Project description:MicroRNAs (miRNAs) are small (18-22 nucleotides), non-coding RNAs that suppress the translation of target mRNAs by binding to their 3` untranslated region, and regulate gene networks, helping to control cell function and phenotype. Recently, the existence of extracellular miRNAs enclosed in exosomes has raised the possibility that they play an important role in cell-cell communication. The goals of this study were to elucidate whether or not miRNAs secreted from neoplastic cells transfer into endothelial cells and works functionally active in the recipient cells. In the present study, we investigated the interaction of a leukemia cell line (K562) and human umbilical vein endothelial cells (HUVECs) using a non-contact co-culture system, and assess the expression profiles of intercellular and extracellular miRNAs in HUVECs and K562 cells using Taqman MicroRNA Array v2.0 (Applied Biosystems, Bedford, MA). We compared the miRNA expression profiles between 1) K562 cells or HUVECs; 2) intercellular and extracellular; 3) mono-culture medium and co-culture medium. K562 cells and HUVECs were non-contact co-cultures using Transwell (Corning, pore size: 0.45µm) for 24 hr. The culture medium was collected and filtered through a 0.45 µm PVDF filter (Millipore, Billerica, MA). The intercellular and extracellular RNAs were isolated from K562 cells, HUVECs and each culture medium using the mirVana PARIS kit (Ambion, Austin, TX). The expression profile was determined using the Human Taqman MicroRNA Arrays A (Applied Biosystems). QRT-PCR was carried out on an Applied Biosystems 7900HT thermal cycler. The thermal cycling conditions consisted of 10 min at 95°C, followed by 40 cycles at 92°C for 15 s and 60°C for 1 min.
Project description:MicroRNAs (miRNAs) are small (18-22 nucleotides), non-coding RNAs that suppress the translation of target mRNAs by binding to their 3` untranslated region, and regulate gene networks, helping to control cell function and phenotype. Recently, the existence of extracellular miRNAs enclosed in exosomes has raised the possibility that they play an important role in cell-cell communication. The goals of this study were to elucidate whether or not miRNAs secreted from neoplastic cells transfer into endothelial cells and works functionally active in the recipient cells. In the present study, we investigated the interaction of a leukemia cell line (K562) and human umbilical vein endothelial cells (HUVECs) using a non-contact co-culture system, and assess the expression profiles of intercellular and extracellular miRNAs in HUVECs and K562 cells using Taqman MicroRNA Array v2.0 (Applied Biosystems, Bedford, MA). We compared the miRNA expression profiles between 1) K562 cells or HUVECs; 2) intercellular and extracellular; 3) mono-culture medium and co-culture medium.
Project description: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).
Project description: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 manufacturerM-bM-^@M-^Ys recommended program. Finally, all the raw data from each array was run on Data Assist Software ver.3.1 (Applied Biosystems).
Project description: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 RPMI8226 cells, as donor cells, and HUVECs as recipient cells. Exosomes derived from RPMI8226 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 RPMI8226 cells in hypoxic condition significantly enhanced tube formation by HUVECs when compared with exosome obtained from RPMI8226 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 RPMI8226 cells cultured in normoxia (20%) or hypoxia (1%) for 24 h using Taqman MicroRNA Array v2.0 (Applied Biosystems, Bedford, MA).
Project description: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 SUDHL4 cells, as donor cells, and HUVECs as recipient cells. Exosomes derived from SUDHL4 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 SUDHL4 cells in hypoxic condition significantly enhanced tube formation by HUVECs when compared with exosome obtained from SUDHL4 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 SUDHL4 cells cultured in normoxia (20%) or hypoxia (1%) for 24 h using Taqman MicroRNA Array v2.0 (Applied Biosystems, Bedford, MA).
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes