bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentiation of abelson murine leukemia virus‐infected promonocytic leukemia cells
Authors: Hines David L.
Published: February 2007

Virus‐producing, tumorigenic, promonocytic leukemia cell lines were derived from Abelson murine leukemia virus‐infected mice. This study shows that, of these 25 cloned lines, 22 were capable of extensive differentiation. It also shows that granulocyte‐macrophage colony‐stimulating activity increased the proportion of differentiating cells in 17/22 lines. Cells from agar colonies with a diffuse colony morphology had an increased expression of mature macrophage phenotypic characteristics, and a reduced proliferative capacity in vitro, compared to cells from agar colonies with a compact colony morphology. Cells from diffuse colonies also produced less Abelson virus, and were less tumorigenic in vivo than cells from compact colonies. Together, these results suggest some Abelson virus‐producing leukemic cells are not blocked in their capacity to differentiate and are capable of reversing the transformed phenotype.
Two distinct human myeloma cell lines originating from one patient with myeloma
Authors: Katagiri Shuichi , Yonezawa Takeshi , Kuyama Jun , Kanayama Yoshio , Tamakl Toshiharu , Ohnishi Mitsunobu , Tarui Seiichiro , Nishida Kazuhiro , Abe Tatsuo
Published: February 2007

Two distinct cell lines (OPM‐l and OPM‐2) were established from the peripheral blood of a 56‐year‐old female myeloma patient at the stage of terminal leukemic evolution associated with loss of cytoplasmic immunoglobulin heavy chain (Gλ ± λ). The lines grew in suspension with a doubling time of 36‐42 hr and 30‐36 hr, respectively. EBNA was absent from both lines. The lines synthesized cytoplasmic λ‐chain, but had no detectable surface immunoglobulins. Fc receptors and complement receptors could not be detected in either line. The lines had very complex chromosomal abnormalities, but the patterns of chromosomes differed greatly between the two lines. The two lines, together with the RPMI 8226 line established by Matsuoka et al. (1967), were analyzed for phenotypic expression as defined by a panel of monoclonal antibodies to B cells (B1, BA‐1, BA‐2, BA‐3, OKla‐1 and OKT10/BMA0100). Neither OPM‐I nor OPM‐2 reacted with any of the antibodies tested except OKT10. OPM‐l cells reacted weakly ( < 30%) with OKT10/BMA0100, while OPM‐2 cells showed a fluctuating reactivity, ranging from 40 to 80%, with OKT10/BMA0100. In contrast, RPMI 8226 reacted strongly with OKT10 and BA‐2. These results demonstrate the presence of phenotypic heterogeneity in all 3 myeloma cell lines, suggesting that the lines might represent different stages of terminal B‐cell development.
An immunohistological study of leukocyte localization in benign and malignant breast tissue
Authors: Lwin Khin Y. , Sloane John P. , Zuccarini Ombretta , Beverley Peter C. L.
Published: February 2007

Using morphometric ana immunohistological techniques, we investigated the distribution of T lymphocytes and subsets, B lymphocytes, macrophages and plasma cells in sections of human breast tissue. In normal lobules and ducts, leukocytes were found in greater density in the epithelium than in the stroma. The intra‐epithelial cells consisted largely of suppressor/cytotoxic T lymphocytes with a smaller number of macrophages; inducer T cells were seen in only 1 out of 10 subjects and were present in very low numbers. In the stroma, there were roughly equal numbers of suppressor/cytotoxic cells, macrophages and plasma cells containing IgA or IgM. Small numbers of stromal inducer lymphocytes were seen in only 2 cases. Although the density of suppressor/cytotoxic cells in the epithelium was considerably greater than in the stroma, macrophages were present in roughly similar density in both locations. In carcinoma, the ratio of epithelial to stromal leukocyte density was reversed, due to a marked reduction in intra‐epithelial cells and to an increase in those in the stroma. Between 10% and 30% of lymphocytes expressed activation markers in contrast to the normal breast in which virtually all were negative. Inducer lymphocytes were identified in 9/10 carcinomas. The possible relationship of inducer cells to breast carcinoma and pre‐neoplasia is discussed and warrants further investigation. No alteration in stromal plasma cell numbers was observed.
Induction of cell differentiation in burkitt lymphoma lines. BLA: A glycolipid marker of B‐cell differentiation
Authors: Balana Anne , Wiels Joëlle , Tetaud Cécile , Tursz Thomas , Mishal Zohar
Published: February 2007

We have previously described an MAb referred to as 38.13 which reacts with a glycolipid membrane antigen (named BLA) on Burkitt lymphoma (BL) lines. The BLA antigen and other B‐cell differentiation markers have been studied on BL lines treated with sodium butyrate, agents from the phorbol‐diester series (with or without differentiating properties) and teleocidin. With all differentiation inducers tested, expression of BLA as well as of surface IgM decreased on the induced cells whereas that of B1 increased and that of HLA DR remained stable. No BL cells studied reacted with anti‐IgD, with B2 or with LBI MAbs, either before or after induction. An EBV‐negative line (BJAB) was compared to its Epstein‐Barr virus (EBV)‐converted subline (BJAB/B95). Both EBV‐positive and EBV‐negative lines gave comparable results. These data demonstrate that BL cells could be moved along their differentiation pathway by chemical inducers and suggest that BLA represents a new glycolipid marker of early B‐cell differentiation.
Phorbol myristate acetate (PMA) suppresses polarization and locomotion and alters F‐actin content of walker carcinosarcoma cells
Authors: Keller H. D. , Zimmermann A. , Cottier H.
Published: February 2007

This study demonstrates a novel feature of PMA, its ability to suppress chemokinetic polarization and locomotion of tumor cells. Walker carcinosarcoma cells exhibit two distinct types of polarization and locomotion, i.e. spontaneous polarization characterized by ruffles at the front and stimulated polarization and locomotion in response to the microtubule‐disassembling agents colchicine, vinblastine and nocodazole, which are characterized by bleb bing at the front. The tumor promotor phorbol myristate acetate (PMA), but not phorbol, was found to suppress both types of polarization and random locomotion at concentrations between 10−8 and 10−6M. The effect of 10−6M PMA was virtually complete within 5 min. Inhibition of locomotion was due to both a reduction in the speed of migrating cells and the proportion of migrating cells. Changes in shape and chemokinesis of Walker carcinosarcoma cells were associated with alterations in the relative amount and the topographical distribution of F‐actin as determined by NBD‐phallacidin binding. Suppression by PMA was associated with loss of the polar topographical distribution of F‐actin visualized by NBD‐phallacidin binding. In the presence of PMA, the relative amount of F‐actin was higher than in unstimulated controls and lower in cells exposed to microtubule‐disassembling agents.
Induction and maintenance of flattened morphology in highly adhesive friend leukemia clones depends on the time‐ and space‐specific assembly of microtubular networks
Authors: Benedetto A. , Amici C. , Djaczenko W. , Zaniratti S. , Elia G.
Published: February 2007

Indirect immunofluorescent staining with anti‐tubulin antibodies, SEM and TEM were applied to study microtubule (MT) assembly in clones isolated from Friend leukemia cells (FLC, 745 A strain) on the basis of their sensitivity to exogenous fibronedin (FN). Kinetics of cell spreading and elongation were studied using computerized image analysis and SEM. In contrast to 745 A cells, FN‐sensitive clones (referred to as FF clones) showed elaborate MT networks when observed by immunofluorescent staining as well as by TEM. A good correlation was found between the degree of spreading and elongation of FF cells and the degree and cellular distribution of their MT. The highest concentration of MT networks oriented parallel to the main cellular axis was observed in very elongated FF cells. The majority of MT in interphase FF cells radiated from the centrosomes; some MT apparently originated from the nuclear membranes. TEM showed the existence of morphological differences between centrosomes of 745 A and FF cells. The characteristic ultrastructure of the centrosomes of FF cells was maintained in trypsinized cells, even if such FF cells lost MT's and acquired a spherical morphology. FF cells, treated with a wide spectrum of MT ‐ disrupting agents, promptly acquired a rounded morphology with rapid dissolution of polymerized tubulin. Removal of MT‐disrupting agents from the culture medium rapidly restored a flattened morphology with concurrent regeneration of MT's. During recovery from MT‐disrupting agents, FF cells showed increased numbers of centrosomes per cell. We conclude that MT networks cooperate in the attachment, spreading and elongation of FF cells isolated from FLC. Moreover, we hypothesize the existence in FF cells of a variant form of centrosomes as compared with those of 745 A cells.
DBA/2‐like minor histocompatibility antigens on a BALB/c lymphoma. A balb/c anti‐DBA/2 serum which lyses the tumor and blocks balb/c anti‐tumor and anti‐DBA/2 effectors
Authors: Ballinari Dario , Grazioli Laura , Sensi Maria Luisa , Parmiani Giorgio , Borrello Maria Grazia
Published: February 2007

We have previously shown that BALB/c anti‐DBA/2 T cells can lyse the Moloney virus‐induced BALB/c lymphoma YC8. In order to determine whether serologically defined minor histocompatibility antigens (MiHA) cross‐reacting with those of DBA/2 tissues are present on YC8, we produced an antiserum directed against non‐H‐2 antigens by immunizing BALB/c mice with DBA/2 Con A and lipopolysaccharide (LPS)‐induced lymphoblasts. In a direct complement‐dependent cytotoxicity assay, the antiserum (OR‐I) lysed DBA/2 and YC8 but not BALB/c lymphocytes and blasts. No reactions against viral antigens were detected in the antisera as shown by the lack of cytotoxicity on a panel of lymphomas expressing a variety of viral antigens. In addition, OR‐I was able to specifically block a cytotoxic T lymphocyte (CTL), H‐2‐restricted BALB/c anti‐DBA/2 cytotoxic response when bound to DBA/2 or to YC8 target cells. These results indicate that antigens cross‐reacting between YC8 lymphoma and DBA/2 tissues are serologically defined MiHA of DBA/2 background and that OR‐I serum can block a CTL reaction by binding to target antigen rather than to major histocompatibility complex products.
Improved detection of labile cell‐surface components with zinc chloride‐aprotinin: Demonstration of glycoprotein differences in K‐1735 metastatic melanoma variants
Authors: Rieber Manuel , Rieber Mary S.
Published: February 2007

Metabolic labelling of K‐1735 melanoma variants with 3H‐glucosamine and cell harvesting with the commonly used protease inhibitor phenylmethylsulfonylfluoride revealed a Triton‐insoluble fibronection‐like 230 kd component in poorly metastatic cells. This component was not evident in highly metastatic cells. Significantly improved surface labelling and detection of the 230 kd glycoprotein in the highly metastatic variant was achieved by zinc chloride‐aprotinin treatment of cells prior to harvesting. This procedure also revealed an increase in a trypsin‐sensitive glycoprotein of higher molecular weight in the Triton‐insoluble fraction of the highly metastatic cell variant. Glycoprotein labelling in this fraction showed an electrophoretic pattern strongly resembling that reported by others for the high‐molecular‐weight human melanoma‐associated glycoprotein complex. The differential detection of the high‐molecular‐weight glycoprotein species in melanoma variants with differing metastatic abilities in an animal model provides a means of studying their possible relevance to metastatic melanoma. Our data also suggest that zinc chlorideaprotinin can be used to improve the detection of labile cell‐surface components.
Trends in morbidity and mortality for oesophageal cancer in linxian county, 1959–1983
Authors: Lu Jian‐Bang , Yang Wen‐Xian , Qin Yu‐Min , Lru Jin‐Ming , Li Yun‐Shu
Published: February 2007

Data on morbidity and mortality from oesophageal cancer (EC) over the 25 years from 1959‐1983 indicate that this malignancy has been the commonest cause of death in Linxian (LX) county during that period, accounting for 16% of deaths from all causes and 65% of deaths from cancer. Whereas incidence and mortality of EC were high but stable during this period, a decline in mortality has been noted recently in younger age groups, coinciding with an improvement in nutritional standards. Cohort analysis for the period 1879‐1954 demonstrates mortality peaks among individuals born late in the last century and early in the present one. It also shows that a decline in mortality appears to have started among natives of the county born during the period 1935‐1954.
Prevalence of HTLV‐I in arctic regions
Authors: Robert‐Guroff Marjorie , Clark Jeffrey , Lanier Anne P. , Beckman Gunhild , Melbye Mads , Ebbesen Peter , Blattner William A. , Gallo Robert C.
Published: February 2007

Sera of native inhabitants of Arctic regions were assayed for antibodies to HTLV‐I by the ELISA technique followed by competition experiments to confirm antibody specificity. Residents of 7 widely separated Alaskan villages exhibited prevalence rates of 0 to 12% for HTLV‐I antibodies. Less than 1 % of Greenland Eskimos were HTLV‐I antibody‐positive. Residents of 3 northern Swedish regions ranged in HTLV‐I antibody prevalence from 0 to 5%. Sera of healthy native inhabitants of Alaska and northern Sweden were similarly assayed for antibodies to HTLV‐II. No additional sera were shown to be positive for HTLV‐II antibodies. While some of the HTLV‐I antibody‐positive sera exhibited cross‐reactivity with HTLV‐II antigens, competition experiments using disrupted HTLV‐II or purified HTLV‐I p24 as test antigens indicated that the primary antibody response in all cases tested was elicited by HTLV‐I. Our results show that HTLV‐I distribution is not restricted to endemic areas in warm, humid climates, but extends to Arctic regions. Within these regions, HTLV‐I exhibits the same restricted distribution seen in other areas where virus infection is prevalent. The Arctic does not seem to be a reservoir for HTLV‐II infection. The origin of HTLV‐I in Arctic areas is not known. One may speculate that foreign visitors introduced the virus into Aleut and Lapp populations, and that it has been maintained there and restricted in its distribution as a result of close familial relationships.
Possible association of a new translocation, t(7; 11)(p15;p15), with Ph1 chromosome‐negative chronic myelogenous leukemia
Authors: Kaneko Yasuhiko , Maseki Nobuo , Takasaki Nobuko , Sakurai Masaharu , Kawai Kazuo , Sakurai Minoru
Published: February 2007

A Ph1 chromosome‐negative chronic myelogenous leukemia (CML) with t(7;11)(p15;p15) in a 6‐year‐old girl is reported. Three cases of 7;11 translocation have been reported so far. The patients concerned were between 37 and 72 years of age; 2 of them had CML and the other had acute myelomonocytic leukemia. Data from these 4 cases suggest that the 7;11 chromosome translocation may be related to a subgroup of Ph1‐negative CML, specifically to one that may easily proceed to blast phase, or to „subacute”︁ myelogenous leukemia. The present case demonstrates that CML with this chromosome abnormality is not restricted to adults but also affects children. The t(1;11)(q21or23;p15) reported in another case with Ph1‐negative CML may be a variant of this translocation.
06‐Methyldeoxyguanosine in oesophageal dna among individuals at high risk of oesophageal cancer
Authors: Umbenhauer D. , Wild C. P. , Montesano R. , Saffhill R. , Boyle J. M. , Huh N. , Kirstein U. , Thomale J. , Rajewsky M. F. , Lu S. H.
Published: February 2007

A radioimmunoassay using monoclonal antibodies (MAb) against 06‐medGuo and 06‐etdGuo enabled the presence of these DNA adducts to be detected in human tissues. With this methodology and with I mg of hydrolysed DNA it is possible to detect approximately 25 fmol 06‐medGuo or 12.5 fmol 06‐etdGuo per mg DNA. The analysis comprised a total of 37 human tissue specimens derived from patients who underwent surgery for cancer of the oesophagus in Linxian County (People's Republic of China); for comparison 12 tissue samples obtained from hospitals in Europe were similarly analysed. Seventeen samples from Linxian County showed a level of 06‐medGuo ranging from 15 to SO fmol/mg DNA, 10 showed higher levels up to 160 fmol/mg DNA, and the remaining 10 samples were below the limit of detection. All the tissue samples from Europe showed levels below 45 fmol 06‐medGuo/mg DNA, 7 being below the limit of detection. No 06‐etdGuo was detected in any of the samples. 06‐alkylguanine DNA alkyltransferase activity observed in tissue extracts from Linxian County. ranged from 190 to 326 fmol (mean values) of 06 medGuo removed per mg protein and lower values were obtained for the removal of 06‐etdGuo. The findings obtained using this approach appear promising in assessing the role of alkylating agents, e.g. nitrosamines, in the aetiology of human cancer.
Evidence for increased epidermal growth factor receptors in human sarcomas
Authors: Cowley Gerard , McIlhinney Jeffrey , Gusterson Barry , Ozanne Bradford , Fisher Cyril , Reeves Brian
Published: February 2007

The results of an immunocytochemical study of the epidermal growth factor receptor (EGFR) in 35 human soft‐tissue sarcomas, using a murine monoclonal antibody (MAb) EGF‐RI, are reported. In many of the tumours staining was stronger than in the adjacent stroma, suggesting increased levels of receptor. Particularly strong staining was seen in one epithelioid sarcoma and in the spindle‐cell component of a synovial sarcoma. Binding studies carried out on an epithelioid sarcoma cell line established from one of the specimens, using radiolabelled EGF, showed that approximately 8% of the receptors were of high affinity with a dissociation constant (Kd) of approximately 10−10m, while the remainder were of lower affinity with a Kd of 10−9m. The cells expressed a total of 1.7 × 106 receptors/cell which is equivalent to that found in some epidermoid tumours where gene amplification has been demonstrated. These data suggest that, as with other tumours recently reported, increased levels of epidermal growth factor receptor may be related to transformation.
Mast cells and tumour angiogenesis: The tumour‐mediated release of an endothelial growth factor from mast cells
Authors: Roche William R.
Published: February 2007

Exposure to tumour cells has previously been shown to induce mast cells to degranulate and release heparin. Isolated mast‐cell granules were found to be mitogenic for endothelial cells in vitro. This effect was a property of mast‐cell heparin, whose potency as a mitogen exceeded that of commercial heparins. The basis of this difference lay in the proteoglycan structure of the molecule. The release of heparin in mastcell‐tumour co‐cultures was examined by both endothelial cell proliferation and isotopic techniques. The kinetics and mode of release are described. The results are discussed in relation to the role of the mast cell in angiogenesis assays and tumour neovascularization.
Estrogen and progesterone receptors in benign breast tumors and lesions: Relationship with histological and cytological features
Authors: Giani C. , D'Amore E. , Delarue J. C. , Mouriesse H. , May‐Levin F. , Sancho‐Garnier H. , Breccia M. , Contesso G.
Published: February 2007

The pattern of estrogen (ER) and progesterone receptors (PR) and their relationship to histo‐ and cytopathological parameters has been studied in 97 cases of benign breast disease and benign phyllode tumors (95 women, of whom 76 were premenopausal, and 2 men). Total (cytosolic + nuclear) ER and PR were assayed by a single‐saturating dose method using a tris‐KCI buffer. The cut‐off between positive and negative ER and PR assay was 100 femtomoles/g tissue. All specimens were processed for histological examination: epithelial and fibroblastic proliferation, epithelial/stromal ratio and presence of focal or diffuse hyalinosis. In 33% of the 46 cases of fibrocystic disease one receptor at least was present (13% ER+, 31% PR+). All the 8 cases in which infiltrating epitheliosis was present were PR+ and 4 of them were also ER+. In 72% of the 31 fibroadenomas one receptor at least was present (19% ER+, 71% PR+). In all these cases levels of receptors were lower than in malignant tumors. An inverse correlation between PR + prevalence and fibrohyalinosis was observed; on the other hand a positive relationship between PR + and fibroblastic (p<0.001) or epithelial (p<0.01) proliferation was found. In all 5 benign phyllode tumors examined PR + were present at a very high level, almost as high as in malignant tumors. Of the 15 other benign breast lesions, all but one (I hamartoma) were ER− and PR−.
Invasion of lung tissue by bronchogenic squamous‐cell carcinomas: Interaction of tumor cells and lung parenchyma in the tumor periphery
Authors: Dingemans Koert P. , Mooi Wolter J.
Published: February 2007

We collected multiple samples from 43 human bron‐chogenic squamous‐cell carcinomas and studied the ultrastructure of the tumor‐cell‐lung parenchyma interaction in the tumor periphery. Since, in the periphery of a growing tumor, the surrounding tissue has only recently been reached by the tumor cells, it is the initial stage of interaction which can be observed here. The main findings were: (1) The tumor cells in the tumor periphery always penetrated the lung parenchyma along the epithelial side of the alveolar basal lamina. (2) The non‐neoplastic alveolar epithelial cells were either detached from their basal lamina or overgrown by the tumor cells, without being visibly damaged or destroyed. When the alveolar epithelial cells were overgrown by the tumor, they retracted and formed extra‐ or intracellular lumina much smaller than the original alveoli. (3) The contact between tumor cells and alveolar epithelial cells resulted in the formation of common desmosomes and complete junctional complexes and the common lining of lumina. (4) Although the tumor cells extended small pseudopods through the basal lamina, they virtually never migrated through it to reach the interstitial compartment. These results indicate that the initial invasion of lung parenchyma is characterized by a smooth integration of tumor cells and elements of the preexisting tissue, leading to orderly associations of neoplastic and non‐neoplastic cells, rather than by tissue destruction by the tumor cells.
Parity and breast cancer risk: Possible effect on age at diagnosis
Authors: Pathak Dorothy R. , Speizer Frank E. , Willett Walter C. , Rosner Bernard , Lipnick Robert J.
Published: February 2007

We examined the effect of parity on breast cancer risk on the basis of information from 107,146 married female nurses followed prospectively between 1976–1980. For everparous women, a significant protective effect against breast cancer was observed with increasing parity (χ 2for trend = 14.2, ρ<0.001). Adjustment for age at first birth and other potential confounders by multiple logistic regression did not materially affect this trend. After controlling for these risk factors, the overall relative risk of breast cancer for women with four or more pregnancies lasting 6 months or longer was 0.68 (95% confidence limits 0.51‐0.90) compared with women with only one pregnancy. When nulliparous and everparous women were compared, an interaction of age and everparous status in 1976 was observed. The logistic regression coefficient for the interaction was 0.3419 (95% confidence limits 0.0374‐0.6464). Specifically, for women of parity 2 relative to nulliparous, the relative risk of breast cancer and the 95% confidence intervals were 1.85 (1.09, 3.14), 1.32 (0.92, 1.89), and 0.93 (0.62, 1.41) for 30‐39, 40‐49 and 50‐55‐year‐old women, respectively. This points to the need of presenting age‐specific, rather than age‐adjusted, relative risks in future studies of breast cancer and parity.
Antigens related to three core proteins of HTLV‐I (p24, p19 and p15) and their intracellular localizations, as defined by monoclonal antibodies
Authors: Tanaka Yuetsu , Lee Bunsho , Inoi Takeshi , Tozawa Hideki , Yamamoto Naoki , Hinuma Yorio
Published: February 2007

Three distinct monoclonal antibodies (MAbs) specific for human T‐cell leukemia virus type‐I (HTLV‐I) core proteins with molecular weights of 24 kDa (p24), p19 or p15 were produced, characterized and compared. These antibodies were named NOR‐I (anti‐p24, IgG2a). GIN‐7 (anti‐p19, IgG2b) and FR‐45 (anti‐p15, IgG2a). Immunofluorescence assay showed that they reacted specifically with methanol‐fixed cells of virus‐bearing cell lines, and that only GIN‐7 bound, albeit weakly, to the surface of a small percentage of viable cells. Like natural antibodies to HTLV‐I in human serum, GIN‐7 stained the fixed cells brightly and diffusely, and gave more intense fluorescence than NOR‐I and FR‐45, which stained restricted areas of the cells. NOR‐I, GIN‐7 and FR‐45 specifically precipitated core proteins p24, p19 and p15, respectively, from a lysate of HTLV‐Imt‐2 labelled with 35S‐cysteine. NOR‐I precipitated p53, p36, and p24, GIN‐7 precipitated p53, p32, p28 and p19, and FR‐45 precipitated p53, p36, and p15 from a lysate of 35S‐cysteine‐labelled MT‐2 cells. GIN‐7 also precipitated p32, p28 and p19 from a lysate of MT‐2 cells, labelled by surface iodination, but NOR‐I and FR‐45 did not detect any proteins in this lysate. GIN‐7 also detected p28 in 3H‐glucosamine‐labelled MT‐2 cells. Antibody binding competition assay showed that the sera of ATL patients significantly interfered with the binding of NOR‐I and GIN‐7 but not with that of FR‐45, to antigens of disrupted virus of MT‐2 cells. This complete set of MAbs against the HTLV‐I gag gene products is useful for biological and functional studies of the HTLV‐I core proteins.
Cytotoxic t‐cell precursors against non‐immunogenic rat tumors: Limiting dilution analysis
Authors: Zöller M.
Published: February 2007

After in vitro stimulation of lymphocytes with syngeneic tumor cells in the presence of interleukin 2 (IL‐2), a cytotoxic T‐cell response was observed against these spontaneously arising BDX tumors, which are non‐immunogenic in the syngeneic host. The response was due to cytotoxic T‐cells (CTL), which were specific for syngeneic tumor cells, i.e. neither syngeneic lymphoblasts, allogeneic lymphoblasts, allogeneic tumor cells, nor NK targets were lysed. The frequencies of anti‐tumor lymph‐node (LN) and spleen CTL precursors (CTLp) against a panel of syngeneic tumors of different histology varied between 1/6,000 and 1/16,000. Further analysis of the reactivity pattern of anti‐tumor CTL revealed some degree of cross‐reactivity within the syngeneic system. By a limiting dilution (LD) split culture approach in combination with cold target (CT) inhibition, it could be shown that tumors carry a panel of tumor‐associated antigens (TAAs). Some tumors express individually specific as well as cross‐reactive TAAs, while others carry cross‐reactive TAAs only.
Treatment of murine L1210 lymphoid leukemia and melanoma B16 with lipophilic cytosine arabinoside prodrugs incorporated into unilamellar liposomes
Authors: Rubas W. , Supersaxo A. , Weder H. G. , Hartmann H. R. , Hengartner H. , Schott H. , Schwendener R.
Published: February 2007

Lipophilic prodrugs of 1‐β‐D‐arabinofuranosyl cytosine (Ara‐C), namely N4‐ and 5′‐oleyl‐1‐β‐D‐arabinofuranosyl cytosine (N4‐oleyl‐ara‐C, 5′‐oleyl‐ara‐C) and N4‐palmitoyl‐1‐β‐D‐arabinofuranosyl cytosine (N4‐palmara‐C) were incorporated into liposomes of various lipid compositions. The phospholipid vesicles were prepared by controlled dialysis of lipid/prodrug/detergent micelles yielding homogeneous and stable unilamellar liposomes. The liposome size ranged from 70 to 120 nm depending on the lipid composition and the amounts of prodrug incorporated. Depending on the total amount of micellized Ara‐C prodrugs, a maximal incorporation rate of 250 μg prodrug per mg egg phosphatidylcholine was achieved. The incorporation efficiency was in the range of 85 to 97%. The in vivo antitumor activity of the liposome preparations against L1210 lymphoid leukemia was clearly superior by factors of 2–8 depending on the therapy schedule and route of drug application. The treatment of melanoma B16 with free Ara‐C as well as with the prodrug‐liposomes exhibit rather weak antitumor activity. Drug application by means of prodrug‐liposomes yields equal or higher tumor‐inhibitory effects at drug concentrations which were 2 ‐ 4 times lower than those of free Ara‐C. Although drug tolerance and myelosuppression studies with Swiss albino mice revealed that the prodrug‐liposomes were 5–10 times more toxic than free Ara‐C, a substantial improvement of efficiency could be observed. The incorporation of the ara‐C prodrugs into liposomes provides protection against fast degradation and systemic elimination which might be an explanation for the improved antitumor effect of these preparations.
Tissue‐specific markers in flow cytometry of urological cancers. II. Cytokeratin and vimentin in renal‐cell tumors
Authors: Feitz W. F. J. , Karthaus H. F. M. , Beck H. L. M. , Romijn C. , van der Meyden A. P. M. , Debruyne F. M. J. , Vooijs G. P. , Ramaekers F. C. S.
Published: February 2007

Nine primary human renal‐cell tumors (RCT), one lymph‐node metastasis, 4 human xenografts of a RCT in nude mice and a rat RCT line were analyzed by flow cytometry (FCM) using propidium iodide for DNA analysis and antibodies to cytokeratin and vimentin in the indirect immunofluorescence technique for labelling of specific tumor‐cell populations. By means of 2‐dimensional FCM analysis, vimentin‐ and cytokeratin‐positive (tumor) cells were compared and their DNA content and proliferative fraction analyzed separately from those of cytokeratin‐negative stromal and inflammatory cells. In primary human RCT, 2 subpopulations of cells were detected and analyzed separately. Small numbers of tumor cells with an abnormal DNA stemline were also detected. In addition, co‐expression of intermediate filament proteins of both the cytokeratin and the vimentin types was detected in the aneuploid cell population. Comparison of 2 model systems of RCT with primary human RCT revealed a similar pattern of tumor‐cell subfractions within these tumors. The 2‐parameter FCM analysis permits the detection of subpopulations in complex cell suspensions and the quantification of these fractions, as well as analysis of their cellular DNA content.
Media conditioned by human leukemic T‐cells induce expression of IL2 receptors and proliferation of normal T lymphocytes
Authors: Kosmatopoulos Constantinos , Allouche Michèle , Triebel Frédéric , Zanti Maria , Clemenceau Corine , Gluckman Jean‐Claude , Jasmin Claude , Georgoulias Vassilis
Published: February 2007

Peripheral blood T‐colony‐forming cells (T‐CFC) from patients with T‐cell acute lymphoblastic leukemias (T‐ALL) and T‐cell non‐Hodgkin lymphomas (T‐NHL) can generate colonies in methylcellulose in the absence of added growth factors and/or mitogenic stimulation. In the present study, we show that media conditioned (LCM) by unstimulated mononuclear cells (MNC) from these patients can induce proliferation (proliferating inducing activity; PIA) and promote colony growth (T‐cell colony promoting activity; T‐CPA) of normal T lymphocytes in the absence of any other mitogenic stimulation. Preincubation of normal E+ lymphocytes with some TCPA+, PIA−‐LCM for 48 hr leads to IL2‐induced cell proliferation in the absence of any other stimulation. Moreover, staining of the cells with anti‐Tac monoclonal antibody (Mab) reveal 9%‐26% Tac+ cells. Both PIA and IL2 receptor‐inducing activities were abrogated by treatment of LCM with proteolytic enzymes or by heating at 47°C for 30 min. Modulation of the T3 molecule by OKT3 MAb on normal E+ cells did not abrogate the capacity of LCM to induce expression of IL2‐receptors, suggesting that this activity was not mediated by triggering the Ti‐T3 molecular complex. These activities were detected in media conditioned by both unfractionated MNC and blast‐enriched cell fractions, and their production required DNA and RNA synthesis by actively dividing cells. Taken together, these findings indicate that human leukemic T cells spontaneously release activites which can activate normal resting T lymphocytes.
Immunological consequences of tumor excision: From active immunity to immunological memory
Authors: Bursuker Isia , North Robert J.
Published: February 2007

Excision of the immunogenic Meth‐A fibrosarcoma during generation by the host of concomitant antitumor immunity resulted in the appearance in sequence of two qualitatively distinct states of post‐excision immunity. Immunity expressed on the day of excision was dependent on Ly‐I−2+, cyclophosphamide‐sensitive T cells, whereas immunity expressed 2 weeks later was dependent on cyclophosphamide‐resistant T cells which can be functionally eliminated by either anti‐Ly‐1 or anti‐Ly‐2 monoclonal antibody and complement. The data suggest that antitumor immunity expressed shortly after tumor excision represents active concomitant immunity that is acquired by the host before excision is performed. In contrast, immunity expressed 2 weeks later is based on immunological memory.
Use of a cocktail of monoclonal antibodies and human complement in selective killing of acute lymphocytic leukemia cells
Authors: Sugita Kenichi , Majdic Otto , Stockinger Hannes , Holter Wolfgang , Köller Ursula , Peschel Christian , Knapp Walter
Published: February 2007

Autologous remission bone marrow is a potential source of repopulative stem cells after ablative chemoradiotherapy of tumor patients. Even with remission bone marrow, one major obstacle to use of autologous bone‐marrow support is the danger of reinfusing viable tumor cells. This report describes a purging protocol with human complement, which seems suitable for eliminating acute lymphatic leukemia (ALL) cells of the common ALL type. Lysis of ALL blasts is induced with a cocktail of 3 monoclonal antibodies of IgM type (termed VIB‐pool). These are directed against the CALLA (CD 10) antigen (VIL‐AI antibody) and against 2 different epitopes of the CD24 surface structure (VIB‐C5 and VIB‐E3 antibodies). The purging efficiency was evaluated with leukemic cell lines of the common ALL type (Reh‐6 and Nalm‐6) and with blast cells from common ALL patients. Optimal lysis was obtained with antibody and human serum concentrations as low as I μg/ml and 7% respectively. As a standard purging protocol we propose one 20‐min incubation at room temperature with antibody followed by two 30‐min incubations at 37°C with 25% human complement. In dye exclusion tests 99% purging efficiency and in clonogenic assays detecting elimination of up to 5 logs of clonogenic tumor cells 99.99% (= 4 logs) purging efficiency were achieved. Treatment with VIB‐pool and human complement had no negative effect on the growth of the normal hemopoietic progenitor cells CFU‐GM, CFU‐E and BFU‐E.
Synergistic antiproliferative effect of human interferons in combination with mismatched double‐stranded RNA on human tumor cells
Authors: Hubbell Howard R.
Published: February 2007

Four human tumor cell lines were studied for their response to antiproliferative effects of various interferons (IFNs) alone and in combination with the novel mismatched dsRNA, r(I)n r(C12,U)n (Ampligen). RT4 cells (bladder carcinoma) were resistant to Ampligen alone, while A2182 (lung carcinoma), HT1080 C14 (fibrosarcoma) and RT112 (bladder carcinoma) cells were inhibited in a dose‐dependent manner. In contrast, RT4 cells were sensitive to the antitumor effects of IFNs as were HT1080 C14 and RT112 cells, while A2182 cells were resistant. In 3 of the 4 cell lines, the recombinant IFNs were less effective than the corresponding natural IFNs when compared by analysis of variance on an IRU/ml basis over a range of concentrations. In all cell lines, a synergistic antiproliferative effect was seen with all IFN preparations studied in combination with Ampligen, as calculated by the isobole method according to Berenbaum (1981). The antiproliferative effect of IFN was potentiated >3.3‐ to > 250‐fold, depending on the cell lines, IFN, and concentrations used. Varying the concentration of βser‐IFN while holding the Ampligen concentration constant gave synergy at all of the physiologically achievable concentrations tested in RT4 cells. These results indicate that: (1) Ampligen worked synergistically with all IFNs in all cell lines studied; (2) growth inhibition of cells resistant to IFNs can be potentiated by low doses of Ampligen; (3) the antiproliferative effect of IFNs can be potentiated by Ampligen in Ampligen‐resistant cells; and (4) Ampligen may work by a mechanism other than, or in addition to, the induction of IFNs.
Epstein‐Barr virus status and tumour cell phenotype in sporadic Burkitt's lymphoma
Authors: Rowe M. , Rooney C. M. , Edwards C. F. , Lenoir G. M. , Rickinson A. B.
Published: February 2007

Burkitt's lymphoma (BL) biopsy cells and derived cell lines can be grouped according to their patterns of reactivity with 6 selected monoclonal antibodies (MAbs) against B cell‐associated surface antigens. Group I cells react only with MAbs J5 and 38.13, recognising the common acute lymphoblastic leukaemia antigen and a BL‐associated antigen respectively; group II cells react with J5 and 38.13 and with one or more of a set of MAbs (Ki‐24, MHM6, AC2, Ki‐I) against “lymphoblastoid” antigens; group III cells react only with these anti‐“lymphoblastoid” MAbs. Tumour biopsy cells from 17 cases of sporadic BL, 9 positive for the Epstein‐Barr (EB) virus genome and 8 negative, have been analysed during the process of cell line establishment in vitro. In early passage the EB virus‐negative BL cells showed either a group I phenotype or gave an additional reactivity with MAb Ki‐24 which placed them in group II; these phenotypes remained essentially stable with continued growth of the cell lines for up to 50 passages. By contrast the EB virus‐positive BL cells were much more susceptible to phenotypic change in vitro. Although such cells displayed a group I or group II phenotype in early passage, many of the lines soon moved into group III whilst retaining the karyotypic markers indicative of their malignant origin. These observations suggest that a resident EB virus genome can drive the in vitro progression of BL cells towards a more “lymphoblastoid” phenotype. This was confirmed in subsequent experiments where virus‐negative BL cell lines were converted to EB virus positivity by in vitro infection. Clearly, therefore, phenotypic analysis of long‐established lines can lead to false distinctions being drawn between the EB virus‐positive and ‐negative forms of sporadic BL; both may derive from the same sub‐population of target B cells in vivo.
Characteristics of in vitro transformed cells essential for their in vivo survival, selection and metastasizing activity
Authors: Deichman G. I. , Vendrov E. L.
Published: February 2007

Two questions were investigated: (1) the dynamics of in vivo selection of tumor cells possessing metastasizing activity (MA) at the time preceding the appearance of visible lung metastases, and (2) the possible connection of in vivo selection of metastatic tumor cells with their susceptibility to H2O2 produced by the cytotoxic oxidative burst of activated neutrophils, monocytes and macrophages. Spontaneously in vitro transformed Syrian hamster embryo cells (strain STHE), never selected in vivo and possessing low MA, were used as parental cells. STHE cells were injected i.v. and, after various time intervals (1 to 21 days), isolated from lungs of injected hamsters. A total of 43 STHE cell variants were isolated from individual animals. Their MA, natural‐resistance‐depressing (NRD) activity and susceptibility to H2O2 were determined.

Selection of metastatic tumor cell variants capable of forming experimental metastasis (EM) begins a few hours after injection. The vast majority of injected cells die and the few cells which survive do not proliferate for a long period. The majority of variants isolated at days 5 to 6 after injection and later possess increased MA, depending on the duration of the in vivo selection, and varying among individual hosts. The ability to form spontaneous metastasis (SM) in the lungs and in other organs appears among cell variants isolated at days 10 to 21 after inoculation. This qualitatively new characteristic of cell variants correlates with the restoration of their proliferative activity and in most cases with their NRD activity.

With respect to susceptibility to H2O2, (1) parental STHE cells and their 5 in vivo isolated cell variants, all possessing low MA, were highly susceptible to H2O2 injury; (2) 15 highly‐metastatic variants were 10 to 200 times more resistant; and (3) 4 variants obtained from s.c. transplants of parental cells were highly resistant to H2O2. Hamster embryo cells in vitro transformed with SV40 or bovine adenovirus type 3, were susceptible to high doses of H2O2 (14–28 mm) but resistant to lower doses. In contrast, the same cells, once passaged in vivo and the cells of tumors induced in vivo by the same viruses were resistant to high doses of H2O2. In vitro transformed cells and their in vivo selected variants thus appear to differ widely in terms of their susceptibility to H2O2. Extremely rare cell variants which are resistant to H2O2 and apparently present in the original populations of in vitro‐transformed cells possess an essential selective advantage in vivo, that is resistance to H2O2 appears necessary for in vivo survival of tumor cells and their growth in s.c. nodules and metastases.
Substrate‐dependent effect of epidermal growth factor on intercellular adhesion and synthesis of triton‐insoluble proteins in human carcinoma A431 cells
Authors: Rieber Manuel , Gil Francisco , Rieber Mary S. , Urbina Cecilia
Published: February 2007

Human epidermoid carcinoma A431 cells attach more rapidly to collagen type‐I and ‐IV substrates than to surfaces coated with laminin or fibronectin. The diminished intercellular interaction and rounding up manifested when these cells are exposed to epidermal growth factor (EGF) in tissue culture plastic or collagen films is not shown when the assay is performed on 3‐dimensional collagen. In the latter substrate, cells exposed to EGF reveal greater cell cohesion with interdigitations and desmosomal junctions, compared to the limited intercellular interaction detected in similarly treated cells assayed in tissue culture substrate. Although the protein synthesis inhibitor, cycloheximide, did not prevent these EGF‐mediated changes, metabolic labelling indicated a substrate‐dependent effect of EGF on the synthesis of proteins associated with the Triton‐insoluble cytoskeletal matrix. The involvement of cytoskeleton components in the EGF effects on intercellular adhesion was shown by its susceptibility to cytochalasin B, known to disorganize actin‐containing microfilaments. Some of the mechanisms of epithelial morphogenesis and the influence of extracellular matrix components on cell‐receptor/growth‐factor interactions may now be suitably analyzed by examining the EGF effects on A431 cells grown on different substrata.
Enhanced spontaneous metastasis of mouse carcinoma cells transfected with an activated c‐Ha‐ras‐1 gene
Authors: Vousden K. H. , Eccles S. A. , Purvies H. , Marshall C. J.
Published: February 2007

To investigate whether the presence of an activated ras oncogene influences the ability of tumour cells to metastasize, the c‐Ha‐ras‐1 oncogene cloned from EJ/T24 cells was introduced into MT1 C1.5/7 mouse mammary carcinoma cells. Since the MT1 C1.5/7 cells are already tumorigenic but have a low metastatic capacity, this experimental design allows a distinction to be made between the effects of the ras gene on metastasis and tumorigenicity. MT1 C1.5/7 containing the EJ c‐Ha‐ras‐1 metastasized more readily and to more tissue sites than control cells (2.8 sites/mouse vs 0.9 sites/mouse). The metastases expressed the EJ c‐Ha‐ras‐1 p21 ras proteins; however, one metastasis was discovered that had lost the expression of the c‐Ha‐ras‐1 gene. When these cells were re‐tested for metastasis, the rate of metastasis was indistinguishable from that of controls. This observation, coupled with a demonstration that lung colonization potential following intravenous inoculation is unaffected by the presence of the activated ras gene, argues that the effect of mutant ras genes is exerted on the ability of cells to escape from the primary tumour, rather than on a survival in the circulatory systems and ability to seed a second site.
The role of tumor‐cell surface carbohydrate in experimental metastasis
Authors: Stanford David R. , Starkey Jean R. , Magnuson James A.
Published: February 2007

Quantitative studies on the binding of concanavalin A (Con A) and wheat‐germ agglutinin (WGA) to a series of rat hepatocarcinoma metastatic variants revealed a positive correlation between the amount of cell‐surface‐bound lectin and lung colonization potential. Scatchard analysis of Con A and WGA binding to 10 individual clones isolated from a subcutaneous (s.c.) tumor transplant and to tumor‐cell isolates from 10 individual spontaneous lung metastases from the same animal showed diverse binding characteristics for these cell populations. Nevertheless, the expression of Con A receptor sites accurately predicted the lung colonization potential of 3 isolates from the lung metastases. Higher lectin binding curves were observed for the clones from the subcutaneous tumor than for the isolates from lung metastases. These data suggest that a high Con‐A binding potential is indicative of a high lung colonization potential for these hepatocarcinoma cells, but that this phenotype may be rapidly lost during tumor outgrowth in the lungs. The binding of tumor cells to vascular endothelial cell monolayers was inhibited in the presence of Con A; however, no inhibition was observed with 2 other lectins. Attachment of tumor cells to endothelial cell monolayers was also inhibited by the monosaccharides methyl α‐D‐mannopyranoside and N‐acetyl‐D‐galactosamine. Other monosaccharides tested did not alter the attachment of tumor cells to endothelial cell monolayers.
Comparative inhibitory effects of suramin and other selected compounds on the infectivity and replication of human T‐cell lymphotropic virus (HTLV‐III)/lymphadenopathy‐associated virus (LAV)
Authors: Balzarini Jan , Mitsuya Hiroaki , De Clercq Erik , Broder Samuel
Published: February 2007

Suramin and various other selected compounds were evaluated for their in vitro inhibitory effects on the infectivity and replication of human T‐cell lymphotropic virus (HTLV/III)/iymphadenopathy‐associated virus (LAV). As parameters for infectivity and replication, respectively, we followed the cytopathic effect of HTLV‐III/LAV on ATH 8 cells, a T‐cell clone with high susceptibility to HTLV‐III/LAV, and the expression of HTLV‐III/LAV p24 gag protein in H9 cells infected with HTLV‐III/LAV. As the most effective inhibitors of HTLV‐III/LAV the following substances emerged (in order of decreasing activity): Evans Blue ⋍ suramin > phosphonoformic acid > Direct Yellow 50. Several purine nucleoside analogues including vidarabine, tubercidin, neplanocin A, dihydroxypropyladenine, pyrazofurin and ribavirin were not inhibitory to HTLV‐III/LAV. In our test systems, involving a high multiplicity of infection, HPA‐23, previously reported to be effective against LAV reverse transcriptase, showed no inhibitory effect on HTLV‐III/LAV infectivity for ATH 8 cells and proved only weakly inhibitory to HTLV‐III/LAV replication in H9 cells. Thus, among the anionic dyes that are structurally related to suramin, compounds were found which were as active as suramin itself, if not more so.