XPO1 enables adaptive regulation of mRNA export required for genotoxic stress tolerance in cancer cells
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA871300 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Exportin-1 (XPO1), the main soluble nuclear export receptor in eukaryotic cells, is frequently overexpressed in diffuse large B-cell lymphoma (DLBCL). A selective XPO1 inhibitor, selinexor, received approval as single agent for relapsed or refractory (R/R) DLBCL. Elucidating the mechanisms by which XPO1 overexpression supports cancer cells could facilitate further clinical development of XPO1 inhibitors. We uncovered here that XPO1 overexpression increases tolerance to genotoxic stress, leading to a poor response to chemoimmunotherapy. Upon DNA damage induced by MYC expression or exogenous compounds, XPO1 bound and exported EIF4E and THOC4 carrying DNA damage repair mRNAs, thereby increasing synthesis of DNA damage repair proteins under conditions of increased turnover. Consequently, XPO1 inhibition decreased the capacity of lymphoma cells to repair DNA damage and ultimately resulted in increased cytotoxicity. In a phase I clinical trial conducted in R/R DLBCL, the combination of selinexor with second-line chemoimmunotherapy was tolerated with early indication of efficacy. Overall, this study reveals that XPO1 overexpression plays a critical role in the increased tolerance of cancer cells to DNA damage while providing new insights to optimize the clinical development of XPO1 inhibitors.SignificanceXPO1 regulates the dynamic ribonucleoprotein nuclear export in response to genotoxic stress to support tolerance and can be targeted to enhance the sensitivity of cancer cells to endogenous and exogenous DNA damage. See related commentary by Knittel and Reinhardt, p. 3.
| S-EPMC10758694 | biostudies-literature
Project description:Proper nucleocytoplasmic distribution of proteins is essential to cellular homeostasis but what role the altered nuclear export machinery commonly described in cancer cells plays in cancer initiation is not known. Here, genomic analysis of 42,793 cancers identified recurrent mutational hotspots in XPO1, the main nuclear export receptor in eukaryotic cells. Expression of XPO1 mutations in vivo was sufficient to initiate clonal, B-lymphoproliferative disorders by altering the constellation of proteins exported from the nucleus based on amino acid charge C-terminal to their nuclear export signal. Impaired export of one such protein, the NFkB inhibitor IB enhanced NFkB signaling, a pathway frequently activated by somatic mutations in cancers enriched in XPO1 mutations. These data identify change-of-function mutations in nuclear export as novel drivers of tumorigenesis.
2021-09-01 | GSE120231 | GEO
Project description:To determine how exposure to CHOP, Selinexor or their combination affects gene expression in DLBCL, we first established a patient-derived xenograft model of DLBCL. Next, mice were randomized to receive either vehicle, CHOP, Selinexor or their combination. Tumors were harvested at the end of treatment and gene expression profile analyzed by RNA-sequencing.
2023-08-30 | GSE211684 | GEO
Project description:XPO1 is a nuclear export protein that is frequently overexpressed in cancer and functions as a driver of oncogenesis. Currently small molecules that target XPO1 are being used in the clinic as anti-cancer agents. We identify XPO1 as a target for natural killer (NK) cells. Using immunopeptidomics we have identified a peptide derived from XPO1 that can be recognized by the activating NK cell receptor KIR2DS2 in the context of HLA-C. The peptide can be endogenously processed and presented to activate NK cells specifically through this receptor. Although high XPO1 expression in cancer is commonly associated with a poor prognosis, we show that the outcome of specific cancers, such as hepatocellular carcinoma, can be substantially improved if there is concomitant evidence of NK cell infiltration. We thus identify XPO1 as a bona fide tumor antigen recognised by NK cells, that offers an opportunity for a personalized approach to NK cell therapy for solid tumors.
2024-10-17 | PXD053264 | Pride
Project description:SF3B1 mutations are the most frequent spliceosomal alterations across cancers, yet no successful therapy exists to target this pathway. Previous findings from a phase 2 clinical trial of the XPO1 inhibitor selinexor in patients with high-risk myelodysplastic neoplasms (MDS) relapsed or refractory to hypomethylating agents (HMA) revealed increased activity in patients with SF3B1 mutations. XPO1 (Exportin-1) is responsible for the export of over 200 proteins, but also plays a role in the transport of multiple RNA species, including small nuclear RNAs (snRNAs), ribosomal RNAs (rRNAs), and select messenger RNAs (mRNAs) out of the nucleus. We therefore hypothesized that XPO1 inhibition perturbs RNA export and may preferentially affect SF3B1 mutants via altered splicing, given the role of XPO1 in exporting snRNAs, which form the catalytic portion of the spliceosome. To evaluate the mechanism underlying preferentially sensitivity of SF3B1-mutants to XPO1 inhibition, we performed nuclear and cytoplasmic fraction followed by RNA sequencing before and after XPO1 inhibition in SF3B1 wildtype and SF3B1 K666N cells (subcellular RNA-seq). Whole transcriptomic analysis of subcellular RNA-seq data revealed more nuclear retention of global RNA transcripts after XPO1 inhibition in the SF3B1 mutant cell line. Similarly, we performed subcellular RNA-seq for small RNAs and found snRNAs to be increased in the nucleus after XPO1 inhibition in the SF3B1 mutant cells. We then performed total cellular RNA sequencing to understand the effect of XPO1 inhibition on global RNA expression and RNA splicing. Differential gene expression analysis identified that XPO1 inhibition had the greatest effect on cell cycle in SF3B1 wildtype cells but in SF3B1-mutant cells differentiation pathways were more significantly affected. Alternative splicing analysis showed increased 3’ alternative splicing events in SF3B1 mutant after XPO1 inhibition. These results signify the mechanistic basis for preferential sensitivity of SF3B1 mutant cells to nuclear export inhibition arises through nuclear retention of spliceosomal snRNAs and select mRNAs that result in perturbation of differentiation pathways.
2024-08-05 | GSE255179 | GEO
Project description:BCL6 Enables Cancer Cells to Evade Genotoxic Stress
| PRJNA679550 | ENA
Project description:XPO1 gene encodes exportin 1 (XPO1) that controls the nuclear export of cargo proteins and RNAs. Almost 25% of primary mediastinal B-cell lymphomas (PMBL) and classical Hodgkin lymphomas (cHL) cases harboured a recurrent XPO1 point mutation (NM_003400, chr2:g61718472C>T) resulting in the E571K modification within the hydrophobic groove of the protein, the site of cargo proteins binding. We investigated the functional impact of XPO1E571K mutation using cell lines having various XPO1 status. We first confirmed that the mutation was present both within the XPO1 mRNA and the corresponding protein. In the U2940 cell line having a wild-type (wt) XPO1 gene, we introduced the E571K mutation using several CRISPR-Cas9 strategies. Using a barcoding method to trace the mutation, we observed that the mutation gave no advantage in vitro. Indeed, the effects of XPO1E571K mutation were hidden by the presence of the XPO1 wt allele. Strikingly, XPO1E571K mutation never occurred as homozygous or hemizygous in our patients��������� cohort. We further showed that XPO1E571K mutation modified selinexor binding to XPO1 and in turn, its sensitivity to this drug. We concluded that the balance between the wild-type and the mutated allele of XPO1 is a key element in defining XPO1 functions and oncogenic properties.
2020-10-01 | PXD016916 | Pride
Project description:Purpose: Exportin 1 (XPO1/CRM1) is a key mediator of nuclear export with relevance to multiple cancers, including chronic lymphocytic leukemia (CLL). Whole exome sequencing has identified hot-spot somatic XPO1 point mutations which we found to disrupt highly conserved biophysical interactions in the NES-binding groove, conferring novel cargo-binding abilities and forcing cellular mis-localization of critical regulators. However, the pathogenic role played by change-in-function XPO1 mutations in CLL is not fully understood. Thus, we aimed to identify disrupted cellular pathways in response to the E571K XPO1 mutation, the mutation most frequently cited in CLL patients, via high-throughput RNA-sequencing Results & Conclusion: Multidimensional scaling (MDS) analysis of the top 1000 most variable genes demonstrated distinctly unique clustering along the first dimension for XPO1-E571K patient and XPO1-wt patient samples. This clustering pattern was driven by a number of genes that were either over- or under-expressed in XPO1-E571K patient cells, contributing to a unique gene expression pattern in patients with this mutation signature.
2021-01-21 | GSE163370 | GEO
Project description:Cancer -associated mutations in XPO1 transform cells through altered nuclear export signal recognition
| PRJNA492253 | ENA
Project description:Mislocalization of oncogenes and tumor suppressors resulting from aberrant nuclear export promotes uncontrolled cell proliferation and growth transformation of cancer cells. We performed a genome-wide CRISPR-Cas9 screening in matched primary and KSHV-transformed cells, and identified genes that were pro-growth and growth-suppressive of both types of cells, of which exportin XPO1 was a critical factor for the survival of transformed cells. Using XPO1 inhibitor KPT-8602 and by siRNA-mediated knockdown, we confirmed the essential role of XPO1 in cell proliferation and growth transformation of KSHV-transformed cells, as well as cell lines of other types of cancer including gastric cancer and liver cancer. XPO1 inhibition induced cell cycle arrest and p53 activation, which depended on the formation of PML nuclear bodies. Furthermore, XPO1 induced relocalization of autophagy adaptor protein p62 (SQSTM1), recruiting p53 for activation in PML nuclear bodies. Our findings highlight a novel mechanism of p53 activation and identify XPO1 as a vulnerable target of cancer cells.
2019-05-21 | GSE125507 | GEO