Pten deletion cooperates with β-catenin activation in T-cell leukemogenesis. (A) CGH-array analysis of a region of chromosome 19 from 10 R26-βcat tumors. The y-axis represents the log₂ of the ratios of the normalized hybridization signals of leukemic/control DNA (black circle). The red line depicts status assignment (+1, 0, or −1 for gained, normal or lost alleles, respectively; PISSCO algorithm). The position of the CGH probes is indicated on the x-axis. The arrow indicates the location and orientation of the Pten gene. (B) Relative levels of Pten mRNA from seven R26-βcat tumors compared with control thymocytes, analyzed by quantitative reverse-transcription PCR. Values are shown relative to Hprt mRNA and represent the average of 2 independent experiments performed in triplicate (mean ± SD). (C) Western blot analysis of Pten in total cell extracts from 8 R26-βcat tumors and 2 control thymuses. (D) Western blot for Pten from 3 primary R26-βcat tumors (T) and their derived cell lines (CL) compared with control thymocytes. A vertical line has been inserted to indicate a repositioned gel lane. (E) Kaplan-Meier plot showing the survival curves of control mice, R26-βcat mice with wild type or heterozygote Pten alleles. P value was obtained from the log-rank test. (F) Western blot analysis of Pten expression in tumor cells from 4 Pten^f/+R26-βcat mice as well as splenocytes (Spl) and pretransformed thymocytes (PT) from 6-week-old Pten^f/+R26-βcat mice and control thymocytes.