Please note that we have stopped the regular imports of Gene Expression Omnibus (GEO) data into ArrayExpress. This may not be the latest version of this experiment.
E-GEOD-45289 - Dynamics of intercellular and extracellular (exosomal) miRNAs in hypoxic K562 cells
Released on 3 December 2013, last updated on 2 June 2014
Recently, the existence of extracellular miRNAs enclosed in exosomes has raised the possibility that they play an important role in cell-cell communication. To gain more insight into cell-cell communication via exosomal miRNAs, we investigated whether or not tumor cells exposed to hypoxia secrete exosomes which may affect angiogeneic activity. We used K562 cells, as donor cells, and HUVECs as recipient cells. Exosomes derived from K562 cells cultured in normoxia (20%) or hypoxia (1%) for 24 h were used for validation of angiogeneic activity, such as tube formation assay. The exosome secreted from K562 cells in hypoxic condition significantly enhanced tube formation by HUVECs when compared with exosome obtained from K562 cell in normoxic condition. To identify cellular and exosomal miRNAs universally responding to hypoxic condition, we assess the expression profiles of intercellular and extracellular miRNAs in K562 cells cultured in normoxia (20%) or hypoxia (1%) for 24 h using Taqman MicroRNA Array v2.0 (Applied Biosystems, Bedford, MA). K562 cells were cultured for 24 hours under hypoxic conditions (1% O2) or normoxic conditions (20% O2). The exosome fraction was obtained from culture medium using Exoquick Exosome Precipitation Solution (System Biosciences, Mountain View, CA, USA). Isolation of cellular and exosomal miRNAs was performed using the miRNsasy kit (Qiagen). The expression profile of miRNAs was determined using the Human Taqman miRNA Arrays A (Applied Biosystems). RNU6B and a spike control (ath-miR159) were used as an invariant control for the cell and exosome, respectively. QRT-PCR was carried out on an Applied Biosystems 7900HT thermal cycler using the manufacturer’s recommended program. Finally, all the raw data from each array was run on Data Assist Software ver.3.1 (Applied Biosystems).
Exosomes derived from hypoxic leukemia cells enhance tube formation in endothelial cells. Tadokoro H, Umezu T, Ohyashiki K, Hirano T, Ohyashiki JH. , PMID:24133215