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PubMed1995

Effects of bolesatine on a cell line from the SP2/O thymic lymphosarcoma.

Bolesatine, a toxic protein isolated from Boletus satanas Lenz inhibits in vitro protein synthesis in a concentration-dependent manner in a cell line from a radiation-induced thymic lymphosarcoma (SP2/O) with a 50% inhibitory concentration (IC50) of 9.5 nM (0.6 microgram/ml). In vivo, an i.p. single injection of bolesatine, corresponding to 1/6 and 1/10 of 24-h 50% lethal dose, in Balb/c mice having ascitic tumour induced by the i.p. preinjection of SP2/O cells allows a remission of 50% and 30%, respectively. Treated mice survived 120 days after the treatment, i.e. 90 days after the death of control animals.

Animals↗

PubMed1993

Measurements and analyses of electrophoretic mobilities of RAW117 lymphosarcoma cells and their variant cells.

The electrophoretic mobilities of the cells of malignant lymphosarcoma cell line RAW117-P and its variant H10 with a highly metastatic property to the liver have been measured at various ionic strengths. The cells of parental cell line (RAW117-P) show higher mobility values in magnitude than those of its variant line (RAW117-H10) in the whole range of electrolyte concentration measured. We have also measured the sialic acid amount carried by cells of both lines. The content of sialic acids in RAW117-H10 cells is observed to be about 27% less than that in RAW117-P cells. The mobility data obtained have been analyzed by a novel mobility formula for colloidal particles with ion-penetrable surface charge layers. The observed mobility difference between RAW117-P cells and RAW117-H10 cells is found to be due to the difference in friction exerted by the cell surface layers on the liquid flow around the cells between these two types of cells and to the difference in fixed-charge density in their surface layers, which is caused by the 27% decrease in sialic acid content. A possible explanation for this mobility difference between these two types of cells is given.

Animals↗

PubMed1980

Properties of a cell-culture line derived from lymphosarcoma P1798.

A cell culture line has been derived from lymphosarcoma P1798. Cells will not divide in the prescence of 10(-8) M dexamethasone. Half-maximal inhibition of proliferation occurs at about 10(-9) M. Half-maximal inhibition of [3H] thymidine incorporation occurs at somewhat higher concentrations of dexamethasone. When cells are cultured in the presence of 2 x 10(-7) M dexamethasone they remain 88% viable after 5 days. No decrease in cell number occurs. These cells can be rescued by in vivo passage, and they responded in culture to dexamethasone in exactly the same fashion as do untreated cells. Both dexamethasone rescued and untreated cultured cells contain about 104 dexamethasone receptor sites which bind with a dissociation constant of 4 x 10(-9) M. Cultured cells retain the ability to proliferate both subcutaneously and in ascites. The properties of such tumors resemble those of the parental tumor cell lines.

Animals↗

PubMed1984

Isolation and characterization of lymphosarcoma P1798 variants selected for resistance to the cytolytic effects of glucocorticoids in vivo and in culture.

Clonal subpopulations of lymphosarcoma P1798 have been subjected to glucocorticoid selection in vivo and in culture and the glucocorticoid binding and responsiveness of the resistant variants have been compared with those of the parental lines. Cell populations that are resistant to the cytolytic effects of glucocorticoids in vivo exhibit a slightly reduced level of glucocorticoid binding, although nuclear translocation of the hormone-receptor complex is not reduced. Sensitive and resistant tumors exhibit similar kinetics of hormone uptake and dissociation following a single injection of dexamethasone. Selection for glucocorticoid resistance in vivo does not result in an increase in the modal number of chromosomes. Cells that are resistant to the cytolytic effects of glucocorticoids in vivo are completely sensitive to the antiproliferative effects of glucocorticoids in culture. Moreover, dexamethasone increases the expression of mouse mammary tumor provirus in cytolysis-resistant and sensitive cells both in vivo and in culture. Selection for glucocorticoid resistance in culture yields variants with decreased glucocorticoid binding and/or nuclear translocation of the hormone-receptor complex. These cells appear to express classical receptor-defective phenotypes. Nevertheless, cells that are resistant to glucocorticoids in culture undergo cytolysis when treated with glucocorticoids in vivo. These data indicate that, under certain circumstances, different mechanisms may be involved in loss of glucocorticoid responsiveness in vivo and in culture.

Animals↗

PubMed1989

Isolation and characterization of cortisol-sensitive and -resistant P1798 mouse lymphosarcoma cell lines.

Three cell lines have been isolated and characterized from the P1798 mouse lymphosarcoma. One line, derived from a glucocorticoid-resistant tumor, was glucocorticoid-resistant in vitro. The other two cell lines, derived from glucocorticoid-sensitive and -resistant parental tumors, respectively, were shown to be glucocorticoid-sensitive in vitro. The glucocorticoid receptor from all three cell lines bound glucocorticoid with similar affinity and capacity. However, based on Sephacryl S-300 gel filtration, the glucocorticoid receptor from the resistant cell line was smaller than that of the two sensitive cell lines. Moreover, the glucocorticoid receptor from the resistant cell line accumulated to a greater extent in the nucleus. This resistant cell line thus resembles the nti variant of the S49 lymphoma cell line. All three cell lines were tumorigenic and metastatic when reimplanted into mice, contained the normal mouse diploid complement of 40 chromosomes and exhibited the same responsiveness to cortisol in vivo as they did in vitro. It is concluded that the ready passage of these cell lines in vitro or in vivo and the presence of the small receptor in the resistant line should make them excellent model systems for the study of glucocorticoid resistance.

Animals↗

PubMed1992

Effect of dexamethasone on nucleolar casein kinase II activity and phosphorylation of nucleolin in lymphosarcoma P1798 cells.

Ribosomal RNA (rRNA) synthesis in murine P1798 lymphosarcoma cells is reversibly inhibited by glucocorticoids. The effects of dexamethasone upon nucleolin phosphorylation and upon the amount and activity of casein kinase II have been examined. P1798 cells were exposed to 0.1 microM dexamethasone for 36 h. Cells were labeled in vivo with [32P]orthophosphate followed by immunoprecipitation with anti-nucleolin antibody. Nucleolin phosphorylation was reduced by 60% in dexamethasone-treated cells. Nucleoli were isolated and labeled with [gamma-32P]ATP in vitro. Nucleolin protein was reduced to 40% of control in nuclei from dexamethasone-treated cells. Nucleolin phosphorylation was reduced to 20% of control. Nucleolar casein kinase II activity and protein were also reduced (30-55% and 35-50% of control, respectively) by treatment with dexamethasone. Cycloheximide (10 micrograms/ml for 3 h) reduced the amount and activity of casein kinase II, but did not cause a decrease in nucleolin protein. These observations are discussed relative to the hypothesis that glucocorticoids regulate the amount or activity of proteins of short biological half-life that are involved in the regulation of rRNA synthesis.

Animals↗

PubMed2004

Regulation of activity of cathepsins B, L, and D in murine lymphosarcoma model at a combined treatment with cyclophosphamide and yeast polysaccharide.

Changes in the activity of cysteine (cathepsins B and L) and aspartyl (cathepsin D) proteases were investigated at the development of susceptible and resistant variants of murine lymphosarcoma (LS). It has been demonstrated that the variant resistant to the cyclophosphamide treatment is characterized by a lower activity of all three cathepsins in the tumor tissue. Application of a higher dose of cyclophosphamide led to a more pronounced increase of the studied enzymatic activity in mice with a resistant variant of LS, than in those with a susceptible one. Administration of a yeast polysaccharide derivative - sulfoethyl glucan - enhanced therapeutic effect of cyclophosphamide in mice with both variants of LS, while the most efficient dose was found to be that of 10mg/kg body mass. In the intact mice, usage of both cyclophosphamide and sulfoethyl glucan led to a similar increase of the cathepsins activity in liver and spleen.

Animals↗

PubMedDate not supplied

Sequence of an exon of the feline p53 gene--mutation in a lymphosarcoma.

Exon 8 of tumour suppressor gene p53 was sequenced in domestic cats and showed remarkable similarity to the human sequence. Only four of the 13 nucleotide differences gave rise to interspecific amino acid differences. In an investigated lymphosarcoma we detected a mutation cgg --> tgg (arginine --> tryptophan) in codon no. 282.

Amino Acid Sequence↗

PubMed1991

C cell hyperplasia and carcinoma developing in sheep with experimentally-induced lymphosarcoma.

Two cases of C cell hyperplasia and one case of C cell carcinoma of the thyroid glands were bilaterally recognized in 11 sheep with experimentally-induced lymphosarcoma. The serum calcium concentration in the C cell carcinoma case was slightly increased above the normal concentration of around 9 mg per dl. Bilateral C cell hyperplasia also developed in the thyroid lobes of the C cell carcinoma case. Immunohistochemically, hyperplastic C cells and tumour cells were positive for calcitonin, calcitonin gene-related peptide, chromogranin A and neurone-specific enolase. No amyloid deposition nor multiple endocrine neoplasia was demonstrated in any of the cases. Ultrastructurally, many secretory granules were observed in the cytoplasm of neoplastic cells constituting the C cell carcinoma and in the hyperplastic C cells.

Animals↗

PubMed1984

A spontaneous transplantable lymphosarcoma of the Syrian golden hamster (Mesocricetus auratus): Experimental induction of metastases after subcutaneous and intravenous inoculation.

A spontaneously occurring lymphosarcoma of the Syrian golden hamster was both subcutaneously and intravenously inoculated into 300 female and male animals each. Tumor growth was observed at a 100% rate. Using both types of inoculations, metastases occurred in 50% of the inoculated animals, preferentially in lungs, liver, pancreatic lymph nodes, spleen and kidney. The participation of different lymph node groups was more frequent after subcutaneous application. The transplantable tumor described might serve as a mode for additional studies on experimentally induced metastasis.

Animals↗

PubMed1978

Lymphosarcoma of the mandible associated with macroglobulinemia of Waldenström.

Waldenström macroglobulinemia is a rare progressive immunoproliferative disorder involving lymphocytes and occasionally plasma cells. Unlike the multiple myeloma, this disease has minimal osseous lesions. Lesions in the jaws are very rare. This paper presents a case of lymphosarcoma in the mandible in a 68-year-old woman, who was diagnosed as suffering from Waldenström macroglobulinemia. The possibility of immunosuppression by Leukeran as an aetiologic factor causing the bone lesions is suggested.

Aged↗

PubMed2001

Role of cystatin C and cysteine proteinases in the development of mouse LS-lymphosarcoma.

The growth of LS-lymphosarcoma in CBA mice was accompanied by a decrease in the content of the major extracellular inhibitor cystatin C in the tumor, plasma and, to a lesser extent, in tissues not involved in tumor process (liver and spleen). Cyclophosphamide in a dose of 50 mg/kg prolonged the life-span of animals and decreased tumor size by 80%. Cathepsin B and L activities in the tumor tissue increased by 3 and 7 times, respectively. Cystatin C content in the tumor tissue, spleen, and plasma also increased. Cystatin C assay in tumor tissue and plasma helps to predict the rate of tumor growth and to evaluate the efficiency of antitumor therapy.

Animals↗

PubMed1980

Development of virus non-producer lymphosarcomas in pet cats exposed to FeLv.

Naturally occurring oncoviruses of several species are transmitted contagiously and cause lymphosarcoma (LSA) or leukaemia in their hosts. All naturally occurring oncoviruses replicate in vivo in the tumours they induce or, as with bovine leukaemia virus, can be isolated from tumour cells grown in short-term cell culture. However, we have shown that feline leukemia virus (FeLV) is not present in a significant minority of pet cats that develop LSA. Unlike experimentally induced virus-negative leukaemias and sarcomas of other species, LSA cells from FeLV-negative LSA cats lack any FeLV proteins, including p15 or p12, and complete functional copies of FeLV provirus and thus do not produce FeLV when grown in cell culture. Thus, except for FeLV, the naturally occurring animal leukaemogenic oncoviruses seem to induce only virus-producing lymphoid tumours. Our earlier findings prompted a study to determine the frequency of occurrence of FeLV non-producer (NP) LSA in pet cats and whether NP LSAs develop in cats exposed to FeLV. We report here epidemiological data which indicate that development of NP LSAs in pet cats is associated with exposure to FeLV and suggest that FeLV may be the aetiological agent for FeLV NP feline LSAs. Thus, feline NP LSAs may be suitable for studying the potential viral aetiology and mechanism of leukaemogenesis of human lymphoid tumours in which no oncoviruses have, as yet, been proved to cause the disease.

Animals↗

PubMed1973

The effect of irradiating a transplanted murine lymphosarcoma on the subsequent development of metastases.

Mice were implanted with a lymphosarcoma on either the thorax or leg. Some of these tumours were given a single dose of 240 kV x-rays on reaching a predetermined size, whilst others were left unirradiated.Metastases developed in specific lymph nodes, depending on the position of the transplanted tumour, and were larger if the tumour had been irradiated than if not. The growth rate of metastases in the ipsilateral axillary lymph node was faster than that of the transplanted tumours, irrespective of the radiation dose the tumour had received.

Animals↗

PubMed1978

Arrest patterns of circulating lymphosarcoma cells in tumour-bearing mice as modified by previously injected cell suspensions.

The effects were determined of an initial i.v. injection of 0.2 ml suspensions of 125IUdR-labelled lymphosarcoma cells on the early arrest patterns of a second injection of cancer cells into tumour-bearing mice. The results indicate that interactions between the first injection and the host markedly affected the arrest pattern of the second dose in the lungs, but not the livers, of tumour-bearing animals. These observations are explained on the basis of the injected fluid volumes, which are considerable in mice, in relation to their total blood volumes of approximately 2 ml.

Animals↗

PubMed1980

Surface properties of cells isolated from non-metastasizing and metastasizing hamster lymphosarcomas.

Present evidence suggests that the cell surface has an important role in metastasis. To examine this idea further, the surface properties of single cells isolated from the primary growths of a liver-metastasizing (ML) and a non-metastasizing (NML) lymphosarcoma were compared for adhesion to cell monolayers, cytopherometry, isoelectric focusing, adhesion to immobilized lectins and surface labelling with lactoperoxidase-catalysed radioiodination. It was found that the ML cells had increased adhesion to 3 out of 4 of the monolayers studies; a lower overall surface charge but greater peripheral concentrations of charge; and increased surface expression of the fucose moiety. No consistent difference between the two cell types was detected in the electrophoretic pattern of the labelled surface proteins. These findings are discussed in the light of present knowledge of the cell surface, and it is concluded that the significance of any of the observed changes in relation to metastasis has yet to be established.

Animals↗

PubMed1984

Differences in surface expression of WGA-binding proteins of cells from a lymphosarcoma and its liver metastases.

The protein and glycoprotein compositions of a subcutaneous lymphosarcoma (1 degree) and its metastatic deposits in the liver (2 degrees) have been investigated in Triton X-100 extracts obtained from tissue, single cells and membrane preparations. No consistent differences in the electrophoretic patterns for 1 degree and 2 degrees tissue or cells were observed for separations visualized with the protein stain Coomassie Blue. Substantial and consistent reductions in the glycoprotein content of extracts from 2 degrees tissue or cells were observed if the separated proteins were treated with the radioiodinated lectin, Wheat Germ Agglutinin (WGA). Densitometric scans of autoradiographs indicated that WGA binding occurred in 4 major areas; the approximate mol. wts of these were 180,000, 102,000, 84,000 and 23,000 daltons. All these components except the 23,000 component were shown to be located in the cell membrane and to be reduced in 2 degrees preparations. Possible sources of host contamination were also investigated, but these did not show WGA binding patterns that were similar to that obtained for the tumour. If 2 degrees tumour was transplanted into the 1 degree site, the resultant growth exhibited a WGA-binding pattern normally shown by a 1 degree tumour growing in this site. Conversely, if 1 degree tumour was transplanted into the liver, the WGA binding of the resultant growth was substantially reduced. The results suggest that local and metastatic tumours do contain cells that express different glycoproteins on their surfaces but that the site of tumour growth is a very important factor in determining this difference in surface expression.

Animals↗

PubMed1996

Heat shock selectively inhibits ribosomal RNA gene transcription and down-regulates E1BF/Ku in mouse lymphosarcoma cells.

The effect of heat shock on RNA polymerase I (pol I)-directed transcription of the rRNA gene was studied in S-100 extract derived from mouse lymphosarcoma cells, and by in vivo labelling of rRNA. Exposure of cells to 42 degrees C for 2 h resulted in complete inhibition of rRNA synthesis in vivo. Pol I transcription was inhibited by 50% within 2 h of heat shock and was abolished after 3 h exposure at 42 degrees C. Under this condition, the core-promoter-binding activity of the factor (CPBF) that modulates pol I transcription was unaffected. In contrast, the promoter-binding activity of enhancer-1-binding factor, a protein related to the Ku autoantigen, which is involved in pol I transcription initiation, was reduced by 50 and 90% after 2 and 3 h of heat shock respectively. Western-blot analysis with antibodies specific for the two subunits of Ku protein showed the absence of p72 subunit after 3 h of heat shock. Under this condition, pol II transcription from the adenovirus major late promoter and pol III transcription of 5 S RNA gene remained unaffected. Mixing experiments ruled out the possibility that the inhibition of transcription was due to activation of nucleases or other inhibitors. This is the first report to show selective down-regulation of pol I transcription in vitro by heat shock and of the potential involvement of a pol I transcription factor in this process.

Adenoviridae↗