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Biomedical subjects

E I Frolova

Publications and source records attributed to E I Frolova.

At least 19 recordsLinked to original sources
PubMed1998

The human RIL gene: mapping to human chromosome 5q31.1, genomic organization and alternative transcripts.

The ril gene encoding a LIM domain protein of an unknown function was previously identified by differential expression cloning as a candidate tumor suppressor gene in rat fibroblasts (Kiess, M., Scharm, B., Aguzzi, A., Hajnal, A., Klemenz, R., Schwarte-Waldhoff, I., Schafer, R., 1995. Expression of ril, a novel LIM domain gene, is down-regulated in HRAS-transformed cells and restored in phenotypic revertants. Oncogene 10, 61-68). Searching for novel genes on human chromosome 5q31.1 by the cDNA selection technique, we isolated a cDNA clone identical with the cDNA of the human RIL gene (GenBank Accession No. X93510). The human 5q31.1 region is of interest because it contains the cytokine gene cluster and is frequently deleted in the malignant cells of patients with myelodysplasia and myeloid leukemia. Using Southern blot analysis and restriction mapping of genomic YAC (yeast artificial chromosome) and cosmid clones, we located the human RIL gene 240-260 kb telomeric to the IRF1 gene and characterized its genomic structure. PCR analysis indicated the presence of two alternative RIL transcripts in human fetal brain mRNA. The major transcript is identical with the RIL cDNA previously deposited in GenBank and contains seven exons distributed over 14.5 kb of genomic DNA with the two last 3'-exons coding a LIM domain. The minor transcript lacks the sixth exon compared with the major transcript, which leads to the loss of the LIM domain. We also identified two putative transcription start points (tsp) and sequenced the 5'-flanking region of RIL to reveal potential binding sites for transcriptional factors.

Alternative Splicing↗
PubMed1995

Tandem arrangement of human genes for interleukin-4 and interleukin-13: resemblance in their organization.

The genes encoding human interleukin-4 (IL-4) and interleukin-13 (IL-13) are located on segment q23-31 of chromosome 5 and encode two multifunctional lymphokines with some common functions. We have cloned 72 kb of human genomic DNA that contain IL-4 and IL-13 and their flanking sequences, and constructed a restriction map of this region. Using Southern analysis, we have shown that IL-13 is located 12 kb 5' to IL-4 and linked in a 'tail-to-head' fashion. We have also determined the complete nucleotide sequence of the DNA fragment (about 4.8 kb) containing IL-13 and its 5' flanking regulatory region (2.1 kb) with a 'CpG island'. We identified potential binding sites for a different transcription factors in the 5' flanking region and in the first intron of IL-13. Comparison of IL-13 and IL-4 revealed considerable similarity in the structural organization of these genes and also many potential binding sites for transcription factors common to both genes: AP1, AP2, AP3, PEA3, HRE, TCF-1, GATA-3 and the interferon-inducible and enhancer elements. These results, along with the similarity in functional activity of IL-4 and IL-13 suggests that their expression may be coregulated.

Amino Acid Sequence↗
PubMed1993

Comparison of interactions of 5'-derivatives of deoxyoctathymidylate with human DNA polymerize alpha and HIV reverse transcriptase.

Km and Vmax values for d(pT8) and its derivatives containing various 5'-end groups were estimated in the reaction of DNA polymerization alpha catalyzed by DNA polymerase alpha and HIV-RT. The effect of 5'-end modification of primer is more pronounced in the case of HIV-RT. Strong influence is observed for an intercalating (ethidium) group. The affinity of EtpT8 is 200-fold higher than that of d(pT8). Attachment of Phn-, Dnm- and Hem-groups results in the increase of affinity of modified primer from 10 up to 20 times. For DNA polymerase alpha the influence of modifiers on primer affinity is much weaker. The effect of 5'-end residues on the Vmax values is also more pronounced for HIV RT. The way to improve selective interaction of oligonucleotide derivatives with the primer site of HIV RT is suggested.

DNA↗
PubMed1993

Kinetic study of the addressed modification by hemin derivatives of oligonucleotides.

Kinetics of oligonucleotide pd(TGAATGGGAAGA) modification by a hemin derivative of the complementary oligonucleotide pd(TTCCCATT) in the presence of hydrogen peroxide was investigated. The treatment of experimental data permitted to evaluate the association and rate constants at 25 degrees C: Kx = (3.40 +/- 0.38) x 10(5) M-1 (association constant of the reagent with the target), kd = 152 +/- 6 M-1 min-1 (degradation constant of the hemin group of the reagent in a parallel reaction), ko = 51.0 +/- 1.7 M-1 min-1 (target modification constant in the reactive duplex). The modification of DNA is incomplete due to competition of the modification reaction with the degradation of the hemin group of the reagent in a parallel reaction.

Base Sequence↗
PubMed1993

[Porphyrin derivatives of oligonucleotides. I. Synthesis of oligonucleotide derivatives bearing 2,4-di(alpha-(2-hydroxyethoxy)ethyl)- deuteroporphyrin IX or a metal complex of it and study of the oxidative modification of DNA by these derivatives].

A method for coupling 2,4-di[alpha-(2-hydroxyethoxy)ethyl] deuteroporphyrin dimethyl ether (IX), DDPOH and its complexes with metals to the 5'- or 3'-end of oligonucleotides was elaborated. In the presence of an oxidizing agent (H2O2), Fe(III)DDP-derivatives of oligonucleotides modified single-stranded DNA. The reaction was strictly site-specific and occurred at two neighbouring guanosine residues. A few types of modification were observed: cross-linking, modification leading to DNA cleavage upon piperidine treatment, and direct chain scission. The total modification yield reached 90%. Covalent attachment of Fe(III)DDP-group to oligonucleotides increased the efficiency of their uptake and the melting temperature of their complementary complexes.

Base Sequence↗
PubMed1991

Linkage mapping of the human CSF2 and IL3 genes.

Interleukin 3 (encoded by the IL3 gene) and granulocyte-macrophage colony-stimulating factor (encoded by the CSF2 gene) are small secreted polypeptides that bind to specific cell surface receptors and regulate the growth, gene expression, and differentiation of many of the hematopoietic cell lineages, particularly nonlymphoid cells. The IL3 and CSF2 genes have been cloned and mapped to human chromosome bands 5q23-31. Only 10 kilobases of DNA separates the two genes, suggesting that they have a common origin and/or regulation. We have cloned 70 kilobases of genomic DNA that includes the IL3 and CSF2 genes, as well as flanking sequences, and report a physical map of this region. Several unique-sequence DNA segments have been identified in this region, and one of these fragments detects two restriction fragment length polymorphisms in DNA from unrelated Caucasians. Segregation of these DNA polymorphisms was followed in the Centre Etudé du Polymorphisme Humaine (CEPH) panel of 40 large three-generation pedigrees, and linkage was detected with 17 genetic markers previously typed in these families. Multipoint linkage analysis permits the placement of the region containing the IL3 and CSF2 structural genes on the recombination-genetic linkage map of chromosome 5q and thereby allows the role of these genes in leukemogenesis to be more critically examined.

Base Sequence↗
PubMed1991

5'-derivatives of oligonucleotides as primers of DNA polymerization catalyzed by AMV reverse transcriptase and Klenow fragment of DNA polymerase 1.

The Km and Vmax values for d(pT)8 and its derivatives containing various 5'-end groups were estimated in the reaction of polymerization catalyzed with AMV-RT and FK. The change in affinity of modified primers was more pronounced in the case of AMV-RT than in the case of FK. Introducing in d(pT)8 of intercalators such as phenazinium, ethidium and daunomycin residues results in 2.7-, 8.7- and 11-fold increases in the primer affinity to AMV-RT, respectively. However, in the case of hemin and cholesterol derivatives the Km values were 3 and 5 times higher than those for d(pT)8. Compared to d(pT)8, the affinity of FK to all the above analogs was 2.3-3.6 times higher with the exception of cholesterol derivative to which it was 2.4-fold lower. The effect of the 5'-end residues on the Vmax values of d(pT)8 was small and ranged from 44% to 120% of that for d(pT)8. Therefore such reactive derivatives of oligonucleotides can be used as effective primers of AMV-RT and FK. Possible reasons for various effects of the 5'-end residues of the primer on its interaction with FK or AMV-RT in the presence of poly(A) are discussed.

Avian Myeloblastosis Virus↗
PubMed1991

Hydroxyl radical generation by oligonucleotide derivatives of anthracycline antibiotic and synthetic quinone.

For the first time the covalent binding of anticancer anthracycline drugs and their potential synthetic analogs to oligonucleotides of different sequences is proposed for obtaining site-specific DNA scission in systems in vitro and in vivo. New compounds such as daunomycin (Dm) and synthetic naphthoquinone (NQ), covalently bound to the heptadeoxynucleotide of pCCAAACA (Dm-pN7) and decadeoxythymidilate (pT10p-NQ), have been obtained. These oligonucleotide derivatives can form specific complexes with complementary oligonucleotide sequences; these compounds and their complementary complexes can be reduced by purified NADPH-cytochrome P-450 reductase. Using the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO), it has been shown that in aerobic conditions Dm-pN7 and pT10p-NQ are capable of generating OH radicals with and without complementary oligonucleotides. The chemical stability of the compounds in redox reactions has been studied. Oligonucleotide derivatives of natural and synthetic quinones capable of generating OH radicals seem to be a promising tool for site-specific scission of DNA in solution and in cells.

Base Sequence↗
PubMed1989

Hydroxyl radical generation and DNA strand scission mediated by natural anticancer and synthetic quinones.

Using ESR and spin-trapping techniques, it was found that synthetic 2-dimethylamino-3-chloro-1,4-naphthoquinone and the natural anticancer quinone daunomycin, when added to a system containing purified NADPH-cytochrome P-450 reductase, NADPH, ferric ions, and oxygen, (i) generated hydroxyl radicals and (ii) caused single-strand scission of supercoiled DNA of the plasmic pBR322. Since these two effects of the quinones were correlated to each other, we propose that potential anticancer quinones can be effectively screened by measuring their ability to form hydroxyl radicals in the above system.

DNA Damage↗
PubMed1989

[Features of structural organization of mouse centrometric heterochromatin, detected during differential decondensation of chromosomes].

The centromeric heterochromatin (CH) of mouse metaphase and interphase chromosomes has been shown to be practically devoid of the chromonemal and chromomeric levels of DNP organization. CH decondensation into DNP-fibrils caused by decreasing Ca2+-ions concentration is accomplished without formation of chromonemata and chromomeres. The peripheral regions of CH, immediately contacting the inner surface of kinetochores, display the highest stability towards the factors inducing the artificial decondensation.

Animals↗
PubMed1988

[Electron microscopic study of the minichromosomes in murine fibroblast cells fixed in situ].

The ultrastructure and differential staining of minute chromosomes (MC) from mouse fibroblasts line C3H10T1/2 (LS9/0.1) was studied. MC in mitotic cells of this line contain R-positive material and are not stained according to the G- and C-methods. Reconstruction of ultrathin serial sections made it possible to identify MC in situ. It is shown that the basic structural unit of MC is a DNP fibril 20-30 nm in diameter. The density of packing of the MC material corresponds to that of normal chromosomal arms. In some cases the fibrillar material is present between MC and normal chromosomes. It is suggested therefore that some MC may be structurally linked to a normal chromosome arm. The MC structure is discussed in terms of the ultrastructural properties of R- and C-positive segments.

Animals↗