Project description:Acute Lung Injury (ALI) can cause Acute Respiratory Distress Syndrome (ARDS), a lethal condition with limited treatment options and currently a common global cause of death due to COVID-19-induced ALI. ARDS secondary to Transfusion-Related Acute Lung Injury (TRALI) has been recapitulated pre-clinically by anti-MHC-I antibody administration to LPS-primed mice. In this model, we demonstrated that inhibitors of PTP1B, a protein tyrosine phosphatase that regulates signaling pathways of fundamental importance to homeostasis and inflammation, prevented lung injury and increased survival. Treatment with PTP1B inhibitors attenuated the aberrant neutrophil function that drives ALI, and was associated with release of myeloperoxidase, suppression of Neutrophil Extracellular Trap (NET) formation, and inhibition of neutrophil migration. Mechanistically, reduced signaling through the CXCR4 chemokine receptor, particularly to the activation of mTOR, was essential for these effects, linking PTP1B in hibition to promoting an aged neutrophil phenotype. Considering dysregulated activation of neutrophils is implicated in sepsis and can cause collateral tissue damage, we demonstrated also that PTP1B inhibitors improved survival and ameliorated lung injury in the LPS-induced sepsis model. Our data highlight PTP1B inhibition for prevention of TRALI and ARDS from multiple etiologies.
Project description:To investigate the effect of the MDS-associated U2AF1-S34F mutation on gene expression and pre-mRNA splicing in mouse neutrophils, we performed RNA-seq on RNA isolated from bone marrow neutrophils expressing either U2AF1-S34F or U2AF1-WT transgenes
Project description:Endometrial cancer had a relatively high prevalence of MMR deficiency. MMR-D/MSI-H endometrial cancer patients are suggested to be potential beneficiaries of PD-1/PD-L1 inhibitor therapy. Here, we explored the prognostic value of MSI subtype in endometrial cancer and its correlation with immune environment. Based on expression and clinical data of 78 POLE, 123 MSI and 299 Other EC samples from the TCGA-UCEC project, we found that the MSI tumors were identified more often in early stage, had a lower age, better patient survival, enriched CD8+ T cells, and regulatory T cells and less M2 macrophages and activated dendritic cells than the Other group, and shared a relatively similar expression profile with POLE group by differential analysis. In addition, we established the immune landscape of an MMR-D endometrial cancer tissue using unbiased single-cell RNA-seq analysis of 3371 cells. By immunohistochemistry analysis, we found that the MMR-D tumors showed a higher trend of CD20+ B cells infiltration. Our study might expand our understanding of the role of immune subsets in MSI endometrial carcinomas and provide guidance of immunotherapy for endometrial cancer.
Project description:Inhibition of the nonsense mediated decay (NMD) mechanism in cells results in stabilization of transcripts carrying premature translation termination codons. A strategy referred to as gene indentification by NMD inhibition (GINI) has been proposed to identify genes carrying nonsense mutations (Noensie & Dietz, 2001). Genes containing frameshift mutations in colon cancer cell line have been identifying mutatnt genes using GINI, we have now further improved the strategy. In this approach, inhibition of NMD with emetine is complemented with inhibiting NMD by blocking the phosphorylation of the hUpf1 protein with caffeine. In addition, to enhance the GINI strategy, comparing mRNA level alterations produced by inhibiting transcription alone or inhbiiting transcription together with NMD following caffeine pretreatment were used for the efficient identification of false positives produced as a result of stress response to NMD inhibition. To demonstrate the improved efficiency of this approach, we analyzed colon cancer cell lines showing microstellite instability. Bi-allelic inactivating mutations were found in the FXR1, SEC1L1, NCOR1, BAT3, PHD14, ZNF294, C190ORF5 genes as well as genes coding for proteins with yet unknown functions. Experiment Overall Design: Using GINI2 as a method of identifying novel biallelic truncating mutations in MSI+ colon cancer cells, various treatment conditions were applied to cultured colon cancer cell lines LS180 (MSI+) and SW480 (MSI-) and gene expression profiling was measured using Affymetrix GeneChip U133 Plus 2 arrays.
Project description:Microsatellite instability (MSI), caused by defective mismatch repair, is observed in a subset of colorectal cancers (CRCs). We evaluated somatic mutations in microsatellite repeats of genes chosen based on reduced expression in MSI CRC and existence of a coding mononucleotide repeat. Expression profiling of 34 MSI colorectal cancers and 15 normal colonic mucosas was performed in 2002. Comparison of malignant and healthy tissue.
Project description:Microsatellite instability high (MSI-H) tumors are malignant tumors that, despite harboring a high mutational burden, often have intact TP53. One of the most frequent mutations in MSI-H tumors is a frameshift mutation in RPL22, a ribosomal protein. Here, we identified RPL22 as a modulator of MDM4 splicing through an alternative splicing switch in exon 6. RPL22 loss increased MDM4 exon 6 inclusion, cell proliferation, and augmented resistance to the MDM inhibitor Nutlin-3A. RPL22 represses expression of its paralog, RPL22L1, by mediating the splicing of a cryptic exon corresponding to a truncated transcript. Therefore, RPL22 loss is a driver of oncogenic MDM4 induction and key to a common splicing circuit in MSI-H tumors that may inform therapeutic targeting of the MDM4-p53 axis and oncogenic RPL22L1 induction.
Project description:Gastric cancers with mismatch repair (MMR) inactivation are characterised by microsatellite instability (MSI). In this study, the transcriptional profile of 38 gastric cancers with and without MSI was analysed. Unsupervised analysis showed that the immune and apoptotic gene networks efficiently discriminated these two cancer types. Hierarchical clustering analysis revealed numerous gene expression changes associated with the MSI phenotype. Amongst these, the p53-responsive genes maspin and 14-3-3 sigma were significantly more expressed in tumours with than without MSI. A tight immunosurveillance coupled with a functional p53 gene response is consistent with the better prognosis of MSI cancers. Frequent silencing of MLH1 and downregulation of MMR target genes, such as MRE11 and MBD4, characterised MSI tumours. The downregulation of SMUG1 was also a typical feature of these tumours. The DNA repair gene expression profile of gastric cancer with MSI is of relevance for therapy response.
Project description:Gastric cancers with mismatch repair (MMR) inactivation are characterised by microsatellite instability (MSI). In this study, the transcriptional profile of 38 gastric cancers with and without MSI was analysed. Unsupervised analysis showed that the immune and apoptotic gene networks efficiently discriminated these two cancer types. Hierarchical clustering analysis revealed numerous gene expression changes associated with the MSI phenotype. Amongst these, the p53-responsive genes maspin and 14-3-3 sigma were significantly more expressed in tumours with than without MSI. A tight immunosurveillance coupled with a functional p53 gene response is consistent with the better prognosis of MSI cancers. Frequent silencing of MLH1 and downregulation of MMR target genes, such as MRE11 and MBD4, characterised MSI tumours. The downregulation of SMUG1 was also a typical feature of these tumours. The DNA repair gene expression profile of gastric cancer with MSI is of relevance for therapy response. Experiment Overall Design: Genes differentially expressed between MSI and MSS tumours were identified as follows: (i) gene probe sets were pre-selected for being flagged as ‘PRESENT’ in at least 10 tumour samples (21,324 probe sets); (ii) the probe set signal values on the pre-selected probe sets were used to run a t-test between the two types of tumour samples; (iii) the false discovery rate (FDR) method was applied to the t-test calculated p-values to correct for multiple testing and (iv) a false discovery rate <0.05 and a t-test p-value < 0.01 were chosen as threshold criteria to identify the genes differentially expressed in tumours with and without MSI