Figure 6.

Cyclin E1 and cyclin D1 expression was increased in merlin-deficient cells. (A) Transcript levels of cyclin E1 and cyclin D1 were measured in MENII-1 cells using quantitative PCR. At least a 2.5-fold increase in the transcript levels of cyclin E1 was seen in MENII-1-NF2-siRNA cells compared with MENII-1-Control cells, whereas transcript levels of cyclin D1 were unchanged. Asterisk denotes statistical significance (P < .05). (B) Western blot analysis of cell lysates derived from AC1, MENII-1, and KT21MG1 stable cells was used to show that protein levels of cyclin E1 were increased in the absence of merlin. Levels of α-tubulin were determined in the same samples as a loading control. (C) Western blot analysis of cell lysates derived from MENII-1 and KT21MG1 stable cells was used to show that protein levels of cyclin D1 were unchanged in the absence of merlin. Levels of α-tubulin were determined in the same samples as a loading control.