Transient activation of Ras-dependent signalling at the early stages of Herbimycin A induced erythroid differentiation of human K562 cells.

Aim: To study the dynamics of Ras-dependent signalling in the course of Herbimycin A induced erythroid differentiation of human erythroleukemia K562 cells.

Methods: p21Ras functional activity was analyzed by direct measurement of GTP/GDP ratio in anti-p21Ras immunoprecipitates of K562 cells previously incubated with H3(32)PO4. Dynamics of protein tyrosine phosphorylation was studied using Western blotting.

[Division of regulatory cellular systems (Lvov)].

Two departments of the A. V. Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine were founded in 1969 in Lviv.

[Synergism in the stimulating effect of transforming growth factor beta and insulin on the substrate-independent proliferation of the CHO-719 cell line].

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.

[Heat shock modulates the ability of A-549 cell line from human lung adenocarcinoma to regulate the intensity of DNA and protein biosynthesis by an autocrine mechanism].

A-549 cells of human lung adenocarcinoma were subjected to heat shock (30 min, 44 degrees C) which caused substantial decreases in the rates of biosynthesis of the great bulk of cellular proteins with simultaneous increases in the synthesis rates of the 70 kDa protein predominantly localized in cell cytosol. By the 6th hour after the heat shock cessation this protein synthesis reached its maximum; by the 18th hour it was no longer detectable, while the protein itself was not denatured. During the recovery after the heat shock the ability of the serum-free culture medium conditioned by A-549 cells in autocrine regulation of [3H]thymidine incorporation into DNA and [3H]leucine incorporation into proteins changed also.