Transcriptional analysis of the PTEN/MMAC1 pseudogene, Psi PTEN

PTEN/MMAC1 is a recently characterized tumor suppressor. A pseudogene deriv ed from the human PTEN/MMAC1 phosphatase, Psi PTEN, has been reported. Rece nt analysis of the pseudogene revealed conflicting results about the expres sion of Psi PTEN. In this study, we show that the PTEN/MMAC1 pseudogene is actively transcribed in all cells and tissues examined. In some cases, pseu dogene transcripts were found to represent as much as 70% of the total PTEN /MMAC1 RNA. As Psi PTEN is transcribed, there is a potential for misinterpr etation of PTEN/MMAC1 mutations when RT - PCR techniques are used, as well as potential for a Psi PTEN-encoded translation product, Although we were u nable to detect a pseudogene protein product in the cell lines examined, a baculovirus produced GST pseudogene fusion protein exhibited phosphatase ac tivity comparable to wild type. The results of this study, taken together, indicate the potential complication of PTEN/MMAC1 molecular analysis caused by the expression of Psi PTEN.