NAT10 mediated ac4C tRNA modification promotes EGFR mRNA translation and gefitinib resistance in cancers
Ontology highlight
ABSTRACT: The diverse RNA modifications play essential functions in gene expression regulation. Aberrant RNA modifications are frequently associated with cancers, while the underlying mechanisms and clinical significance remain poorly understood. Here we revealed that the ac4C RNA acetyltransferase NAT10 is significantly upregulated in esophageal cancers (ESCA) and associated with poor ESCA prognosis. In addition, using cancer cell lines, xenograft tumor models, Nat10 conditional knockin and conditional knockout mice, in vivo ESCA tumorigenesis model and chemical inhibition approaches, we uncovered the critical physiological functions of NAT10 in promoting esophageal cancer tumorigenesis and progression in vitro and in vivo. Mechanistically, NAT10 depletion reduced the abundance of ac4C-modified tRNAs and significantly decreased the translation efficiencies of mRNAs enriched for ac4C-modified-tRNA decoded codons. We further identified EGFR as a key downstream target that facilitates NAT10’s oncogenic functions in promoting esophageal cancer progression. In terms of clinical significance, we demonstrated that NAT10 promotes esophageal cancer resistance to EGFR inhibitor gefitinib, and combination of NAT10 depletion and gefitinib treatment synergistically inhibits esophageal cancer progression in vitro and in vivo. Our data uncovered novel molecular mechanisms underlying esophageal cancer progression at the layer of mRNA translation control and provided molecular insights for development of effective cancer therapeutic strategies.
Project description:N4-acetylcytidine (ac4C) is an evolutionarily conserved RNA modification that is deposited on diverse RNAs by N-acetyltransferase 10 (NAT10), a protein with high biological significance for aging and cancer. Here, we performed a comprehensive survey of ac4C using metabolic labeling, sodium cyanoborohydride chemical treatment coupled to next generation sequencing (NGS) and ac4C antibody-based cell and molecular biology techniques. Our NGS analysis confirms robust ac4C modification of rRNA and specific tRNA species in a NAT10-dependent manner, but suggests low or spurious ac4C acetylation in mRNA. Analysis of RNA-seq data also revealed an induction of inflammatory responses as well as mutagenesis at transcriptionally active sites in NAT10-KO cells. This finding led us to further explore the role of NAT10 in R-loops, which have recently been shown to induce APOBEC3B-mediated mutagenesis. Our analysis revealed that R-loops are modified with ac4C in a NAT10-dependent manner. Furthermore, NAT10 restrains the levels of R-loops at a subset of differentially expressed genes in a manner dependent on its catalytic activity. Together with cellular biology data showing ac4C containing RNA in endosomal structures, we propose that increased levels of ac4C-unmodified RNAs, likely derived from R-loops, in endosomal structures induce inflammatory responses.
Project description:N4-acetylcytidine (ac4C) is an evolutionarily conserved RNA modification that is deposited on diverse RNAs by N-acetyltransferase 10 (NAT10), a protein with high biological significance for aging and cancer. Here, we performed a comprehensive survey of ac4C using metabolic labeling, sodium cyanoborohydride chemical treatment coupled to next generation sequencing (NGS) and ac4C antibody-based cell and molecular biology techniques. Our NGS analysis confirms robust ac4C modification of rRNA and specific tRNA species in a NAT10-dependent manner, but suggests low or spurious ac4C acetylation in mRNA. Analysis of RNA-seq data also revealed an induction of inflammatory responses as well as mutagenesis at transcriptionally active sites in NAT10-KO cells. This finding led us to further explore the role of NAT10 in R-loops, which have recently been shown to induce APOBEC3B-mediated mutagenesis. Our analysis revealed that R-loops are modified with ac4C in a NAT10-dependent manner. Furthermore, NAT10 restrains the levels of R-loops at a subset of differentially expressed genes in a manner dependent on its catalytic activity. Together with cellular biology data showing ac4C containing RNA in endosomal structures, we propose that increased levels of ac4C-unmodified RNAs, likely derived from R-loops, in endosomal structures induce inflammatory responses.
Project description:N4-acetylcytidine (ac4C) is an evolutionarily conserved RNA modification that is deposited on diverse RNAs by N-acetyltransferase 10 (NAT10), a protein with high biological significance for aging and cancer. Here, we performed a comprehensive survey of ac4C using metabolic labeling, sodium cyanoborohydride chemical treatment coupled to next generation sequencing (NGS) and ac4C antibody-based cell and molecular biology techniques. Our NGS analysis confirms robust ac4C modification of rRNA and specific tRNA species in a NAT10-dependent manner, but suggests low or spurious ac4C acetylation in mRNA. Analysis of RNA-seq data also revealed an induction of inflammatory responses as well as mutagenesis at transcriptionally active sites in NAT10-KO cells. This finding led us to further explore the role of NAT10 in R-loops, which have recently been shown to induce APOBEC3B-mediated mutagenesis. Our analysis revealed that R-loops are modified with ac4C in a NAT10-dependent manner. Furthermore, NAT10 restrains the levels of R-loops at a subset of differentially expressed genes in a manner dependent on its catalytic activity. Together with cellular biology data showing ac4C containing RNA in endosomal structures, we propose that increased levels of ac4C-unmodified RNAs, likely derived from R-loops, in endosomal structures induce inflammatory responses.
Project description:N-acetyltransferase 10 (NAT10), the only known mRNA ac4C “writer,” plays a significant role in several human diseases, including CRC and gastric cancer. As NAT10 can activate or repress important signaling pathways, such as the EMT pathway, DNA damage repair, or apoptosis, by catalyzing the ac4C modification of oncogene mRNA, targeting NAT10 shows great potential for inhibiting cancer cell malignant progression in vitro and in vivo. This complex network of colorectal cancer progression mediated by NAT10 remains to be identified, which can expand cancer therapy options. To identify potential NAT10-regulated ac4C targets, we checked ac4CRIP Sequencing in human colorectal cancer cell SW620.
Project description:N-acetyltransferase 10 (NAT10), the only known mRNA ac4C “writer,” plays a significant role in several human diseases, including CRC and gastric cancer. As NAT10 can activate or repress important signaling pathways, such as the EMT pathway, DNA damage repair, or apoptosis, by catalyzing the ac4C modification of oncogene mRNA, targeting NAT10 shows great potential for inhibiting cancer cell malignant progression in vitro and in vivo. This complex network of colorectal cancer progression mediated by NAT10 remains to be identified, which can expand cancer therapy options. To identify potential NAT10-regulated ac4C targets, we checked mRNA sequencing in human colorectal cancer cell SW620.
Project description:N-acetyltransferase 10 (NAT10), the only known mRNA ac4C “writer,” plays a significant role in several human diseases, including CRC and gastric cancer. As NAT10 can activate or repress important signaling pathways, such as the EMT pathway, DNA damage repair, or apoptosis, by catalyzing the ac4C modification of oncogene mRNA, targeting NAT10 shows great potential for inhibiting cancer cell malignant progression in vitro and in vivo. This complex network of colorectal cancer progression mediated by NAT10 remains to be identified, which can expand cancer therapy options. To identify potential NAT10-regulated ac4C targets, we checked RIP-Transcriptome Sequencing in human colorectal cancer cell SW620.
Project description:N4 acetylcytidine (ac4C) modification mainly occurs on tRNA, rRNA, and mRNA, playing an important role in the expression of genetic information. However, it is still unclear whether microRNAs have undergone ac4C modification and their potential physiological and pathological functions. In this study, we identified that NAT10/THUMPD1 acetylates primary microRNAs (pri-miRNAs) with ac4C modification. Knockdown of NAT10 suppresses and augments the expression levels of mature miRNAs and pri-miRNAs, respectively. Molecular mechanism studies found that pri-miRNA ac4C promotes the processing of pri-miRNA into precursor miRNA (pre-miRNA) by enhancing the interaction of pri-miRNA and DGCR8, thereby increasing the biogenesis of mature miRNA. Knockdown of NAT10 attenuates the oncogenic characters of lung cancer cells by regulating miRNA production in cancers. Moreover, NAT10 is highly expressed in various clinical cancers and negatively correlated with poor prognosis. Thus, our results reveal that NAT10 plays a crucial role in cancer initiation and progression by modulating pri-miRNA ac4C to affect miRNA production, which would provide an attractive therapeutic strategy for cancers.
Project description:Massive numbers of modified bases in mRNAs sculpt the epitranscriptome and play vital roles in RNA metabolism. The only known acetylated RNA modification, N-4-acetylcytidine (ac4C), is highly conserved across cell types and among species. Although the GCN5-related acetyltransferase 10 (NAT10) functions as an ac4C writer, the mechanism underlying the acetylation process is largely unknown. In this study, we identified the NAT10/PCBP/TDP43 complex as an mRNA ac4C writer in mammalian cells. We identified RNA-binding proteins (RBPs) affiliated with two different families, PCBP1/2 (poly(rC)-binding protein 1/2) and TDP43 (TAR DNA binding protein 43), as NAT10 adaptors for mRNA tethering and substrate selection. Knockdown of the adaptors resulted in decreased mRNA acetylation abundance in HEK293T cells, with globally reduced density in 5`-untranslated region (UTR) and coding sequence (CDS) and ablated cytidine-rich ac4C motifs. The adaptors also affect the ac4C sites by recruiting NAT10 to their binding sequences. The presence of the NAT10/PCBP/TDP43 complex in mouse testes highlights its potential physiological functions in vivo. These findings reveal the composition of the mRNA ac4C writer complex in mammalian cells and expand our knowledge of mRNA acetylation and ac4C site preferences.
Project description:Massive numbers of modified bases in mRNAs sculpt the epitranscriptome and play vital roles in RNA metabolism. The only known acetylated RNA modification, N-4-acetylcytidine (ac4C), is highly conserved across cell types and among species. Although the GCN5-related acetyltransferase 10 (NAT10) functions as an ac4C writer, the mechanism underlying the acetylation process is largely unknown. In this study, we identified the NAT10/PCBP/TDP43 complex as an mRNA ac4C writer in mammalian cells. We identified RNA-binding proteins (RBPs) affiliated with two different families, PCBP1/2 (poly(rC)-binding protein 1/2) and TDP43 (TAR DNA binding protein 43), as NAT10 adaptors for mRNA tethering and substrate selection. Knockdown of the adaptors resulted in decreased mRNA acetylation abundance in HEK293T cells, with globally reduced density in 5`-untranslated region (UTR) and coding sequence (CDS) and ablated cytidine-rich ac4C motifs. The adaptors also affect the ac4C sites by recruiting NAT10 to their binding sequences. The presence of the NAT10/PCBP/TDP43 complex in mouse testes highlights its potential physiological functions in vivo. These findings reveal the composition of the mRNA ac4C writer complex in mammalian cells and expand our knowledge of mRNA acetylation and ac4C site preferences.
Project description:RNA modification play vital roles in renal fibrosis. However, whether ac4C modification functions in renal fibrogenesis remains unknown. Here, we found that NAT10-ac4C axis plays pro—fibrotic role in kidney. ac4C RIP sequencing demonstrated NAT10-ac4C axis functions via regulating multiple master genes of exosome secretion in tubular epithelial cells. In summary, targeting NAT10-ac4C axis is a promising strategy for renal fibrosis.