Biomedical subjects

Valentin V Vlassov

Publications and source records attributed to Valentin V Vlassov.

23 records · Page 2Linked to original sources

PubMed2004

Cell-surface-bound nucleic acids: Free and cell-surface-bound nucleic acids in blood of healthy donors and breast cancer patients.

Concentrations of extracellular DNA and RNA in the blood of healthy donors and patients with malignant and nonmalignant breast tumors were investigated. Cell-surface-bound extracellular DNA and RNA were detached by PBS-EDTA treatment or mild trypsin treatment of erythrocytes and leukocytes. In healthy donors, almost all extracellular nucleic acids (98%) are bound at the surface of blood cells. In the blood of cancer patients, extracellular nucleic acids were found in plasma and not at the cell surface. In patients with nonmalignant breast tumors, extracellular nucleic acids were found both at the surface of blood cells and in plasma. In healthy donors, the cell-surface-bound DNA is represented by 20-kbp DNA fragments and smaller fragments that varied in amounts in different fractions.

Breast Neoplasms↗

PubMed2004

Isolation of nucleic acid binding proteins: an approach for isolation of cell surface, nucleic acid binding proteins.

An approach for isolation of cell surface, nucleic acid binding proteins is described. This approach relies on affinity modification of the proteins of living cells with reactive oligonucleotides bearing a haptenic group. Covalently modified proteins were isolated by hapten-specific affinity chromatography with subsequent SDS-PAGE. Isolated 68-kDa proteins responsible for the binding of oligonucleotides were MS/MS sequenced and identified as keratin K1, keratin K10, keratin K2e, and albumin.

Carcinoma, Squamous Cell↗

PubMed2004

Extracellular nucleic acids in cultures of long-term cultivated eukaryotic cells.

Investigation of the kinetics of nucleic acid release by HeLa (human cervical carcinoma cell line) and A431 (human squamous carcinoma cell line) cells is presented. The released DNA and RNA were shown to accumulate in culture medium and at the cell surface. A portion of cell surface bound RNA can be eluted with PBS/EDTA. Mild trypsin treatment is required for complete detachment of cell surface bound RNA and cell surface bound DNA. Electrophoretic analysis reveals characteristic patterns of cell-associated and free RNA and DNA molecules.

Cell Line, Tumor↗

PubMed2003

Fluorometric quantification of RNA and DNA in solutions containing both nucleic acids.

A fluorescence-based method for quantitative determination of RNA and DNA in probes containing both nucleic acids has been developed. The total concentration of nucleic acids is determined using SYBR Green II dye under conditions providing independent binding of the fluorophore with DNA and RNA. The concentration of DNA is specifically measured using the Hoechst 33258 dye and the RNA concentration is calculated from these data. The procedure allows for accurate determination of DNA concentration in the range 10-1000 ng/ml in the presence of 200-fold excess of RNA and determination of RNA concentrations in the range 10-1000 ng/ml in the presence of large excess of DNA. An absence of the treatment of mixed samples with RNase-free DNase I provides rapid, reproducible, and accurate RNA quantification.

Bisbenzimidazole↗

PubMed2002

Downregulation of PGY1/MDR1 mRNA level in human KB cells by antisense oligonucleotide conjugates. RNA accessibility in vitro and intracellular antisense activity.

Inhibition of PGY1/MDR1 (multidrug resistance gene 1) mRNA expression in multidrug resistant KB-8-5 cells by 5'-bis-pyrenyl-3'-aminohexyl oligodeoxyribonucleotide conjugates targeted to four sites of this mRNA has been investigated. Three of the tested oligonucleotide conjugates specifically inhibited the expression of PGY1/MDR1 mRNA as monitored by the RT-PCR assay. The oligonucleotide conjugate targeted to the region (+178; +194) of the PGY1/MDR1 mRNA decreased level of this mRNA to 10% compared to the control. Nuclease-resistant analogs of oligonucleotide, complementary to this MDR1 mRNA region therefore, might be considered as a prototype compounds for development of gene-targeted therapeutic agents for overcoming the MDR phenotype caused by the overexpression of the PGY1/MDR1 gene.

ATP Binding Cassette Transporter, Subfamily B, Mem↗