Deletion of Pten in mouse brain causes seizures, ataxia and defects in soma size resembling Lhermitte-Duclos disease.
Initially identified in high-grade gliomas, mutations in the PTEN tumor-suppressor are also found in many sporadic cancers and a few related autosomal dominant hamartoma syndromes. PTEN is a 3'-specific phosphatidylinositol-3,4,5-trisphosphate (PI(3,4,5)P3) phosphatase and functions as a negative regulator of PI3K signaling. We generated a tissue-specific deletion of the mouse homolog Pten to address its role in brain function. Mice homozygous for this deletion (PtenloxP/loxP;Gfap-cre), developed seizures and ataxia by 9 wk and died by 29 wk. Histological analysis showed brain enlargement in PtenloxP/loxP;Gfap-cre mice as a consequence of primary granule-cell dysplasia in the cerebellum and dentate gyrus. Pten mutant cells showed a cell-autonomous increase in soma size and elevated phosphorylation of Akt. These data represent the first evidence for the role of Pten and Akt in cell size regulation in mammals and provide an animal model for a human phakomatosis condition, Lhermitte-Duclos disease (LDD).
Backman
S A
SA
Department of Medical Biophysics, University of Toronto and Ontario Cancer Institute, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada.
Stambolic
V
V
Suzuki
A
A
Haight
J
J
Elia
A
A
Pretorius
J
J
Tsao
M S
MS
Shannon
P
P
Bolon
B
B
Ivy
G O
GO
Mak
T W
TW
D000818:Animals; D001259:Ataxia / Q000235:genetics*; D001483:Base Sequence; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D016923:Cell Death / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D002526:Cerebellar Diseases / Q000235:genetics*; D017931:DNA Primers; D017353:Gene Deletion; D016147:Genes, Tumor Suppressor; D007150:Immunohistochemistry; D051379:Mice; D008817:Mice, Mutant Strains; D009474:Neurons / Q000473:pathology; D051059:PTEN Phosphohydrolase; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics*; D012640:Seizures / Q000235:genetics*; D025521:Tumor Suppressor Proteins / Q000235:genetics*
D017931:DNA Primers; D025521:Tumor Suppressor Proteins; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase