bluuebunny/crossref_metadata_2025 huggingface dataset:
Transformation‐related changes in the expression of endogenous cell lectins
Authors: Raz Avraham , Meromsky Leonid , Zvibel Isabel , Lotan Reuben
Published: February 2007

Endogenous lectins purified from UV‐2237‐IP3 murine fibrosarcoma cells by affinity chromatography consisted of two polypeptide species of Mr 14,500 (L‐14.5) and Mr 34,000 (L‐34). Antibodies against this material immunoprecipitated the lectins from cells radiolabelled on the cell surface as well as in the cytoplasmic compartment. Similar analyses of normal rat embryonal fibroblasts revealed the presence of only the L‐14.5. In contrast, both L‐14.5 and L‐34 were found in oncogenetransfected, immortalized cell clones derived from the normal rat cells, as well as in untransformed BALB/c‐3T3 clone A31 and its descendant subclones selected for expression of the transformed, the tumorigenic and the metastatic phenotypes. Among the cells constituting the latter system, a marked increase in the amount of cellular and cell‐surface lectins was observed upon progression to the metastatic phenotype. These results suggest that the expression of endogenous tumor‐cell‐surface lectins is associated with transformation and metastasis.
Lack of fibronectin‐binding plasma membrane proteins may explain defective pericellular matrix formation in transformed fibroblasts and fibrosarcoma cells
Authors: Virtanen Ismo , Lehto Veli‐Pekka , Vartio Tapio
Published: February 2007

Affinity of iodinated fibronectin (Fn) and its defined proteolytic fragments to electrophoretically separated polypeptides of normal and malignant cells was studied in an overlay assay. Cellular 125I‐Fn and a major 125I‐Fn fragment (Mr 120,000 ‐ 140,000), containing the cell‐binding site, revealed in fibroblasts Mr 170,000, Mr 140,000, and Mr 47,000 Fn‐binding polypeptides of which the first two could also be found in the plasma membrane preparations. Binding of 125I‐Fns to Mr 170,000 and Mr 140,000 polypeptides was inhibited by the synthetic peptide Arg‐Gly‐Asp‐Ser and to all 3 polypeptides by Fns and Mr 120,000‐140,000 fibronectin fragment. Both fibrosarcoma cells and SV40‐virus‐transformed fibroblasts appeared to lack the Mr 140,000 Fn‐binding polypeptide. Binding was similar when Fn from normal fibroblasts or fibrosarcoma cells was used in the assay, while plasma 125I‐Fn had weaker affinity towards the Mr 140,000 polypeptide. Instead, proteolytic Fn‐fragments, lacking the cell binding site, did not bind to any proteins in the assay. Radioactive cell‐surface labelling showed differences in the corresponding surface polypeptide profiles of normal and malignant cells. The results suggest that the failure of pericellular matrix deposition in malignant cells could be due to either defective surface exposition or defective binding property of the Fn‐receptor‐like polypeptides.
Thrombin stimulates arachidonate metabolism in murine tumor cells
Authors: Lampugnani Maria Grazia , Donati Maria Benedetta
Published: February 2007

Thrombin can be formed in the tumor cell microenvironment following activation of the clotting cascade by procoagulants of cancer or host cells. We have tested here the effects of thrombin, either “endogenous” or “exogenous” (see below), on arachidonate mobilization from membrane phospholipids of mouse mammary tumor virus‐induced (MMTV) carcinoma cells. These tumor cells exhibit in vitro a tissue type procoagulant activity (130 thromboplastin units/10cells) and are therefore able to induce thrombin formation in a plasmatic milieu.

To verify the effect of thrombin formation by tumor cell procoagulant (“endogenous thrombin”), either human or mouse platelet‐free plasma (20% in DMEM) was added to the cell layer (prelabelled for 5 hr with a trace amount (0.013 μm) of H‐arachidonate) and the system was recalcified (15 mm CaCl2). Thin‐layer radiochromatography of the culture medium showed a significant release of H‐labelled arachidonate products PGE2, PGF2α and 6‐ketoPGFIα after 1 hr of incubation.

To verify the effect of thrombin formation from host sources (“exogenous thrombin”), either bovine or purified human α‐thrombin (0.1–10 U/ml) was added to the cells for different periods (from 5 min to 20 hr). Exogenous thrombin stimulated arachidonate release and metabolism in a dose‐related manner. With short labelling periods (0.013 μm H‐arachidonate for 30 min‐1 hr) thrombin stimulated the release of unmetabolized H‐arachidonate, but not of H‐arachidonate metabolites. These processes were inhibited by a specific inhibitor of thrombin enzymatic activity (α‐NAPAP, 140 μm) and by a cyclo‐oxygenase inhibitor (ASA 4mm). Tumor‐associated procoagulants may thus contribute not only to fibrin deposition but also to generation of multipotent mediators such as arachidonate metabolites.
Cytogenetic studies on B‐cell leukemias of akr origin
Authors: Trakhtenbrot Luba , Peled Alpha , Haran‐Ghera Nechama
Published: February 2007

The karyotype of B‐cell leukemias of AKR origin was studied by G‐banding. In contrast to previous observations indicating trisomy of chromosome 15 in spontaneous and chemically‐induced B‐cell leukemias, 11 out of 15 tumors analyzed had normal diploid karyotypes. Four tumors with the modal number 39‐41 had different chromosome markers specific for each tumor. The possible correlation between non‐random chromosomal changes and the target cell involved in the initial transformation in AKR leukemogenesis is discussed.
Transformation sensitivity in early S‐phase and clonogenic potential are target‐cell characteristics in liver carcinogenesis by n‐methyl‐N‐nitrosourea
Authors: Maguire S. , Rabes H. M.
Published: February 2007

Changes in the transformation sensitivity of hepatocytes during the cell cycle were in relation to clonogenicity investigated in partially resected rat liver. The hourly rate of the G1‐S transit was measured in a control group by means of tritium‐labelled thymidine (H‐TdR). At defined periods after partial hepatectomy the animals were injected with a single dose of N‐methyl‐N‐nitrosourea (MNU) (25mg/kg) and subsequently exposed to phenobarbital (0.05% in the diet) for 80 days. ATPase‐deficient cell populations which arise by clonal growth (Rabes et al., 1982) were determined in the liver 90 days after MNU treatment and served as a marker for the initiating action of the carcinogen. The number of foci appeared to be related to the hourly rate of influx of hepatocytes into DNA synthesis at the time of MNU administration. Few foci were observed after MNU exposure in G1 and their frequency increased steeply when MNU treatment coincided with the first peak of cellular G1‐S transit. As the rate of influx into S‐phase decreased, so did the number of foci, despite the proportion of cells in S‐phase still being at a maximum. The possibility of a gradient of clonogenicity existing within the cells of the liver lobule is envisaged. It is suggested that proliferative cells of the peri‐portal region, which begin DNA synthesis early after partial hepatectomy, have the greatest ability to form clones of ATPase‐deficient putative pre‐neoplastic foci after initiation by a carcinogen and might thus represent, if exposed to carcinogen in early S‐phase, the effective target cell population for the induction of hepatocellular carcinomas.
EBV‐transformed lymphoblastoid cell lines down‐regulate ebna in parallel with secretory differentiation
Authors: Wendel‐Hansen Vidar , Rosén Anders , Klein George
Published: February 2007

Four monoclonal and one polyclonal lymphoblastoid cell line (LCL) were studied with regard to cytoplasmic immunoglobulin (clg) expression, presence of the Epstein‐Barr virus (EBV)‐determined nuclear antigen (EBNA) and DNA synthesis. Each line was found to consist of two subpopulations, with only minimal overlap. Proliferating, EBNA‐positive, clg‐negative cells formed the majority. The minority were EBNA‐negative, contained abundant clg and were largely non‐proliferating. This suggests the continuous occurrence of a maturation process within each LCL. The concomitant downregulation of EBNA raises the interesting question whether continued synthesis of the nuclear antigen is incompatible with differentiation for epigenetic reasons, or, alternatively, whether differentiation takes place when the viral genomes are suppressed or lost.
Increased therapeutic efficacy of CIS‐platinum complexes of poly‐L‐glutamic acid against a murine carcinoma
Authors: Schechter B. , Wilchek M. , Arnon R.
Published: February 2007

Cis‐diamminedichloroplatinum(II) (cis‐DDP) and cis diamminediaquoplatinum(II) nitrate (cis‐aq) were complexed to poly‐L‐glutamic acid (PG) of Mr 13,000 or 58,000. Soluble complexes were formed by mixing the platinum(II) compounds with the PG preparations in water at a molar ratio of one platinum(II) to 5 glutamyl residues of the PG. Compared to free cis‐DDP, the complexes were about 2 to 6 times less cytotoxic to F9 embryonal carcinoma cells in vitro. In vivo studies with this tumor indicated that when administered i.p. one day after the tumor cells, the complexes were somewhat less active than cis‐DDP. However, in comparison to the free drug which, due to its toxicity, was effective only within a very narrow dose range, the complexes were much less toxic, manifesting a wide therapeutic range in which no mortality occurred either from the tumor or as a result of the toxic effects of the drug. Cis‐DDP and cis‐aq complexes of PG Mr‐58,000 were somewhat more toxic than the complexes of PG Mr, 13,000. The in vivo anti‐tumor activity of most complexes was superior to that of free cis‐DDP when tested in mice carrying high tumor loads. Due to their wide therapeutic range, the complexes could be given at high drug doses resulting in increased life span of the tumor‐bearing mice. Moreover, 3 repeated injections of these high doses did not cause death from toxicity and resulted in partial or total eradication of advanced tumors.
A line of non‐tumorigenic mouse melanocytes, syngeneic with the B16 melanoma and requiring a tumour promoter for growth
Authors: Bennett Dorothy C. , Cooper Philip J. , Hart Ian R.
Published: February 2007

An immortal line of pigmented melanocytes, “melan‐a”, has been derived from normal epidermal melanoblasts from embryos of inbred C57BL mice. The conditions favouring proliferation of these cells largely resemble those for normal, non‐established mouse melanoblasts and melanocytes, and include a low extracellular pH and the presence of a tumour promoter, tetradecanoyl phorbol acetate (TPA) or teleocidin. Melan‐a cells have the diploid chromosome number and do not form tumours in syngeneic or nude mice. They are therefore the first known line of non‐tumorigenic mouse melanocytes, although an aneuploid melanocyte line of untested tumorigenicity has been reported (Sato et al., 1985). Melan‐a cells are syngeneic with the B16 melanoma and its sublines, and provide an excellent parallel non‐tumorigenic line for studies of the cellular and molecular basis of melanoma malignancy.
Use of oral contraceptives and risk of invasive cervical cancer in previously screened women
Authors: Ebeling K. , Nischan P. , Schindler Ch.
Published: February 2007

Within the context of a larger hospital‐based case‐control study carried out to assess the efficacy of cervical cancer screening, the possible association between oral contraceptives and risk of invasive cervical cancer has been studied as well. Because in the GDR cytological screening is an integral part of the gynaecological basic care, only a few women reported oral contraceptive use but had no Pap‐smears in that study. Thus, the analysis was confined to those 129 cases and 275 controls who had at least one screening Pap‐smear in their history and were below the age 55. The significantly increased relative risks for users decreased after adjustment for factors of sexual behaviour and interval since last Pap‐smear but remained statistically significant or at borderline significance for some categories of usage. This concerns, in particular, long‐term use (7+ years) and early onset of use (⩽ 24 years) with relative risks of 1.8 and 3.0, respectively.
Comparison of circulating mam‐6 and cea levels and correlation with the estrogen receptor in patients with breast cancer
Authors: Hilkens J. , Bonfrer J. M. G. , Kroezen V. , Van Eykeren M. , Nooyen W. , De Jong‐Bakker M. , Bruning P. F.
Published: February 2007

MAM‐6 and CEA serum levels of 136 staged breast cancer patients were determined concomitantly. The sensitivities of the MAM‐6 assay using monoclonal antibody (MAb) II5D8 and a polyclonal CEA assay were equally low and only a limited number of patients with early stages of breast cancer showed elevated antigen levels. However, the sensitivity rose to 75% for MAM‐6 and to 60% for CEA in stage‐IV patients. The levels of both antigens correlated well in the sera of these patients, although MAM‐6 serum levels were elevated more frequently, while only in a few cases were MAM‐6‐negative sera CEA‐positive. A group of stage‐II breast cancer patients who eventually developed distant metastases was followed in a longitudinal study. Tumor progression or regression was clinically determined and compared with the MAM‐6 and CEA serum levels in order to establish the value of each assay for the monitoring of breast cancer. The course of the disease correlated significantly better with changes in MAM‐6 antigen levels than with changes in CEA levels (p<0.05), being 79% and 42% respectively. The lower correlation of CEA levels with the course of the disease was mainly due to a lower sensitivity of the CEA assay for advanced breast cancer. The specificity of changing MAM‐6 and CEA levels was not significantly different. The main advantage of the MAM‐6 assay over the CEA assay is the higher sensitivity of the former. In a preliminary study among stage‐IV patients a correlation was found between elevated MAM‐6 levels and the presence of the estrogen receptor in the primary tumor.
Analysis of the results of the micronucleus test in patients presenting upper digestive tract cancers and in non‐cancerous subjects
Authors: Mandard A. M. , Duigou F. , Marnay J. , Ph.‐Masson  , Qiu‐Song‐Lang  , Yi‐Jing‐Shu  , Barrellier P. , Lebigot G.
Published: February 2007

A micronucleus test was performed on 75 subjects of whom 38 presented with cancer of the upper digestive tract and 37 were free of disease; the absence of cancerous or pre‐cancerous lesions in this latter group was confirmed by endoscopy and vital staining. The daily levels of alcohol and tobacco consumption of the 75 subjects were determined by precise questioning: 78% of the non‐cancerous subjects smoked less than 10 g of tobacco per day whereas 79% of the cancer patients smoked 10 g or more daily. The alcohol intake of 78% of the non‐cancerous subjects and 63% of the cancer patients was less than 101 ml per day. Only 10% of the cancer patients had combined daily intake levels corresponding to the threshold of sensitivity of the micronucleus test as defined by previous studies. The mean frequency of micronucleated buccal cells was 0.26% in the cancer patients and 0.13% in the non‐cancerous subjects. All non‐cancerous patients presented a negative test. Only 5% of the cancer patients presented a micronucleated cell frequency above 1% and could thus be considered as positive. It thus appears that the micronucleus test was not significantly positive in our population of 38 cancer patients.
Characterization of a murine monoclonal‐antibody‐defined B‐lymphocyte carcinoma cross‐reacting antigen (BLCa) from nasopharyngeal carcinoma tissues
Authors: Yip T. C. , Chan K. H. , Choy Damon , Chan C. W. , Ng M. H.
Published: February 2007

Biopsies were obtained from 12 patients suspected of having nasopharyngeal carcinoma (NPC). A portion of the tissue was submitted for histopathology and another for Western blotting using a murine monoclonal antibody (MAb), MA6. Touch smears of the tissues were also prepared immediately prior to extraction and Western blotting for immunoenzymic staining. The results showed that a B‐lymphocyte carcinoma cross‐reacting antigen (BLCa), or an antigen similar to it, was the major antigen in the tumor tissue recognized by MA6. The antigen was detected in tissues from 8 patients, of whom 7 had confirmed NPC and one had eskimoma, but not in tissue from the remaining 4 patients who did not have histologically confirmed malignancy. Immunocytology showed that tumour cells were present in the touch smears from all but one of the tumour patients but not in the other patients, and that the tumour cells comprised the large majority of the MA6‐reactive cell population. The other MA6‐reactive cell types present included certain weakly reactive epithelial cells and occasional lymphoid cells, presumably B lymphocytes. However, these cell types were similarly distributed between the tissues obtained from patients with or without malignant diseases. It was concluded, therefore, that the tumour cells in these tissues are the principal source of BLCa and, as such, the antigen may constitute an objective and reliable marker of NPC.
Characterization of a human B‐lymphocyte carcinoma cross‐reacting antigen (BLCa) in B lymphocytes identified by two murine monoclonal antibodies
Authors: Yip T. C. , Chan K. H. , Ng M. H.
Published: February 2007

The murine monoclonal antibody (MAb) MA6 is selectively reactive against a large variety of human B lymphocytes including those in early stages of B‐cell differentiation such as committed progenitors of B lymphocytes, pre‐B lymphocytes, Burkitt lymphoma cells, and those at later stages of differentiation such as peripheral blood B lymphocytes and myeloma cells. The major antigen identified by this antibody on such B lymphocytes (BLCa) is a 55‐kDa glycoprotein or a group of similar glycoproteins, with the MA6‐reactive determinant localized on the carbohydrate moiety. On isoelectric focusing, this antigen exhibits a degree of charge microheterogeneity, migrating as a diffused band with an average isoelectric point at pH 5.7. BLCa was also identified by another murine MAb, MAS. The antigenic determinant recognized by this antibody is also localized on the carbohydrate moiety of the molecule, but, unlike the MA6‐reactive determinant, it is shared by other glycoproteins from different types of cells.
Susceptibility of various human tissues to transformation in vivo with human papillomavirus type 11
Authors: Kreider John W. , Howett Mary K. , Stoler Mark H. , Zaino Richard J. , Welsh Patricia
Published: February 2007

Human papillomaviruses (HPVs) are associated with proliferative lesions in a variety of human epithelial types. In some cases, the associations are highly specific in that a certain papilomavirus type may infect only one human epithelial cell phenotype. In other cases, one papilomavirus apparently infects several tissue types and not others. Further, HPV replication capacity varies considerably in different epithelia. Due to the lack of a suitable method, it has not been possible, until now, to define the role of the host cell phenotype in determining the outcome of infection with an HPV. We recently developed a system in which human epithelium was exposed to HPV‐II and transplanted to athymic mice. Cervix and skin grafts developed into typical condylomata. We now test the hypothesis that the outcome of infection of diverse epithelial types with a single human papillomavirus is largely determined by the phenotype of the original epithelial cell. For example, skin obtained from a number of disparate sites from a single patient varied dramatically in its capacity for morphological transformation with HPV‐II. Skin from penis was highly susceptible, but skin from abdomen did not transform. Vocal cord from 3 children and 2 adults responded to HPV‐II infection by producing typical laryngeal papillomata. A variety of tissues were obtained from 11 donor infants and infected with HPV‐II. Foreskin and cervical tissues of these children were transformed at a frequency of 100%. Vocal cord was transformed at an incidence of 88% and urethra at 73%. Only 37% of esophagus samples were transformed and both abdominal skin and urinary bladder from the same infants were totally resistant to morphological transformation. In a separate study, ureteral tissues from a child and an adult were completely resistant to HPV‐II infection. Papillomavirus replication was readily detected as capsid antigen in foreskin, cervix, and urethra, but was poorly expressed in morphologically‐transformed esophagi and vocal cords. In the last two tissues HPV‐II DNA and RNA were demonstrated in cells by in situ hybridization techniques. We conclude that the epithelial cell phenotype is a major determinant of HPV‐II infection, controlling both morphological transformation and viral replication.
Tumor progression in human malignant melanoma: Five stages defined by their antigenic phenotypes
Authors: Holzmann Bernhard , Bröcker Eva B. , Lehmann JüRgen M. , Ruiter Dirk J. , Sorg Clemens , Riethmüller Gert , Johnson Judith P.
Published: February 2007

The antigenic profile of melanocytic cells in the course of local and systemic tumor progression of human malignant melanoma was investigated by the reactivity of a panel of monoclonal antibodies (MAbs) in frozen sections of histologically defined melanocytic lesions. Specific antigenic phenotypes made it possible to distinguish 5 groups of lesions which could be ranked in relation to each other due to the sequential acquisition or loss of progression markers. On this basis, a scheme of antigenic changes which accompany the stepwise transformation of normal skin melanocytes into highly malignant metastatic melanoma cells is proposed. The steps of tumor progression identified solely by phenotyping with MAbs were in complete concordance with the concept of melanoma progression derived from histological, statistical and clinical analyses. Furthermore, our finding that the expression of gp89 as well as HLA‐DR antigens can be induced by interferon‐γ in vitro provides evidence that immune interferon may play a role in the regulation of genes leading to phenotypic changes in progressing melanoma cells.
Characterization of ebv‐carrying b‐cell populations in healthy seropositive individuals with regard to density, release of transforming virus and spontaneous outgrowth
Authors: Lewin Nongnit , Åman Pierre , Masucci Maria Grazia , Klein Eva , Klein George , Öberg Bo , Strander Hans , Henle Werner , Henle Gertrude
Published: February 2007

Peripheral or tonsil lymphocyte populations of EBV‐ seropositive donors give rise to EBV‐ carrying LCLs upon In vitro explanation. Such lines can arise either by a 2‐step mechanism, namely release of virus from some of the explanted cells followed by infection of previously uninfected B cells, or by direct outgrowth of virus‐harboring B cells (Rickinson et al., 1974; Dalens et al., 1975; Hinuma and Katsuki 1978; Katsuki et al., 1979). We observed that cells responsible for both the 2‐step mechanism and for direct outgrowth are found in the purified B‐cell compartment. Virus release was more frequent than direct outgrowth. The majority of virus‐releasing cells were found in the low‐density fraction that contains large, activated B blasts. Cells that were capable of spontaneous outgrowth in the presence of the viral inhibitor PFA and of virus‐neutralizing antibody gave rise to cell lines that carried the sex chromosome marker of the original donor, rather than that of admixed cord blood lymphocyte of the opposite sex. Such cells were found in both the low‐ and the highdensity fractions. The majority of the EBV‐carrying B cells in vivo are thus low‐density blasts. Rare small B cells of high density harboring EBV were capable of spontaneous outgrowth. This may be indicative of a host control mechanism that is removed upon cultivation in vitro.
Serum ca 50 as a tumor marker in pancreatic cancer: A comparison with CA 19‐9
Authors: Haglund Caj , Kuusela Pentti , Jalanko Hannu , Roberts Peter J.
Published: February 2007

CA 50 is a new tumor marker based on a monoclonal antibody (MAb) against a human colorectal carcinoma cell line. The CA 50 antigen is similar, but not identical, to the tumor marker CA 19‐9. The serum concentrations of CA 50 were measured by an immunoradiometric assay (CA 50 IRMA) in 95 patients with pancreatic cancer and in 94 patients with benign pancreatic, biliary and hepatocellular diseases. The CA 50 concentration was above the cut‐off limit of 17 U/ml in 71% of the patients with pancreatic cancer. Elevated CA 50 levels were also seen in 29% of the patients with benign diseases (up to 250 U/ml), especially in patients with extra‐hepatic cholestasis (34%) and hepatocellular jaundice (46%). The results of the immunoradiometric assay were compared to those of the commercially available CA 50 RIA inhibition test. The sensitivities of the two CA 50 assays for pancreatic cancer were similar, but the specificity of the IRMA assay was higher. The CA 50 and CA 19‐9 values showed a strong positive correlation and the assay parameters of the tests were almost similar. CA 50 seems a promising tumor marker in the detection and follow‐up of patients with pancreatic cancer.
Proteins phosphorylated on tyrosine as markers of human tumor cell lines
Authors: Giordano S. , Di Renzo M. F. , Cirillo D. , Naldini L. , Piat L. Chiado , Comoglio P. M.
Published: February 2007

Previous work has shown that proteins phosphorylated on tyrosine are selectively detectable by antibodies against phosphotyrosine (P‐Tyr) in cells transformed by retroviral class‐1 oncogene‐encoded kinases endowed with non‐regulated activity (Di Renzo et al., 1986). In this work P‐Tyr antibodies were used to investigate the existence of human tumors expressing abnormal levels of tyrosine phosphoproteins and tyrosine kinases. Among 18 cell lines examined, the antibodies identified a number of tumors with a detectable level of proteins phosphorylated on tyrosine. Among these were a major protein with an approximate Mr of 150,000 in a gastric carcinoma; 2 proteins, with Mr of 130,000 and 110,000 in a colon carcinoma; a major protein with Mr of 170,000, tyrosine phosphorylated in both a urinary bladder and an epidermoid carcinoma; a 100,000 Mr protein phosphorylated in lung and breast carcinomas. An 80,000 Mr tyrosine phosphorylated protein was found in a fibrosarcoma and in a rhabdomyosarcoma. Among the hemopoietic malignancies screened, in 2 Philadelphia‐positive chronic myelogenous leukemias P‐Tyr antibodies recognized the chimeric bcr‐abl 210,000 Mr protein and its substrates. Two tyrosine phosphorylated proteins, one of Mr 70,000 and one of Mr 60,000, were detected in a Burkitt lymphoma line. These phosphoproteins were not found in samples harvested from normal gastro‐intestinal or urinary bladder epithelium, nor in control fibroblasts and lymphocytes. Two of the above proteins have associated tyrosine kinase activity: the 170,000 Mr protein of bladder carcinoma cells was found to be a constitutively phosphorylated EGF receptor.
Expression of multiple growth factors in a human lung cancer cell line
Authors: Betsholtz Christer , Bergh Jonas , Bywater Margaret , Pettersson Monica , Johnsson Ann , Heldin Carl‐Henrik , Ohlsson Rolf , Knott Timothy J. , Scott James , Bell Graeme I. , Westermark Bengt
Published: February 2007

U‐1810, a human large‐cell lung cancer line, was found to express a PDGF‐like growth factor. 35S‐cysteine labelling and immunoprecipitation revealed the synthesis and secretion of a 31‐kDa PDGF‐like protein. Serum‐free conditioned medium contained PDGF‐receptor‐competing and mitogenic activity when tested on human fibroblasts. Whereas the receptor‐competing activity was fully neutralized by anti‐PDGF antibodies, the mitogenic activity was only partially affected. We therefore probed U‐1810 mRNA with a panel of growth‐factor DNA clones. We found expression of the genes for PDGF A‐ and B‐chains, TGF‐α, TGF‐β and IGF‐11 but not EGF or IGF‐1. U‐1810 cells lacked specific binding sites for PDGF but showed specific binding of EGF and expressed EGF‐receptor transcripts. Thus, U‐1810 is an example of a human tumor cell line that expresses multiple growth factor genes; in the intact tumor the corresponding growth factors may operate in autocrine stimulation of the tumor cells as well as in paracrine growth reactions (i.e. stroma recruitment).
Structure and expression of mos sequences in spontaneous and moloney murine sarcoma virus‐induced yolk sac carcinomas in rats
Authors: Decock B. , Sobis H. , Van Hove L. , Vandeputte M. , Billiau A.
Published: February 2007

Facilitation of yolk‐sac carcinoma (YSCa) development in fetectomized rats by the Moloney murine sarcoma virus/murine leukemia virus (Mo‐MSV/MLV) complex was found to be closely associated with the presence of Mo‐MSV sequences in the genomes of the YSCa cells. The virus‐induced YSCas consisted of cells of mono‐ or oligoclonal origin which always contained in their genomes at least 1 randomly integrated Mo‐MSV provirus. In YSCas which developed in the absence of virus, no rearrangement or amplification of c‐mos could be detected. In addition, blot hybridization analysis of cellular RNA failed to detect mos‐related RNA in cell lines derived from Mo‐MSV‐induced as well as from non‐virally induced YSCas. The methylation level of c‐mos DNA was low in all YSCa cell lines. In contrast, v‐mos DNA in cell lines derived from Mo‐MSV‐induced YSCas was heavily methylated.
Influence of the administration schedule on the therapeutic effect of interleukin‐2
Authors: Vaage Jan , Pauly John L. , Harlos James P.
Published: February 2007

The local and systemic therapeutic effects of multiple peritumoral injections of recombinant human interleukin‐2 (IL‐2) were tested against the syngeneic, immunogenic mammary carcinoma MC2 implanted subcutaneously into C3H/He mice. Multiple (12) low‐dose injections had a greater local therapeutic effect than the same total amount of IL‐2 given in 2 injections. Peri‐tumoral injections were equally effective in inhibiting the growth of the injected tumors in normal and in immunized mice. The systemic therapeutic effect was manifested by the inhibition of tumors implanted contra‐laterally to the injected tumors, and was only discernible in non‐immunized mice.
Benzo(a)pyrene metabolism by lymphocytes from normal individuals and individuals carrying the mediterranean variant of glucose‐6‐phosphate dehydrogenase
Authors: Feo F. , Ruggiu M. E. , Lenzerini L. , Garcea R. , Daino L. , Frassetto S. , Addis V. , Gaspa L. , Pascale R.
Published: February 2007

In vitro growing human lymphocytes (HL) and fibroblasts, isolated from glucose‐6‐phosphate dehydrogenase (G6PD)‐de‐ficient subjects (Mediterranean variant), show a sharp decrease in this enzymatic activity and in NADPH:NADP+ ratio. These cells are less able than controls to hydroxylate benzo(a)pyrene (BaP) when tested in the absence of an exogenous NADPH‐generating system. They exhibit great resistance to the toxic effect of BaP. G6PD‐deficient fibroblasts are less prone than controls to in vitro transformation by BaP. To investigate whether this depends on a decreased production of active BaP metabolites and BaP:DNA adducts by G6PD‐deficient cells, BaP metabolism was studied in G6PD‐deficient HL cultured in vitro in the presence of mitogens and treated with BaP for 24 hr. HPLC profiles of organo‐ and water‐soluble metabolites revealed that both types of benzo(a)anthracene (BaA)‐induced HL produced: 4,5‐, 7,8‐, 9,10‐diols, 1,3‐, 3,6‐quinones, 3‐, 9‐hydroxy and 2 peaks of more polar metabolites. There was a 25‐76% decrease of organo and water‐soluble metabolites in the G6PD‐deficient cells. When HL were incubated with 7,8‐diol, the formation of metabolites mutagenic for Salmonella typhimurium (His‐) was very low in G6PD‐deficient cells. BaP:deoxyadenosine (dAde) and BaP:deoxyaguanosine (dGua) adducts were identified after incubation of both types of HL with BaP. There was a 31‐79% fall in adduct formation by G6PD‐deficient cells. Our results indicate that G6PD‐deficient human lymphocytes are less able to metabolize BaP than normal lymphocytes. We suggest that the NADPH pool is inadequate, in deficient cells, for active BaP metabolism.
Aryl hydrocarbon hydroxylase in lymphocytes and lung tissue from lung cancer patients and controls
Authors: Kärki Niilo T. , Pokela Risto , Nuutinen Lauri , Pelkonen Olavi
Published: February 2007

The inducibility of aryl hydrocarbon hydroxylase (AHH) activity in peripheral mitogen‐treated lymphocytes, and of AHH and other monoxygenase activities in lung samples, was studied in 41 patients–34 with pulmonary carcinoma, 4 with a benign lung tumour and 3 with chronic obstructive pulmonary disease. Lymphocyte AHH induction alone was studied in 43 non‐smoking and 37 smoking surgical patients. Absolute induced and non‐induced AHH activities were at about the same level in the lymphocytes from the lung cancer patients as in those from the non‐smoking controls, whereas the activities in smoking controls were about 100% higher. The mean inducibility ratios were very similar in all groups, ranging from 4.4 in the benign tumour patients to 5.4 in both control groups. Thymidine incorporation was on average about 40% lower in the lymphocytes from the lung cancer patients. AHH activity was detectable in all the peripheral lung samples, both normal or tumorous tissue, and its inter‐individual variation was more than 67‐fold. ECDE activity was also detectable in all the samples studied and its correlation with AHH activity was statistically significant (r = 0.888), suggesting that the same enzyme metabolizes both substrates. ERDE was detectable only in the samples with the highest AHH and ECDE activities. There was no correlation between basal or induced lymphocyte AHH activities and lung tissue AHH activity, but there were statistically significant correlations between lung AHH activity and the inducibility ratio with (r = 0.618) or without correction by thymidine incorporation (r = 0.442). These correlations suggest that there are common regulatory factors for AHH inducibility in different tissues. No significant difference in any drug metabolism parameter measured was observed between the lung cancer patients and the controls.
Human papillomavirus type 17 transcripts expressed in skin carcinoma tissue of a patient with epidermodysplasia verruciformis
Authors: Yutsudo Masuo , Hakura Akira
Published: February 2007

Certain types of human papillomavirus (HPV) are involved in skin carcinogenesis in epidermodysplasia verruciformis. However, no gene or gene product of HPV associated with skin carcinogenesis has yet been identified. Here, we report HPV‐17 transcripts expressed in skin carcinoma tissue of an epidermodysplasia verruciformis patient infected with HPV‐17. Further, we show that one of these transcripts was localized to a portion of the genome which contains the 3′ open reading frames of the early region (E2, E3, E4 and E5). The analogous region in bovine papillomavirus type I has been shown to contain a transforming gene (Nakabayashi et al., 1983; Sarver et al., 1984; Yang et al., 1985a).
Ultrastructural evidence of collagenolytic activity in ductal infiltrating carcinoma of the human breast
Authors: Pucci‐Minafra Ida , Luparello Claudio , Schillaci Rosario , Sciarrino Serafina
Published: February 2007

The stroma of ductal infiltrating carcinoma of the human breast shows characteristic and localized areas of collagen rarefaction and fragmentation. This finding has been correlated with a peculiar type of fibrillar damage, observed in a small percentage of collagen fibrils isolated in the native state from the tumour stroma. The same pattern of lesion has been reproduced in vitro by human collagenase digestion on reconstituted fibrils. No effect has been detected by other nonspecific proteases in the same system.
Karyotypic analyses of metastatic and non‐metastatic mouse tumor cells by g‐and c‐banding
Authors: Verschaeve L. , De Baetslier P. , Kirsch‐Volders M.
Published: February 2007

Cytogenetic studies using G‐ and C‐banding were performed in order to compare non‐metastasizing BWO mouse thymoma cells with their metastatic BW‐IS‐Li and BW‐O‐Lil variants. BW‐IS‐Li and BW‐O‐Lil cells were obtained from liver metastases generated respectively after intra‐splenic or intravenous inoculation of mice with BWO cells. BW‐O‐Lil cells contained normal chromosomes 4 and 18 which were never found in BWO or BW‐IS‐Li cells. As they also contained several markers common to the BWO parental cell line, our data provide definite evidence that the BW‐O‐Lil cell line results from spontaneous in vivo cell fusion between a BWO cell and a normal host cell. Chromosome 3 was also shown to be “rearrangement‐prone” and was less represented among metastatic cell variants. These variants also lack a C‐band‐deficient marker chromosome which was found in most of the BWO cells. However, as many complex chromosome rearrangements were found in all 3 cell lines, at least some chromosomal material may be present in a hidden form. We were not able in this particular cell system to link the presence or absence of a single chromosome, chromosome fragment or rearrangement to the acquisition or expression of metastatic properties.
Evidence for a warfarin‐sensitive serum factor that participates in factor x activation by lewis lung tumor cells
Authors: Fasco Michael J. , Wilson Adrian C. , Lincoln David , Gierthy John
Published: February 2007

Mouse Lewis lung (LL) carcinoma cells possess a factor X activator (procoagulant) that is inhibited in vivo by warfarin treatment or diet‐induced vitamin K deficiency. This inhibition suggests that vitamin‐K‐dependent proteins are involved in LL cell activation of factor X. A LL primary tumor clone (LL13) was isolated which contained a warfarin‐sensitive vitamin‐K cycle of metabolism and expressed factor X procoagulant activity. LL13 cells exposed to media containing warfarin or deficient in vitamin K grew as well as cells in normal media, and activated factor X to similar extents. In contrast, administration of warfarin to mice bearing LL13 cells inhibited factor X procoagulant activity as well as the vitamin K cycle of metabolism in the primary tumors. In relation to LL13 cells grown in media containing fetal bovine serum, those incubated for 20 hr in media containing mouse serum or the sera from LL13‐bearing mice exhibited 9‐ to 10‐times higher levels of factor X procoagulant activity. However, LL13 cells exposed to media containing the sera of warfarin‐treated LL‐13‐bearing mice or to barium‐sulfate‐adsorbed normal mouse serum activated factor X much less efficiently. Collectively, these data suggest that inhibition of vitamin K function in LL cells does not affect the extent of factor X activation and thus the intrinsic factor X procoagulant is not a vitamin‐K‐dependent protein. They further suggest that both a warfarin‐sensitive (vitamin‐K‐dependent) protein present in normal mouse serum and a LL13 cell component participate in factor X procoagulant activity.
Lifespan extension of basal cell nevus syndrome fibroblasts by transfection with mouse pro or v‐myc genes
Authors: Shimada T. , Dowjat W. K. , Gindhart T. D. , Lerman M. I. , Colburn N. H.
Published: February 2007

Dermal fibroblasts from patients with the autosomal dominant cancer‐prone disease Basal Cell Nevus Syndrome (BCNS) exhibit a serum dependence, anchorage dependence and in vitro lifespan (about 20 population doublings or less) similar to those of fibroblasts from normal age‐, race‐ and sexmatched controls. Transfection with v‐myc or with an activated mouse pro‐1 gene (which specifies sensitivity to promotion of neoplastic transformation in JB6 mouse epidermal cells) specifically conferred partial immortality on the BCNS fibroblasts by substantially extending their population doubling levels by more than 19 population doublings. This suggests that either v‐myc or pro‐1 gene can cooperate with BCNS gene(s) to produce an extension of lifespan or partial immortality. However, the transfected BCNS fibroblasts that escaped senescence were anchorage‐dependent even after exposure to the tumor promoters 12‐O‐tetradecanoyl‐phorbol‐13‐acetate (TPA), epidermal growth factor (EGF) or plateletderived growth factor (PDGF). These observations indicate that BCNS fibroblasts differ from their normal counterparts in susceptibility to extended growth and may therefore be pre‐neoplastic. It is clear that they require more than an activated pro or myc gene for progression to the tumor cell phenotype.
Monoclonal antibody DLC‐48: An effective reagent for use in the depletion of malignant lymphoma from human bone marrow
Authors: Winter Jane N. , Marder Robert J. , Radosevich James A. , Epstein Alan L.
Published: February 2007

A combination of large‐cell lymphoma cell lines was used as immunogen in the production of DLC‐48, a mouse monoclonal antibody (MAb) to a B‐cell‐associated antigen. This reagent identifies a protein found on a majority of peripheral blood B‐cells, B‐cell derived tumor cell lines, and lymphoma biopsy specimens. In reactive lymph‐node sections, DLC‐48 stains both germinal center and mantle zone B‐lymphocytes when the immunoperoxidase technique is used. DLC‐48 is an IgM, and is highly cytotoxic in the presence of human serum complement. The conditions for complement‐mediated cytotoxicity were first optimized by utilizing the chromium‐release assay with 2 large‐cell lymphoma cell lines, and were then applied to the treatment of the cell lines prior to cloning in agar. A single treatment with antibody and human serum eliminated 4 orders of magnitude of target cells. The cytolytic activity of this antibody was not inhibited by the presence of a 20‐fold excess of normal human bone marrow. Treatment with antibody and autologous serum did not affect the growth of human hematopoietic progenitor cells (CFU‐GEMM and CFU‐GM). These results suggest that DLC‐48, either alone or in combination with other MAb reagents, should be effective in eliminating malignant cells of B‐lineage from human bone marrow for purposes of autologous bone‐marrow transplantation.
A comparison of fresh and cultured T lymphocytes from patients with ataxia telangiectasia using T‐cell subset markers and chromosome translocations
Authors: Butterworth S. V. , Taylor A. M. R.
Published: February 2007

Ataxia telangiectasia (A‐T) is an autosomal recessive disorder in which patients show an unusual predisposition to lymphoid malignancies including T‐cell leukaemia. We compare here the surface phenotypes of fresh and cultured A‐T T cells. A total of 17 T‐cell cultures from 8 A‐T patients are compared with each other and with 5 T‐cell cultures from normal individuals. The large, cytogenetically abnormal t(14;14) and t(X;14) clones in 2 of the patients both occurred only in the CD8 + population of T lymphocytes. There was no difference in the rate of growth of A‐T T cells in vitro compared with those from normal individuals, although many of the original characteristics of the T cells were lost, including the cytogenetically abnormal clones seen in fresh A‐T lymphocytes.
Distribution pattern of human papilloma virus 16 genome in cervical neoplasia by molecular in situ hybridization of tissue sections
Authors: Schneider Achim , Oltersdorf Tilman , Schneider Volker , Gissmann Lutz
Published: February 2007

Using a highly sensitive method with single‐stranded RNA probes, we analyzed the distribution pattern of HPV 16 DNA by in situ hybridization in CIN 11 (10 cases), CIN III (11 cases) and in invasive cervical carcinoma (17 cases). The technique used detected as little as 20–50 viral genomes per cell. This sensitive technique unmasked HPV 16 genomes in the basal cells of all forms of CIN. In CIN III viral genomes were present throughout the entire thickness of the epithelium. There was a striking difference in the distribution of viral DNA in CIN II compared with CIN III and invasive cancer. Variable viral genome distribution was observed in CIN II with the highest copy number in the area of epithelial differentiation. In contrast, CIN III showed a uniform distribution pattern of HPV genomes reflecting the lack of epithelial maturation. The majority of invasive carcinomas showed the same uniform distribution of the HPV 16 genomes as CIN III.
Comparison between the effects of dietary fat level and of calorie intake on methylnitrosourea‐induced mammary carcinogenesis in female sd rats
Authors: Beth Maren , Berger Martin R. , Aksoy Meral , Schmähl Dietrich
Published: February 2007

The aim of this study was to separate the effects of calorie intake on tumorigenesis from those of fat content and fat composition in an animal model. Our principal observations were the following. (1) Decreasing the calorie level by 30% significantly inhibited tumor development in any observed parameter of tumorigenesis, independently of the level of fat. (2) The fat content of semi‐synthetic diets, although varying by 44.4%, did not significantly influence mammary tumorigenesis; in fact, carcinogenic expression was discontinuously related to the fat level. A plateau of tumor incidence was observed at the level of 35 energy percentage of fat. (3) Fat composition did not influence tumorigenesis or body weight gain. The role of caloric restriction is thus stressed in relation to possible dietary prevention of cancer.
Establishment of a new human myeloma cell line (u‐2030) and selection of a hat‐sensitive subline
Authors: Jernberg H. , Björklund G. , Nilsson K.
Published: February 2007

We have established a new human myeloma cell line from the pleural effusion of a patient with an IgAλ myeloma, using special tissue culture conditions and selection procedures to prevent the outgrowth of contaminating Epstein‐Barr virus (EBV)‐carrying normal B‐lymphoblastoid cells present in the explant. The myeloma cell line, U‐2030, is aneuploid and EBNA‐negative and has morphological features, reactivity with cytochemical markers and cell‐surface antigen expression typical of plasmablasts. The cell line thus appears to be representative of the malignant clone in vivo. However, functionally the line is a non‐lg‐producer and must therefore be derived from a non‐secretory variant cell present within the highly aneuploid myeloma cell clone in vivo. The U‐2030 differs from previously established human myeloma cell lines in that it has a comparatively high growth rate, is clonable and can be made HAT‐sensitive relatively easily. This, together with the facts that it is a non‐lg‐producer and mycoplasma‐free, suggests that the 6‐thioguanine‐resistant, HAT‐sensitive subline, U‐2030 TG, derived from this cell line may be used as a malignant fusion partner for the production of human‐human hybridomas. An EBV‐carrying lymphoblastoid cell line (U‐2031) was also established. This line was diploid and had all the phenotypic properties of lymphoblastoid lines established from normal individuals.