aHIF but not HIF-1α transcript is a poor prognostic marker in human breast cancer

Background Hypoxia-inducible factor-1α (HIF-1α) is part of a transcriptional factor that regulates genes involved in metabolic and vascular adaptation of tumours to oxygen restriction. A splicing variant lacking exon 14 (sHIF-1α) encodes a truncated protein that competes with the normal HIF-1α protein, decreasing its activity. A natural antisense transcript (aHIF) complementary to the 3'-untranslated region of HIF-1α mRNA was described recently.