CD24 positive cells identify a tumour forming cell population in <i>Ptch1</i>^{<i>lox/lox</i>}<i>;GFAP</i>^<i>cre</i> medulloblastoma.

(A) Kaplan-Meier plot of CD24 positive and negative cell-induced tumour formations in SCID mice following injections of 1x106 primary cells. Arrow indicates time point of a statistically significant difference between CD24+ and CD24- tumour onset times. (B) Gross tumour morphology. Tumours resulting from both CD24+ and CD24- cells appeared morphologically similar as a vascularised tumour mass consisting of dense nucleated cells. (C) Kaplan-Meier plot of subcutaneous tumour formation following injections of 0.4x106 CD24+ cells, but not CD24- cells. (D-E) Quantitative real-time PCR identified endogenous Gli1 (D) and Nmyc (E) expression in CD24+ cell-induced subcutaneous SCID tumours comparable to primary P17+ Ptch1lox/lox;GFAPcre cells. (F) RT-PCR confirmed Ptch1 exon 3 deletion in CD24+ subcutaneous tumours. (G, H) CD24 expression in isolated CD24+ and CD24- induced tumours. (I-L) Co-immunostaining of CD24 with GFAP and Olig2in CD24+ and CD24- induced tumours. Scale bar in B 2.0mm and 1.0mm; G-L 20μm. * p<0.05.