Polypyrimidine tract binding protein (PTB) is expressed in developing mammalian
astrocytes, absent in mature adult astrocytes, and aberrantly elevated in gliomas. It is
unclear whether PTB is a coincidental marker of tumor progression or a significant mediator
of tumorigenesis. In developing Drosophila, the absence of the PTB homolog, hephaestus,
results in increased Notch activity. Since Notch is a well-known inducer of glial cell fate, we
determined whether overexpression of PTB in glial cell tumors provides a selective growth …