Project description:We performed RNA immunoprecipitation (IP) and microarray (RIP-chip) analyses to identify and compare the biological mRNA targets of two RNA-binding protein (RBP), TDP-43 and FUS, associated to cytoplasmic ribonucleoprotein (RNP) complexes of motoneuronal NSC34 cells with the final aim to unravel their role in mRNA transport, stability, and translation in neuronal cells. To identify the transcripts contained and bound in the isolated RNP complexes, a chip analysis was performed using the recovered mRNAs from triplicate experimantal RIP samples (TDP-43-IP samples, the FUS-IP samples and the control IgG-IP sample).
Project description:Although EWS/FLI-1 fusion protein is responsible for most Ewing’s sarcoma family tumors (ESFT), the function of native EWS remains largely unknown. Here, we first showed that EWS repressed protein expression in a tethering assay. mRNAs bound to EWS were determined by RNA-immunoprecipitation Chip assay, and one of them, proline-rich Akt substrate of 40 kDa (PRAS40) mRNA, directly interacted with EWS. The inhibitor of AKT, API-2, repressed ESFT cell proliferation. We demonstrate that EWS negatively regulated PRAS40 protein expression through binding to PRAS40 3’UTR. Furthermore, PRAS40 knockdown inhibited the proliferation and metastatic potential of ESFT cells.
Project description:Although EWS/FLI-1 fusion protein is responsible for most EwingM-bM-^@M-^Ys sarcoma family tumors (ESFT), the function of native EWS remains largely unknown. Here, we first showed that EWS repressed protein expression in a tethering assay. mRNAs bound to EWS were determined by RNA-immunoprecipitation Chip assay, and one of them, proline-rich Akt substrate of 40 kDa (PRAS40) mRNA, directly interacted with EWS. The inhibitor of AKT, API-2, repressed ESFT cell proliferation. We demonstrate that EWS negatively regulated PRAS40 protein expression through binding to PRAS40 3M-bM-^@M-^YUTR. Furthermore, PRAS40 knockdown inhibited the proliferation and metastatic potential of ESFT cells. Cytoplasmic lysates or whole cell lysates were prepared from HeLa S3 cells transfected with pFLAG-EWS , and incubated with anti-FLAG M2 Affinity Gel (Sigma) at 4M-BM-0C for 2 h. RNAs from lysates and immunoprecipitates were analysed using GeneChip Human Genome U133 Plus 2.0 Array (Affymetrix).
Project description:To understand the mechanistic basis of YB-1’s regulation of mRNA splicing in response to DNA damage in Multiple Myeloma, we performed RNA immunoprecipitation (RIP) and sequencing of ILF2-bound transcripts under both physiological and DNA damage (melphalan treatment) conditions. Cells were treated with melphalan for 10 hours. (RIP) and sequencing of YB-1-bound RNAs was performed in the JJN3 line (two biological replicates/condition).
Project description:Ewing sarcoma (EWS) is a malignant pediatric bone cancer. Most Ewing sarcomas are driven by EWS-FLI1 oncogenic transcription factor that plays roles in transcriptional regulation, DNA damage response, cell cycle checkpoint control, and alternative splicing. USP1, a deubiquitylase which regulates DNA damage and replication stress responses, is overexpressed at both the mRNA and protein levels in EWS cell lines compared to human mesenchymal stem cells, the EWS cell of origin. The functional significance of high USP1 expression in Ewing sarcoma is not known. Here, we identify USP1 as a transcriptional target of EWS-FLI1 and a key regulator of EWS cell survival. We show that EWS-FLI1 knockdown decreases USP1 mRNA and protein levels. ChIP and ChIP-seq analyses show EWS-FLI1 occupancy on the USP1 promoter. Importantly, USP1 knockdown or inhibition arrests EWS cell growth and induces cell death by apoptosis. We observe destabilization of Survivin (also known as BIRC5 or IAP4) and activation of caspases-3 and -7 following USP1 knockdown or inhibition in the absence of external DNA damage stimuli. Notably, EWS cells display hypersensitivity to combinatorial treatment of doxorubicin or etoposide, EWS standard of care drugs, and USP1 inhibitor compared to single agents alone. Together, our study demonstrates that USP1 is regulated by EWS-FLI1, the USP1-Survivin axis promotes EWS cell survival, and USP1 inhibition sensitizes EWS cells to standard of care chemotherapy.
Project description:The purpose of the study was to identify mRNA bound to HuR in the presence of doxorubicin in MCF7 cells. We collected cytoplasmic RNA from untreated and treated cells and detected differentially expressed genes (DEGs). We also coimmunoprecipitated HuR and IgG (as control) from doxorubicin treated cells. Comparison between HuR RIP and IgG RIP signals was used to discriminate specific mRNA bound to HuR. HuR coimmmunoprecipitated material was hybridized together with cytoplasmic mRNA of doxorubicin treated cells, enabling the fold enrichment calculation and the selection of mRNAs bound to HuR. Keywords: RIP-Chip, HuR, doxorubicin, MCF7, HuR consensus binding, post-transcriptional regulation. We subjected MCF7 cells to starvation for 24h and then we added doxorubicin at final concentration of 10 uM, profiling before and after 4 hours of treatment in biological quadruplicate (only on cytoplasmic mRNAs, as HuR was found in the cytoplasm). Differentially expressed genes, altered during the treatment, were identified. Data derived from HuR RIP-Chip and IgG RIP-Chip (in biological quadruplicate) allowed the identification of specific mRNAs bound to HuR. The comparison between HuR RIP-Chip and cytoplasmic extracts from doxorubicin treated cells (in biological triplicate) identified those genes that were more strictly bound to HuR independently from their expression levels.
Project description:To understand the mechanistic basis of ILF2’s regulation of mRNA splicing in response to DNA damage in Multiple Myeloma, we performed RNA immunoprecipitation (RIP) and sequencing of ILF2-bound transcripts under both physiological and DNA damage (melphalan treatment) conditions. Cells were treated with melphalan for 10 hours. RNA immunopreciptation (RIP) and sequencing of ILF2-bound RNAs was performed in the JJN3 and H929 cell lines (two biological replicates/condition). Cells were treated with melphalan for 10 hours.
Project description:The purpose of the study was to identify mRNA bound to HuR in the presence of doxorubicin in MCF7 cells. We collected cytoplasmic RNA from untreated and treated cells and detected differentially expressed genes (DEGs). We also coimmunoprecipitated HuR and IgG (as control) from doxorubicin treated cells. Comparison between HuR RIP and IgG RIP signals was used to discriminate specific mRNA bound to HuR. HuR coimmmunoprecipitated material was hybridized together with cytoplasmic mRNA of doxorubicin treated cells, enabling the fold enrichment calculation and the selection of mRNAs bound to HuR. Keywords: RIP-Chip, HuR, doxorubicin, MCF7, HuR consensus binding, post-transcriptional regulation.