Identification of PTEN-related sequences in glioma cells and in non-neoplastic cell lines

The PTEN gene, which encodes a tumor suppressor with phosphatase activity, is located on chromosome 10q23 and is mutated in different tumors, including glioblastomas (GBM). We found evidence for a PTEN-related sequence (PTEN-rs) on genomic DNA of GBM and non-neoplastic cells. PTEN-rs does not contain introns and presents several conserved missense mutations, including a T to G transversion at the initiation codon. Rsa I digestion may help to identify this putative PTEN pseudogene which, according to RT–PCR analysis on glioma, fibroblast, brain and lung cells, does not appear to be transcribed.