[Synergism in the stimulating effect of transforming growth factor beta and insulin on the substrate-independent proliferation of the CHO-719 cell line]. / Sinergizm stimuliruiushchego vliianiia transformiruiushchego faktora rosta beta i insulina na substratnezavisimuiu proliferatsiiu kletok linii CHO-719.

Cells of line CHO-719 from the Chinese hamster ovary have no epidermal growth factor receptors. It was detected that these cells were significantly stimulated to proliferate in a semisolid culture medium containing 0.33% agar by transforming growth factor beta (TGF-beta) in combination with insulin. This effect was even more pronounced when the cells of line CHO-719, adapted to the growth in the presence of low concentration (3%) of fetal bovine serum, were used. TGF-beta and insulin utilized separately exerted no influence on the cellular growth.

[The autocrine regulation of the proliferation of cell line A-549 under conditions facilitating the acidification of the culture medium]. / Autokrinnaia reguliatsiia proliferatsii kletok linii A-549 v usloviiakh, sposobstvuiushchikh zakisleniiu kul'tural'noi sredy.

The influence of serum-free media, previously conditioned by A-549 line cells of the human lung adenocarcinoma (c-medium), on the intensity of 3H-thymidine incorporation into DNA of the same cells was studied. It was found that, depending on the duration of conditioning (2, 4 and 6 days), the c-media were obtained with corresponding values of pH--7.2, 6.9 and 6.3, in the latter case the contact inhibition of cell growth being seen. On culturing the A-549 line cells in the c-medium at pH 7.2 and 6.9, the intensity of DNA biosynthesis was shown to be 2.4 and 1.8 times higher, respectively, compared to that under condition of the fresh serum-free medium. The cell culturing in the c-medium at pH 6.3 (here and in the case of pH 6.9 c-medium the media pH were made up to 7.2 before utilization) leads to the inhibition of DNA biosynthesis intensity in the cells. It was also detected that a temporary acidification of the pH 7.2 c-medium to pH 4.0 or 2.0, using, respectively CO2 bubbling or HCl titration, caused the growth inhibiting manifestation in this medium. The results obtained testify that the carcinoma cells of A-549 line are able to secrete into the cultured medium both stimulators and inhibitors of DNA biosynthesis, with a transforming growth factor beta being of primary importance among the latter.

[The effect of epidermal growth factor and insulin on the specific binding of transforming growth factor beta by NRK-49F and A-459 cell lines]. / Vliianie épidermal'nogo faktora rosta i insulina na spetsificheskoe sviazyvanie transformiruiushchego faktora rosta beta kletkami linii NRK-49F i A-459.

The influence of the epidermal growth factor (EGF, 5 ng/ml) and(or) insulin (1 microgram/ml) on the number of transforming growth factor beta (TGF-beta) specific binding sites in cells with different proliferative response on the TGF-beta action and on the affinity (Kd) of these sites to the ligand was studied. The total amount of TGF-beta binding sites (49,300 +/- 3000) in the cells of NRK-49F line, which are stimulated to proliferation by TGF-beta in the presence of EGF and insulin, decreased under the influence of the mixture of the latter factors (31,300 +/- 4000). In the presence of EGF, this amount did not change (40,900 +/- 6000), while in the presence of insulin it increased (81,200 +/- 9000). Kd of TGF-beta receptors (27.3 +/- 3.0 pM) in the above mentioned variants of experiments did not change. When the cells of A-549 line from human lung adenocarcinoma were investigated (the proliferation of these cells is inhibited by TGF-beta), it was shown that EGF induced the elevation of the amount of TGF-beta binding sites from 9700 +/- 700 to 21,600 +/- 900. Insulin or its mixture with EGF did not change that amount. EGF and(or) insulin did not influence the Kd (27.0 +/- 6.0 pM) of TGF-receptors in these cells. The obtained data are compared with the results of the influence of TGF-beta and of its combinations with EGF, and (or) insulin on the intensity of DNA synthesis and on proliferation in both the investigated cell lines.(ABSTRACT TRUNCATED AT 250 WORDS)

[The cells of murine sarcoma PC-103 induced by a polymeric plate secret transforming growth factor alpha]. / Kletki sarkomy PS-103 myshei, indutsirovannoi polimernoi plastinkoi, sekretiruiut transformiruiushchii faktor rosta al'fa.

It was shown previously that cells of sarcoma PS-103 induced in mouse by subcutaneous transplantation of plastic film produce growth-stimulating activity. In this communication clone 3 sb, isolated from sarcoma PS-103, was studied. Growth factor produced by the cells of this clone stimulated proliferation of quasi-normal (3T3, NRK) cells and transformed cells both in monolayer and in semi-solid medium. It was shown by gel filtration chromatography that the main growth-stimulating activity migrated with the protein fraction m.m. 10-15 kDa. The addition of this growth factor to the culture medium significantly (90%) inhibited 125I-EGF (epidermal growth factor) binding by A-431 cells. These data suggest that the growth factor produced by the studied tumor cells is transforming growth factor alpha.

[The effect of transforming growth factor beta on the intensity of cellular DNA synthesis in relation to the type and conditions of cultivation]. / Vliianie transformiruiushchego faktora rosta beta na intensivnost' sinteza DNK kletok v zavisimosti ot ikh tipa i uslovii kul'tivirovaniia.

A study was made of the influence of transforming growth factor beta (0.05-50.00 ng/ml) on the intensity of 3H-thymidine incorporation in the DNAs of pseudonormal mouse fibroblasts of NIH 3T3 line, of cells of NRK-49F line from normal rat kidney, and of cells of A-549 line from human lung adenocarcinoma. The experiments were carried out in the absence and in the presence of epidermal growth factor (5 ng/ml), and(or) insulin (1 micrograms/ml), as well as in the presence of different concentrations of fetal calf serum, and while using different time of incubation of cells with the above mentioned growth factors. It was shown that depending on the culture conditions the transforming growth factor beta exerted stimulatory, inhibitory or no action on the intensity of DNA synthesis in the cells of the same type. An attempt was made to analyse the reasons, which may significantly determine the direction of regulatory influence of the transforming growth factor beta on DNA replication in the cells.

[The effect of the beta-type transforming growth factor and its combination with epidermal growth factor and insulin on substrate-dependent proliferation of normal and tumor cells]. / Vliianie transformiruiushchego faktora rosta beta-tipa i ego kombinatsii s épidermal'nym faktorom rosta i insulinom na substratnezavisimuiu proliferatsiiu normal'nykh i opukholevykh kletok.

The influence of different concentrations of a transforming growth factor of type beta (TGF-beta) and of its combinations with the epidermal growth factor (EGF) and insulin exerted on proliferation of different types of cells in the culture medium with semisolid agar was determined. The following cell lines were tested: mouse fibroblasts of NIH-3T3 and Swiss-3T3 lines, fibroblastic line NRK-49F from rat kidney, cells of A-549 line from human lung carcinoma, HT-1080 line from human fibrosarcoma, and PS-103 line (clone 384/5) from sarcoma stimulated by polychlorvinyl plate implantation to mouse. It is detected that TGF-beta alone does not affect the substrate-independent proliferation of pseudonormal lines of fibroblastic cells, but stimulates it significantly in sarcoma and inhibits in carcinoma cells. If EGF and/or insulin are added to the culture medium besides TGF-beta, certain proliferative effect specific of either type of pseudonormal and malignant cells is detected. The results of the action of TGF-beta, and of its combinations with the most important polypeptide growth factors on several types of cells of different origin may be useful for determination of regulatory functions of TGF-beta in cell proliferation in vivo to promote better grounding of its utilization in the practice of medicine.

[Polypeptide growth factors from the loach embryo at the blastula stage]. / Polipeptidnye faktory rosta zarodyshei v'iuna na stadii blastuly.

Substances which (depending on their dose) stimulate [3H]thymidine incorporation into the trichloracetic acid insoluble fraction of the in vitro cultured mouse NIH-3T3 cells were isolated from the blastoderm and from the yolk of the teleost fish loach embryos (8-9 hours after the eggs' fertilization) by the acid-ethanol extraction method. In the medium which contained the 0.5% fetal calf serum with addition of 100 micrograms/ml of the above mentioned substances the stimulation of labeled thymidine incorporation into cellular DNA achieved 44-56% of the level which was detected in the presence of 10% serum. The pepsin and trypsin treatment led to a significant decrease in the mitogenic activity of the both investigated factors, that confirmed their polypeptide structure. The factors are sufficiently thermostable as they retain almost completely the activity after 30 min heating at 56 degrees C and lose less than 70% of their activity after boiling for 5 min. Gel-filtration of the growth factors from the loach embryos' yolk on the Biogel P-60 column has shown that the growth stimulating activity is mainly concentrated in the fraction which contains the polypeptides with molecular weight about 5 kDa. The significance of mitogenic factors in the loach embryos at the earliest stages of the embryonic development is discussed.