Figure 7.

Signaling pathway and transcription factors involved in HPR1 gene expression in cancer. Mutations and/or overexpression of the growth factor receptor genes such as EGFR and its downstream signaling molecules such as RAS and BRAF genes result in increased expression and/or translocation of the Ets family transcription factors such as GABP and Ets-1. These transcription factors in cooperation with several other transcription factors overexpressed in cancer, such as Sp1 and Egr-1, lead to HPR1 expression in cancer. HPR1 promoter demethylation and p53 mutations also contribute to increased HPR1 gene expression (not shown).