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GSE39294
Homo sapiens
6 Downloadable Samples
Illumina HumanHT-12 V4.0 expression beadchip
Description
Oncogenic mutations in BRAF and NRAS occur in 70% of melanomas. Here we identify a microRNA, miR-146a, that is highly upregulated by oncogenic BRAF and NRAS. Expression of miR-146a increases the ability of human melanoma cells to proliferate in culture and form tumors in mice, whereas knockdown of miR-146a has the opposite effects. We show these oncogenic activities are due to miR-146a targeting the NUMB mRNA, a repressor of Notch signaling. Previous studies have shown that pre-miR-146a contains a single nucleotide polymorphism (C>G rs2910164). We find that the ability of pre-miR-146a/G to activate Notch signaling and promote oncogenesis is substantially higher than that of pre-miR-146a/C. Analysis of melanoma cell lines and matched patient samples indicates that during melanoma progression pre-miR-146a/G is enriched relative to pre-miR-146a/C, resulting from a C-to-G somatic mutation in pre-miR-146a/C. Collectively, our results reveal a central role for miR-146a in the initiation and progression of melanoma.
Publication Title
miR-146a promotes the initiation and progression of melanoma by activating Notch signaling.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 5 Downloadable Samples
Illumina Genome Analyzer
Description
Oncogenic mutations in BRAF and NRAS occur in 70% of melanomas. Here we identify a microRNA, miR-146a, that is highly upregulated by oncogenic BRAF and NRAS. Expression of miR-146a increases the ability of human melanoma cells to proliferate in culture and form tumors in mice, whereas knockdown of miR-146a has the opposite effects. We show these oncogenic activities are due to miR-146a targeting the NUMB mRNA, a repressor of Notch signaling. Previous studies have shown that pre-miR-146a contains a single nucleotide polymorphism (C>G rs2910164). We find that the ability of pre-miR-146a/G to activate Notch signaling and promote oncogenesis is substantially higher than that of pre-miR-146a/C. Analysis of melanoma cell lines and matched patient samples indicates that during melanoma progression pre-miR-146a/G is enriched relative to pre-miR-146a/C, resulting from a C-to-G somatic mutation in pre-miR-146a/C. Collectively, our results reveal a central role for miR-146a in the initiation and progression of melanoma. Overall design: WI-38 cells were either infected with BRAFV600E or Empty retroviral vectors and small RNA were prepared from these cells. As an additional control, WI-38 cells were serum starved and used to generate quiscent cells, which were also used to prepase small RNA. The small RNA were then used to generate small RNA library and were used on Illumina genome analyzer.
Publication Title
miR-146a promotes the initiation and progression of melanoma by activating Notch signaling.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Homo sapiens
- 12 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
Oncogene-induced DNA methylation-mediated transcriptional silencing of tumor suppressors frequently occurs in cancer, but the mechanism and functional role of this silencing in oncogenesis is not fully understood. Here, we show that oncogenic epidermal growth factor receptor (EGFR) induces silencing of multiple unrelated tumor suppressors in lung adenocarcinomas and glioblastomas by inhibiting DNA demethylase TET oncogene family member 1 (TET1) via the C/EBP transcription factor. After oncogenic EGFR inhibition, TET1 binds to tumor suppressor promoters and induces their re-expression via active DNA demethylation. Ectopic expression of TET1 potently inhibits lung and glioblastoma tumor growth, and TET1 knockdown confers resistance to EGFR inhibitors in lung cancer cells. Lung cancer samples exhibited reduced TET1 expression or TET1 cytoplasmic localization in a majority of cases. Collectively, these results identify a conserved pathway of oncogenic EGFR-induced DNA methylation-mediated transcriptional silencing of tumor suppressors, which may have therapeutic benefit for oncogenic EGFR-mediated lung cancers and glioblastomas.
Publication Title
Oncogenic EGFR Represses the TET1 DNA Demethylase to Induce Silencing of Tumor Suppressors in Cancer Cells.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 10 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
To identify altered pathways in SCA28 LCLs, we performed a whole genome expression profiling, based on Affymetrix Human Genome U133A 2.0 Chip Array, on LCLs from four unrelated patients, each carrying a different AFG3L2 mutation.
Publication Title
Genome-wide expression profiling and functional characterization of SCA28 lymphoblastoid cell lines reveal impairment in cell growth and activation of apoptotic pathways.
Sample Metadata Fields
Sex, Specimen part
View Samples