Figure 5: MADR glioma models utilizing recurrent mutations observed in pediatric glioblastoma multiforme has phenotypes consistent with human subtypes.
A) Schematic of donor plasmid for MADR with multiple recurrent pediatric glioma driver mutations
B) Schematic of the plasmid delivery and electrode sweep employed to target striatal and cortical germinal niches simultaneously
C) Zoomed view from B showing the respective cortical (magenta) and striatal (orange) germinal niches that are targeted
D) Representative tumor formation in heterozygous mTmG 100 days post-EP. Nuclear EGFP+ Rosa26H3f3a-K27M/Pdgfra/Trp53 cells form a large striatal tumor. Inset D-1 shows a lack of significant cortical infiltration.
E) A littermate Rosa26H3f3aG34R/Pdgfra/Trp53 exhibits a glial hyperplasia in the striatum and cortex but no tumor is evident.
F) K27M tumor at 120 days post-EP is predominantly sub-cortical.
G) Cortically-infiltrating G34R tumor at 120 days post-EP.
H-I) Confocal pathology of K27M tumor at low mag (H), and high mag (I).
J) Low mag pathology of G34R tumor.
K) Comparison of survival across H3.3. groups (wildtype-blue, K27M-green, and G34R-red) all containing Pdgfra D842V and Trp53 R270H.
L) Chart of the site of K27M versus G34R tumors. *Because of the later onset of tumor growth in G34R groups and their inconsistent survival times, we were unable to collect 2 of 7 G34R samples before death to definitively ascertain initial tumor site.
M-N) Experimental schematic for co-EP of K27M and G34R plasmids
O-P) G34R and K27M immunostaining of co-EPed tumors in sequential sections. (smFP-myc shown in insets).
Q) Quantification of normalized cell counts from tumor