Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA258123 | ENA |
REPOSITORIES: ENA
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Project description:The genome-wide miRNA expression analysis was performed in clinical samples, comprising 15 BRAF-mutant and 15 non-KRAS/BRAF-mutant colorectal cancers by using a SurePrint G3 Human miRNA microarray. clinical samples, comprising 15 BRAF-mutant and 15 non-KRAS/BRAF-mutant colorectal cancers by using a SurePrint G3 Human miRNA microarray.
2016-04-01 | E-GEOD-66548 | biostudies-arrayexpress
Project description:KRAS mutation is one of the major genetic alterations in colorectal cancer (CRC). Treating patients with KRAS mutant CRC remains one of the biggest challenges in oncology. In this study, we aimed to discover an effective therapeutic microRNA (miRNA) that could target KRAS mutant CRC. For this purpose, we investigated the functional relevance of dysregulated miRNAs in KRAS mutant cancers. We transfected exogenous KRASG12V into human embryonic kidney 293 (HEK293) cells and human lung fibroblasts (MRC5) cells, and performed comprehensive microRNA expression profiling by microarray analysis. The results showed that 6 miRNAs are significantly upregulated in KRAS-transfected HEK293 and MRC5 cells. Among 6 miRNAs, we identified mature miRNA-29b-1-5p as potent growth inhibitor in CRC cell proliferation. However, miRNA-29b-1-5p was found to be a passenger strand with a star form (miRNA-29b-1-5p*), and did not function in CRC cells. Proliferation assay revealed that completely opposite complementary strand to miRNA-29b-1-5p possessed a potent anti-tumor effect. We named this novel anti-tumor siRNA sequence “MIRTX”. MIRTX induced apoptosis and significantly inhibited cell proliferation in KRAS mutant CRC in vitro. In addition, MIRTX suppressed NF-κB signaling pathway, which is downstream effector of KRAS in CRC. Furthermore, MIRTX directly targeted 3'-UTR of PIK3R1 and CXCR2 mRNA, and indirectly suppressed KRAS itself. In vivo xenograft mouse models, systemic administration of MIRTX significantly inhibited the tumor growth with no particular toxicity, using carbonate apatite as a vehicle. These findings indicate that inhibition of NF-κB signaling by siRNA-based therapeutic could be a promising strategy against KRAS mutant CRC.
2018-03-17 | GSE83634 | GEO
Project description:Colorectal cancer (CRC) is still one of the most common causes of cancer-related death worldwide (World Health Organization, Fact sheet NM-BM-0297, October 2011). Though, therapeutic options improved over the past years, the prognosis of metastatic colorectal cancer (mCRC) remains poor with a median survival of 18-21 months. Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR) are used for the palliative treatment of metastatic colorectal cancer (mCRC) carrying a KRAS-wildtype. Among the tumors with a KRAS-wildtype, only 35% respond, and alterations of other signaling molecules and pathways modulate therapeutic response. In this study we analyzed the effect of KRAS-mutations on intracellular signaling cascades to find new therapeutic approaches for patients with mCRC. Reverse-phase protein array and gene array technology was applied to sixteen adenocarcinomas of the sigmoid colon carrying either wildtype (n=8) or mutant (n=8) KRAS. Differential expression was validated on 49 sigmoid cancers by RT-PCR, Western blot and immunohistochemistry. In a screening for members of signaling pathways known to have a high impact on tumor development in colon cancer, we found 14 proteins downregulated in tumors with mutated KRAS. Subsequently, we compared the data of the protein arrays with the results of gene expression arrays performed with the same samples. We confirmed the differential expression of eight genes as a function of the KRAS genotype of the tumor. To further validate the differential expression of these candidates, we performed quantitative expression analysis and immunohistochemical staining of an independent validation series comprising 49 CRC patient samples. It was clearly demonstrated that the expression of EGFR is decreased in colorectal carcinomas with a mutant KRAS genotype. mRNA was obtained from 16 patients with colorectal cancer (8 with and 8 without KRAS-mutation). mRNA was extracted from neoplastic and non-neoplastic colon mucosa and analyzed separately by Affymetrix Human Gene 1.1 ST GeneChips finally generating 32 separate data sets.
2012-05-17 | E-GEOD-38026 | biostudies-arrayexpress
Project description:We analyzed miRNA-based shRNA off-target effects by transducing Trp53-/- MEFs at single- and high-copy with six well-characterized, potent and weak Trp53 shRNAs. To advance RNAi therapy for KRAS-mutant cancer, we developed a functionally validated library of siRNAs against RAS pathway genes that minimize off-target effects and enable combination gene silencing at low dose. We developed an in vivo model for real-time tracking of nanoparticle-based siRNA delivery and offer proof-of-principle that siRNA-mediated inhibition of a single gene (KRAS) or combinations of genes (A/B/C-RAF or KRAS+PIK3C-A/B) can impair the growth of KRAS-mutant colorectal cancer xenografts.
2014-08-01 | GSE59952 | GEO
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
2014-08-06 | GSE58734 | GEO
Project description:The genome-wide miRNA expression analysis was performed in clinical samples, comprising 15 BRAF-mutant and 15 non-KRAS/BRAF-mutant colorectal cancers by using a SurePrint G3 Human miRNA microarray.
2016-04-01 | GSE66548 | GEO
Project description:microRNA expression profile between KRAS/BRAF wild and BRAF mutant colorectal cancer
| PRJNA277301 | ENA
Project description:Although long thought to act cell autonomously, mutant KRAS colorectal cancer (CRC) cells release protein-laden exosomes that can alter the tumor microenvironment. We have previously shown that mutant KRAS induces EGFR-ligand trafficking to exosomes and drastically alters exosomal protein contents, leading to activities that contribute to neoplastic growth. We have performed small library RNAseq analysis on cells and matched exosomes from isogenic CRC cell lines differing only in KRAS status to determine whether mutant KRAS regulates the composition of secreted small RNAs. Exosomal small RNA profiles were distinct from cellular profiles, with principle component analysis showing clusters of mutant KRAS cell-derived exosomes distinct from wild type KRAS cell-derived exosomes. Secreted RNA species encompassed several different classes of small RNAs, including ribosomal and tRNA fragments, as well as mature miRNA sequences. miR-10b, was selectively increased in wild type KRAS-derived exosomes, whereas miR-100 was selectively increased in mutant KRAS-derived exosomes. Ceramide inhibition resulted in accumulation of miR-100 in mutant KRAS cells, suggesting KRAS-dependent miRNA export. In Transwell cell culture experiments, mutant, but not wild type, KRAS donor cells conferred miR-100-mediated target repression in wild type KRAS recipient cells
2015-08-28 | GSE67004 | GEO
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the French National League Against Cancer (http://cit.ligue-cancer.net ) : 165 lung adenocarcinomas without prior chemotherapy, hybridized on Illumina SNP HumanCNV370 and Affymetrix HGU133Plus2 arrays. Project leader : Prof. Pierre FOURET (pierre.fouret@igr.fr). Note: Bronchiolo-alveolarComponent : a non invasive tumor component shown in well differentiated tumor cells. EGFR Gene Mutation Status: Gene mutation status of epidermal growth factor receptor (erythroblastic leukemia viral (v; -erb-b) ; oncogene homolog, avian) ; HGNC:3236 ; Approved Symbol:EGFR; Chromosome:7p12 ; UniProt ; ID:P00533 ; OMIMID:131550 ; EntrezGeneID:1956 ; ; RefSeq:NM_201283 ; M=mutated ; WT=non mutated=wild type. KRAS Gene Mutation Status: Gene mutation status of v-Ki-ras2 Kirsten rat ; sarcoma viral oncogene homolog ; HGNC:6407 ; Approved Symbol:KRAS ; Chromosome:12p12.1 ; UniProtID:P01116; OMIM ID:190070 ; EntrezGeneID:3845 ; ;RefSeq:NM_033360 ; M=yes=mutated ; WT=non mutated.
2012-10-19 | E-MTAB-923 | biostudies-arrayexpress
Project description:Mutations of the KRAS oncogene are predictive for resistance to treatment with antibodies against the epithelial growth factor receptor in patients with colorectal cancer. Overcoming this therapeutic dilemma could potentially be achieved by the introduction of drugs that inhibit signaling pathways that are activated by KRAS mutations. To comprehensively identify such signaling pathways we profiled pretreatment biopsies from 65 patients with locally advanced rectal cancer – 30 of which carried mutated KRAS - using global gene expression microarrays. By comparing all tumor tissues exclusively to matched normal mucosa, we could improve assay sensitivity, and identified a total of 22,297 features that were differentially expressed (adjusted p-value p<0.05) between normal mucosa and cancer, including several novel potential rectal cancer genes. We then used this comprehensive description of the rectal cancer transcriptome as the baseline for identifying KRAS-dependent alterations. The presence of activating KRAS mutations resulted in significant upregulation of 13 genes (adjusted p-value < 0.05), among them DUSP4, a MAP-kinase phosphatase, and SMYD3, a histone methyltransferase. Inhibition of the expression of both genes has been achieved therapeutically with the MEK1-inhibitor PD98059 and the antibacterial compound Novobiocin, respectively, suggesting a potential approach to overcome resistance to treatment with antibodies against the epithelial growth factor receptor in patients with KRAS-mutant rectal carcinomas. Paired samples of tumor and mucosa from a total of 65 patients, i.e. 130 arrays
2011-03-11 | E-GEOD-20842 | biostudies-arrayexpress