A Search for Gli Expression in Tumors of the Central Nervous System

Abstract

The gli gene was originally isolated from DNA amplified in double minutes in a glioblastoma (D259MG). Using a sensitive RNA-RNA hybridization, we tested a series of central nervous system tumors for expression of the gli gene. These included 8 glioblastoma cell lines, plus cell cultures of 5 glioblastomas, 4 anaplastic astrocytomas, 3 different ependymal tumors, a malignant menin-gioma, and a medulloblastoma. Two normal glial cell cultures were also examined. There was no gli expression in any of these specimens. In glioblastoma D259MG, approximately 130 molecules of gli mRNA per cell were present and the half-life of the mRNA was approximately 5 h. By reverse transcription and PCR, gli mRNA was observed in 4 cell lines and in normal human glial cells, but the level was estimated to be less than one five hundredth of that in the D259MG cell line. The results suggest that gli expression in central nervous system tumors is a rare event and mostly likely associated with amplification of the gene.

Gli Activity Correlates with Tumor Grade in Platelet-Derived Growth Factor–Induced Gliomas

“…It has also been shown that mRNAs encoding elements of the SHH pathway are expressed in gliomas, and cyclopamine inhibits proliferation of glioma cell lines and gliomaspheres in vitro, as well as in orthotopic xenografts (37)(38)(39)(40). However, other studies using glioma cell lines have suggested that the SHH pathway plays a relatively minor role in gliomagenesis (41,42), and one study suggested that the SHH pathway inversely correlates with histologic malignancy (43). One potential reason for the conflicting data on the SHH pathway in gliomas could be explained in part by our demonstration that an intact tumor microenvironment or neurospheres conditions are required to maintain Gli activity, as it is down-regulated in vitro when gliomas are cultured as adherent cells with serum.…”

Involvement of Protein Kinase Cϵ in the Stimulation of Anionic Amino Acid Transport in Cultured Human Fibroblasts

“…the plasma membrane, as demonstrated in the present report for PKC⑀. This isoform, although not typical of cells from nervous tissue (30,31), is clearly detectable in the particulate fraction of C6 rat glioma cells (31), the cell model used by Casado et al (10,11).…”

The Gli code: an information nexus regulating cell fate, stemness and cancer

“…However, the suggestion that amplification was important was denied shortly after [50]. Later, the HH-GLI pathway was implicated independently in familial basal-cell carcinomas (through loss of PTCH1; reviewed in Ref.…”