Project description:RNA N6 -methyladenosine (m6A) modification and its regulators fine tune gene expression and contribute to tumorigenesis. This study aims to uncover the essential role and the underlying molecular mechanism(s) of the m6A reader YTHDC1 in promoting triple negative breast cancer (TNBC) metastasis.MethodsIn vitro and in vivo models were employed to determine the pathological function of YTHDC1 in TNBC metastasis. To identify bona fide YTHDC1 target RNAs, we conducted RNA-seq, m6A-seq, and RIP-seq, followed by integrative data analysis and validation assays.ResultsBy analyzing The Cancer Genome Atlas (TCGA) dataset, we found that elevated expression of YTHDC1 is positively correlated with poor prognosis in breast cancer patients. Using a mammary fat pad mouse model of TNBC, YTHDC1 significantly promoted lung metastasis of TNBC cells. Through multiple transcriptome-wide sequencing and integrative data analysis, we revealed dysregulation of metastasis-related pathways following YTHDC1 depletion and identified SMAD3 as a bona fide YTHDC1 target RNA. Depletion of YTHDC1 caused nuclear retention of SMAD3 mRNA, leading to lower SMAD3 protein levels. Loss of YTHDC1 led to impaired TGF-β-induced gene expression, leading to inhibition of epithelial-mesenchymal transition (EMT) and suppressed TNBC cell migration and invasion. SMAD3 overexpression was able to restore the response to TGF-β in YTHDC1 depleted TNBC cells. Furthermore, we demonstrated that the oncogenic role of YTHDC1 is mediated through its recognition of m6A as m6A-binding defective mutants of YTHDC1 were unable to rescue the impaired cell migration and invasion of YTHDC1 knockout TNBC cells.ConclusionsWe show that YTHDC1 plays a critical oncogenic role in TNBC metastasis through promoting the nuclear export and expression of SMAD3 to augment the TGF-β signaling cascade. Overall, our study demonstrates that YTHDC1 is vital for TNBC progression by enhancing TNBC cell survival and TGF-β-mediated EMT via SMAD3 to enable the formation of distant metastasis and highlights the therapeutic potential of targeting the YTHDC1/m6A/SMAD3 axis for TNBC treatment.
Project description:RNA N6-methyladenosine (m6A) modification and its regulators fine tune gene expression and contribute to tumorigenesis. Here, we uncover the oncogenic role and mechanism of YTHDC1, an m6A reader positively correlated to poor prognosis in breast cancer patients. In a mammary fat pad mouse model, YTHDC1 significantly promoted lung metastasis of triple negative breast cancer (TNBC) cells. Using transcriptome-wide sequencing techniques, we found dysregulation of metastasis-related pathways following YTHDC1 depletion and demonstrated that YTHDC1 is critical for nuclear export of SMAD3 mRNA. YTHDC1 depletion desensitizes TNBC cells to TGF-β, resulting in impaired TGF-β-induced gene signature and inhibition on epithelial-mesenchymal transition (EMT) and cell migration/invasion, which could be at least partially restored by SMAD3 overexpression. Furthermore, we show that the ability of YTHDC1 to recognize m6A on SMAD3 RNA is important for its oncogenic role. Collectively, our study unravels YTHDC1 as vital for distant TNBC metastasis by promoting TGF-β-mediated EMT via SMAD3.
Project description:RNA N6-methyladenosine (m6A) modification and its regulators fine tune gene expression and contribute to tumorigenesis. Here, we uncover the oncogenic role and mechanism of YTHDC1, an m6A reader positively correlated to poor prognosis in breast cancer patients. In a mammary fat pad mouse model, YTHDC1 significantly promoted lung metastasis of triple negative breast cancer (TNBC) cells. Using transcriptome-wide sequencing techniques, we found dysregulation of metastasis-related pathways following YTHDC1 depletion and demonstrated that YTHDC1 is critical for nuclear export of SMAD3 mRNA. YTHDC1 depletion desensitizes TNBC cells to TGF-β, resulting in impaired TGF-β-induced gene signature and inhibition on epithelial-mesenchymal transition (EMT) and cell migration/invasion, which could be at least partially restored by SMAD3 overexpression. Furthermore, we show that the ability of YTHDC1 to recognize m6A on SMAD3 RNA is important for its oncogenic role. Collectively, our study unravels YTHDC1 as vital for distant TNBC metastasis by promoting TGF-β-mediated EMT via SMAD3.
Project description:RNA N6-methyladenosine (m6A) modification and its regulators fine tune gene expression and contribute to tumorigenesis. Here, we uncover the oncogenic role and mechanism of YTHDC1, an m6A reader positively correlated to poor prognosis in breast cancer patients. In a mammary fat pad mouse model, YTHDC1 significantly promoted lung metastasis of triple negative breast cancer (TNBC) cells. Using transcriptome-wide sequencing techniques, we found dysregulation of metastasis-related pathways following YTHDC1 depletion and demonstrated that YTHDC1 is critical for nuclear export of SMAD3 mRNA. YTHDC1 depletion desensitizes TNBC cells to TGF-β, resulting in impaired TGF-β-induced gene signature and inhibition on epithelial-mesenchymal transition (EMT) and cell migration/invasion, which could be at least partially restored by SMAD3 overexpression. Furthermore, we show that the ability of YTHDC1 to recognize m6A on SMAD3 RNA is important for its oncogenic role. Collectively, our study unravels YTHDC1 as vital for distant TNBC metastasis by promoting TGF-β-mediated EMT via SMAD3.
Project description:N6-methyladenosine (m6A) modification on viral RNAs has a profound impact on infectivity. m6A is also a highly pervasive modification for influenza viral RNAs. However, its role in virus mRNA splicing is largely unknown. Here, we identify the m6A reader protein YTHDC1 as a host factor that associates with influenza A virus NS1 protein and modulates viral mRNA splicing. YTHDC1 levels are enhanced by IAV infection. We demonstrate that YTHDC1 inhibits NS splicing by binding to an NS 3' splicing site and promotes IAV replication and pathogenicity in vitro and in vivo. Our results provide a mechanistic understanding of IAV-host interactions, a potential therapeutic target for blocking influenza virus infection, and a new avenue for the development of attenuated vaccines.
Project description:Aortic dissection (AD) develops pathological changes in the separation of the true and false aortic lumen, with high lethality. m6A methylation and oxidative stress have also been shown to be involved in the onset of AD. Through bioinformatics methods, three differentially expressed m6A regulators (YTHDC1, YTHDC2, and RBM15) were excavated from the GSE52093 dataset in the Gene Expression Omnibus (GEO) database, and functional enrichment analysis of the differentially expressed genes (DEGs) regulated by m6A regulators was performed. Then, the genes with oxidative stress-related functions among these genes were found. The protein interaction network of the oxidative stress-related genes and the competing endogenous RNA- (ceRNA-) miRNA-mRNA network were constructed. Among them, DHCR24, P4HB, and PDGFRA, which have m6A differences in AD samples, were selected as key genes. We also performed immune infiltration analysis, as well as cell-gene correlation analysis, on samples from the dataset. The results showed that YTHDC1 was positively correlated with macrophage M1 and negatively correlated with macrophage M2. Finally, we extracted AD and healthy aorta RNA and protein from human tissues that were taken from AD patients and patients who received heart transplants, performed quantitative real-time PCR (qRT-PCR) on YTHDC2 and RBM15, and performed qRT-PCR and western blot (WB) detection on YTHDC1 to verify their differences in AD. The mRNA and protein levels of YTHDC1 were consistent with the results of bioinformatics analysis and were downregulated in AD. Immunofluorescence (IF) was used to colocalize YTHDC1 and endothelial cell marker CD31. After knocking down YTHDC1 in human umbilical vein endothelial cells (HUVECs), reactive oxygen species (ROS) levels had a tendency to increase and the expression of peroxide dismutase SOD2 was decreased. This study provides assistance in discovering the role of m6A regulator YTHDC1 in AD. In particular, m6A modification participates in oxidative stress and jointly affects AD.
