HIF-2α expression is suppressed in SCLC cells, which survive in moderate and severe hypoxia when HIF-1α is repressed.

HIF-2α expression is suppressed in SCLC cells, which survive at moderate and severe hypoxia when HIF-1α is repressed

Blockade of Hypoxia: The Impact on Tumor Growth in an Experimental Tumor Model

Background: Tumor microenvironment is an active factor participating in immunoregulation, thereby preventing immunosurveillance and limiting the efficacy of anticancer therapies. Hypoxia as a major characteristic of solid tumors causes the expression of Hypoxia-Inducible Factor-1α (HIF-1α). This is a transcription factor that mediates hypoxic responses of tumor cells and involves in the express...

Myc-induced glutaminolysis bypasses HIF-driven glycolysis in hypoxic small cell lung carcinoma cells

We previously demonstrated that small cell lung carcinoma (SCLC) cells lack HIF-2α protein expression, whereas HIF-1α in these cells is expressed at both acute and prolonged hypoxia. Here we show that low HIF2A expression correlates with high expression of MYC genes. Knockdown of HIF1A expression had no or limited effect on cell survival and growth in vitro. Unexpectedly, hypoxic ATP levels wer...

Molecular Biology, Pathobiology, and Genetics Oncogenic KRAS and BRAF Differentially Regulate Hypoxia-Inducible Factor-1α and -2α in Colon Cancer

KRAS and BRAF mutations are frequently observed in human colon cancers. These mutations occur in a mutually exclusive manner, and each is associated with distinctive biological features. We showed previously that K-ras can interact with hypoxia to activate multiple signaling pathways. Many hypoxic responses are mediated by hypoxia-inducible factor (HIF)-1α and HIF-2α, and we sought to define th...

Effects of 2-methoxyestradiol on apoptosis and HIF-1α and HIF-2α expression in lung cancer cells under normoxia and hypoxia

Hypoxic tumor cells are known to be more resistant to conventional chemotherapy and radiation than normoxic cells. However, the effects of 2-methoxyestradiol (2-ME), an anti-angiogenic, antiproliferative and pro-apoptotic drug, on hypoxic lung cancer cells are unknown. The aim of the present study was to compare the effects of 2-ME on cell growth, apoptosis, hypoxia-inducible factor 1α (HIF-1α)...