Neither the T24 Ha-ras oncogene nor adenovirus early region 1A (E1A) is individually able to transform an established cell line (REF52); however the two genes collaborate to transform REF52 to an oncogenic phenotype. REF52 thus resemble primary cells with regard to transformation by ras oncogenes and provide a model for multistep transformation induced by separate and complementing oncogenes. The requirement for oncogene collaboration in this system will be investigated for the purpose of learning more about the physiological functions of the E1A and T24 Ha-ras encoded proteins. First, E1A and T24 Ha-ras will be tested for the ability to complement activities required for cell cycle progression which are normally induced by serum growth factors. The ability to induce the expression cellular genes normally induced by growth factors will be assessed. Second, cells expressing E1A and T24 Ha-ras will be tested for the ability to produce and respond to transforming growth factors. Third, cells expressing E1A and T24 Ha-ras will be compared to determine whether changes in cyclic AMP and inositol phosphatide metabolism correlate with oncogene induced phenotypes. Fourth, the effects on E1A on expression of the T24 Ha-ras 1 gene will be assessed. In addition, E1A and cellular myc genes will be introduced into HL60, U937 and F9 cells and the effects of these genes on cell growth during in vitro differentiation will be determined. These studies will determine whether the activities of E1A and myc which can circumvent the commitment of cultured primary cells to growth arrest and senescence can also block the growth arrest associated with in vitro differentiation. Finally, the minimal sequences of E1A required to collaborate with T24 Ha-ras in primary cell transformation will be determined. Point mutations will be introduced into this region by misincorporating thionucleoside phosphates in an effort to correlate E1A functions and primary structure. (X)
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