Fig. 2

Increased proliferation and decreased apoptosis in CP cells overexpressing c-MYC. a, b Slightly enlarged CP was observed in NestinCre;STOPfloxc-MYC mice at P7 as compared to controls. No histological atypia was noted. c-f Patchy hyperplasia with mild nuclear atypia was seen in NestinCre;STOPfloxc-MYC mice at P15 in comparison to controls. The hyperplastic areas showed GFP positivity in NestinCre;STOPfloxc-MYC mice, in keeping with activation of c-MYC construct. g, h At 3 months, widespread CP hyperplasia with mild nuclear atypia was observed in c-MYC overexpressing mice. i-k A trend toward increased proliferation was observed in the CP of NestinCre;STOPfloxc-MYC mice at E12.5, E16.5, P7 and P15, a finding which reached statistical significance from 3 months onwards (n = 6 in each cohort for 3 months and 6 months; n = 4 in each cohort for 9 months). l Immunolabelling for transthyretin (TTR) confirmed the epithelial nature of the majority of the cultured cells. m GFP expression upon transduction with adeno-Cre (A-Cre) confirmed construct activation. n-p Increased proliferation on Edu immunoassay and q-s decreased apoptosis on cCasp3 immunoassay upon c-MYC overexpression by A-Cre induced construct activation (cMYC^OverCP) as compared to control CP cells. t Soft agar colony formation assay demonstrating cMYC^overCP cultures forming colonies as compared to control CP. A negative (no cells) and positive control (DAOY, medulloblastoma cell line) are included on the left; bottom panel shows high magnification images. t Quantification of the finding (n = 3). k, m, p, s, u– Bar graph representing Mean ± SEM; * P < 0.05; ** P < 0.01; *** P < 0.001. Scale bar is 125 μm (l, n, o, q, r)