Project description:In our study, we valided DHX9 and NPM1 interact with KIMAT1, whereas DHX9 also interacts with HIF1A-As2. DHX9 is a highly conserved DEAD-box protein expressed in the nucleus and the cytoplasm, involved in many processes including transcriptional activation, miRNA biogenesis and tumor cell maintenance. NPM1 is predominantly localized in the nucleoplasm, where it associates with active RNA polymerase II and transcriptionally activates genes involved in cancer. We silenced DHX9 and NPM1 and performed RNA-seq to examine the dysregulated genes by DHX9 and NPM1.
Project description:Hypoxia inducible factor-1 (HIF-1) is a central transcriptional regulator of genes associated with adaptive responses to hypoxia. NPM1 is a histone chaperone found to associate with HIF-1α in a phosphorylation dependent manner and increase its activty. The aim of this study was to find if HIF-1α and NPM1 regualate gene expression under hypoxia. Transcriptome analysis using Quant-RNA-seq after HIF-1α or NPM1 silencing under hypoxia reveals a significant number of genes, the hypoxic expression of which depends on both proteins.
Project description:Cell division ensures that both genetic information and non-genetic contents are inherited by daughter cells. Whereas considerable detail has been learned about the processing of intact or damaged DNA during the cell cycle (Branzei & Foiani, 2008; Klaasen et al., 2022),(Bakhoum & Cantley, 2018),(Hustedt & Durocher, 2016), how daughter cells deal with other forms of inherited damage is unknown. Here we identified a special kind of cytoplasmic granules responsible for the compartmentalisation of parental RNA damage. We found that ultraviolet (UV)-induced RNA, but not DNA, damage triggered assembly of this unique type of granules characterized by the presence of RNA helicase DHX9. By developing a novel methodology, FANCI, we discovered that DHX9 granules are enriched in damaged intron RNA and pre-mRNA-binding proteins, which is in contrast to other classical stress granules (SGs) that are composed of mature mRNA. Intron damage impeded proper splicing and intron decay, and induced generation of circRNA and dsRNA in the granules. Moreover, we showed that intron damage induced DHX9 granules assembled specifically in postmitotic daughter cells and triggered a cellular dsRNA immune response. Condensation with dsRNA is crucial for DHX9 localization to the granules and the modulation of dsRNA in these granules by DHX9 was crucial for daughter cell survival. Our observations revealed that DHX9 granules constitute a dedicated non-membrane-bound cytoplasmic compartment that protects daughter cells from parental damaged RNA.
Project description:The ATP-dependent DExH/D-box helicase DHX9 is a key participant in a number of gene regulatory steps, including transcriptional, translational, microRNA-mediated control, DNA replication, and maintenance of genomic stability. DHX9 has also been implicated in maintenance of the tumorigenic process and in drug response. Here, we report that inhibition of DHX9 expression is lethal to multiple human and mouse cancer cell lines. In contrast, using a novel conditional shDHX9 mouse model, we demonstrate that sustained and prolonged suppression of DHX9 is well tolerated at the organismal level. Our results demonstrate a robust tolerance for DHX9 knockdown in non-transformed cells and supports the targeting of DHX9 as an effective and specific chemotherapeutic approach. Comparison of gene expression in large intestine of mice with or without reduced expression of DHX9.
Project description:Prostaste cancer (PC) is the most commonly diagnosed male malignancy and an important cause of mortality. Androgen signaling plays a key role in PC pathogenesis and the understanding of the mechanisms involved in the regulation of AR function might pave the ground for the development of more efficacious and long-lasting therapeutic strategies for PC patients. DNA/RNA helicases are emerging as important regulators of many cellular processes. Among them, DHX9 has been implicated in the control of genomic stability, transcription and DNA replication. To investigate the role of DHX9 in PC we perform RNA-sequencing analysis in androgen-sensitive LNCaP cells affects upon DHX9 silencing.
Project description:Transposable elements increase genetic diversity thus making them an important part of evolution and gene regulation in all organisms that carry these sequences. Bulk of our nascent transcriptome is comprised of transposable elements that have the propensity to form strong secondary structures. It is essential to resolve such strong secondary structures to maintain normal cellular function. Here, we show that the major nuclear RNA helicase DHX9/RHA interacts and remodels embedded Alu retrotransposable elements in the human transcriptome and B1 retrotransposable elements in the mouse transcriptome. To understand the function of DHX9 we used FLASH (Fast cloning of RNA After some Sort of affinity purification for High-throughput sequencing) to identify the in-vivo targets of human DHX9.
Project description:Transposable elements increase genetic diversity thus making them an important part of evolution and gene regulation in all organisms that carry these sequences. Bulk of our nascent transcriptome is comprised of transposable elements that have the propensity to form strong secondary structures. It is essential to resolve such strong secondary structures to maintain normal cellular function. Here, we show that the major nuclear RNA helicase DHX9/RHA interacts and remodels embedded Alu retrotransposable elements in the human transcriptome and B1 retrotransposable elements in the mouse transcriptome. To understand the function of DHX9 we used FLASH (Fast cloning of RNA After some Sort of affinity purification for High-throughput sequencing) to identify the in-vivo targets of human DHX9.
Project description:Transposable elements increase genetic diversity thus making them an important part of evolution and gene regulation in all organisms that carry these sequences. Bulk of our nascent transcriptome is comprised of transposable elements that have the propensity to form strong secondary structures. It is essential to resolve such strong secondary structures to maintain normal cellular function. Here, we show that the major nuclear RNA helicase DHX9/RHA interacts and remodels embedded Alu retrotransposable elements in the human transcriptome and B1 retrotransposable elements in the mouse transcriptome. To understand the function of DHX9 we used FLASH (Fast cloning of RNA After some Sort of affinity purification for High-throughput sequencing) to identify the in-vivo targets of human DHX9.