Project description:Brain metastasis is a major cause of cancer mortality, but its molecular mechanisms are severely understudied. We found that YTHDF3 overexpression clinically correlates with brain metastases in breast cancer patients and is required for brain metastasis. Silencing YTHDF3 suppressed the brain metastasis of breast cancer cells in vitro and in vivo. Integrated transcriptome and m6A-seq analysis revealed alter expression of selected YTHDF3 target genes, including ST6GALNAC5, GJA1, and EGFR by promoting m6A-dependent translation of these target transcripts. Our work uncovers an essential role of YTHDF3 in controlling the interaction between cancer cells and brain microenvironment, thereby gaining brain metastatic competence.
Project description:Brain metastasis is a major cause of cancer mortality, but its molecular mechanisms are severely understudied. We found that YTHDF3 overexpression clinically correlates with brain metastases in breast cancer patients and is required for brain metastasis. Silencing YTHDF3 suppressed the brain metastasis of breast cancer cells in vitro and in vivo. Integrated transcriptome and m6A-seq analysis revealed alter expression of selected YTHDF3 target genes, including ST6GALNAC5, GJA1, and EGFR by promoting m6A-dependent translation of these target transcripts. Our work uncovers an essential role of YTHDF3 in controlling the interaction between cancer cells and brain microenvironment, thereby gaining brain metastatic competence.
Project description:N6-methyladenosine (m6A) is an abundant mRNA modification in the brain which plays important roles in neurodevelopment and brain function. However, due to technical limitations, global profiling of m6A sites within the individual cell types that make up the brain has not been possible. Here, we develop a mouse model that enables transcriptome-wide m6A detection in any tissue of interest and at single-cell resolution. We use these mice to map m6A across different brain regions and within single cells of the mouse cortex and discover a high degree of shared methylation across brain regions and cell types. However, we also identify a small number of differentially methylated mRNAs in neurons that encode important regulators of neuronal signaling, and we discover that microglia have lower levels of m6A compared to other cell types. Finally, we perform single-cell m6A mapping in aged mice and identify many transcripts with age-dependent changes in m6A.
Project description:N6-methyladenosine (m6A) is an abundant mRNA modification in the brain which plays important roles in neurodevelopment and brain function. However, due to technical limitations, global profiling of m6A sites within the individual cell types that make up the brain has not been possible. Here, we develop a mouse model that enables transcriptome-wide m6A detection in any tissue of interest and at single-cell resolution. We use these mice to map m6A across different brain regions and within single cells of the mouse cortex and discover a high degree of shared methylation across brain regions and cell types. However, we also identify a small number of differentially methylated mRNAs in neurons that encode important regulators of neuronal signaling, and we discover that microglia have lower levels of m6A compared to other cell types. Finally, we perform single-cell m6A mapping in aged mice and identify many transcripts with age-dependent changes in m6A.
Project description:N6-methyladenosine (m6A) is an abundant mRNA modification in the brain which plays important roles in neurodevelopment and brain function. However, due to technical limitations, global profiling of m6A sites within the individual cell types that make up the brain has not been possible. Here, we develop a mouse model that enables transcriptome-wide m6A detection in any tissue of interest and at single-cell resolution. We use these mice to map m6A across different brain regions and within single cells of the mouse cortex and discover a high degree of shared methylation across brain regions and cell types. However, we also identify a small number of differentially methylated mRNAs in neurons that encode important regulators of neuronal signaling, and we discover that microglia have lower levels of m6A compared to other cell types. Finally, we perform single-cell m6A mapping in aged mice and identify many transcripts with age-dependent changes in m6A.
Project description:N6-methyladenosine (m6A) is an abundant mRNA modification in the brain which plays important roles in neurodevelopment and brain function. However, due to technical limitations, global profiling of m6A sites within the individual cell types that make up the brain has not been possible. Here, we develop a mouse model that enables transcriptome-wide m6A detection in any tissue of interest and at single-cell resolution. We use these mice to map m6A across different brain regions and within single cells of the mouse cortex and discover a high degree of shared methylation across brain regions and cell types. However, we also identify a small number of differentially methylated mRNAs in neurons that encode important regulators of neuronal signaling, and we discover that microglia have lower levels of m6A compared to other cell types. Finally, we perform single-cell m6A mapping in aged mice and identify many transcripts with age-dependent changes in m6A.
Project description:N6-methyladenosine (m6A) is an abundant mRNA modification in the brain which plays important roles in neurodevelopment and brain function. However, due to technical limitations, global profiling of m6A sites within the individual cell types that make up the brain has not been possible. Here, we develop a mouse model that enables transcriptome-wide m6A detection in any tissue of interest and at single-cell resolution. We use these mice to map m6A across different brain regions and within single cells of the mouse cortex and discover a high degree of shared methylation across brain regions and cell types. However, we also identify a small number of differentially methylated mRNAs in neurons that encode important regulators of neuronal signaling, and we discover that microglia have lower levels of m6A compared to other cell types. Finally, we perform single-cell m6A mapping in aged mice and identify many transcripts with age-dependent changes in m6A.
Project description:The aging brain is highly vulnerable to cellular stress, and neurons often employ numerous mechanisms to combat neurotoxic proteins and promote healthy brain aging. The RNA modification m6A has been shown to be a critical regulator of RNA stability and translation in cells during stress. m6A is highly enriched in the Drosophila brain and is critical for the acute heat stress response. Here we examine m6A response to chronic stresses of aging and degenerative disease. In the brain, m6A levels dynamically increased with age and disease, marking critical signaling pathway transcripts that become downregulated in age and disease. Unexpectedly, there is opposing regulation of m6A transcript translation in neural vs glial cells, which conferred different outcomes on animal healthspan with Mettl3 knockdown to reduce m6A. Moreover, these data reveal that knockdown of Mettl3 in glial tauopathy is beneficial, leading to increased animal survival. These findings provide mechanistic insight into regulation of m6A modified transcripts with age and disease that varies based on cell type.