HUMAN ENDOTHELIAL-CELL LINES ESTABLISHED BY MUTATED FORMS OF THE SIMIAN-VIRUS-40 LARGE T-ONCOGENE

The large T oncoprotein of Simian Virus 40 is widely used to improve t he growth characteristics of primary cells in culture. Beside growth s timulation and immortalization, expression of the large T protein in h uman cells frequently leads to a loss of differentiated characters and changes in the karyotype. We have constructed mutated forms of the la rge T protein by deletion of various fragments of the DNA binding doma in to test, whether this region is responsible for undesired influence s on cell differentiation. After transfection into human umbilical vei n endothelial cells, the resulting cell lines showed no improvement in expression of the differentiation marker von Willebrand factor compar ed to cell lines transfected with the wild type oncogene. Changes in t he karyotype were still observed. Our results contribute to the mappin g of functional domains of the large T protein. The truncated large T proteins retained growth stimulating activity after removal of 111 and 241 amino acids of the DNA binding region. (C) 1997 Elsevier Science B.V.