Figure 4.
MAPK, but not PI3K signalling is upregulated in UroIICRE+ β-cateninexon3/exon3 H-RasQ61L bladder tumours. Immunoblotting demonstrates upregulation of pMEK1/2 and pERK1/2 in the UroIICRE+β-cateninexon3/exon3H-RasQ61L tumours, but not pAKT, which is upregulated in the UroIICRE+β-cateninexon3/exon3Ptenfl/fl (but not pMEK1/2 or pERK1/2). We demonstrate that MEK inhibition can regress the UroIICRE+β-cateninexon3/exon3H-RasQ61L tumours in terms of size and proliferation (b–c) (P<0.05, Mann–Whitney). We see no difference in the UroIICRE+β-cateninexon3/exon3Ptenfl/fl tumour size nor proliferation after MEK inhibition (b–c). We also notice a reduction in pERK1/2 and pMEK1/2 protein levels on IHC in the UroIICRE+β-cateninexon3/exon3H-RasQ61L tumours (d–e) (P<0.05, Mann–Whitney). Uβ H-RasQ61L (UroIICRE+β-cateninexon3/exon3H-RasQ61L) and Uβ Ptenfl/fl (UroIICRE+β-cateninexon3/exon3Ptenfl/fl)