hypoxia-inducible factors activate CD133 promoter through ETS family transcription factors.

Abstract

CD133 is a cellular surface protein that has been reported to be a cancer stem cell marker, and thus it is considered to be a potential target for cancer treatment. However, the mechanism regulating CD133 expression is not yet understood. In this study, we analyzed the activity of five putative promoters (P1-P5) of CD133 in human embryonic kidney (HEK) 293 cells and colon cancer cell line WiDr, and found that the activity of promoters, particularly of P5, is elevated by overexpression of hypoxia-inducible factors (HIF-1α and HIF-2α). Deletion and mutation analysis identified one of the two E-twenty six (ETS) binding sites (EBSs) in the P5 region as being essential for its promoter activity induced by HIF-1α and HIF-2α. In addition, a chromatin imunoprecipitation assay demonstrated that HIF-1α and HIF-2α bind to the proximal P5 promoter at the EBSs. The immunoprecipitation assay showed that HIF-1α physically interacts with Elk1; however, HIF-2α did not bind to Elk1 or ETS1. Furthermore, knockdown of both HIF-1α and HIF-2α resulted in a reduction of CD133 expression in WiDr. Taken together, our results revealed that HIF-1α and HIF-2α activate CD133 promoter through ETS proteins.

• Authors: Shunsuke Ohnishi, Osamu Maehara, Koji Nakagawa, Ayano Kameya, Kanako Otaki, Hirotoshi Fujita, Ryosuke Higashi, Kikuko Takagi, Masahiro Asaka, Naoya Sakamoto, Masanobu Kobayashi, Hiroshi Takeda
• Journal: PloS one (PLoS One) Vol. 8 Issue 6 Pg. e66255 ( 2013) ISSN: 1932-6203 [Electronic] United States
• PMID: 23840432 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• AC133 Antigen
• Antigens, CD
• Basic Helix-Loop-Helix Transcription Factors
• ELK1 protein, human
• ETS1 protein, human
• Glycoproteins
• HIF1A protein, human
• Hypoxia-Inducible Factor 1, alpha Subunit
• PROM1 protein, human
• Peptides
• Proto-Oncogene Protein c-ets-1
• ets-Domain Protein Elk-1
• endothelial PAS domain-containing protein 1

Topics

• AC133 Antigen
• Antigens, CD (genetics, metabolism)
• Basic Helix-Loop-Helix Transcription Factors (physiology)
• Binding Sites
• Cell Hypoxia
• Cell Line, Tumor
• Gene Expression
• Gene Knockdown Techniques
• Glycoproteins (genetics, metabolism)
• HEK293 Cells
• Humans
• Hypoxia-Inducible Factor 1, alpha Subunit (physiology)
• Peptides (genetics, metabolism)
• Promoter Regions, Genetic
• Protein Binding
• Proto-Oncogene Protein c-ets-1 (physiology)
• Transcriptional Activation
• Up-Regulation
• ets-Domain Protein Elk-1 (physiology)