Project description:We here report ALKBH5, a m6A RNA demethylase, as a crucial oncogene in multiple myeloma (MM). Using various MM models, we demonstrated a critical requirement of ALKBH5 for MM cell proliferation in vitro and in vivo. RNA-seq was applied to compare the expression profile of MM cells with or without ALKBh5 knockdown.
Project description:We here report ALKBH5, a m6A RNA demethylase, as a crucial oncogene in multiple myeloma (MM). Using various MM models, we demonstrated a critical requirement of ALKBH5 for MM cell proliferation in vitro and in vivo. To identify the potential mRNA targets of ALKBH5, we conducted m6A-seq with mRNA samples enriched from MM cells with or without ALKBH5 knockdown.
Project description:The dynamic and reversible N6-methyladenosine (m6A) RNA modification installed and erased by N6-methyltransferases and demethylases regulates gene expression and cell fate. Here, we show that the m6A demethylase ALKBH5 is highly expressed in glioblastoma stem-like cells (GSCs). Silencing ALKBH5 suppresses the proliferation of patient-derived GSCs in vitro and in vivo. Integrated transcriptome and m6A-seq analyses revealed altered expression of select ALKBH5 target genes, including FOXM1, a critical transcription factor for the ALKBH5-dependent cell cycle gene expression. ALKBH5 binds to and demethylates FOXM1 nascent transcripts, leading to enhanced FOXM1 expression. Further, a long noncoding RNA antisense to the FOXM1 (FOXM1-AS) interacts with ALKBH5 and FOXM1 nascent transcripts and promotes their interaction. Depleting ALKBH5 and FOXM1-AS disrupted GSC tumorigenesis through the FOXM1 axis. Our work uncovers a novel function for ALKBH5 in maintaining GSC tumorigenicity and provides insight into critical roles of the m6A RNA methylation in human brain tumor.
Project description:N6-methyladenosine (m6A) is the most prevalent internal modification of messenger RNA (mRNA) in higher eukaryotes. Here we report ALKBH5 as a new mammalian demethylase that oxidatively removes the m6A modification in mRNA in vitro and inside cells. This demethylation activity of ALKBH5 significantly affects mRNA export and RNA metabolism as well as the assembly of mRNA processing factors in nuclear speckles. Alkbh5-deficient male mice are characterized by impaired fertility resulting from apoptosis that affects meiotic metaphase-stage spermatocytes. In accordance with this defect, we have identified in mouse testes 1552 differentially expressed genes which cover broad functional categories and include spermatogenesis-related mRNAs involved in the p53 functional interaction network. We show that Alkbh5-deficiency impacts the expression levels of some of these mRNAs, supporting the observed phenotype. The discovery of this new RNA demethylase strongly suggests that the reversible m6A modification plays fundamental and broad functions in mammalian cells. RNA-seq in two cell types
