UMLS:C0027651 - FACTA Search

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Query: UMLS:C0027651 (tumor)
685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RA 233, a pyrimido-pyrimidine analogue developed originally as an antiplatelet agent, has reduced the incidence of tumor metastases in clinical trials. However, in animal tumor models antimetastatic therapy using RA 233 has been inconsistent. We therefore tested RA 233 for additional effects, such as its direct action on tumor cells. Using the rat 13726NF mammary adenocarcinoma tumor system, low, nontoxic concentrations of RA 233 had pleiotropic and differential effects on two 13762NF tumor cell clones. The growth of MTC cells (low spontaneous metastatic potential) was not affected by low concentrations of RA 233 (50 microM) or epidermal growth factor (EGF) (up to 10 ng/ml) for 3 days in 0.5-10% fetal bovine serum. In contrast, MTLn3 (high spontaneous metastatic potential) cell cultures maintained for 3 days in low (0.5-1%) serum in the presence of 1.25-10 ng/ml EGF doubled in cell numbers compared with control cultures, and addition of 50 microM RA 233 abrogated the growth-stimulatory effect of EGF. The inhibitory effect of RA 233 on MTLn3 cells was dose dependent and not due to cell toxicity as determined by cell viability, cell growth, and colony formation properties after drug removal. In addition, incubation of MTLn3 cells with 50 microM RA 233 resulted in an increase of p21ras protein expression, whereas there was no effect on the level of p21ras in identically treated MTC cells or when either clone was treated with 10 ng/ml EGF. The results suggest that among the heterogeneous effects of RA 233 on tumor cells, modulation of growth factor responses and regulatory molecules may be important.
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PMID:Pyrimido-pyrimidine modulation of EGF growth-promoting activity and p21ras expression in rat mammary adenocarcinoma cells. 305 58

A rat hybridoma producing IgM monoclonal antibody (MAb) GP21:56 was generated with specificity for a high-molecular-weight, mucin-like glycoprotein (gp580) present on highly metastatic 13762NF rat mammary adenocarcinoma cells. The hybridoma was made by fusing rat Y3 Ag1.2.3 myeloma cells with spleen cells from a rat immunized i.d. with purified gp580. The gp580 appeared to be of low immunogenicity in syngeneic F344 rats because a total of 27 fusions were required to produce one hybridoma with specificity for this glycoprotein. Immunoblotting of purified gp580 after electrophoresis in 1% agarose and antibody-binding assays using purified gp580 linked to microtiter plates confirmed that MAb GP21:56 bound specifically to gp580. Other MAbs made against breast mucins were negative for gp580 reactivity. Enzyme-linked immunoabsorbent assays (ELISA) and radiolabelled antibody binding assays demonstrated that MAb GP21:56 bound to 13762NF adenocarcinoma cell lines and clones in relation to their spontaneous metastatic potentials; significantly more MAb GP21:56 bound to highly metastatic MTLn3 cells than to low metastatic MTC cells, and MAb GP21:56 showed little reactivity towards the majority of other cell lines tested, whether of rodent or of human origin. Kinetic binding studies indicated that MAb GP21:56 does not have a high affinity for gp580 but, once bound, it shows high avidity for this sialogalactoprotein. Localization studies using frozen tissue sections of 13762NF tumors indicated that MAb GP21:56 reacts with tumor cells grown in vivo in an analogous manner to in vitro cultured cells. Using immunoperoxidase techniques, less than 50% of the highly metastatic MTLn3 tumor cells were stained, whereas approximately 20% of the intermediate metastatic MTF7 and MTLn2 cells and less than 10% of low metastatic MTC and MTPa cells were stained with MAb GP21:56. The cell-to-cell reactivity was heterogeneous and mainly associated with the tumor-cell surface and extracellular matrix.
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PMID:Development and characterization of a syngeneic monoclonal antibody to a rat mammary tumor metastasis-associated mucin-like cell-surface antigen (gp580). 317 31

Metastatic lines and clones of the rat 13762NF mammary adenocarcinoma have been established that show reproducible spontaneous metastasis from the mammary fat pad to regional lymph node and lung. Poorly (MTC) and highly (MTLn3) metastatic cloned lines derived from tumor growing in the mammary fat pad (MTC) and its spontaneous lung metastasis (MTLn3) were tested in vitro for their abilities to attach to and invade into syngeneic organ tissue and to survive and grow in medium conditioned by target and nontarget syngeneic organ tissues. The highly metastatic MTLn3 cells adhered to and invaded target lung tissue at significantly higher rates than the MTC cells, and bound to and invaded other organ tissues although at lower rates than lung tissue. Similarly, the MTLn3 cells showed significantly higher growth stimulation by lung-conditioned medium than medium conditioned by other tissues. Poorly metastatic MTC cells were not significantly stimulated by any of the organ-conditioned media. The results are consistent with previous proposals that explain preferential organ metastasis in terms of 'seed and soil', and further suggest that metastasis of mammary tumors to specific organ secondary sites is mediated by specific properties, such as those involved in tumor-cell organ-cell adhesion, invasion, and growth.
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PMID:Differential organ tissue adhesion, invasion, and growth properties of metastatic rat mammary adenocarcinoma cells. 324 47

A rat mammary adenocarcinoma cell clone, MTC, and a rat lung endothelial cell clone, RLE cl.4, both syngeneic to the Fisher 344 rat, were compared for proteins synthesized at 37 degrees C and after a 1-h, 42 degrees C heat dose. The heat stress-induced or -enhanced synthesis of a series of molecular mass groups and isoelectric point species (isomers) was observed in both equilibrium and nonequilibrium two-dimensional gel electrophoresis. Tumor and endothelial cell heat-stress proteins (hsp) were strikingly similar with most hsp in 11 or 13 molecular mass groups having from 1 to 12 major isomers. In comparing the two cell types, 6 of about 23 major hsp isomers appeared different in equilibrium pH gels, with tumor cells seemingly exhibiting less synthesis of these 6 isomers. Four additional endothelial cell hsp isomers were apparent in nonequilibrium pH gels. Since two of these later hsp can be found at higher heat doses in tumor cells, some of these apparent differences between tumor and endothelial cells may be attributable to different dose ranges for induction of hsp. Fluorograms and silver-stained gels showed that several hsp were being synthesized at appreciable levels in unheated cells. However, there were hsp whose synthesis appeared to be de novo rather than representing enhanced synthesis of existing proteins. These last two observations were made in both tumor and normal cells. The constitutive levels of hsp synthesis appeared to be generally similar in unheated tumor and normal cells in vitro with few exceptions. These results indicate the presence of few unique hsp in syngeneic tumor and normal cells in vitro. However, focusing subsequent studies on the few differences may lead to insights concerning hyperthermic biology of tumor and normal cells, phenotypic differences between these cells, and roles of some hsp.
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PMID:Heat-stress proteins of rat lung endothelial and mammary adenocarcinoma cells. 356 92

Three rat 13762NF mammary adenocarcinoma clones and cell lines of different metastatic potentials (MTLn3, MTC, and MTPa) were studied for their proton nuclear magnetic resonance spectral characteristics as intact cells in vitro and after chloroform/methanol, neuraminidase, or ethanol treatments. The intact-cell spectral characteristics of the highly metastatic tumor cell clone MTLn3 were clearly distinguished from the less metastatic clone MTC or the parental MTPa cell line on the basis of spectral peaks in the range of 0.9 to 1.45 p.p.m. broad peaks near 2.0 p.p.m., and peaks in the range of 2.75 to 3.2 p.p.m. Glycoproteins are among the molecules known to have resonances in these upfield spectral regions, and these tumor cell subpopulations have previously been shown to possess characteristic quantitative differences in cell surface, metastasis-associated glycoproteins. Treatment of the cells with neuraminidase or ethanol, or extraction with chloroform/methanol increased spectral detail and also revealed characteristic differences in spectral peaks between the tumor cell subpopulations. The identity of the cellular components responsible for these spectral characteristics are unknown, but some clearly arise from differences in the extractable lipids present in the tumor cell subpopulations. Further study will be required to determine if the spectral differences described in this preliminary report are directly related to the known biochemical characteristics of the highly metastatic clone, and if the observations have general relevance to metastatic potential or are a singular feature of these cells. However, these initial results suggest that manipulation of factors which allow unmasking of spectral detail combined with the use of prescribed tumor cell subpopulations may aid in using proton NMR to identify and define biochemical or structural differences related to the metastatic potential of tumor cells.
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PMID:Proton NMR examination of tumor cells of high or low metastatic potential. 365 55

Spleen cells from rats bearing syngeneic metastatic 13762NF mammary adenocarcinoma clone MTLn3 tumors were fused with the rat myeloma Y3 Ag1.2.3 to generate a panel of monoclonal antibodies (MAbs). The MAbs could be divided into three groups: those cross-reactive with all 13762NF cells; those reactive with cloned MTLn3 and MTC cells; and those predominantly reactive with the highly metastatic MTLn3 cells. One of these MAbs, MT10:21 (an immunoglobulin G2a), binds predominantly to highly metastatic MTLn3 cells and has a high tumor-cell affinity as determined by its saturation kinetics. MAb MT10:21 has a 6-h half-life on the MTLn3 cell surface and a 24-h half-life in the blood of syngeneic rats. Immunoblotting experiments using lysates from the cloned 13762NF sublines revealed that MAb MT10:21 binds to several proteins having relative molecular weights of 72,000, 73,000, and 120,000. Using an immunohistochemical procedure with frozen tissue sections, MAb MT10:21 shows little reactivity with normal rat mammary tissue, irrespective of the stage of the estrous cycle, and it failed to react with a number of other normal fetal and adult tissues. Furthermore, MAb MT10:21 is heterogeneous in its reactivity to cloned sublines of the 13762NF mammary adenocarcinoma, on both tissue cultured cells and tissue sections prepared from tumors growing in situ in the mammary fat pads of syngeneic rats. MAb MT10:21 reacted with certain human breast cancer cell lines and with a subpopulation of metastatic human breast cancer cells in frozen tissue sections from biopsies and autopsies. Metastases from breast cancers reacted more intensely than the primary tumors from which they were derived.
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PMID:Monoclonal antibodies against cell-surface antigens of the metastatic rat 13762NF mammary adenocarcinoma and their cross-reactivity with human breast carcinomas. 377 54

Tumor cell subpopulations have been shown to be heterogeneous in a number of phenotypic characteristics, including responses to cytotoxic drugs. This phenotypic heterogeneity has been used here to study mechanisms associated with Adriamycin (doxorubicin HCl)-induced cytotoxicity. Clonogenic survival and alkaline elution methods were employed to examine the response of two tumor cell subpopulations to Adriamycin. The cells were derived from a primary 13762NF rat mammary adenocarcinoma (clone MTC) and a lung metastasis in the same animal (clone MTLn3). The MTC cells were significantly more resistant to Adriamycin than were the MTLn3 cells; the dose effective in reducing cell survival by 50% was 10-fold higher. Protein-associated DNA strand breakage assayed by alkaline elution was dose-dependent in both clones, and MTC cells were again more resistant to break induction than were MTLn3. These results showed that clonal tumor subpopulations isolated from a primary tumor and its metastases possessed different intrinsic survival responses to Adriamycin treatment in vitro and that this survival response correlated with Adriamycin-induced production of protein-associated DNA single-strand breaks.
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PMID:Survival of rat mammary tumor cell clones and DNA strand damage following adriamycin treatment. 379 58

Tissue cultures of four C-cell carcinomas (medullary thyroid carcinoma, MTC) were prepared to study the basal and stimulated calcitonin (CT) and carcinoembryonic antigen (CEA) release. Immunohistological staining of the explants for CT and CEA have been performed after various periods of culture. These MTC explants were able continuously to release CT and CEA for periods up to 157 days. The spontaneous CT and CEA release decreased sharply during the 1st week of culture, then remained nearly constant over the observation period. THE CEA/CT secretion ratio slightly declined during long-term culture; CEA release seems to drop earlier than CT production. CT and CEA could be detected in the same cells by immunocytochemical technique. The septal tissue consisting of dense connective tissue and amyloid produced by tumor cells seemed to increase during long-term culture. CT, but not CEA, was stimulated by pentagastrin (10(-5) M), glucagon (6 x 10 (-6) M), and dose related by calcium (2.5-20 mM) in vitro. The MTC explant organ long-term culture proved to be a useful model for studies of human CT and CEA secretion.
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PMID:Secretion of calcitonin and carcinoembryonic antigen in long-term organ culture of human medullary thyroid carcinoma: biochemical and immunocytochemical studies. 399 Jan 62

NMR can discriminate between malignant and normal tissues. This study attempts to determine if NMR can discriminate between tumor clones of differing metastatic potential derived from the same parent tumor. Rat 13762NF mammary adenocarcinoma clones of either high (MTLn3), intermediate (MTC), or low (MTPa) metastatic potential were grown in roller-bottle tissue culture, harvested during exponential growth phase, centrifuged to form a 0.75-cm3 pellet, and analyzed in a Varian 360L spectrometer operating at 60.0 MHz. Dimethyl sulfoxide (10%) was used as an internal standard at 3.1 ppm downfield from tetramethyl silane (TMS). NMR spectra of replicate samples were analyzed and compared. The position of the water peak for MTLn3 (n = 7) was 5.14 +/- 0.0301 vs 5.07 +/- 0.0207 for MTC (n = 5) and 5.05 +/- 0.009 for MTPa (n = 5) (P less than or equal to 0.001). Integrated area of upfield peaks (where glycoproteins residues are expected to resonate) was 47.43 +/- 7.17 for MTLn3 (n = 6) and 40.95 +/- 5.48 for MTC (n = 4) vs 32.06 +/- 10.1 for MTPa (n = 5) (P less than or equal to 0.05). Previous work with these tumor clones suggests quantitative changes in surface glycoproteins are associated with differences in metastatic behavior. This study demonstrates differences in water peaks between cells of high, intermediate, and low metastatic potential and differences in the integrated area of upfield spectral peaks. How these observations relate to the biologic properties of the cells is uncertain. If they prove to have general validity, NMR could be used to profile biologic potential of human malignancies.
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PMID:Differences in NMR spectra between tumor clones of defined metastatic potential. 399 Feb 81

A slow temperature transient from 37 to 42 degrees C over 3 hr instead of the usual rapid 4- to 7-min transient increases thermal resistance twofold in MTC tumor cells and yet reduces the rates of synthesis of the 70- and 22-kDa heat-stress proteins (hsp) immediately prior to and during expression of thermal resistance--2 to 8 hr after reaching 42 degrees C [S. P. Tomasovic, P. A. Steck, and D. Heitzman, Radiat. Res. 95, 399-413 (1983)]. However, examination of hsp synthesis at earlier times reaching 42 degrees C (0.5 to 2 hr) has revealed differential expression of the individual hsp that is dependent on the rate of heating. Within 30 min of reaching 42 degrees C, cells exposed to slow transients had higher rates of synthesis of the 112- and 90- but not the 70-kDa hsp. However, cells exposed to rapid transients had a higher rate of synthesis of the 70-kDa hsp by 1 hr after reaching 42 degrees C. The rate of synthesis of the 22-kDa hsp was similar in cells heated by either method. Rates of synthesis of the 112-, 90-, and 22-kDa hsp in cells exposed to rapid transients did not equal or surpass the rates for cells exposed to slow transients until between 2 and 3 hr of heating, just before expression of thermal resistance. Rate of heating also had differential effects on total protein synthesized and transport. The total protein synthesized was observed to be 40% higher in slow-transient-treated cells over the first 2 hr. Transport of an amino acid analog, aminoisobutyric acid, was significantly inhibited in rapid-transient cells immediately after reaching 42 degrees C and had not recovered 1 or 5 hr later. Similar to total protein synthesis transport in slow-transient-treated cells was unaffected. There was no significant difference between slow- and rapid-transient-treated cells in hsp degradation, cell-cycle distribution, or amino acid pool sizes in the first 4 to 6 hr after reaching 42 degrees C. These results suggest that although the ultimate thermal dose was about 10-fold higher under slow-transient conditions, the cells receiving this treatment made regulatory or metabolic adjustments, including altered hsp synthesis patterns, that reduced initial heat damage. Either the protection of total protein synthesis or that combined with higher initial rates of synthesis of some hsp could explain the previously reported increased initial D0, increased thermotolerance, and reductions in latter hsp synthesis rates seen following slow temperature transients.
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PMID:Heat transient related changes in stress-protein synthesis. 407 May 48

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