Figure 1.
p16Ink4a and p19Arf are expressed in some pre-B cell transformants. (A) Total RNA from established Ab-MLV-transformed pre-B cell lines was analyzed by Northern blotting by using probes specific for exons 1α and 1β and β-actin. Wt1, Wt2, and Wt3 are 298-18, 204-3-1, and 38B9, respectively; Mut1, Mut2, and Mut3 are 379-10, 143-2M, and 300-31, respectively; Null is L1-2. (B) Cell lysates from the same cells were analyzed by Western blotting. Levels of the P120 or P160 v-Abl protein or CDK-6 control for protein loading. Lane +, lysate from MEL cells known to express both p16Ink4a and p19Arf (33, 34); lane −, lysate from NIH 3T3 cells.