DNA, RNA, and protein synthesis by porcine oocyte-cumulus complexes during expansion

The experiments described in this report were designed to determine three biosynthetic functions of oocyte-cumulus complexes during expansion. The events investigated were DNA, RNA, and protein synthesis during a 24-h in vitro culture; these were determined by 3H-thymidine, 3H-uridine, and 3H-leucine incorporation into oocyte-cumulus complexes, respectively. The quality of proteins produced was also determined by slab-gel electrophoresis. Results indicated that, during follicle-stimulating hormone-induced cumulus expansion, total DNA synthesis was significantly (P less than 0.05) reduced whereas RNA synthesis remained unchanged. Overall protein synthesis was markedly increased (P less than 0.05), with one major band (Mr = 22,000) and two minor bands (Mr = 19,500 and 78,000) being produced during expansion.     

Studies on the mechanism by which prolactin regulates protein, RNA, and DNA synthesis in Nb2 node lymphoma cells

Specific aspects of the prolactin stimulation of RNA, DNA and protein synthesis in the Nb2 node lymphoma cell line were determined. In time sequence studies the onset of the prolactin stimulation of the incorporation of radiolabeled precursors into these macromolecules was found to be 0.5-1 h for [3H]uridine incorporation into RNA, 1-2 h for [3H]leucine incorporation into protein, and 4-8 h for [3H]thymidine incorporation into DNA. The total DNA content of the cell cultures was increased by 12-18 hours after addition of prolactin. Amiloride, an inhibitor of the plasma-membrane-bound Na+/H+ antiporter, was found to inhibit the mitogenic effects of prolactin. Amiloride was also found to inhibit the prolactin stimulation of DNA, RNA and protein synthesis, thus suggesting that the initial regulation of the Na+/H+ antiporter may initiate these responses as well as the mitogenic effect of prolactin. In contrast, H-7, a drug which inhibits protein kinase C, had no effect on the magnitude of the prolactin stimulation of DNA, RNA or protein synthesis at a drug concentration (100 muM) that abolished the mitogenic effect of prolactin. The early effects of prolactin on RNA, DNA and protein synthesis would therefore appear not to involve an activation of protein kinase C.     

The effect of saffron on intracellular DNA, RNA and protein synthesis in malignant and non-malignant human cells.

Extract of saffron (Crocus sativis) has previously been shown to inhibit colony formation and cellular DNA and RNA synthesis by HeLa cells in vitro. In order to compare the sensitivity of malignant and non-malignant cells to saffron, we examined the effect of the extract on macromolecular synthesis in three human cell lines: A549 cells (derived from a lung tumor), WI-38 cells (normal lung fibroblasts) and VA-13 cells (WI-38 cells transformed in vitro by SV40 tumor virus). We found that the malignant cells were more sensitive than the normal cells to the inhibitory effects of saffron on both DNA and RNA synthesis. There was no effect on protein synthesis in any of the cells.     

Studies on DNA content, RNA synthesis, and DNA template activity in aging cells of Paramecium aurelia.

Investigations by Feulgen microspectrophotometry in Paramecium aurelia indicated that as fission age increased the amount of macronuclear DNA decreased. It was also found that the amount of RNA synthesis as determined by the in vivo incorporation of [³H]uridine decreased as the fission age increased. An alternative in situ assay of the DNA template activity determined by the RNA polymerase-catalyzed incorporation of [³H]UTP is described. The DNA template activity of older cells was shown to be significantly lower on a per cell basis than that of younger cells. The majority of this reduction was shown to be due to the gradual loss of DNA template with an increase in fission age. The specific activity of the DNA template, however, does show a small but significant decrease as the fission age of the cell increases.     

Inhibitory studies of DNA, RNA and protein synthesis in Escherichia coli by platinum containing complexes

Previous studies have shown various platinum containing compounds to be effective anti-tumor agents in man and animals. Many of these compounds have also been shown to be effective inhibitors of bacterial DNA, RNA and protein synthesis. Data is presented here which compares the inhibitory effectiveness of a number of recently synthesized platinum compounds toward the inhibition of the synthesis of DNA, RNA and protein in Escherichia coli. We also compared the effectiveness of these compounds toward the inhibition of bacterial growth. Some of these new derivatives appear to be nearly 3-fold more potent than the more thoroughly studied cis-diamminedichloroplatinum(II) (cis-PDD) and trans-diamminedichloroplatinum(II) (trans-PDD).     

RNA synthesis and RNA polymerase activity in hepatic nuclei isolated from rats fed the carcinogen 2-acetylaminofluorene.

An assessment was made of the activity of RNA polymerase I and the capacity for RNA synthesis, under conditions optimized for RNA polymerase I activity, in hepatic nuclei isolated from rats fed a diet containing the hepatic carcinogen AAF. Animals were maintained on the carcinogenic diet for either 4, 7 or 14 days. RNA polymerase activity progressively increased with time on the carcinogenic diet. However, the capacity for RNA synthesis remained quite constant. These results are suggestive of a progressive inhibition of DNA template activity during the early stages of AAF-induced hepatocarcinogenesis. The “permanance” of the increase in polymerase activity was examined by switching carcinogen fed animals to a control diet for either 2 or 5 days prior to making an assessment of the above parameters.     

Differentiated inhibition of DNA, RNA and protein synthesis in L1210 cells by 8-methoxypsoralen

The synthesis of DNA, RNA and protein was measured in L1210 cells following treatment with 8-methoxypsoralen in combination with long wavelength ultraviolet irradiation. The results show that the DNA synthesis is strongly inhibited (approximately 95%) at 200 ng/ml reaching a minimum within 2 hours while RNA synthesis is only weakly affected at this concentration (approximately 40% inhibition). At 2 micrograms/ml the RNA synthesis is inhibited approximately 90%. Even at this concentration only a moderate effect is seen on the protein synthesis. These results strongly indicate that the phototoxic action of 8-methoxypsoralen is primarily due to inhibition of DNA synthesis.     

Differential antibacterial activity of genistein arising from global inhibition of DNA, RNA and protein synthesis in some bacterial strains

Antibacterial activities of various flavonoids have been reported previously, but mechanism(s) of their action on bacterial cells remain(s) largely unknown. Here, we investigated effects of genistein, an isoflavone, and representatives of other flavonoids: daidzein (another isoflavone), apigenin (a flavone), naringenin (a flavanone) and kaempferol (a flavonol), on commonly used laboratory strains of model bacterial species: Escherichia coli, Vibrio harveyi and Bacillus subtilis. We found that E. coli was resistant to all tested flavonoids at concentrations up to 0.1 mM, while high sensitivity of V. harveyi to most of them (except daidzein, which exhibited significantly less pronounced effect) was observed. Effects of the flavonoids on B. subtilis were relatively intermediate to the two extremes, i.e., E. coli and V. harveyi. Action of genistein on bacterial cells was investigated in more detail to indicate changed cell morphology (formation of filamentous cells) of V. harveyi and drastic inhibition of global synthesis of DNA and RNA as shortly as 15 min after addition of this isoflavone to a bacterial culture to a final concentration of 0.1 mM. Protein synthesis inhibition was also apparent, but delayed. Both cell morphology and synthesis of nucleic acids and proteins were unaffected in E. coli cultures under analogous conditions. Studies on cell survival suggest that genistein is a bacteriostatic agent rather than a bactericidal compound.     

Stabilization of RNA strands in protein synthesis by type I procollagen C-proteinase enhancer protein, a potential RNA-binding protein, in hepatic stellate cells.

Type I procollagen C-proteinase enhancer (PCPE) exists in hepatic stellate cells (HSCs) which can produce collagen. The deduced amino acid sequence of PCPE contains motifs specific for RNA-binding proteins. The effect of PCPE on the syntheses of collagen and noncollagenous protein was studied using an HSC clone derived from cirrhotic rat liver. When the cells were cultured in the presence of an antisense oligonucleotide (AS) against PCPE mRNA, the synthesis of noncollagenous protein as well as collagen was reduced compared to the cells cultured with addition of a nonsense oligonucleotide (NS). The extent of the reduction was similar in both syntheses. The total RNA content of the AS-treated cells and NS-treated cells did not differ. In the presence of actinomycin D, however, such total RNA content was decreased more rapidly in the AS-treated cells than in the NS-treated cells. PCPE may be involved in stabilization of RNA strands in noncollagenous protein synthesis as well as collagen synthesis.     

Mononuclear metal complexes with piroxicam: synthesis, structure and biological activity

Piroxicam (=Hpir) is a non-steroidal anti-inflammatory and an anti-arthritic drug. VO(2+), Mn(2+), Fe(3+), MoO(2)(2+) and UO(2)(2+) complexes with deprotonated piroxicam have been prepared and characterized with the use of infrared, UV-Vis, nuclear magnetic resonance and electron paramagnetic resonance spectroscopies. The experimental data suggest that piroxicam acts as a deprotonated bidentate ligand in all complexes and is coordinated to the metal ion through the pyridine nitrogen and the amide oxygen. Molecular mechanics calculations in the gas state have been performed in order to propose a model for the Fe(3+), VO(2+) and MoO(2)(2+) complexes. Potential anticancer cytostatic and cytotoxic effects of piroxicam complexes with VO(2+), Mn(2+) and MoO(2)(2+) on human promyelocytic leukemia HL-60 cells have been investigated. Among all complexes, only VO(pir)(2)(H(2)O) clearly induces apoptosis after 24-h incubation, whereas piroxicam induces apoptosis after 57-h incubation.     

The effect of parabens on DNA, RNA and protein synthesis in Escherichia coli and Bacillus subtilis

The effect of methyl, propyl and butyl esters of p-hydroxybenzoic acid on DNA and RNA synthesis has been tested in toluenized cells of Escherichia coli and Bacillus subtilis. Both RNA and DNA synthesis of these bacteria were inhibited. The inhibitory concentrations were higher than those previously reported for growth inhibition. Protein synthesis in cell-free extracts (S-30 fraction) of B. subtilis was even more sensitive to parabens than DNA and RNA synthesis, while protein synthesis in Esch. coli was largely unaffected.     

Effect of 2 MHz ultrasound on DNA, RNA and protein synthesis in Pisum sativum root meristem cells.

The amounts of DNA, RNA and protein synthesis were determined in Pisum sativum root meristem cells at various times after a 1 min exposure to 1 MHz ultrasound at a power density of 30 W/cm2. Immediate depressions in all three macromolecular syntheses occurred after sonication, followed by an apparent recovery several hours later. These events appear to correlate in time with the subsequent reduction and recovery in mitotic index in Pisum sativum root meristem cells exposed to 2 MHz ultrasound.     

Effects of semicarbazide on DNA, RNA and protein hepatic levels on four subsequent generations of Wistar rats

1. The offspring (F1) of a parent generation (P) were mated on a brother-to-sister system to produce a second generation (F2), which was then mated in the same way to produce a third generation (F3). 2. Each of these generations were divided into two groups, controls and treated. 3. A single dose of 100 mg/kg of semicarbazide was administered to the treated Wistar rats on the 10th day of their pregnancy. 4. DNA, RNA and protein hepatic levels were measured in the livers of either 21-day-old foetuses or 1, 7, 15 or 30-day-old offspring. 5. These levels were also studied in the pregnant rats on day 21 of gestation. 6. Semicarbazide produced a significant decrease of these levels not only in the foetuses, offspring and pregnant rats but also in the controls, F2 and F3, from treated P and F1 respectively.     

The effect of parabens on DNA, RNA and protein synthesis in Escherichia coli and Bacillus subtilis

The effect of methyl, propyl and butyl esters of p -hydroxybenzoic acid on DNA and RNA synthesis has been tested in toluenized cells of Escherichia coli and Bacillus subtilis. Both RNA and DNA synthesis of these bacteria were inhibited. The inhibitory concentrations were higher than those previously reported for growth inhibition. Protein synthesis in cell-free extracts (S-30 fraction) of B. subtilis was even more sensitive to parabens than DNA and RNA synthesis, while protein synthesis in Esch. coli was largely unaffected.