Expression of stress response protein glucose regulated protein-78 mediated by c-Myb

Abstract

Glucose regulated protein-78, GRP78 has been implicated in the protection of tumor cells from cytotoxic damage and apoptosis. When protein profiles of colon cell lines were investigated we found remarkably high GRP78 expression in two cell lines. These cell lines express elevated levels of the transcription factor c-Myb due to genomic amplification of the c-myb locus and we hypothesized that c-Myb regulates GRP78 expression in colon cancer cells. The promoters of human and murine GRP78 and the related family member GRP94 were examined and potential c-Myb binding sites were identified and characterized. DNA binding studies with recombinant c-Myb and nuclear extracts together with ChIP assays ..