Project description:To identify the direct target of miR-490-3p, we used whole genome microarray expression profiling to screen for genes potentially regulated by the microRNA. AGS cells were transfected with control mimics or miR-490-3p mimics and gene expression was determined 72 hours after transfection.
Project description:To identify the direct target of miR-490-3p, we used whole genome microarray expression profiling to screen for genes potentially regulated by the microRNA.
Project description:Oxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major unsolved problem. Consequently, predictive markers and a better understanding of resistance mechanisms are urgently needed. To investigate if the recently identified predictive miR-625-3p is functionally involved in oxPt resistance, stable and inducible models of miR-625-3p dysregulation were analyzed. Ectopic expression of miR-625-3p in CRC cells led to increased resistance towards oxPt. The mitogen-activated protein kinase (MAPK) kinase 6 (MAP2K6/MKK6) – an activator of p38 MAPK - was identified as a functional target of miR-625-3p, and, in agreement, was down-regulated in patients not responding to oxPt therapy. The miR-625-3p resistance phenotype could be reversed by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signaling as a possible driving force behind oxPt resistance. We conclude that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks.
Project description:Applying Next Generation Sequencing technique we compared the miRNA expression pattern of tumor tissue sample of 6 GPs and peritumoral region of 6 lower grade (I-II) Glioma patients, serving as control group. To determine the difference on miRNA expresion level between GBM and control cases, we performed cluster analysis on the NGS dataset of 6 replicates for each of the two goups of samples with iDEP 96 software. In order to characterize the extent of up- or downregulation, log2FC values were calculated using the iDEP.96 web tool applying the DESeq2 algorithm. On the base of that 117 known miRNAs were identified to be differentially expressed using a threshold of false discovery rate (FDR) <0.05 and fold-change> 2 during the analysis. Among them, 35 miRNAs were upregulated (log2FC > 2) and 82 miRNAs were downregulated (log2FC < -2) with biological revelance in tissue samples comparing with the control samples. To validate our results obtained by NGS, five upregulated miRNAs: hsa-miR-196a-5p, hsa-miR-21-3p, hsa-miR-92b-5p, hsa-miR-10b-3p, hsa-miR-503-5p and three downregulated miRNAs: hsa-mir-383-5p, hsa-mir-490-3p, hsa-mir-1224-3p were chosen for RT-qPCR analysis. As the result of that hsa-miR-196a-5p, hsa-miR-21-3p, and hsa-miR-10b-3p was significantly upregulated while hsa-mir-383-5p and hsa-mir-490-3p was significantly downregulated, compared with those in the control samples. The other three miRNAs: hsa-miR-1224-3p, hsa-miR-92b-5p, hsa-miR-503-5p did not show significant difference between the control group and GPs.
Project description:Oxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major unsolved problem. Consequently, predictive markers and a better understanding of resistance mechanisms are urgently needed. To investigate if the recently identified predictive miR-625-3p is functionally involved in oxPt resistance, stable and inducible models of miR-625-3p dysregulation were analyzed. Ectopic expression of miR-625-3p in CRC cells led to increased resistance towards oxPt. The mitogen-activated protein kinase (MAPK) kinase 6 (MAP2K6/MKK6) – an activator of p38 MAPK - was identified as a functional target of miR-625-3p, and, in agreement, was down-regulated in patients not responding to oxPt therapy. The miR-625-3p resistance phenotype could be reversed by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signaling as a possible driving force behind oxPt resistance. We conclude that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks. Experimental design for mass spectrometry SILAC experiments can be found at https://figshare.com/s/8e79f008e0e58ec6efc2 or https://doi.org/10.6084/m9.figshare.4888139