[Effect of narrow fractions of chromatin non-histone proteins on the expression of membrane tumor-associated antigen MA-50 and phosphorylation of proteins of cultured rat hepatocytes]. / Vliianie uzkikh fraktsii negistonovykh belkov khromatina na ékspressiiu membrannogo opukholevoassotsiirovannogo antigena MA-50 i fosfolirovanie belkov kul'tiviruemykh gepatotsitov krysy.

As earlier reported, the main component of narrow fractions of chromosomal non-histone proteins (NHP) of kidney and of Zaidel hepatoma cells has its own protein kinase activity, and is identified as a heteroorgan NHP-antigen, which is intrinsic to the definite renal tissue and absent in the liver. Effects of narrow fractions of kidney and Zaidel hepatoma NHP on biosynthetic processes and sizes of hepatocytes were studied in vitro. It has been shown that as a result of a 5 h incubation of rat hepatocytes with a narrow fraction of renal NHP the proportion of small hepatocytes increases approximately by 12% as compared with that of cells cultivated without NHP. Besides, binding of organ-specific anti-kidney immune serum with a small hepatocyte population rises by more than 20%, which results from the expression of tumor-associated heteroorgan kidney-specific antigen on the hepatocyte surface. According to immunoprecipitation and subsequent electrophoresis, the molecular mass of a membrane heteroorgan antigen on the surface of hepatocytes amounts approximately to 65 kDa, and an active phosphorylation of cellular proteins takes place. The same effect on hepatocytes is produced by a narrow NHP fraction of chromatin of Zaidel hepatoma cells, whereas no phosphorylation is observed in the presence of liver NHP as well as in the absence of NHP. It is suggested that the heteroorgan NHP-antigen induces biosynthetic processes including synthesis of membrane tumorassociated antigen on the surface of hepatocytes cultivated in vitro by activation of cellular protein phosphorylation, which can lead to changes in size of cultivated cells.

[Comparative study of chromosomal nonhistone proteins pp23 in cells from different types of tissue]. / Sravnitel'noe izuchenie khromosomnykh negistonovykh belkov pp23 v kletkakh razlichnoi tkanevoi prinadlezhnosti.

A specific immunoserum against nonhistone chromosomal protein pp23 from rat kidney was produced. A similar protein was obtained in cells of different tissue specificity (in the liver cells of rats submitted to a single effect of hepatocarcinogens, in rat hepatomas G-27, HTC, Zajdela, in cultivated non-tumor myogenic L6 cells and in kidney cells of newborn rats) by means of immunofluorescent method on using this immunoserum. In all cases a specific fluorescence of the nucleus and nuclear membrane was observed.

[The detection of membrane tumor-associated antigens of Zajdela's hepatoma on the surface of cultured rat cells]. / Vyiavlenie membrannykh opukholeassotsiirovannykh antigenov gepatomy Zaidela na poverkhnosti kul'tiviruemykh kletok krys.

Membrane tumor-associated antigens of the rat hepatoma Zajdela were revealed using immune serum against cell membranes of this hepatoma. By means of SDS-polyacrylamide gel electrophoresis and the following immunoblotting, it was shown that the membrane tumor-associated antigens of hepatoma Zajdela consisted, at least, of 10 components with molecular weights near 22, 25, 31, 33, 42, 46, 56, 65, 96 and 180 kDa. Specific binding of the immune serum with antigens of cultured hepatomas 27 and HTC cell membranes, of myogenic cells and rat kidney fibroblasts may be suggestive of the expression of some tumor-associated hepatoma Zajdela antigens on the surface of these cultured cells.

[The membrane hetero-organic antigens of tumors of hepatocellular and myogenic origins]. / Membrannye geteroorgannye antigeny opukholei gepatotselliuliarnogo i miogennogo proiskhozhdeniia.

Cell-surface antigens of some tumors and homologous definitive tissues were investigated with organospecific immunoserum against rat kidney membranes using methods of immunofluorescence and enzyme immunoassay. Myogenic cells were also tested to resolve the role of the membrane hetero-organic antigens in the process of proliferation. Membrane hetero-organic antigens, commonly attributed to definitive kidney tissue, were found on the cell surface of rat rhabdomyosarcoma RA-2 and cultured cells of rat hepatomas HTC and 27. However, hetero-organic antigens on the surface of active proliferating myogenic cells were not found. It is concluded that membrane hetero-organic antigens, usually attributed to definitive kidney tissue, represent one of characteristic manifestations of neoplastic cell transformation rather than results of intensive proliferation of the cells.

[A comparative study of the nonhistone chromosomal proteins (pp23) from rat and bull kidneys]. / Sravnitel'noe izuchenie khromosomnykh negistonovykh belkov (pp23) iz pochek krysy i byka.

The bovine nonhistone protein pp23 differs from that of rat origin both immunologically (precipitation, specific interaction with monoclonal antibodies to rat pp23) and functionally (capability to stimulate expression of hetero-organic antigens on the membrane of intact hepatocytes cultured in suspension). These differences, however, are not recognized in the experiments on stimulation of DNA synthesis in Swiss 3T3 cell resting culture, when a more general cell function (proliferation) is dealt with, rather than a narrow specific one, such as synthesis of tumor-associated hetero-organic antigen of kidney origin.

[The isolation and characteristics of a protein from human and bovine kidneys close in molecular and biochemical properties to non-histone chromosomal antigen PP23]. / Vydelenie i kharakteristika belka iz pochek cheloveka i byka, blizkogo po molekuliarno-biokhimicheskim svoistvam NGB-antigenu PP23.

By ion-exchange gradient chromatography, autophosphorylated protein fractions were separated from nonhistone chromosomal protein (NHCP) samples isolated from bovine and human kidney and liver. Fractions, eluted from the phosphocellulose column with 0.4-0.5 M NaCl, could occur only in the case of kidney rather than liver NHCP-fractionation. The molecular weight of the major phosphorylated protein component, eluted in this zone, is about 20-26 kDa, which is close to the molecular weight of protein pp23, previously observed during similar fractionation of NHCP from rat kidney rather than from liver.

[The isolation of monoclonal antibodies to hepatoma-associated nonhistone chromosomal proteins from rat kidneys]. / Poluchenie monoklonal'nykh antitel k negistonovym belkam khromatina pochek krys, assotsiirovannym s gepatomami.

A monoclonal antibody (5D2) has been produced to a fraction of nonhistone proteins of kidney origin, associated with the rat hepatoma 27 and not obtained in normal liver. The 5D2 antibody was found to precipitate three proteins with molecular weights of 22-23 kDa. Indirect immunofluorescence studies on fixed hepatoma cell-preparations showed speckled nuclear staining patterns. In contrast, the 5D2 antibody was unreactive with intact hepatocytes.

[The expression of hetero-organic antigens of kidney origin on the surfaces of cultured rat hepatocytes under the influence of the narrow-band fractions of non-histone chromosomal proteins]. / Ekspressiia geteroorgannykh antigenov pochechnoi prirody na poverkhnosti kul'tiviruemykh gepatotsitov krys pod vliianiem uzkikh fraktsii khromosomal'nykh negistonovykh belkov.

Narrow fractions of nonhistone chromosomal proteins (NHCP) eluted with 0.4-0.5 M NaCl from the phosphocellulose column stimulate expression of hetero-organic antigens of kidney origin on the membrane of intact hepatocytes cultured in suspension. These fractions of NHCP were isolated from the intact rats kidney, from cells of hepatoma 27 and Zajdela hepatoma, and from the carcinogenic liver after a single diethylnirozamine injection. The membrane hetero-organic antigens were identified by means of indirect immunofluorescence using specific immune serum.

[The effect of preparations of non-histone chromosomal proteins on the expression of hetero-organic membrane antigens of kidney origin in a primary rat hepatocyte culture]. / Vliianie preparatov negistonovykh belkov khromatina na ékspressiiu membrannykh geteroorgannykh antigenov pochechnoi prirody v pervichnoi kul'ture gepatotsitov krys.

The expression of membrane hetero-organic antigens of kidney origin, associated with the rat hepatomas in primary culture of intact adult rat hepatocytes, was investigated by means of the indirect immunofluorescence method using a specific immune serum. These antigens were observed on the membrane of some hepatocytes after their contact with nonhistone chromosomal proteins (NHCP), which were obtained from the kidney of intact rats from cells of hepatoma 27 and Zajdela hepatoma, or from the carcinogenic liver after a single diethylnitrosamine injection. Negative results were obtained after the incubation of hepatocytes in the medium lacking some of NHCP, or in that with NHCP obtained from the liver of intact rats.

[The stimulation of DNA synthesis in resting Swiss 3T3 cells by non-histone chromosomal proteins]. / Stimuliatsiia sinteza DNK v pokoiashchikhsia kletkakh Swiss 3T3 negistonovymi khromosomal'nymi belkami.

Nonhistone chromosomal proteins (NHC), isolated from the kidney and liver of intact rats, the liver of rats treated with hepatocarcinogen DEN and the rat hepatoma, stimulate DNA synthesis in Swiss 3T3 cells in resting culture. The maximum stimulating effect was obtained in the presence of narrow NHC fractions eluted with 0.4-0.5 M NaCl from the phosphocellulose column and identified as hetero-organic NHC protein antigens of the kidney origin associated with hepatocellular tumors.

[Molecular weights of the hetero-organic NHCP antigens of kidney origin associated with rat hepatomas]. / Molekuliarnye massy assotsiirovannykh s gepatomami krys geteroorgannykh NGB-antigenov pochechnoi prirody.

The narrow NHCP protein fractions, possessing a proper phosphoprotein kinase activity, were isolated from kidney of intact rats, hepatoma tissue and liver cells of rats treated with hepatocarcinogen in the process of phosphocellulose gradient chromatography by elution of 0.4-0.5 M NaCl. The gel filtration on Sephadex G-75 and SDS-PAAG electrophoretic data demonstrate that all the NHCP protein fractions mentioned above include a general molecular component with the mass of 23 kD, and display identical antigenic properties. Thus, in accordance with the data obtained, the role of the hetero-organic NHCP protein antigen of kidney origin associated with hepatoma may be played by the general molecular component of NHCP protein fractions possessing properties of a specific chromosomal phosphoprotein kinase.

[Comparative study of protein kinase C in the normal rat liver and in Zajdela's hepatoma. I. Electrophoretic analysis]. / Sravnitel'noe izuchenie proteinkinazy C pecheni krys v norme i gepatomy Zaidela. I. Elektroforeticheskii analiz.

The heterogeneity of protein kinase C (PKC) derived from rat liver and the Zajdela hepatoma was studied by sodium dodecyl sulfate electrophoresis in polyacrylamide gel. Proteins with PKC-activity of molecular weight equal to 67,000 Da and 80,000 Da and an active fragment of 50,000 Da were detected in samples from the normal rat liver. The samples from the Zajdela hepatoma contained PKC with molecular weight equal to 67,000 Da and the active fragment of 50,000 Da. PKC with molecular weight of 80,000 Da was absent.

[Radiometric detection of nonvisualizable immunoprecipitates formed by hepatoma-associated hetero-organic renal antigens of 33P-phosphorylated fractions of non-histone chromatin proteins]. / Radiometricheskoe vyiavlenie nevizualiziruemykh immunopretsipitatov, obrazuemykh assotsiirovannymi s gepatomami geteroorgannymi antigenami pochechnoi prirody 33P-fosforilirovannykh fraktsii negistonovykh belkov khromatina.

A study was made of the antigenic properties of nuclear nonhistone proteins (NHP) from rat tissue eluted with 0.4-0.5 M NaCl gradient on phosphocellulose at very low concentrations. 33P-labeled proteins were obtained by phosphorylation of NHP fractions in the presence of [gamma-33P] ATP. Some non-visual precipitates which appeared during the reaction of specific inhibition of precipitation in agarose gel of 33P-labeled NHP-fractions from rat solid hepatoma 27 cells or rat liver after single hepatocarcinogen diethylnitrosamine injection were detected by means of a calculable radiometric method, proposed by the authors. These precipitates appear only if the rabbit immune sera against NHP-DNA complexes of intact rat kidneys exhausted with liver NHP-antigens was used, never appearing in the case of kidney NHP-antigen exhaustion. Therefore the NHP-fractions prepared from "carcinogenic" liver and rat solid hepatoma cells which possess proper phosphoprotein kinase activity and form specific immune precipitates must be identified as hetero-organic antigens of kidney origin.