[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 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.