Malignant melanoma has poor prognosis because of its high metastatic potential and resistance to chemotherapy. A possible approach to more effective therapy is induction of p53-dependent apoptosis. This approach is promising, since the wild-type p53 is expressed in most melanomas. An attempt was made to estimate the functional activity of p53 in several malignant melanoma cell lines. Most lines were characterized by a high protein level and nuclear localization of p53. All cell lines expressing the wild-type p53 showed stabilization of p53, its translocation into the nucleus, and activation of several target genes in response to DNA-damaging agents, suggesting that p53 was functionally active. A high-molecular-weight protein localized in the cytoplasm and mimicking a p53 epitope was found in several cell lines. It was shown that the DO-1 epitope of this protein does not derive from p53, ruling out cytoplasmic retention of p53 in melanoma cell lines. A mechanism of camptothecin-induced stabilization of p53 by decreasing the level of the HDM2 mRNA was described for melanoma cells but not for normal melanocytes, which suggested a differential effect of camptothecin on tumor-derived and primary cells.

Described in the paper are the results of a study of differential expression of pathogenicity of B. cepacia and P. aeruginosa in subinhibiting concentrations (SIC) of cyprofloxacyne. While identifying genes expressing differentially in the antibiotic SIC, genes cepR B. cepacia and P. aeruginosa expressing without cyprofloxacyne in the cultivation medium and not expressing in the antibiotic SIC were detected. Finally, involvement of cepR B. cepacia in regulating the pathogenicity expression factors according to "quorum sensing" is under discussion.

The action of amixin and cycloferon on the expression of genes in the systems of interferon (IF) and cell apoptosis (CA) was studied by semi-quantitative RT-PCR in human blood microsamples before and after the administration of the drugs. Individual changes were determined in the transcription activity of genes of IF (alpha, beta, gamma), enzymes 2',5' oligoadenylatesynthetase (OAS), RNSase L, dsRNA-dependent proteinkinase (dsPK) and of CA effectors (FasAg, bcl-2, gamma-actin) registered dynamically in 24 h and 48 h. The activity parameters of IF genes were compared with the results of biological titration of IF activity in blood samples in vivo and in vitro. A pronounced ability of cycloferon to stimulate selectively the activity of genes of human IF, type I (beta IF--by 100 times and alpha IF--by 10 times), without affecting essentially the activity of other genes in blood cells, was detected. Amixin was found to inhibit the titration of genes with high activity levels. (alpha-, beta-IF, RNAases L, bcl-2 and gamma-actin). The antiviral and IF-induced properties of the drug are explained to a great extent by the apoptotic effect (activation of genes Fas, gamma-IF, OAS and affected transcription of gene bcl-2). A positive correlation was observed between the processes of activation of IF-genes transcription and the production of the total circulating IF. Antagonistic relations between type I and II IFs in human blood cells were shown.

The effects of ladasten on the activation-induced expression of Fas-receptor on T-lymphocytes, their sensitivity to Fas-induced apoptosis, and the expression of mitogen-activated ERKI/ERK2 protein kinases have been studied. In the range of concentrations 0.1-10 microM, ladasten exhibited a comitogenic effect on the TCR-mediated stimulation of T-lymhocytes ion the peripheral human blood, which was accompanied by an increase in the level of phosphorylated form of ERK-2. At the same time, ladasten virtually did not change the activation-induced expression of Fas-receptor on T-lymphocytes, but reduced the rate of the Fas-induced apoptosis. It was concluded that the immunoprotective effect of ladasten is probably based on a decrease in the rate of Fas-induced apoptosis.

The effect of treatment of males from an isogenic Drosophila melanogaster strain by limiting doses of ethanol fumes on transpositions of MGE 412 was examined. Validity of the phenomenon of transposition induction was demonstrated. We estimated rates of induced transposition (approximately 10(-2) events per site, per sperm, per generation versus < 10(-3) in control) and showed dose dependence of the rate on the exposure time of the males to ethanol fumes. Experiments with alcohol treatment at limiting doses must end either in death of the individuals or bursts of genetic variability in their progeny. In terms of genetics of an individual, this may mean loss of vital hereditary basis followed by mass degradation of the progeny of the "hard drinkers." In terms of populations genetics, this mode of MGE transposition induction can rapidly create a burst of novel genetic variation, which, apart of great losses, may generate a number of advantageous individuals, i.e., be significant for population survival in new, stressful environments.

Derivatives with insertional inactivation of prqA and mvrA genes were obtained and studied in the Synechocystis sp. PCC6803 wild-type strain and in the mutant Prq20 resistant to methyl viologen (MV). It was shown that the formation of resistance to MV is associated with the operation of two systems: constitutive and inducible. The prqA gene encoding drug efflux proteins controls the constitutive system of cell resistance to MV. Derepression of the prqA gene is the main reason for an enhanced MV resistance in the Prq20 mutant with impaired repressor function of the PrqR protein. The mvrA gene encoding the transmembrane protein from the family of transporters of sugar and other compounds controls the inducible MV resistance. It is assumed that the MvrA protein is required for efficient elimination from cells of toxic substances formed upon oxidative stress or participates in the repair of membranes destroyed by oxidants. The data obtained demonstrated for the first time that transport systems are involved in the formation of MV resistance in photosynthetic organisms.

Data are provided on the upregulation of heterochromatin protein binding protein 74 gene (hpl-bp74) at RNA transcription level under the influence of stimulation of 1,25-dihydroxyvitamin D3. We also showed the absence of action of 17 beta-estradiol on the transcription level of hpl-bp74 breast adencarcinoma cell line (MCF7). The protein encoded by gene hpl-bp74 can be involved in generalized transcriptional regulation and thus take part in inhibition of proliferation by 1,25(OH)2D3. Computer analyses of DNA sequences of hpl-bp74 enabled us to identify some potential hormone responsive elements responsible for the binding of nuclear receptor for vitamin D with the DNA motifs.

The effects of intracerebroventricular administration of the non-competitive NMDA-receptor blocker Dizocilpine (MK-801) on delta sleep-inducing peptide (DSIP) suppression of c-fos induction, were studied. The data obtained indicate that preliminary i.c.v. MK-801 injection inhibits immediate early gene c-fos suppression by DSIP in the parvocellular paraventricular hypothalamus.

A consensus nucleotide sequence of long terminal repeats (LTRs) of endogenous human-specific retroviruses of the K family (HERV-K) was constructed and used for the genome-wide search for homologies in international databases. There were revealed 142 LTRs, 12 of which were localized in introns of unique human genes. It was found for the first time that ten intron LTRs are absent in the orthologic loci of the chimpanzee genome and the orientation of nine of them is opposite to the transcription direction of the corresponding human genes. A hypothesis was propounded that the found LTRs affect the gene expression by initiation of the antisense RNA synthesis.

In WAG/Rij rats with genetic absence epilepsy, inborn changes in behavior were observed such as decreased level of locomotion, exploratory activity, and grooming reactions in the open-field test, increased immobility in the forced-swimming test, and decreased sucrose consumption (anhedonia) as compared to Wistar rats completely lacking in seizure pathology. These behavioral alterations in WAG/Rij rats resemble the symptoms of human depression (psychomotor retardation, depressed mood, and anhedonia). No significant behavioral changes were found in the light-dark choice, social interaction, and elevated plus-maze tests. This suggests the absence of increased anxiety in WAG/Rij rats. In contrast to Wistar, WAG/Rij rats were sensitive only to chronic treatment with antidepressant imipramine like depressive patients. Behavioral "despair" induced by forced swimming led to C-fos gene expression in three brain structures (frontal cortex, nucleus accumbens, and striatum), which are, respectively, terminal regions of three dopaminergic brain systems (mesocortical, mesolimbc, and nigrostriatal). c-fos gene expression in the brain of WAG/Rij rats was substantially different from that in the brain of Wistar rats in both intensity (in WAG/Rij the c-fos gene expression was higher than in Wistar rats in all involved brain structures) and its distribution between the structures. The results suggest that WAG/Rij strain is a new experimental (genetic) model of absence epilepsy-related depression unassociated with increased anxiety.

We considered the biological effects of some chemical compounds, that stimulate cell differentiation, on the cells of tumor lines. Induced changes were analyzed in the expression of several transcriptional factors involved in the regulation of cell proliferation and apoptosis. Based on the generalized information about differentiating, apoptogenic, and antiproliferative effects of chemical inducers of differentiation, a conclusion was drawn that they affect the sensitivity of differentiated cells to the lytic action of natural killer cells.

A model of the simplest epigene was constructed to have two alternative states, which proved to be stable and transmittable through Escherichia coli cell generations. A switch from one to another state was induced by thermal and chemical external signals. The results gave further insight into the dynamic mechanism of preservation, coding, and transmission of the genetic information.

Patients with acute general peritonitis display in the postoperative period manifest disturbances in the pharmacokinetics of cardiogreen. Conventional therapies, blood ultra-violet irradiation procedures, intravascular irradiation of blood with laser, and hyperbaric oxygenation have no positive effect on the detected inadequacies. Hemosorption embarked on in the complex of therapeutic measures in the above category of patients appeared to have but insignificant positive effect. Benzonal has been shown to have an apparent corrective effect on disordered pharmacokinetics of cardiogreen in patients with acute general peritonitis in the postoperative period.

Data are provided on the up-regulation of keratinocyte growth factor gene (kgf) at mRNA and protein level in prostate cancer cells (LNCaP) stimulated by 1,25-dihydroxy-vitamin D3 and 17-beta-estradiol (E2). The computer analysis of the 5-flanking region of kgf gene using different software and databases (TESS, TRANSFAC etc.) enabled us to identify some potential elements responsible for binding the nuclear receptors of vitamin D3, E2, and some other steroid hormones.

The level of transcription from the promoter of the microcin C51 operon (Pmcc) depends on the growth phase of Escherichia coli cells: transcription proceeds with low efficiency at the exponential phase of growth and with higher efficiency when growth of cells is delayed during entry into the stationary phase. The functioning of Pmcc was studied in cells grown in different media by a single-copy construct, which contained the cloned promoter region of the microcin C51 operon and the promoterless lac operon. A decrease in the rate of cell growth caused by changes in the sole carbon source in minimal medium correlated with an increase in the level of transcription from the Pmcc promoter at the exponential phase of growth; the expression of Pmcc-lac during cell entry into the stationary phase was higher under unfavorable medium conditions. The use of composite rich media impaired this feature. The addition of l-leucine (100 micrograms/ml) to the medium decreased the expression of Pmcc-lac in wild-type cells carrying the delta lrp mutation. A further increase in leucine concentration and the presence of other amino acids in the medium enhanced transcription that started from Pmcc during cell entry into the stationary growth phase. The capacity of the Pmcc promoter and of the wild-type lacZ gene promoter was virtually the same upon IPTG induction. A mutation in the ompR gene did not markedly influence transcription started from Pmcc.

A modification of protein-protein interactions can be considered to be a way to regulate cell death. Chemical cross-linking agents have been traditionally used for protein complexing. This study has been undertaken to test a possibility to induce and(or) to modify cell death by a homobifunctional cross-linker dimethyl suberimidate (DMS). It was shown that the protein cross-linking by DMS resulted in a death of transformed cells by apoptosis. DMS-induced apoptosis was accompanied by cell cycle perturbations and down-regulation of p21/Waf1 mRNA expression. The RT-PCR analysis of bcl-2 family genes revealed the engagement of mitochondria in DMS-induced cytotoxicity. Then, the influence of DMS treatment on TNF-dependent and Fas-mediated apoptosis was investigated. Cell pre-incubation with DMS resulted in their increasing sensitivity for the TNF cytotoxic effect, though activities of anti-Fas cytotoxic antibodies were inhibited. The effects observed are probably due to cross-linking of TNF-receptors. Thus, this study first demonstrated that a chemical cross-linker DMS in capable of inducing apoptosis in transformed cells and modifying TNF-dependent and Fas-mediated apoptosis.