Transcriptional activation of the bcl-2 apoptosis suppressor gene by the paired box transcription factor PAX8.

The bcl-2 proto-oncogene suppresses apoptosis in a variety of cell types and is essential for normal renal development. PAX8 is a member of the paired box class of transcription factors and is developmentally regulated. bcl-2 and PAX8 are both expressed in the kidney during development and throughout life, demonstrating a nearly identical pattern of expression. We used transient transfection reporter assays and electrophoretic mobility shift assays to test PAX8 transcriptional regulation of bcl-2. PAX8 transcriptionally activates the bcl-2 promoter and binds to promoter sequences in vitro. These findings establish that PAX8 can transcriptionally regulate bcl-2 and suggest that suppression of apoptosis is an important event in the development and maintenance of renal tubular epithelial structures.