Table 2

Summary of p21ras activation in control colonocytes and AOM-induced colonic tumors

GTP and [GTP + GDP] bound to p21ras were measured, and the p21ras activation ratio was calculated as described in “Materials and Methods.”

Groupn% Ras GTP:[GDP + GTP]
Control colonocytes63.7 ± 0.4
Tumors with wild-type ras704.2 ± 0.4
Tumors with K-ras mutations13a8.8 ± 1.5b
Tumors with constitutive activation of wild-type p21ras188.0 ± 0.9b
  • a Only 13 of the 14 tumors with K-ras mutations were available for p21ras activation measurements.

  • b P < 0.05, compared with control colonocytes or tumors with wild-type K-ras.