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1.
Sodium L-glutamate inhibited the growth (due to inhibition of cell division and cell death) of mouse neuroblastoma (NB) cells in culture in a dose dependent fashion. The sensitivity of adrenergic (NBA2(1)) and cholinergic (NBE?) clones to L-glutamate was similar. Sodium D-glutamate, L-aspartate, α-ketoglutarate, glutamine, γ-aminobutyric acid and carbachol did not inhibit the growth of NB cells. Methylmercuric chloride (CH3HgCl), inorganic mercury (HgCl2), manganese chloride (MnCl2) and lead tri-butyl acetate, by themselves inhibited the growth of NB cells in culture to a varying degree ranging from 41% to 49%. However, the combination of glutamate with CH3HgCl, HgCl2 and MnCl2, produced a synergestic effect on growth inhibition of NB cells in culture. The combination of glutamate with lead tri-butyl acetate produced only an additive effect. Sodium kainate neither inhibited the growth nor potentiated the growth inhibitory effect of L-glutamate on NB cells. Neuroblastoma cells contained high levels of receptors for glutamate but not for kainate. These results show that neuroblastoma culture may be a useful model to study the mechanisms of glutamate effects and their modification by various agents.  相似文献   

2.
A connection between the processes of cell death and differentiation is suggested by observations which show that chemical inducers of differentiation are cytotoxic to CCRF-CEM human leukaemic lymphoblasts, cells which have properties typical of immature lymphoid cells. Sodium n-butyrate, salts of other short-chain fatty acids, 5-azacytidine, hypoxanthine, L-ethionine and dimethyl sulphoxide were all cytotoxic to these cells at concentrations similar to those reported to produce reversible growth inhibition in more mature lymphocytes or growth inhibition and differentiation in other cell types. Only actively cycling cells were susceptible to killing by n-butyrate. Inhibitory effects of these compounds on DNA methylation are postulated to be responsible for their cytotoxic actions.  相似文献   

3.
K N Prasad  P K Sinha 《In vitro》1976,12(2):125-132
Sodium butyrate produces reversible changes in morphology, growth rate, and enzyme activities of several mammalian cell types in culture. Some of these changes are similar to those produced by agents which increase the intracellular level of adenosine 3',5'-cyclic monophosphate (cAMP) or by analogs of cAMP. Sodium butyrate increases the intracellular level of cAMP by about two fold in neuroblastoma cells; therefore, some of the effects of sodium butyrate on these cells may in part be mediated by cAMP. Sodium butyrate appears to have properties of a good chemotherapeutic agent for neuroblastoma tumors because the treatment of neuroblastoma cells in culture causes cell death and "differentiation"; however, it is either innocuous or produces reversible morphological and biochemical alterations in other cell types.  相似文献   

4.
Effect of sodium butyrate on mammalian cells in culture: A review   总被引:10,自引:0,他引:10  
Summary Sodium butyrate produces reversible changes in morphology, growth rate, and enzyme activities of several mammalian cell types in culture. Some of these changes are similar to those produced by agents which increase the intracellular level of adenosine 3′,5′-cyclic monophosphate (cAMP) or by analogs of cAMP. Sodium butyrate increases the intracellular level of cAMP by about two fold in neuroblastoma cells; therefore, some of the effects of sodium butyrate on these cells may in part be mediated by cAMP. Sodium butyrate appears to have properties of a good chemotherapeutic agent for neuroblastoma tumors because the treatment of neuroblastoma cells in culture causes cell death and “differentiation”; however, it is either innocuous or produces reversible morphological and biochemical alterations in other cell types.  相似文献   

5.
HL-60, a human promyelocytic leukemia cell line, is induced to differentiate by retinoic acid to mature granulocytes. We have now found that after the addition of 1 μM retinoic acid to HL-60 cultures an increase in NAD+-glycohydrolase (NADase) activity is detected by 6 hr and after a 33-fold increase in activity reaches a plateau by 24 hr. Cycloheximide inhibits completely the retinoic acid-induced increase in NADase activity indicating that enzyme induction requires protein synthesis de, novo. An increase of NADase activity was found not only in HL-60 cells but also in two human monoblast cell lines (U-937 and THP-1) and fresh cells in primary culture from two patients with acute promyelocytic leukemia. An increase in synthesis de, novo of NADase does not appear to be obligatory for differentiation of HL-60 because there was no increase of NADase activity in HL-60 cells induced to differentiate with either dimethylsulfoxide, hypoxanthine, butyrate, or 1, 25-dihydroxycholecalciferol and there were marked increases in NADase activity at concentrations of retinoic acid having little or no effect on differentiation.  相似文献   

6.
Aspirin, indomethacin, and phenbutazone at 50 μM concentration inhibit cyclooxygenase in cultured human foreskin fibroblasts as evidence by the suppression of the major prostaglandin species which aaccumulate in the culture medium. In contrast to data reported for mouse interferon on target mouse cells, these agents have no effect on the introduction of antiviral activity by human α and β interferons. Similarly, these agents have no effect on interferon induced inhibition of cell growth in vitro or on interferon induced natural killer cell activity.  相似文献   

7.
Latent collagenase activity was detected in the media of a well-characterized line of human breast carcinoma cells maintained for over two years in culture. The media also contained sufficient plasminogen activator to convert extrinsically added plasminogen to plasmin which in turn activated the collagenase. During culture of the breast carcinoma in serum-free medium, collagenase activity was maximum on day 12 whereas plasminogen activator activity changed little with time. Using type I collagen as a substrate, the activated breast tumor collagenase produced 34 ? 14 fragments consistent with a mammalian collagenase. These findings suggest a pathologic role of plasminogen activator in the activation of latent collagenase during tumor invasion.A number of investigators have postulated that proteases may play a role in tumor invasion (1–5). Collagenase is one such protease which is active at neutral pH and specifically cleaves triple helical collagen into two (34 ? 14 fragments (6). Secretion of collagenase by tumor cells migrating from the primary mass provides an attractive hypothesis for the mechanism of tumor invasion of surrounding host connective tissue—since the local environment would likely be at neutral pH. Consequently, a number of investigators have reported significant levels of collagenase activity in a wide variety of tumors (7–14). Abramson (13) has correlated aggressive in vivo growth in carcinomas of the head and neck with collagenase activity, and Kuettner et al. (14) have postulated that inhibitors of collagenase may prevent tumors from invading cartilage.Collagenase is produced in both latent and active forms (6). The latent form can be activated with brief protease treatment (15). Since one of the proteases capable of activating collagenase is plasmin (15), the possibility arose that tumor cells could activate collagenase through plasminogen activator. Plasminogen activator secreted by tumor cells (4, 5) could convert plasminogen zymogen to plasmin which would in turn activate latent tumor collagenase. Testing this hypothesis in vitro was the subject of the present study.Previous studies on collagenase from human carcinoma (7, 13, 14) have suffered from the drawback that contaminating inflammatory cells and fibroblasts may have been the source of the collagenase. Therefore, we have studied collagenase production from cultured human breast carcinoma cells which have been well characterized to be mammary epithelial in origin, malignant in karyotype, and able to grow in nude mice. Production of collagenase from these cells is therefore unequivocally of human carcinoma origin. The time course of latent collagenase and plasminogen activator secretion by these cultured tumor cells was studied following withdrawal of serum. To test whether plasminogen activator was secreted in sufficient amounts to indirectly activate latent collagenase, collagenase activity of the culture media was studied after the extrinsic addition of plasminogen. Finally, to verify that the tumor-secreted collagenase cleaved type I collagen at a single locus, enzyme degradation products were studied by gel electrophoresis.  相似文献   

8.
Cytotoxicity and adsorption of pyocin S2 produced by Pseudomonas aeruginosa M47 (PAO 3047) to virally transformed mammalian cells, human malignant cells and normal cells in the same species were studied. Pyocin S2 inhibited the growth of not only tumor cells (XC, TSV-5, mKS-A TU-7, HeLa-S3 and AS-II cells) but also normal cells (BALB/3T3 and BHK 21 cells). The inhibitory effects on the cells increased with an increase of pyocin S2 activity. On the other hand, there were some tumor cells (155-4 T2 and HGC-27 cells) and normal cells (normal rat kidney and human embryo lung cells) which were resistant to pyocin S2. The pyosin S2 activity was neutralized by the cell membrane preparations from pyosin S2-sensitive cells, but not by those from pyocin-resistant cells. This neutralization ability was inhibited by high concentrations of D-galactose, N-acetyl-D-galactosamine and N-acetyl neuraminic acid and completely destroyed by periodate and neuraminidase. The inhibition by the saccharides was concentration dependent. These results suggest that the toxicity of pyocin S2 to several mammalian cells is due to the presence of the binding site for pyocin S2 in the cell membrane and further, that the carbohydrate moiety, especially of D-galactose, N-acetyl-D-galactosamine and sialic acid, may play an important role as an initial binding site for pyocin S2.  相似文献   

9.
Cytotoxic actions of various prostaglandins were examined on L1210 mouse leukemia and several human leukemia cell lines, and prostaglandin D2 (PGD2) was found most active. PGD2 exerted a dose dependent inhibition of L1210 cell growth over 3.6 μM. At 14.3 μM growth was completely inhibited, and the number of viable cells remarkably decreased during culture. Microscopically the remaining cells showed degenerative changes with many vacuoles in their cytoplasm. The IC50 value of PGD2 on L1210 cell growth was calculated to be 6.9 μM (2.4 μg/ml), and at this concentration the DNA synthesis in 24 hr cultured cells was also decreased to a half of the level in the control cells. Such growth inhibition by PGD2 was also found at similar concentrations with several human leukemia cell lines such as NALL-1, RPMI-8226, RPMI-8402, and Sk-Ly-16. Among other prostaglandins tested, PGA2 showed a comparable, and PGE2 a less but significant growth inhibitory activity, while PGB2, PGF and PGI2 had no such effects on cell proliferation at 14.3 μM concentration. These results suggest a potential antineoplastic activity of PGD2.  相似文献   

10.
Tritiated glutamine and choline were released from human glioma cells in culture when incubated in permeant-free solution. Counter transport experiments revealed that the two neurotransmitter precursors were taken up and released by facilitated diffussion transport systems. It is suggested that glial cells invivo can provide neurons with glutamine and choline for transmitter synthesis via such systems.  相似文献   

11.
6-methylpurine 2′-deoxyriboside killed mouse macrophages infected with amastigotes of Leishmania donovani and Leishmania mexicana, but did not affect the growth of non-parasitized cells. Leishmania extracts cleaved the non-toxic 6-methylpurine 2′-deoxyriboside to 6-methylpurine, a potent adenine antimetabolite for mammalian cells. By eliminating macrophages latently infected with Leishmania donovani amastigotes, 6-methylpurine 2′-deoxyriboside could augment the effects of leishmanicidal agents in vivo.  相似文献   

12.
Rat glioma C6 cell polyribosomal preparations were tested in a heterologous in vitro system for their ability to direct the synthesis of nerve growth factor related polypeptides. Two major polypeptides of MW ~ 21,000 and ~ 43,000 respectively were found, both of which were immunoprecipitable with specific anti-mouse 2.5S nerve growth factor serum. After incubation of in vitro synthesized proteins with submaxillary gland extract the bulk of these protein species was converted into immunoprecipitable material of MW ~ 13,000, which comigrated in sodium dodecyl sulfate/polyacrylamide gel electrophoresis with mouse 2.5S nerve growth factor.  相似文献   

13.
The effect of dl-alpha-tocopheryl (vitamin E) succinate in modifying the radiation response of mouse neuroblastoma (NBP2) and mouse fibroblast (L-cells) cells in culture was studied on the criterion of growth inhibition (due to cell death and inhibition of cell division). Results show that vitamin E succinate markedly enhanced the effect of 60CO-gamma-irradiation on NB cells, but it did not significantly modify the effect of irradiation on mouse fibroblasts. Sodium succinate plus ethanol (0.25% final concentration) did not modify the radiation response of NB cells or fibroblasts. Butylated hydroxyanisole, a lipid soluble antioxidant, also enhanced the effect of irradiation on NB cells, indicating that the effect of vitamin E in modifying the radiation response may be mediated, in part, by antioxidation mechanisms.  相似文献   

14.
Intermolecular effects in the polymerization of hemoglobin S   总被引:4,自引:0,他引:4  
Monolayer cultures of astrocytes from newborn rat brain hemispheres have been analysed for the glial-specific protein S-100, during their growth cycle. In primary cultures S-100 protein level increases with a pattern close to that observed with rat brain hemispheres in vivo. This finding suggests that some biochemical maturation of the astrocytes occurs in vitro. In secondary cultures the level of S-100 protein decreases and then increases at the end of the proliferation phase. This modulation, similar to that observed in a clonal culture of tumor cells from rat brain (C6) provides a model to study the relationship between gene expression and the phase of growth of the cells and will allow parallel investigations in normal and tumor cells.  相似文献   

15.
The expression of alpha-fetoprotein and albumin genes has been studied in a rat hepatoma cell line (SY/1/80) developed from a liver cell tumor induced with di-ethylnitrosamine. This original tumor produces both proteins. However, in in vitro propagated hepatoma cells, after passages in growth medium containing new born calf serum, the mRNAs of both proteins were undetectable. Supplementation with rat serum, but not serum from calf, horse or human, in growth medium for this cell line led to resynthesis of albumin and AFPmRNAs. These findings suggest that species specific serum factor(s) play an important role in the regulation of gene expression. Although the nature of the factor(s) and of the mechanism of action remains to be elucidated, this phenomenon may explain the general feature of diminshing abilities of cells to produce specific proteins in continuous subculture using standard calf serum.  相似文献   

16.
The effects of vitamin K on the morphology and the growth of mouse neuroblastoma (P2), mouse melanoma (B-16) and rat glioma (C-6) cells in culture were studied. Vitamin K3 inhibited the growth (due to cell death and partial or complete inhibition of cell division) of all three cell types without causing any morphological differentiation. Vitamin K3 was more effective than vitamin K1. Neuroblastoma cells were more sensitive to vitamin K3 than were melanoma or glioma cells. Glioma cells did not grow in hormone-supplemented serum-free medium; however, both neuroblastoma and melanoma cells grew to a level 70–80% of that found in serum-supplemented medium. Neuroblastoma cells and melanoma cells cultured in serum-free medium exhibited a 2–3 fold higher sensitivity to vitamin K3 than those cultured in serum-supplemented medium. This suggests that serum factors attenuate the growth inhibitory effect of vitamin K3 on tumor cells in culture, probably by reducing the availability of this vitamin to the cells. Neuroblastoma cells were more sensitive to vitamin K3 than were melanoma cells even when they were treated in serum-free medium. The fact that micromolar concentrations of vitamin K3 inhibit the growth of tumor cells in culture suggests that this vitamin may be a potentially useful anticancer agent.  相似文献   

17.
A substance was isolated from mouse brain cortical tissue that inhibits both cell division and protein synthesis by cells in culture. The inhibitor was released from cerebral cortex tissue by mild protease treatment. A single exposure of cells to as little as 1.25 μg of the isolated material was sufficient to inhibit BHK-21 cell protein synthesis by 20%. Higher concentrations and continual exposure resulted in 87% reduction in protein synthesis. The inhibition was shown to be independent of amino acid uptake and most effective against primary mouse embryo fibroblasts and neonatal mouse brain cell suspensions. Cells previously adapted to culture or transformed cells derived from the nervous system were less affected by, or refractory to, the inhibitor. The substance was shown to be nondialyzable, relatively resistant to thermal inactivation and the inhibitor activity was not removed by chloroform extraction. Two active fractions were identified by Bio-Gel P-100 chromatography and the protein synthetic inhibitor was removed by affinity chromatography with Ulexeuropus agglutinin.  相似文献   

18.
M Lippman 《Life sciences》1976,18(2):143-152
Steroid hormones induce responses in target tissues by a mechanism involving the specific initial interaction of hormone with cytoplasmic receptor molecules. These receptors, usually localized in target tissues have high binding affinities and limited binding specificities for biologically active steroids. Examination of human leukemic lymphoblasts has revealed these receptors in some tumor samples. Their presence is well correlated with hormone responsiveness of the tumor in vitro. Similar studies on human breast cancer tumor homogenates has indicated that about 23 of primary tumors contain estrogen receptor. The absence of receptor predicts a lack of response to hormone therapy almost invariably, while the presence of receptor increases but does not assure that the tumor will be hormone responsive. Recently in vitro tissue culture systems which mimic the hormone responses observed in vivo have been developed which should significantly aid in the clarification of the mechanisms whereby steroid hormones stimulate and inhibit growth in target tissues.  相似文献   

19.
Controlled, prospective studies were performed to compare detection of cell culture mycoplasmas by ratio of uptake of tritiated uridine (UdR) to tritiated uracil (U) and by microbiological culture. Culture was by standard agar and broth inoculation with aerobic and anaerobic incubation; immunofluorescent staining of indicator cell cultures was used to detect M. hyorhinis. The ratio of uptake of UdR to U (UdRU) and interpretation of test results were by standard published methods and performed in triplicate. 115 cell cultures were simultaneously assayed by the two techniques. 84 cultures (73.1%) yielded agreement between the 2 methods; 2 cultures (1.7%) yielded conflicting results, and 29 cultures (25.2%) yielded UdRU results in the questionable range. Conflicting results consisted of two negative UdRU tests in mouse cell cultures infected with M. orale. In separate studies, 3T-6 cultures freshly infected with M. orale yielded negative UdRU results 3 days after infection, questionable results after 10 days and a positive UdRU 17 days after infection. UdRU detected infection in fibroblast, epithelial, and lymphocyte cell cultures. Highest UdRU ratios were detected in human skin fibroblasts at early population doubling levels (PDLs), 4064 in one culture at PDL4. UdRU was determined for IMR-90, a human diploid fibroblast at 12 different PDLs using the same lot of media. UdRU gradually decreased throughout the life of the culture, from 2 125 at PDL6 to 340 at PDL36. Cultures in phase III and others exhibiting poor growth frequently yielded questionable or false-positive UdRU results and were not included in tabulations of these results. UdRU determined in endothelial cell cultures decreased as population density increased. In a representative experiment performed over a 4-day period, the UdRU values were 1 808, 955 and 356 when the number of endothelial cells in culture were 5.3 × 105, 6.6 × 105 and 1.1 × 106, respectively.  相似文献   

20.
Cyclic AMP was not detected in whole cells, expended culture medium or culture supernatant fluid of selected strains of Bacteroides fragilis. Adenyl cyclase and c-AMP phosphodiesterase activities were also not detected in cell extracts of B. fragilis. The exogenous addition of dibutyryl-c-AMP or sodium cholate to cultures of B. fragilis growing on lactose did not significantly affect the specific activity of β-galactosidase measured in cell extracts of this organism. No diauxic growth pattern could be demonstrated in a chemically defined medium containing 5 mM glucose + 28 mM lactose.  相似文献   

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