The association of HIF-2α expression with stemness and survival genes in human breast cancer stem cells (CD24-/CD44+) exposed to hypoxia

摘要: Similar to normal stem cells, breast cancer cells (BCSCs) exist in prolonged hypoxia vivo and are cultured normoxic conditions (20% O2) vitro. Our previous study showed that the treatment of vitro BCSCs with 1% O2 upregulates HIF-1α. This aimed investigate HIF-2α expression under effects on its downstream gene (Oct-4, ALDH1, KLF4, c-MYC) along an associated survival gene, survivin. Human (CD24−/CD44+) were exposed (1% O2, 5% CO2) at intervals 0.5 h, 4 6 24 h. HIF2α, Oct-4, ALDH-1, c-MYC, survivin mRNA levels relatively quantified using qRT-PCR. Data analyzed Livak's formula one-way ANOVA. In contrast HIF-1α levels, gradually downregulated h treatment. concert, c-MYC as a measure stemness, significantly decreased following from The reduced these transcription factors suggests diminished proliferation possibility differentiation thus sensitizing them cell death. support this, downregulation was also shown throughout 0.5–24 hypoxia, which confirms our result demonstrated enhanced apoptosis. Hypoxia BCSCs, unlike resulted HIF-2 indicating acute may lead decreases stemness viability.