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I N Shvemberger

Publications and source records attributed to I N Shvemberger.

At least 19 recordsLinked to original sources
PubMed2005

Genetic variability of the mouse hepatoma cells MH-22a revealed by RAPD-PCR-fingerprinting under different conditions of cultivation.

AIM: to study genetic variability in clonal lines of the mouse hepatoma MH-22a and the dependence of the capability of different clonal line cells for differentiation on the amount of genetic disturbances revealed by the RAPD-PCR method. METHODS: The hepatoma MH-22a and its ten clonal lines were transplanted into subcutaneous connective tissue (SCT) and the eye anterior chamber (EAC) by injection of the cells to syngenic C3HA mice. The growth of transplants was checked in 15-20 days after transplantation. The tumors were fixed in neutral paraformaldehyde (10%), passed through ethanol of increasing concentrations, embedded in paraffin and stained by hematoxiline and eosine and Van Gisone. The genetic heterogeneity in the hepatoma cell population MH-22a and its clonal lines in vitro and in vivo was revealed by random amplified polymorphic DNA (RAPD-PCR). For the estimation of genetic variability revealed in the fingerprints was used the genetic variability index (GVI), based on the Bootstrep and Mikulinskaya's statistic programme. RESULTS: The comparative analysis of the genetic structure of the clonal line populations in vitro and in vivo has revealed that the amount of clones with the high, intermediate, and low variability is approximately the same in both cases. It was also shown that GVI in various clonal lines in vitro correlated with their vital ability: the clones yielding clone lines had the lowest GVI. The same GVI value was found in the clonal lines proliferated in the EAC regardless of their capability for differentiation. Intraclonal analysis has shown that the highest values of changes revealed on fingerprints of the amplification of DNA products do not prevent from differentiation of tumor hepatoma cells in the EAC. CONCLUSION: These data allow concluding that the mouse hepatoma cells MH-22a can preserve ability for differentiation in spite of significant changes in their genome.

Animals↗
PubMed2005

[The RT-PCR-identified Fas and FasL expression and apoptosis in mouse hepatoma MH-22a and histiocytic sarcoma J-774 clonal lines coupled with in vitro cultivation with syngenic splenocytes].

Malignant growth is associated with various patterns of interaction between tumor cells and those of the body immune system, interaction between Fas-receptor (Fas) and Fas-ligand (FasL) expression being one of them. These mechanisms were simulated in vitro using the main cell populations from murine hepatoma MH-22a, histiocytic sarcoma J-774 and their clonal lines obtained from cocultivation of tumor cells and syngenic splenocytes. Fas and FasL expression was identified by the RT-PCR method while apoptosis--by electrophoresis of low molecular DNA fractions and clonogenic survival.

Animals↗
PubMed2003

[RAPD-polymerase chain reaction analysis of the genetic structure of tumor hepatocyte population MH-22A].

The viability and genetic variability of mouse hepatoma MH-22a were studied by RAPD-PCR method using 3 primers, and the genetic structure of the tumor hepatocyte population based on the number of clonal fingerprint rearrangements was identified: 56% of hepatocytes made up clones with 0-3 rearrangements (the stem line of the population); 32%--the variable part with 4-7 rearrangements per clone and 12%--the aberrant part with 8-12 rearrangements per clone. The stem line appeared the most viable featuring zero or least genetic variability while the clones characterized by the greatest genetic variability were least viable.

Animals↗
PubMed2001

[Clonal analysis of the heterogeneity of neoplastic hepatocytes].

The heterogeneity of hepatoma MH-22a cell line was studied by clonal analysis on the basis of the following factors: splenocyte-induced apoptosis of tumor hepatocytes, tumor hepatocyte-induced apoptosis of splenocytes and profile of B1-associated DNA fragments. Induction of apoptosis of tumor hepatocytes by splenocytes and of splenocytes--by tumor hepatocytes was carried out in the main population of hepatocytes and in five clonal lines of hepatoma MH-22a. Genetic heterogeneity was studied using the same material and PCR primed for murine B1-elements. It was shown that apoptosis of hepatocytes of the main population and two clonal lines of hepatoma MH-22a was induced by splenocytes. The ability to induce apoptosis of splenocytes was observed in the same clonal lines and population of tumor hepatocytes. The latter involved enhanced genetic heterogeneity which was identified by B1-PCR analysis. Thus, a correlation was established in tumor hepatocytes between apoptosis-related characteristics and frequency of genome rearrangements.

Animals↗
PubMed2000

PCR-detected genome polymorphism in malignant cell growth.

In this chapter, we analyze the problem of genetic polymorphism in tumorigenesis, which determines basic capacities of tumors. The study of genome polymorphism with modified PCR methods allows the detection of various forms of polymorphism in tumor cells. This method has made it possible to determine association of DNA polymorphism with conditions of oncogenes, antioncogenes, and genes of apoptosis and with their allelic states. A special type of nonspecific DNA polymorphism that resulted from an increase in the mutation number in the cancer cell genome was discovered. This phenomenon was called the microsatellite mutator phenotype. Because the type of DNA polymorphism correlates with various biological capacities of malignant tumors and has an important prognostic significance, the analysis of DNA polymorphism in benign and malignant tumors of different histogenesis will play an important role both in theoretical studies of cancer and in oncological practice. A modified B1-PCR was used to study the genome polymorphism in the mouse tumor cells. The gain of the band 470 bp and the loss of the band 600 bp were revealed in the hepatoma cell line MH-22a as compared with liver cells of C3HA mice. The differentiation of teratocarcinoma EC F9 cells to endoderm-like cells was not accompanied by any changes in the B1-AF DNA fingerprint.

Animals↗
PubMed1998

[Polymorphism of B1-associated DNA fragments on various stages of ontogenesis of mice in tissues of different histogenesis].

Pattern of B1-associated DNA fragments was studied by means of polymerase chain reaction (PCR) in the mouse tissues of different histogenesis of 15 and 20 day old embryos and of adult mice C57B1/6. As many as 20 DNA fragments were revealed on electrophoregrams differing in their molecular masses (m. m.) and amounts of amplified products. DNA fragments varied within a 100-10,000 bp range. The clusters of B1-associated DNA fragments, containing 100-200, 300-400 and 800-1000 bp, were most intensive in all studied electrophoregrams. The B1-associated DNA fragments from muscles of adult mice differed from those of other tissues by the presence of a DNA fragment with 800 bp. A comparative analysis of the spectra of B1-associated DNA fragments from hepatocytes of two inbred strains, C57B1/6 and C3HA, has shown their general similarities in m. m. values. But a significant distinction, that was found, involved the presence of a DNA fragment with m. m. approximately 6000 bp in the spectra of B1-associated DNA fragments from C3HA strain mice, that is absent in the spectra of respective fragments from hepatocytes of C57B1/6 strain mice. The obtained results allow to use the B1-PCR method for studying genome recombination during ontogenesis, intraspecies divergence and also at malignant cell transformation.

Animals↗
PubMed1998

[Phenotypic variability in gag-myc transgenic mice].

The study of neoplastic growth capacity in gag-myc F3-F4 transgenic mice showed that they retain the capacity to develop hyperplasia and benign and malignant tumors same as F0-F2 transgenic mice do. However, the histological spectrum of tumors was much narrower, chiefly, due to the absence of rare patterns. The tumors in F3-F4 transgenic mice were mainly lymphomas and epithelial tumors of endocrine or exocrine glands. The incorporation of gag-myc in the genome of F3-F4 transgenic mice failed to tell on the variation of such quantitative polygenic characteristics as body mass and growth.

Age Factors↗
PubMed1997

[Polymorphism of B1-associated DNA fragments from normal and transform ed murine hepatocytes].

Our study of B1-associated DNA fragment polymorphism in murine hepatocytes by means of polymerase chain reaction (PCR) allowed to reveal as many as 20 DNA fragments differing in their molecular masses (m. m.) and amount of amplified products varying within the range of 100-1000 bp. Within the same inbred strain of mice (C57B1/6), spectra of B1-associated DNA fragments were similar in different periods of ontogenesis (embryos of 15 and 20 days, adult mice), in different mice of the same or different litters. A comparative analysis of the spectra of B1-associated DNA fragments from hepatocytes of two inbred strains, C57B1/6 and C3HA, has shown in general their similarities in m. m. values. But a significant distinction, that was found, involved the presence of DNA fragments with m.m. approximately 600 bp in the spectra of B1-associated DNA fragments from C3HA strain mice, that is absent in the spectra of respective fragments from hepatocytes of C57B1/6 strain mice. The spectra of B1-associated DNA fragments from transformed hepatocytes of murine hepatoma MH-22a, in general, were the same as those from hepatocytes of C3HA strain mice. At the same time, a DNA fragment with m.m. of 450 bp, not detected in normal hepatocytes, was revealed in transformed ones. Nevertheless a DNA fragment with m.m. of 600 bp, characteristic of normal hepatocytes, was not observed in the transformed hepatocytes. The B1-PCR method can be used for studying genomic polymorphism both in different populations of mice, and during malignant growth.

Animals↗
PubMed1996

Some characteristics of neoplastic cell transformation in transgenic mice.

The role of the expression of different cellular genes and viral oncogenes in malignant cell transformation is discussed. We pay special attention to the role of the genes for growth factors and their receptors and homeobox genes in oncogenesis. Based on both the literature and our own data, specific features of tumors developed in transgenic mice are discussed. All of these data are used to analyze current theories of multistep oncogenesis and the stochastic component in this process. We suggest that all known evidence about the mechanisms of oncogenesis be used in studying the problem at various structural and functional levels in an organism. The chapter shows that transgenic mice are a most suitable model for studying various aspects of malignant transformation from the molecular to the organismal and populational levels.

Animals↗
PubMed1996

[The characteristics of homologous DNA recombination in somatic cells. III. Intrachromosomal recombinations of the aminoglycoside phosphoribosyltransferase gene in transgenic mice].

Intrachromosomal homologous recombination has been revealed in the DNA from transgenic mice of three pedigrees. The recombination DNA of aminoglycosid phosphoribosiltransferase (neo) gene was observed in liver, kidney, spleen, heart, skeletal muscle, germinal glands and tail. It is concluded that the constructed model can be used for studying recombinations in cells of various organs and tissues both in the course of embryogenesis and during their malignant transformation and tumor progression.

Animals↗
PubMed1996

[The use of B1-PCR method for studying the genomic polymorphism involved in malignant growth].

The BI-PCT method showed the profile of BI-associated fragments of LNA in the cell line of the mouse hepatoma MH-22a to differ from that of the liver cells of C3HA mice, hepatoma cells incorporating the DNA fragments with 450 bp and those with 600bp disappearing. Application of the same method failed to reveal any differences in the profiles of BI-associated DNA fragments in the differentiated and non-differentiated cells of the embryonal carcinoma F9 induced by retinoic acid and cAMP dibutyryl treatment. It is suggested that the spectra of BI-associated DNA fragments might correlate with genetic stability in tumor cells.

Animals↗
PubMed1994

[Leukemia in delta-GAG-MYC transgenic mice].

Transgenic mice carrying two delta-gag-myc genetic constructions were produced and kept under observation during their whole life. Nineteen out of 119 transgenic mice developed such hemopoietic diseases as lymphoid tissue hyperplasia, lymphoma, lymphosarcoma and myeloma. Lymphoid tissue hyperplasia and lymphoma generally involved multiple hyperplastic and neoplastic pathologies which were regarded, on the whole, as "malignant disease". In all cases, lymphosarcoma and myeloma were the only deadly pathologies. Lymphomas and myelomas were detected after 3-9 months, lymphosarcomas--18-29 months while lymphoid tissue hyperplasia occurred virtually throughout the entire life span--3-31 months. The study has shown that transgenic mice carrying delta-gag-myc gene in their genome can be used in the designing of special models for investigations of certain patterns of leukemia.

Animals↗
PubMed1994

[Oncogenesis in transgenic mice].

Oncogenesis in transgenic mice is at present a model, most adequately reflecting the natural conditions of tumor development. One of more important traits of this model is that it allows to study malignant growth simultaneously at all the structure-function levels in the context of the whole organism. This paper is a review of results of a series of experiments in which the localization of tumors was dependent or independent on the tissue specificity of a promoter, as well as development of multiple tumors with the use of viral regulatory sequences in genetic constructions. It has been shown that although a transgene is expressed in most of the tissues, tumors develop in some particular tissues only. These observations are interpreted by some authors in favour of the concept of multistep cancerogenesis. In this view, of primary importance are the results of studies on oncogenesis in transgenic mice, which contradict this concept and are regarded by their authors as an evidence of the possibility of a one-step transformation of normal cell into malignant one. The analysis of the obtained material enabled us to put forward an assumption that the key role in oncogenesis is played not only by certain genetic disturbances, but also by multi-level homeostatic mechanisms. Apparently, it is just the transgenic mice with cellular or viral oncogenes in their genome that represent a more adequate model for the detection of certain molecular-biological mechanisms underlying these disturbances. Also, of much importance is abundant material accumulated by now on oncogenesis of transgenic mice which shows a possibility of the effective use of various genetic constructions with prokaryotic and eukaryotic regulatory sequences, a possibility to induce not only tumors of some particular tissues, but also multiple hyperplastic and neoplastic changes in one and the same mouse. Development of tumors in such transgenic mice can be regarded as a model of different types of cancer disease.

Animals↗
PubMed1990

[The production and characteristics of transgenic mice expressing the surface protein gene of the human hepatitis B virus].

Transgenic mice were obtained that contained a gene of human hepatitis B surface antigen (HBsAg). The integrated HBsAg DNA sequences were inherited in the normal Mendelian fashion. 6 of 25 investigated transgenic mice expressed the HBsAg. The expression was detected in the serum and within the cytoplasm of hepatocytes. Specific tissue pathology was shown in these animals, including systemic hyperplasia of lymphoid tissue and degenerative changes in the liver and kidney parenchymatous cell elements.

Animals↗
PubMed1990

[The transgenic characteristics of mice with the gene for the surface antigen of human hepatitis B virus. II. The inheritance of the transgene and its expression in the liver].

The inheritance of the MT-1sAg transgene (a gene of the major envelope polypeptide of human hepatitis B virus under the control of the metallothionein I gene promoter) and its expression in mouse liver cells have been studied. The Mendel inheritance of the transgene for three generations of mice was established. The analysis of transgenic mouse F2 chromosomal DNA by the Southern hybridization revealed the tandem copy insertion of the MT-1sAg plasmid. The expression of the transgene in liver cells, both with MT-1 promoter induction by Cd++ and without it, has been observed. The decrease in mouse liver cell parts containing viral protein HBsAg was observed as well as a reliable decrease in the share of mice with detectable MT-1sAg expression in the liver during the ontogenesis. The MT-1sAg-transgenic mice may be useful for studying the human chronic HBsAg state.

Animals↗
PubMed1989

[The DNA content in the cell nuclei of trophoblastic tumors].

The DNA content in cytotrophoblast (CTB) and syncytiotrophoblast (STB) cell nuclei was assayed in tissue sections of 7 hydatidiform moles (HM) and 27 choriocarcinomas (CH). The procedure involved Feulgen's reaction and scanning cytophotometry. The analysis of summarized histograms showed the DNA distribution in CTB cell nuclei, on the one hand, and that in STB, on the other, to differ significantly in both the tumors. The HM studied cases were referred to as two subtypes on the basis of such parameters as modal class value, its ploidy and degree of nuclear poly- and heteroploidy of CTB and STB. These characteristics were used to identify three patterns of CH. A pronounced modal class (2c--4c) was typical of type 1. A wider range of modal class (2c--10c or 4c--8c) was observed in type 2. Type 3 of tumor was characterized by a pronounced polyploidy with the absence of the modal class. The analysis of individual CTB and histograms showed no significant differences between HM and CH with respect to the DNA content. An increase in the share of highly polyploid cells was associated with a shorter survival of patients.

Cell Nucleus↗
PubMed1988

[Cytogenetic changes in an explanted mouse rhabdomyosarcoma during prolonged cultivation].

Quantitative and qualitative chromosome rearrangements, dynamics of distribution of double-minute chromosomes (DMs), and morphological characteristics of tumor rhabdomyoblasts MH-82 during explantation and following in vitro cultivation are analysed. Cells of the 13th and 27th passages of cultivation were characterized by the epithelial type of growth, although their form and size varied. Chromosome analysis of tumor rhabdomyoblasts was carried out on passages 4, 14, 20, 25 and 30 of in vitro cultivation. The modal class with 53-55 chromosomes was established within 20 passages. Heterogeneity of cell population in concern to the chromosome number and content of hypotetraploid cells (72-78) diminished during cultivation. Chromosome rearrangements (marker chromosomes) in hyperdiploid and hypotetraploid cell subpopulations differed. The number of cells with DMs and the number of DMs per cell decreased till the full disappearance by the 30th passage. It is concluded that the establishment of the MH-82 cell line was completed up to the 30th passage of cultivation.

Animals↗