sodium saccharin were investigated in an assay based on the induction of epithelial foci exhibiting enhanced growth potential in a rat bladder explant culture system. An initiating, nonfocus‐inducing dose was defined for the carcinogen N‐methyl‐N‐nitrosourea (MNU) to make promotion studies possible, Saccharin induced epithelial foci when added to cultures pretreated with an initiating dose of MNU, and also increased the incidence of foci in cultures treated with transforming doses of MNU. Cyclamate was found to induce a high incidence of foci when added to cultures by itself. When MNU and cyclamate treatments were combined, an additive effect could be detected. These results indicate that both cyclamate and saccharin can contribute to epithelial transformation in this system.
Association of adriamycin‐induced resistance to NK‐mediated lysis with sialic acid level and immunological reactivity of transferrin receptors and glycophorin A
Authors: Benoist Hervé , Madoulet Claudie , Trentesaux Chantal , Carpentier Yves , Joly Philippe , Jardillier Jean Claude , Desplaces Andrée
Published: February 2007

Adriamycin (ADM) can increase sialic acid content in K 562 cells and reduce their susceptibility to NK‐mediated lysis. In this report, hypothetical relationship between this resistance and augmentation in sialylation has been investigated. Variations in the time of exposure to ADM showed that 12 hours were sufficient to cause maximal recruitment of benzidinepositive cells, growth inhibition and resistance to NK‐mediated lysis. On the contrary, the membrane sialic acid density seemed stable and 24 hours of drug exposure were necessary to observe a clear rise in sialic acid. Neuraminidase treatment of control and ADM‐treated K 562 cells was associated with an obvious enhancement in their susceptibility to NK‐mediated lysis which can be explained by an increase in the target‐effector binding ability as assessed by a direct conjugate‐forming cell assay. However, the neuraminidase treatment did not modify the sensitivity difference to lysis between untreated and ADM‐treated cells. As compared to control the reactivity of ADM‐treated cells was higher with an antiglycophorin A (GPA) MAb and lower with an antitransferrin receptor (TFR) MAb. Kinetic studies suggested that GPA expression is a better index of ADM‐induced resistance to NK‐mediated lysis than TFR expression. In addition, neuraminidase treatment showed that TFR and GPA modulations induced by ADM can be correlated with sialylation alterations.
The Danish case‐control study of cutaneous malignant melanoma. II. Importance of UV‐light exposure
Authors: Østerlind A. , Tucker M. A. , Stone B. J. , Jensen O. M.
Published: February 2007

A population‐based case‐control study of 474 patients with cutaneous malignant melanoma and 926 population controls, conducted in East Denmark over a 3‐year period, included an evaluation of the relationship of UV‐light exposure to cutaneous melanoma risk. Patients with lentigo maligna melanoma were not included. Significantly increased risk was associated with severe sunburn before age 15 (RR = 2. 7 for 5 + vs. never), sunbathing (RR = 1. 6), boating (RR = 1. 4) and vacations spent in the sun (RR = 1. 4 for very sunny vs. never). A significant decrease in risk was associated with occupational exposure during the summer in males (RR = 0. 7), and no association with cutaneous microtopography was seen. These findings were independent of the effects of constitutional risk factors (naevi, freckles and light hair colour). No association was found between the risk of cutaneous melanoma and exposure to artificial UV‐light (fluorescent light, sun lamps, or sun beds). No significant difference was found between superficial spreading melanoma and nodular melanoma with regard to any of the sun exposure variables. Our data indicate that exposure to intermittent intense sunlight is an important risk factor for cutaneous malignant melanoma, while long‐term continuous exposure does not appear to be a risk factor for cutaneous malignant melanoma, while long‐term continuous exposure does not appear to be a risk factor.
Cancer registration in the European Community
Authors: Coleman Michel P. , Démaret Eva
Published: February 2007

A survey of population‐based cancer registries in the European Community (EC) is reported: 82 (92%) of 89 registries replied. In 3 of the 12 EC countries (Denmark, Netherlands, UK), general cancer registration applies to the entire population; national registration for childhood neoplasms also applies in 3 countries (FRG, Ireland, UK). About 350,000 new cancers were recorded each year during 1982–1985 in the 32% of the EC population which is covered by general registration. It is estimated that during this period about 988,000 new cancers (excluding non‐melanoma skin cancer) occurred each year in the 10 EC countries for which incidence data are available. Most registries report 90–95% completeness of cancer registration, but there is evidence of imprecision in these estimates. Risk factors for cancer are recorded in 43 registries, in particular occupation (38), but recording of occupation is often incomplete. The use of international or compatible systems of coding occupation would facilitate screening of cancer registration data for occupational hazards in the European Community. The quality of cancer information in the Community would be greatly improved by the systematic and widespread use of simple methods to estimate completeness of registration and by allowing registries confidential access to death certificates.
Epidemiology of Kaposi's sarcoma in Sweden prior to the acquired immunodeficiency syndrome
Authors: Dictor Michael , Attwell Robyn
Published: February 2007

We studied retrospectively 529 cases of Kaposi's sarcoma (KS) reported to the Swedish Cancer Registry between 1958 and 1982 to determine incidence rates, survival and rate ratios, together with the frequency and types of associated malignancies. The age‐standardized (Swedish population 1970) incidence rate generally increased over the time period, with a mean of 0.27 cases per 100,000 population per year (males 0.40, females 0.14). The incidence rate ratio (based on 5‐year intervals and relative to the earliest period) reached 2.06 for males and 3.76 for females in the 1968–1972 interval, while the actual peak occurred between 1971 and 1974 for both sexes. Poisson regression modelling suggested a transient shift in the age‐specific male incidence rate pattern with a relative increase of the disease in younger age groups (p = 0.05) up to 1968–1972. The age‐adjusted male: female ratio did not change significantly from 2.9 during the period of study. In relation to the general population, 18% fewer men and 24% fewer women were alive 10 years after the diagnosis had been made. Ninety‐nine (19%) cases had other primaries, of which 17 were neoplasms of lymphocytic origin. Lymphoproliferative malignancy was 2.5 times (95% CI 1.38, 4.37) more common than expected in patients with KS (in particular in females) but a definite increase in other malignancies was not apparent. It is questionable whether immune dysfunction due to other malignant disease or drug therapy can account for the epidemiologic changes in KS, which began almost 2 decades prior to the AIDS epidemic in Sweden.
T‐cell‐mediated inhibition of EBV‐induced B‐cell transformation: Recognition of virus particles
Authors: Bejarano Maria Teresa , Masucci Maria Grazia , Klein George , Klein Eva
Published: February 2007

In order to analyze the components of EBV‐specific immunological memory that contribute to the T‐cell‐mediated inhibition of EBV‐induced B‐cell transformation, we have investigated the growth inhibitory potential of T cells cultured for 3 days with B cells exposed to transforming and nontransforming EBV preparations. T cells cultured for 3 days with EBV‐infected autologous B cells inhibited the transformation of newly infected B lymphocytes. T cells cultured with the virus, with autologous uninfected B cells, or in the presence of 10, ughl Con‐A had a significantly weaker inhibitory capacity. The inhibitory capacity was induced by co‐cultivation with B cells infected with the transforming 895–8 virus strain, with the non‐transforming P3HRI virus strain, and also with UV‐inactivated B95‐8 virus. B‐cells infected with transforming B95‐8 virus induced the strongest growth inhibitory activity. Activation of the T cells was shown by their IL‐2 production, proliferation, and generation of non‐specific cytotoxicity. These results suggest that the initial event of the cell response in EBV‐infected cultures is induced by antigens associated with the viral particles presented by B lymphocytes.
Gastric cancer after gastrectomy
Authors: Arnthorsson Gauti , Tulinius Hrafn , Egilsson Valgardur , Sigvaldason Helgi , Magnusson Bjarki , Thorarinsson Hjalti
Published: February 2007

Inhabitants of Iceland who had undergone gastric resection for non‐malignant diseases between 1930 and 1974 were identified and followed up at the Icelandic Cancer Registry in order to evaluate the risk of gastric cancer subsequent to gastric resection. There were 1,214 males and 581 females, contributing 30,792 person/years. The results show an overall 1.16‐fold, not significant, increase in the relative risk for gastric cancer. In the first 15 years after operation the risk was decreased, 0.49, 95% confidence interval (CI) 0.24–0.90, but from 15 years or more following operation, the risk was 2.17, 95% CI 1.46–3.10. We conclude that for these subjects the risk is not significantly increased. Patients surviving 15 years or more after operation have an increased risk (p < 0.001), but they do not contribute substantially to the number of gastric cancer patients in Iceland.
Localization of radiolabelled F(ab′)2 fragments of monoclonal antibodies in nude mice bearing intraperitoneally growing human ovarian cancer xenografts
Authors: Moseley Karan R. , Battaile Anne , Knapp Robert C. , Haisma Hidde J.
Published: February 2007

The biodistribution and pharmacokinetics of 2 monoclonal antibodies (MAbs) specific for ovarian carcinoma, OC125 and OV‐TL3, were studied in nude mice bearing intraperitoneally (i. p.) growing human ovarian carcinoma xenografts of NIH:OVCAR‐3. The ovarian carcinoma xenografts grew as non‐adherent cells in ascites and as solid implants in the peritoneal cavity of injected mice. The biodistribution and pharmacokinetics were determined by measurement of radioactivity in tumor masses, ascites, blood and other tissues after intravenous (i. v.) and i. p. injection of radioiodinated F(ab′)2 fragments of MAbs. The specificity of the observed tumor localization was then evaluated by comparing the uptake of the anti‐ovarian carcinoma antibodies OCI25 and OV‐TL3 with the uptake of a radioiodinated non‐ovarian carcinomaspecific MAb A2C6. The results of the study indicate that uptake of the anti‐ovarian carcinoma antibodies was highest in the non‐adherent tumor cells in the ascites after i. p. injection. The observed uptake was 85% Injected dose/g for OV‐TL3 and 22% injected dose/g for OCI25. This compares to the observed antibody uptake of 9% injected dose/g for OV‐TL3 and less than I% injected dose/g for OCI25 in solid tumor masses after i. p. injection. After i. v. injection, uptake of OCI25 and OV‐TL3 was less than 3% injected dose/g, both for nonadherent tumor cells and for solid tumor masses. The data support the conclusion that OV‐TL3 is superior to OC125 and that i. p. administration of radiolabelled MAb F(ab′)2 fragments is superior to their i. v. administration for immunotherapy of ovarian carcinoma.
Differential patterns of anti‐tumour drug responses and mechanisms of resistance in a series of independently‐derived VP‐16‐resistant human tumour cell lines
Authors: Lock Richard B. , Hill Bridget T.
Published: February 2007

Resistance to etoposide, which was expressed following exposure of a human tumour cell line (HN‐1) to fractionated X‐irradiation (II fractions to a total dose of 50Gy), was found to be exhibited after delivery of only 5 fractions (total dose of 22.5Gy). In addition, 2 new etoposide‐resistant sublines of these HN‐I cells have been developed by continuous exposure in vitro to sublethal drug concentrations. No significant differences in growth characteristics were shown between all these resistant sublines and the parental line. The drug‐treated line, HN‐1 VP‐2, expressed cross resistance to vincristine, adriamycin and daunomycin, and marginal cross resistance to vinblastine and cisplatin. The X‐irradiation‐treated subline (HN‐I/DXR‐II) also proved cross‐resistant to vincristine and marginally cross‐resistant to vinblastine, but showed unaltered responses to adriamycin and daunomycin, and expressed marginal collateral sensitivity to cisplatin. Comparisons of druguptake characteristics showed that only the HN‐1/VP2 cells and not the HN‐1/DXR‐II cells had reduced uptake of vincristine, vinblastine and daunomycin. However, etoposide uptake was not altered in either resistant subline. Further investigations have shown that the approximately 4‐fold level of resistance to etoposide in these HN‐1/VP‐2 and HN‐I/DXR‐II cells was associated with a reduction in etoposide‐induced DNA single‐strand breakage. However, repair of these lesions, after drug removal, was rapid and similar in the parental and drugresistant sublines, with 50% having resealed within 20–26 min. Resistance to etoposide was also associated with significantly elevated p < 0.01) glutathione peroxidase activity in both sublines, whilst glutathione S‐transferase activity was marginally elevated (117%) only in the HN‐I/DXR‐II cells. There were no significant alterations in total glutathione levels. These results suggest that not only do patterns of response to anti‐tumour drugs differ depending upon the agent employed to “induce” resistance, but that multiple mechanisms appear to be associated with these altered responses.
Monoclonal antibody JSB‐1 detects a highly conserved epitope on the P‐glycoprotein associated with multi‐drug‐resistance
Authors: Scheper R. J. , Bulte J. W. M. , Brakkee J. G. P. , Quak J. J. , van der Schoot E. , Balm A. J. M. , Melier C. J. L. M. , Broxteman H. J. , Kuiper C. M. , Lankelma J. , Pinedo H. M.
Published: February 2007

Resistance to multiple chemotherapeutic agents is a common clinical problem in the treatment of cancer. This resistance may occur before primary therapy or be acquired during treatment. We have generated a monoclonal antibody (MAb) (JSB‐I), specific for a conserved epitope on the plasma membrane 170‐ to 180‐kDa glycoprotein, the expression of which is strongly correlated with the degree of multi‐drug resistance (MDR). JSB‐1 strongly binds to both Chinese‐hamster‐derived MDR cell lines and human MDR cell lines, including cell lines derived from lung and ovary. A drug‐sensitive revertant line, and the corresponding drug‐sensitive parent lines, showed only weak reactivity or none at all. JSS‐l reacts strongly to air‐dried or acetone‐fixed cells and therefore has potential value for diagnostic detection of MDR cells in human tumor samples.
Kinetics of uptake and degradation of an abrin immijnotoxin by melanoma cells and studies of the rates of cellular intoxication
Authors: Godal Aslak , Fodstad Øystein , Pihl Alexander
Published: February 2007

The mechanism of action of an abrin 9.2.27 antimelanoma antibody conjugate has been studied in 2 human melanoma cell lines, FEMX and LOX, which differ in sensitivity to the immunotoxin (IT) and to native abrin. The IT, which had been affinity purified before use to remove molecules with exposed gal‐binding sites on the toxin B‐chain, inhibited cellular protein synthesis at a faster rate in the LOX than in the FEMX cells despite the fact that the LOX cells express less specific antigen and bind less IT to the cell surface. Surface‐bound abrin‐IT, as well as surface‐bound specific antibody, disappeared at equal rates from the cell surface of the 2 cell lines. After binding of labelled IT the disappearance of total cell associated radioactivity, as well as the appearance of TCA precipitable and TCA‐soluble radioactivity in the incubation medium, occurred at faster rates in the LOX than in the FEMX cells. No free abrin or antibody B‐chain complex could be detected in the medium or inside the cells. The results indicate that the different sensitivities of the melanoma cell lines reflect different abilities to process endocytosed IT and to translocate the active A‐chain to the cytosol. Experiments carried out in the presence of lactose are interpreted to mean that the A‐chain may be translocated to the cytosol by two mechanisms, one involving antigen‐antibody interaction and one involving the 8‐chain, and that the lectin binding site contributes to the B‐chain‐facilitated mechanism.
Co‐operation in cell transformation between BK virus and the human C‐harvey‐ras oncogene
Authors: Pagnani M. , Corallini A. , Caputo A. , Altavilla G. , Selvatici R. , Catozzi L. , Possati L. , Barbanti‐Brodano G.
Published: February 2007

Early‐passage hamster embryo cells were transformed by recombinant DNA molecules containing BK virus (BKV) earlyregion gene and either the activated c‐Ha‐ras oncogene (pBK/c‐rasA) or the normal c‐Ha‐ras proto‐oncogene (pBK/c‐rasN). The recombinant DNAs had a greater transforming ability and converted hamster cells to a more malignant phenotype than the single genes transfected separately. pBK/c‐rasA was significantly more powerful than pBK/c‐rasN in conferring to cells all the characteristics of transformation. Transfected DNA sequences were integrated mostly as single insertions into cellular DNA. Specific c‐Ha‐ras p21 and BKV T antigen were detected in transformed cells. Although stimulation of c‐Ha‐ras expression by BKV enhancers cannot be excluded in recombinants, super‐transfection and co‐transfection experiments in hamster embryo cells and pre‐neoplastic cell lines showed that BKV early‐region and c‐Ha‐ras co‐operate in transformation by contributing separate and independent functions.
Effect of retinoids on the proliferation, morphology and expression of glial fibrillary acidic protein of an anaplastic astrocytoma cell line
Authors: Rutka James T. , De Armond Stephen J. , Giblin Jane , McCulloch John R. , Wilson Charles B. , Rosenblum Mark L.
Published: February 2007

We studied the effect of retinoids on the growth and differentiation of a cell line (U 343 MG‐A) derived from a human malignant astrocytoma. Cultures treated with all‐trans or 13‐cis retinoic acid showed a dose‐dependent inhibition of proliferation and a marked reduction in the mean cell number at the plateau phase of growth (3.5 × 106 vs. 1 × 107 cells/25 cm<2>) compared with untreated cultures. At confluence, cells treated with all‐trans or 13‐cis retinoic acid were contactinhibited, whereas control cultures showed crowding, piling, and overgrowth. All‐trans retinol or retinyl acetate did not inhibit growth. Astrocytoma cultures treated with all‐trans retinoic acid (10−6 M) for 5 days were modestly growth‐inhibited but by day 16 had the same numbers of cells as controls; cultures that received all‐trans retinoic acid for 9 days were markedly growth‐inhibited for 7 days after the drug was removed. All‐trans and 13‐cis retinoic acid (10−6 M) prevented the EDTA‐induced cell detachment seen in control cultures. Strongly adherent all‐trans retinoic‐acid‐treated astrocytoma cells grew at a slower rate than did readily detached all‐trans retinoic‐acid‐treated or control cells. Cell spreading, an increased cytoplasmic:nuclear ratio, and greater numbers of broadly bipolar cells, some bearing thin cytoplasmic processes, were seen in cultures treated with 10−6 M all‐trans or 13‐cis retinoic acid. Small tightly packed cuboidal cells and large broadly bipolar cells were seen in astrocytoma cultures from which all‐trans retinoic acid was removed on days 5 and 9. Indirect immunofluorescence revealed more intense staining with antiserum to glial fibrillary acidic protein in cultures treated with 10−6 M all‐trans retinoic acid than in control cultures; electron‐microscope examination of similarly treated cultures revealed more abundant 8–10 nm intermediate filaments than in control cultures. An enzyme‐linked immunosorbent assay showed that all‐trans or 13‐cis retinoic acid caused a dose‐dependent increase in the quantity of glial fibrillary acidic protein in the astrocytoma cells.
Activation of mononuclear cells to be used for hybrid monoclonal antibody‐induced lysis of human ovarian carcinoma cells
Authors: Pupa S. M. , Canevari S. , Fontanelli R. , Ménard S. , Mezzanzanica D. , Lanzavecchia A. , Colnaghi M. I.
Published: February 2007

Recently we reported that cytotoxic T‐cell clones can be retargeted to unrelated tumor cells by bispecific monoclonal antbodies (MAbs), anti‐CD3 and anti‐ovarian carcinoma (αOC/TR) (Mezzanzanica et al., 1988). In the perspective of in vivo tumor immunotherapy, as an alternative to cytotoxic T lymphocytes (CTL) from T‐cell clones, since human peripheral blood mononuclear cells (PBMCs) without stimulation were quite ineffective, a suitable in vitro activation method was developed to render PBMCs lytic for relevant targets in the presence of the bispecific hybrid MAb αOC/TR. This activation protocol was applied to PBMCs from 9 healthy donors (HD) and 6 ovarian carcinoma patients (P) and to tumorassociated lymphocytes (TAL) from 4 ovarian carcinoma P. The method consisted of in vitro stimulation with phytohemagglutinin (PHA) for 2 days, followed by culture with a low dose of recombinant human interleukin‐2 (rIL‐2) for 6 to 10 days. The antibody‐mediated lysis of CTL from HD PBMCs was found to be specifically directed against cells expressing the relevant ovarian tumor antigen when different tumor cell lines and short‐term cultures of tumor and normal cells were tested. The antibody‐mediated lysis of CTL from P PBMCs or TAL was efficient both on autologous and allogeneic ovarian tumor cells, whereas no reactivity with autologous normal cells was observed and LAK activity was only evident in I out of 4 cases. The hybrid antibody induced cytotoxic activity of CTL from P was, however, lower than that of CTL from HD.
RNA polymerase activity and protein synthesis in mouse tumor‐host liver compared to benign para‐neoplastic reactions
Authors: Ternell Marie , Zachrisson Helen , Lundholm Kent
Published: February 2007

Elevated protein synthesis in mouse tumor‐host liver is the net result of both stimulatory and inhibitory responses. This study compares the directional change in transcription and synthesis of liver and plasma proteins in tumor‐host liver as compared with para‐neoplastic conditions, such as malnutrition, inflammation, benign cell proliferation and protein deficiency. A methylcholanthrene‐induced sarcoma was used in weight stable mice (C57B1/6J). Inflammation was induced by s. c. turpentine injection, and benign cell proliferation by injection of heat‐killed Corynebacterium parvum. DNA‐dependent RNA‐polymerase activity (I, II and III) (EC2.7. 7.6) was measured in isolated hepatic nuclei. Protein synthesis was measured by labelling of hepatic and plasma proteins following the injection of a “flooding dose” of the labelled amino acid. Benign hepatic cell proliferation and sterile inflammation caused increased rates of transcription, while malnourished and healthy control animals had lower hepatic transcription than animals bearing a malignant tumor. Inflammation was associated with increased activities of free (nonchromatin engaged) RNA polymerase, which was not found in any other para‐neoplastic condition or in the tumor‐host liver. A protein‐ and calorie‐deficient state was associated with depressed hepatic and plasma protein synthesis compared with the tumor condition. Tumor‐host livers had a nonsecretory protein synthesis rate equal to that of normal livers, but 45% higher plasma protein synthesis. Animals with inflammation and benign cell growth had liver protein synthesis rates which were approximately 50% higher than in tumorbearing animals, but plasma protein synthesis in tumor‐bearing animals was comparable with that of animals which had inflammation. Benign cell growth was not associated with an overall elevated plasma protein synthesis. The translation rate per transcription activity was highest in normal animals and decreased in animals suffering from either tumor, protein deficiency or benign cell proliferation. Hepatic protein synthesis in tumor‐host livers is high considering the degree of anorexia and malnutrition, although not as high as in livers from animals with pronounced inflammation. This counter‐regulation in tumor‐host livers may indicate a compensatory state to maintain protein synthesis against attenuating factors such as the declining food intake. Protein metabolism in tumorhost livers represents an unusual combination of findings.
Urokinase‐type plasminogen activator in colorectal carcinomas and adenomatous polyps: Quantitative expression of active and proenzyme
Authors: Sim Pheng‐Siew , Stephens Ross W. , Fayle David R. H. , Doe William F.
Published: February 2007

Total urokinase‐type plasminogen activator (u‐PA) content (proenzyme plus active enzyme) was significantly higher in 20 colorectal carcinomas and in 27 adenomatous polyps than in metaplastic polyps and autologous normal mucosa. u‐PA content was also markedly increased in adenomatous polyps and autologous colonic mucosa removed from familial polyporis coli patients. Using a new monoclonal antibody technique to distinguish the proenzyme of u‐PA from the active enzyme, we found that 70% of the u‐PA in polyp and cancer tissue was present in the proenzyme form compared to 47% in normal colonic mucosa. For colon cancers, there was a significant correlation between their stage of invasiveness and the levels of proenzyme. No correlation was observed between the u‐PA content of adenomatous polyps and their size or degree of dysplasia. Study of the u‐PA content of the colonic mucosa may offer a useful biochemical correlate of epithelial cell transformation in the colon.
Risk factors for breast cancer in chinese women of Beijing
Authors: Tao Su‐Chang , Yu Mimi C. , Ross Ronald K. , Xiu Kuang‐Wei
Published: February 2007

A self‐administered questionnaire was completed by 497 Chinese women in Beijing with histologically confirmed breast cancer and by an equal number of age‐ and neighborhood matched control women. High body weight (71 + kg) was a risk factor for breast cancer in women aged 50 + (RR = 1.90), but this effect did not quite reach statistical significance. Nulliparity and late age at first birth were associated with an elevated risk of breast cancer. In comparison to parous women who had their first child before age 20, those who delayed this event until after age 29 had an RR of 1.65. The comparable RR for nulliparous women was 3.72. Late age at menopause was a risk factor for breast cancer. The RR for menopause after age 50 compared to menopause before age 45 was 2.16. High parity and long duration of lactation were protective factors against breast cancer. These 2 factors were highly correlated with each other and also with age at first birth. The effect of each on breast cancer risk was somewhat reduced after adjustment for the other two. A personal history of benign breast disease (RR = 3.21) and a family history of breast cancer (RR = 2.17) were also associated with an increased risk of breast cancer.
Triggering of neoplastic B cells via surface IgM and the cell surface antigens CD20 and CDw40. Responses differ from normal blood B cells and are restricted to certain morphologic subsets
Authors: Beiske Klaus , Clark Edward A. , Holte Harald , Ledbetter Jeffrey A. , Smeland Erlend B. , Godal Tore
Published: February 2007

By raising monoclonal antibodies (MAbs) against B cells, a number of cell surface molecules have recently been identified which after binding by their specific antibody can trigger B cells, either alone or in co‐operation with antibodies to surface immunoglobulin (slg). The anti‐CD20 (Bp35) MAb IF5 can deliver a strong activation signal to resting normal B cells, and the anti‐CDw40 (Bp50) MAb G28‐5 can promote activated G1 B cells to enter S phase. These antibodies were tested for their functional effects in vitro on suspended cells from 17 follicle‐center‐cell (FCC) lymphomas, 5 cases of chronic lymphatic B‐cell leukemia (B‐CLL) and 8 cases of various histological types. Changes in cellular volume, RNA and DNA synthesis were compared with the results obtained with a polyclonal anti‐μ [F(ab′)2] antiserum, a MAb to surface IgM (AF6), 12‐O‐tetradecanoyl‐phorbol‐ 13‐acetate (TPA) and B‐cell growth factor (low‐molecular‐weight BCGF). Our data reveal differences in the requirements for triggering of various B‐cell subsets: cells from CLL responded strongly to TPA but not to anti‐μ, which is a potent stimulator not only of normal B cells but also of cells from individual cases of FCC lymphomas. Our observations suggest that the differentiation stage of B‐CLL cells is distinct from that of small resting B cells from peripheral blood. Centrocytic lymphomas could not be activated by any of the reagents. CD20‐mediated triggering was seen in neoplastic B cells from only 4 of 30 cases, Indicating that most B‐cell neoplasias were not responsive to this activation pathway. In contrast, the anti‐CDw40 MAb consistently stimulated DNA synthesis together with anti‐μ or TPA in cells from FCC lymphomas, but not from CLL. Together, these results suggest that activation in different neoplastic B‐cell subsets depends on distinct signal transduction mechanisms.
Differential lysis of melanoma clones by autologous recombinant interleukin 2‐activated lymphocytes. Relationship with spontaneous resistance to doxorubicin (Dx)
Authors: Gambacorti‐Passerini Carlo , Rivoltini Licia , Supino Rosanna , Mariani Mariangela , Parmiani Giorgio
Published: February 2007

To investigate whether human melanoma cells intrinsically resistant to autologous LAKs do exist, and whether a relationship between the level of lysis of LAKs and spontaneous drug resistance can be identified at the clonal level, we studied 44 clones obtained from a metastatic melanoma lesion. The antigenic phenotype of clones revealed a marked heterogeneity in the expression of HLA antigens of classes I and II. The clones were subsequently tested for sensitivity to autologous LAK and for spontaneous resistance to Dx. No clone resistant to autologous LAK was found, although a considerable range of lysis was noted with a normal frequency distribution. Growth in agar of the 2 clones in which lysis was least pronounced (6 and 26) was completely inhibited after co‐culture with LAKs, indicating a lack of absolute resistance to these effectors, Spontaneous resistance to Dx, evaluated as ID50, revealed instead that the majority of clones had a low ID50. The frequency distribution of clones showed a left‐skewed curve. The percentage of specific 51Cr‐release and the ID50 for Dx could be correlated in 25 clones by linear regression. Sensitivity to LAK did not correlate with HLA classes I or II or melanoma‐associated antigen expression. These results support the contention that increased LAK sensitivity of tumor cells is associated with drug resistance.
Ethnic patterns of thyroid cancer incidence in the United States, 1973‐1981
Authors: Spitz Margaret R. , Sider Joanne G. , Katz Ruth L. , Pollack Earl S. , Newell Guy R.
Published: February 2007

Descriptive epidemiological findings for 7,696 patients with newly diagnosed thyroid cancer reported to the Surveillance, Epidemiology, and End Results (SEER) program for the years 1973 through 1981 are summarized. The preponderance of this tumor in women and of the papillary histologic subtype are well documented. The data suggest that previously reported increases in the incidence of thyroid cancer among Whites levelled off in the late 1970s. Differences in the incidence of this cancer according to ethnic group were particularly striking. Compared with White men and women, Puerto Rico Hispanics and Blacks had significantly lower thyroid cancer rates (weighted rate ratios ranged from 0.48 to 0.65). New Mexico Hispanic men and Chinese, Japanese, Hawaiian and Filipino men and women had significantly higher rates (weighted rate ratios ranged from 1.56 to 3.17). Elevated thyroid cancer rates for residents of Hawaii, regardless of ethnic group, were also a noteworthy finding. Variations in thyroid cancer risk according to ethnic group and geographical residence may reflect socio‐economic or local environmental influences, including the possibility of a carcinogenic agent in volcanic lava.
The glioblastoma‐derived T‐cell suppressor factor/transforming growth factor beta2 inhibits the generation of lymphokineactivated killer (LAK) cells
Authors: Kuppner Maria C. , Hamou Marie‐France , Bodmer Stefan , Fontana Adriano , De Tribolet Nicolas
Published: February 2007

Glioblastoma cells release factors (G‐TsF) which inhibit T‐cell proliferation. The G‐TsF is a novel member of the transforming growth factor β family and is identical to TGFβ2. The effect of G‐TsF and TGFβ2 on the induction of LAK cell activity was investigated by culturing PBL obtained from normal blood donors and brain tumour patients in varying concentrations (50–500 U/ml) of interleukin 2 (IL2) alone or IL2 plus GTsF/TGFβ2 (I ng/ml) for 4 days. Subsequent cytolytic activity was measured against autologous and allogeneic glioblastoma targets, fresh NK‐resistant melanoma cells and K562 cells. GTsF/TGFβ2 purified from glioblastoma cell cultures and TGFβ2 isolated from porcine platelets significantly suppressed the generation of LAK cell activity, and the inhibitory effect could be reduced by higher concentrations of IL2. The suppressive effect of TGFβ2 was most significant during the early stages of LAK cell generation and no inhibitory effect was seen when TGFβ2 was added directly to the cytotoxicity assay. These results suggest that human glioblastomas may exert an inhibitory influence on the generation of an immune response in vivo through the production of G‐TsF/TGFβ2, and that the inhibitory effect may be modified by IL2.
A new immunotoxin built by linking a hemolytic toxin to a monoclonal antibody specific for immature T lymphocytes
Authors: Avila A. D. , de Acosta C. Mateo , Lage A.
Published: February 2007

Hybrid molecules built by conjugation between monoclonal antibodies (MAbs) and toxins are currently being experimentally tested as potential new anti‐cancer agents. These immunotoxins have mainly used the plant toxin ricin as the toxic component, which inhibits protein synthesis at the ribosome level. We present an alternative for toxic components using a hemolytic toxin acting at the membrane level, due to its phospholipase activity. The hemolytic toxin (HT), isolated from the sea anemone Stoichactis helianthus, has been conjugated to an antibody towards an antigen expressed on immature T lymphocytes (IOR‐T6), by means of an artificial disulphide bridge. The hybrid IOR‐T6‐HT exhibits no hemolytic activity unless it is reduced. It is toxic for cells (CEM) expressing the IOR‐T6 antigen and non‐toxic for cells (K562) not bearing the antigen. An excess of unconjugated antibody reverses the toxicity. Immunotoxins based on membrane active, hemolytic toxins can be a useful alternative when directed towards antigens which do not mediate internalization, as is the case for most carcinoma antigens.
Rescued human virus (RHV): Association with melanoma
Authors: Závada Jan , Závadová Zuzana , Havránková Marie
Published: February 2007

RHV, which is presumably a defective human retrovirus, has been recovered from the human melanoma cell line HMB2. In the presence of Moloney mouse leukemia virus (MLV), used as a helper, RHV is serially transmissible in mouse NIH‐3T3 cells and can provide envelope antigens for vesicular stomatitis virus pseudotype–VSV (RHV). This pseudotype is neutralizable with an inhibitor, present in all human sera tested; the inhibitory activity is resistant to heating at 100°C. To detect whether any specific response to RHV is connected with the disease, we isolated IgG from 140 human sera (70 melanoma patients and 70 control group donors) and tested it for neutralization of VSV(RHV) pseudotype in a randomized, blind experiment. Sixteen samples of IgG from the sera of melanoma patients, but only one control IgG, neutralized the pseudotype; this difference was significant (p < 0.001). RHV thus appears to be in some way associated with melanoma.
Retinoic‐acid‐induced modulation of c‐myc not dependent on its continued presence: Possible role in pre‐commitment for HL‐60 cells
Authors: Guernsey Duane L. , Yen Andrew
Published: February 2007

Induced differentiation of HL‐60 human promyelocytic cells along the myeloid or monocytic lineages has been previously shown to involve an intermediate regulatory state, the precommitment state. Pre‐commitment cells have completed the early events in the processes leading ultimately to terminal differentiation and require only an abbreviated subsequent exposure to inducer for onset of terminal differentiation. The pre‐commitment state has 2 properties relevant to the present communication: (I) when induced by retinoic acid (RA), it has a characteristic duration following removal of the RA; and (2) it can also be induced by a pulse exposure to hydroxyurea. In the present studies, it was observed that after exposure of HL‐60 human promyelocytic leukemia cells to RA for 24 hr (ca. one division cycle) their levels of c‐myc RNA were elevated. The c‐myc RNA level then remained elevated for several subsequent division cycles despite the removal of retinoic acid. Thus, retinoic acid induced a change in HL‐60 c‐myc RNA levels which was sustained regardless of the continued presence or absence of RA. The elevation, decreasing to control levels 3 division cycles after termination of the pulse exposure, paralleled the known duration of the pre‐commitment memory state. Furthermore, a pulse exposure of HL‐60 cells to a subcytotoxic dose of hydroxyurea, which is also known to induce a pre‐commitment state, also induced an elevation of c‐myc RNA levels. The observed changes in c‐myc levels were not common to all oncogenes. C‐fos responded differently to the retinoic acid treatment. Furthermore, although hydroxyurea affected c‐myc levels, it did not alter c‐fos levels. Most significantly, the present results suggest a cellular function for the c‐myc gene product, which is derivation of the pre‐commitment state.
Tumor necrosis factor α induces early morphologic and metabolic alterations in friend leukemia cell tumors and fibrosarcomas in mice
Authors: Proietti E. , Belardelli F. , Carpinelli G. , Di Vito M. , Woodrow D. , Moss J. , Sestili P. , Fiers W. , Gresser I. , Podo F.
Published: February 2007

Morphologic and metabolic studies have been carried out on Friend leukemia cell (FLC) tumors (grown in DBA/2 mice) or fibrosarcomas (grown in C3H/HeN or C3H/Hej mice) shortly after peritumoral injection of recombinant mouse tumor necrosis factor (TNF) α. Marked vascular congestion and focal extravasation of erythrocytes were observed as soon as I hr after injection of either FLC tumors or fibrosarcomas with TNF. Focal areas of disaggregation of tumor cells were observed I hr after injection of TNF. Intraluminal thrombi (composed of degranulated platelets and fibrin) were detected 3 and 6 hr after TNF treatment, and were associated with areas of depletion of endothelial cell cytoplasm. To correlate these morphologic changes in the tumor with alterations in tumor metabolism, NMR spectroscopy and biochemical studies were undertaken on freshly dissected FLC tumors and fibrosarcomas shortly after injection of TNF. The earliest metabolic alterations observed after I hr in TNF‐treated FLC tumors or fibrosarcomas were: (i) increase in the average intratumoral PH; (ii) decrease in the levels of ATP. These phenomena were not associated with a reduced glycolytic capacity of TNF‐treated tumors as, at these early times after injection, the levels of lactic acid were virtually the same for TNF‐treated or control treated tumors. Alterations in the levels of some products of phospholipid degradation (Gro‐PCho, GroPEtn, Crop and Cho) also occurred in these tumors as early as 3 hr after TNF treatment. These metabolic changes were not observed in ascitic FLC tumors after TNF treatment. We suggest that TNF induces alterations in tumor blood vessels which subsequently lead to changes in tumor metabolism and tumor degeneration.