Table 2.

Cooperation between Ras effector loop mutants and cyclins in inducing anchorage-independent growth of NIH 3T3 cells

Cell lineColony-forming efficiency (% ± SD)a
+pBabePuro+Cyclin D1+Cyclin E+Cyclin A
neo 0 000
12V2.2 ± 0.1 12.1 ± 1.04.7 ± 0.55.1 ± 0.6
12V,35S0b 1.0 ± 0.10.4 ± 0.12.0 ± 0.2
12V,37G0b 2.5 ± 0.11.2 ± 0.11.7 ± 0.4
12V,40C0b 1.7 ± 0.20b 3.7 ± 0.3
  • a A total of 10,000 cells were seeded into 0.3% agar. Macroscopic colonies were scored after 2 weeks of growth. Each infection with cyclin-expressing viruses was performed twice; each pool of infectants was then analyzed twice in duplicate. Values represent averages of all determinations ± 1 standard deviation. See text for further details. +pBabePuro, cells infected with a retroviral vector lacking a cDNA insert; +cyclin D1, E, or A, cells infected with a retroviral vector that drives expression of a human cyclin of the indicated type.

  • b Formation of microscopic colonies (see footnote b to Table 1).