β-Catenin lymphomas do not show Notch activation. (A) Illustration of the expression of Notch family members and target genes that show significant (P < .05) expression changes when comparing microarray data from control LckCre to CD4Cre-CtnnbΔex3 pretransformed thymocytes or the resulting lymphomas. Expression changes are color coded; red indicates up-regulation and blue indicates down-regulation. Columns represent independent RNA preparations as indicated. Rows are independent genes; the identity and accession number of the genes is indicated. (B) Semiquantitative RT-PCR of Notch1, Notch3, Deltex1, Hes1, and Lunatic-Fringe transcription (“Materials and methods”). RNA was isolated from sorted DP thymocytes of LckCre control (lane 1), and CD4Cre-CtnnbΔex3 thymocytes (lane 2), as well as 3 independent CD4Cre-CtnnbΔex3 lymphomas (lanes 3-5). RT-PCR for β-actin was used to equilibrate the samples. Two 5-fold serial dilutions are shown.
