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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National Cancer Institute (NCI)
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Cellular Biology and Physiology Subcommittee 1 (CBY)
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Massachusetts Institute of Technology
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Hicks, G G; Shi, E G; Chen, J et al. (1995) Retrovirus gene traps. Methods Enzymol 254:263-75
Bushel, P; Kim, J H; Chang, W et al. (1995) Two serum response elements mediate transcriptional repression of human smooth muscle alpha-actin promoter in ras-transformed cells. Oncogene 10:1361-70
Hubbard, S C; Walls, L; Ruley, H E et al. (1994) Generation of Chinese hamster ovary cell glycosylation mutants by retroviral insertional mutagenesis. Integration into a discrete locus generates mutants expressing high levels of N-glycolylneuraminic acid. J Biol Chem 269:3717-24
Lowe, S W; Bodis, S; Bardeesy, N et al. (1994) Apoptosis and the prognostic significance of p53 mutation. Cold Spring Harb Symp Quant Biol 59:419-26
Lowe, S W; Jacks, T; Housman, D E et al. (1994) Abrogation of oncogene-associated apoptosis allows transformation of p53-deficient cells. Proc Natl Acad Sci U S A 91:2026-30
Lowe, S W; Bodis, S; McClatchey, A et al. (1994) p53 status and the efficacy of cancer therapy in vivo. Science 266:807-10
Lowe, S W; Ruley, H E; Jacks, T et al. (1993) p53-dependent apoptosis modulates the cytotoxicity of anticancer agents. Cell 74:957-67
Chang, W; Hubbard, S C; Friedel, C et al. (1993) Enrichment of insertional mutants following retrovirus gene trap selection. Virology 193:737-47
Lowe, S W; Ruley, H E (1993) Stabilization of the p53 tumor suppressor is induced by adenovirus 5 E1A and accompanies apoptosis. Genes Dev 7:535-45
Ragozzino, M M; Kuo, A; DeGregori, J et al. (1991) Mechanisms of oncogene cooperation: activation and inactivation of a growth antagonist. Environ Health Perspect 93:97-103

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