PI3K-mTORC2 but not PI3K-mTORC1 Regulates Transcription of HIF2A/EPAS1 and Vascularization in Neuroblastoma.
Författare
Summary, in English
Hypoxia-inducible factor (HIF) is a master regulator of cellular responses to oxygen deprival with a critical role in mediating the angiogenic switch in solid tumors. Differential expression of the HIF subunits HIF1α and HIF2α occurs in many human tumor types, suggesting selective implications to biologic context. For example, high expression of HIF2α that occurs in neuroblastoma is associated with stem cell-like features, disseminated disease, and poor clinical outcomes, suggesting pivotal significance for HIF2 control in neuroblastoma biology. In this study, we provide novel insights into how HIF2α expression is transcriptionally controlled by hypoxia and how this control is abrogated by inhibition of insulin-like growth factor-1R/INSR-driven phosphoinositide 3-kinase (PI3K) signaling. Reducing PI3K activity was sufficient to decrease HIF2α mRNA and protein expression in a manner with smaller and less vascularized tumors in vivo. PI3K-regulated HIF2A mRNA expression was independent of Akt or mTORC1 signaling but relied upon mTORC2 signaling. HIF2A mRNA was induced by hypoxia in neuroblastoma cells isolated from metastatic patient-derived tumor xenografts, where HIF2A levels could be reduced by treatment with PI3K and mTORC2 inhibitors. Our results suggest that targeting PI3K and mTORC2 in aggressive neuroblastomas with an immature phenotype may improve therapeutic efficacy. Cancer Res; 75(21); 1-12. ©2015 AACR.
Avdelning/ar
- Molekylär barnonkologi
- Avdelningen för translationell cancerforskning
- Pediatrik, Lund
- BioCARE: Biomarkers in Cancer Medicine improving Health Care, Education and Innovation
Publiceringsår
2015
Språk
Engelska
Sidor
4617-4628
Publikation/Tidskrift/Serie
Cancer Research
Volym
75
Issue
21
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
American Association for Cancer Research Inc.
Ämne
- Cancer and Oncology
Status
Published
Forskningsgrupp
- Molecular Pediatric Oncology
ISBN/ISSN/Övrigt
- ISSN: 1538-7445