Project description:In this study we analyzed impact of long-term hypoxia on a panel of lymphoma cell lines. Only 2 out of 8 tested lymphoma cell lines (Ramos, and HBL2) survived > 4 weeks under deep hypoxia (1% O2). The hypoxia-adapted (HA) Ramos and HBL2 cells had severely decreased proliferation rate accompanied by complex changes of the transcriptome, proteome, and metabolome. Seahorse analysis demonstrated near complete blockage of both oxidative phosphorylation and glycolytic pathways. Both transcriptome and proteome analyses showed significant downregulation of mitochondrial respiration complexes I and IV, many mitochondrial ribosomal proteins, and increase of proteins regulating glycolysis and mitophagy. Both HA cell lines had an increased total mitochondrial mass, but a decreased mitochondrial DNA content compared to normoxic controls. Sensitivity of HA cells to 2-deoxyglucose, an inhibitor of glycolysis, and to A1155463, a BCL-XL inhibitor were, was markedly increased. Indeed, co-culture on CD40 ligand expressing fibroblasts (that induce BCL-XL expression) significantly increased survival of lymphoma cells under hypoxia. Of note, prolyl hydroxylase P4HA1 involved in the stabilization of hypoxia-induced factor (HIF) 1 alpha was increased in both HA cell lines on both mRNA and protein levels. Transgenic (over)expression of P4HA1 in hypoxia-sensitive MINO cells was associated with increased survival under hypoxia. Our data suggest that under long-term hypoxia, lymphoma cells try to compensate for the decrease in ATP production from the oxidative phosphorylation process by boosting structural machinery of glycolysis, as well as amino-acid recycling by mitophagy, on which they become vitally dependent for survival, and which can be targeted by specific inhibitors. The data also suggest increased dependence of lymphoma cells on BCL-XL under hypoxia. Finally, P4HA1 plausibly represents a novel druggable target for more effective elimination of hypoxia-adapted lymphoma cells.
Project description:We report the application of chromatin immunoprecipitation and next generation sequencing technology for HIF1a binding sites at genome wide level in a RCC (renal cell carcinoma) cell line under hypoxia conditions. We found HIF1a binding sites in Caki-2 cell line under hypoxia conditions. Especially, we found HIF1a bind to SPOP under hypoxia condition, which was further validated. Examination of HIF1a binding sites in Caki-2 cell line under hypoxia condition
Project description:Glioblastoma (GBM) is characterized by a high degree of hypoxia. Hypoxia-inducible factors (HIFs) modulate glioma stem-like cell (GSC) responses to hypoxia and promote GBM progression, therapeutic resistance, and recurrence. Here we identify a new transcript of the long non-coding RNA LUCAT1 and show that it reinforces HIF1⍺ signaling in GSCs under hypoxia. LUCAT1 expression is highly induced under hypoxia in GBM and GSCs in a HIF1⍺-dependent manner. High LUCAT1 expression in human GBM correlates with increased aggression and poor survival. Mechanistically, LUCAT1 associates with chromatin and modulates interaction between HIF1⍺ and coactivator CBP to hypoxia response elements (HREs) to drive HIF1⍺-target gene expression under hypoxia. Thus, LUCAT1 acts as a positive feedback factor to augment HIF1⍺ signaling under hypoxic stress in GSCs. Loss of LUCAT1 reduces tumor growth and prolongs mouse survival in xenograft models of GBM. Our findings provide new insights into how GSCs regulate gene expression under hypoxia and identify LUCAT1 as therapeutic target in GBM.
Project description:We report the application of chromatin immunoprecipitation and next generation sequencing technology for HIF1a binding sites at genome wide level in a RCC (renal cell carcinoma) cell line under hypoxia conditions. We found HIF1a binding sites in Caki-2 cell line under hypoxia conditions. Especially, we found HIF1a bind to SPOP under hypoxia condition, which was further validated.
Project description:Analysis of changes in gene expression of long noncoding RNAs under hypoxia in lung cancer cells by using microarray-based profiling assay Hypoxia plays important roles in cancer progression by inducing angiogenesis, metastasis, and drug resistance. However, the effects of hypoxia on long noncoding RNA (lncRNA) expression have not been clarified. In this study, we evaluated alterations in lncRNA expression in lung cancer cells under hypoxic conditions using lncRNA microarray analyses. Among 40,173 lncRNAs, 211 and 113 lncRNAs were up- and downregulated, respectively, in both A549 and NCI-H460 cells. Genome-wide profiling of lncRNA expression altered under hypoxia may provide a basis for understanding the role of hypoxia-regulated lncRNAs in cancer growth and metastasis under hypoxic conditions as well as the mechanism underlying hypoxia-induced expression of lncRNAs.
Project description:MicroRNAs are hypothesized to play critical roles in the regulation ofhypoxia-induced proximal tubular injury. The aim of this study is to explore novel microRNAs differentially expressed in HK-2 cells under normoxia and hypoxia conditions. RNAs were extracted from HK-2 cells cultured under normoxia and hypoxia for sequencing. Using the next generation sequencing and bioinformatics approaches, we identified 11 differentially expressed microRNAs in HK-2 cells under hypoxia condition.