Project description:Glioblastoma is a universally lethal cancer driven by glioblastoma stem cells (GSCs). Here, we interrogated N6-methyladenosine (m6A) mRNA modifications in GSCs by methyl RNA-immunoprecipitation followed by sequencing (meRIP-seq) and transcriptome analysis, finding transcripts marked by m6A often upregulated. Interrogating m6A regulators, GSCs displayed preferential expression as well as in vitro and in vivo dependency of the m6A reader, YTHDF2, in contrast to normal neural stem cells (NSCs). While YTHDF2 has been reported to destabilize mRNAs, YTHDF2 stabilized the oncogene transcripts, MYC and VEGFA, in GSCs in an m6A-dependent manner. We identified IGFBP3 as a downstream effector of the YTHDF2-MYC axis in GSCs and IGF1/IGF1R inhibitor, Linsitinib, as preferentially targeting YTHDF2-expressing cells, inhibiting the viability of GSCs without affecting NSCs and impairing in vivo glioblastoma growth. Thus, YTHDF2 links RNA epitranscriptomic modifications and GSC growth, laying the foundation for the YTHDF2-MYC-IGFBP3 axis as a specific and novel therapeutic target in glioblastoma.
Project description:Glioblastoma is a universally lethal cancer driven by glioblastoma stem cells (GSCs). Here, we interrogated N6-methyladenosine (m6A) mRNA modifications in GSCs by methyl RNA-immunoprecipitation followed by sequencing (meRIP-seq) and transcriptome analysis, finding transcripts marked by m6A often upregulated. Interrogating m6A regulators, GSCs displayed preferential expression as well as in vitro and in vivo dependency of the m6A reader, YTHDF2, in contrast to normal neural stem cells (NSCs). While YTHDF2 has been reported to destabilize mRNAs, YTHDF2 stabilized the oncogene transcripts, MYC and VEGFA, in GSCs in an m6A-dependent manner. We identified IGFBP3 as a downstream effector of the YTHDF2-MYC axis in GSCs and IGF1/IGF1R inhibitor, Linsitinib, as preferentially targeting YTHDF2-expressing cells, inhibiting the viability of GSCs without affecting NSCs and impairing in vivo glioblastoma growth. Thus, YTHDF2 links RNA epitranscriptomic modifications and GSC growth, laying the foundation for the YTHDF2-MYC-IGFBP3 axis as a specific and novel therapeutic target in glioblastoma.
Project description:Glioblastoma is a universally lethal cancer driven by glioblastoma stem cells (GSCs). Here, we interrogated N6-methyladenosine (m6A) mRNA modifications in GSCs by methyl RNA-immunoprecipitation followed by sequencing (meRIP-seq) and transcriptome analysis, finding transcripts marked by m6A often upregulated. Interrogating m6A regulators, GSCs displayed preferential expression as well as in vitro and in vivo dependency of the m6A reader, YTHDF2, in contrast to normal neural stem cells (NSCs). While YTHDF2 has been reported to destabilize mRNAs, YTHDF2 stabilized the oncogene transcripts, MYC and VEGFA, in GSCs in an m6A-dependent manner. We identified IGFBP3 as a downstream effector of the YTHDF2-MYC axis in GSCs and IGF1/IGF1R inhibitor, Linsitinib, as preferentially targeting YTHDF2-expressing cells, inhibiting the viability of GSCs without affecting NSCs and impairing in vivo glioblastoma growth. Thus, YTHDF2 links RNA epitranscriptomic modifications and GSC growth, laying the foundation for the YTHDF2-MYC-IGFBP3 axis as a specific and novel therapeutic target in glioblastoma.
Project description:YTHDF2 is overexpressed in a broad spectrum of human acute myeloid leukemias (AML). To study the role of YTHDF2 in leukemia, total RNA from Ythdf2CKO (n=4) and Ythdf2CTL (n=4) leukemic stem cells were used for Affymetrix global gene expression analysis.
Project description:Glioblastoma is one of the most malignant brain tumors with poor prognosis and their development and progression are known to be driven by glioblastoma stem cells. Although glioblastoma stem cells lose their cancer stemness properties during cultivation in serum-containing medium, little is known about the molecular mechanisms regulating signaling alteration in relation to reduction of stemness. In order to elucidate the global phosphorylation-related signaling events, we performed a SILAC-based quantitative phosphoproteome analysis of serum-induced dynamics in glioblastoma stem cells established from the tumor tissues of the patient. Among a total of 2,876 phosphorylation sites on 1,584 proteins identified in our analysis, 732 phosphorylation sites on 419 proteins were regulated through the alteration of stem cell characteristics.