Glucocorticoid dexamethasone reversibly complements EJ-RAS oncogene to transform mouse embryo BALB-3T3 cells |
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Authors: | K Kovary M C Armelin H A Armelin |
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Institution: | Departamento de Bioquímica, Instituto de Química Universidade de S?o Paulo, Brasil. |
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Abstract: | EJ-A is a Balb-3T3 transfectant cell line that bears a small number of EJ-ras oncogene copies/cell, has low EJ-ras expression, and resembles the parental cell line in displaying a non-transformed phenotype. The glucocorticoid hormone dexamethasone reversibly induces transformation traits in EJ-A cells, namely: 1) morphological transformation; 2) increased growth rate and saturation density; 3) reduced G1 length; and 4) independence of the FGF requirement to initiate DNA synthesis. Western blot analysis revealed that dexamethasone does not increase the p21ras protein intracellular level. beta-IFN, added to the culture medium, does not suppress the dexamethasone-induced growth stimulation and morphological transformation. Therefore, glucocorticoid hormones can complement low EJ-ras expression to transform Balb-3T3 cells, by a mechanism that is likely to be independent of p21ras increase and beta-IFN decrease. |
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Keywords: | EJ-ras oncogene transfectant glucocorticoid hormone reversible transformation p21ras β-IFN |
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