NUP98::NSD1 and FLT3/ITD co-expression is an independent predictor of poor prognosis in pediatric AML patients.

OBJECTIVE: Patients who carry NUP98::NSD1 or FLT3/ITD mutations are reported to have poor prognosis. Previous studies have confidently reported that the poor outcome in younger AML patients is owning to dual NUP98::NSD1 and FLT3/ITD positivity, with a high overlap for those two genetic lesions. In this study, we assessed the prognostic value of the presence of both NUP98::NSD1 and FLT3/ITD in pediatric AML patients. METHODS: We screened a large cohort of 885 pediatric cases from the COG-National Cancer Institute (NCI) TARGET AML cohort and found 57 AML patients with NUP98 rearrangements. RESULTS: The frequency of NUP98 gene fusion was 10.8% in 529 patients. NUP98::NSD1 fusion was the most common NUP98 rearrangement, with a frequency of 59.6%(34 of 57). NUP98::NSD1 -positive patients who carried FLT3/ITD mutations had a decreased CR1 or CR2 rate than those patients carried FLT3/ITD mutation alone (P = 0.0001). Moreover, patients harboring both NUP98::NSD1 fusion and FLT3/ITD mutation exhibited inferior event-free survival (EFS, P < 0.001) and overall survival (OS, P = 0.004) than patients who were dual negative for these two genetic lesions. The presence of only NUP98::NSD1 fusion had no significant impact on EFS or OS. We also found that cases with high FLT3/ITD AR levels ( > = 0.5) with or without NUP98::NSD1 had inferior prognosis. Multivariate analysis demonstrated that the presence of both NUP98::NSD1 and FLT3/ITD was an independent prognostic factors for EFS (hazard ratio: 3.2, P = 0.001) in patients with pediatric AML. However, there was no obvious correlation with OS (hazard ratio: 1.3, P = 0.618). Stem cell transplantation did not improve the survival rate of cases with NUP98 fusion or NUP98::NSD1 AML in terms of EFS or OS. CONCLUSION: Presence of both NUP98::NSD1 and FLT3/ITD was found to be an independent factor for dismal prognosis in pediatric AML patients. Notably, lack of FLT3/ITD mutations in NUP98::NSD1 -positive patients did not retain its prognostic value.

Clinical features and prognosis of patients with myeloid neoplasms harboring t(7;11)(p15;p15) translocation: a single-center retrospective study.

BACKGROUND: For myeloid neoplasms with t(7;11)(p15;p15) translocation, the prognosis is quite dismal. Because these tumors are rare, most occurrences are reported as single cases. Clinical results and optimal treatment approaches remain elusive. This study endeavors to elucidate the clinical implications and prognosis of this cytogenetic aberration. METHODS: This study retrospectively analyzed 23 cases of myeloid neoplasm with t(7;11)(p15;p15). Clinicopathological characteristics, genetic alterations, and outcomes were evaluated, and the Kaplan-Meier method was employed to construct survival curves. RESULTS: Of these, nine cases were newly diagnosed acute myeloid leukemia (ND AML), seven presented with relapsed refractory AML (R/R AML), four had myelodysplastic syndrome (MDS), two had secondary AML, and one exhibited a mixed germinoma associated with MDS. Patients with t(7;11)(p15;p15) in AML were primarily younger females who preferred subtype M2. Interestingly, these patients had decreased hemoglobin and red blood cell counts, along with markedly elevated levels of lactic dehydrogenase and interleukin-6, and exhibited the expression of CD117. R/R AML patients exhibited a higher likelihood of additional chromosome abnormalities (ACAs) besides t(7;11). WT1 and FLT3-ITD were the most commonly found mutated genes, and 10 of those instances showed evidence of the NUP98::HOXA9 fusion gene. The composite complete remission rate was 66.7% (12/18), while the cumulative graft survival rate was 100% (4/4). However, the survival outcomes were dismal. Interestingly, the median overall survival for R/R AML patients was 4.0 months (95% CI: 1.7-6.4). Additionally, the type of AML diagnosis or the presence of ACAs or molecular prognostic stratification did not significantly influence clinical outcomes (p = 0.066, p = 0.585, p = 0.570, respectively). CONCLUSION: Myeloid leukemia with t(7;11) exhibits unique clinical features, cytogenetic properties, and molecular genetic characteristics. These survival outcomes were dismal. R/R AML patients have a limited lifespan. For myeloid patients with t(7;11), targeted therapy or transplantation may be an effective course of treatment.

Treatment of three pediatric AML co-expressing NUP98-NSD1, FLT3-ITD, and WT1.

During the treatment of 89 pediatric patients with Acute Myeloid Leukemia (AML) at the Hematology Department of Kunming Medical University's Children's Hospital from 2020 to 2023, three patients were identified to co-express the NUP98-NSD1, FLT3-ITD, and WT1 gene mutations. The bone marrow of these three patients was screened for high-risk genetic mutations using NGS and qPCR at the time of diagnosis. The treatment was administered following the China Children's Leukemia Group (CCLG)-AML-2019 protocol. All three patients exhibited a fusion of the NUP98 exon 12 with the NSD1 exon 6 and co-expressed the FLT3-ITD and WT1 mutations; two of the patients displayed normal karyotypes, while one presented chromosomal abnormalities. During the induction phase of the CCLG-AML-2019 treatment protocol, the DAH (Daunorubicin, Cytarabine, and Homoharringtonine) and IAH (Idarubicin, Cytarabine, and Homoharringtonine) regimens, in conjunction with targeted drug therapy, did not achieve remission. Subsequently, the patients were shifted to the relapsed/refractory chemotherapy regimen C + HAG (Cladribine, Homoharringtonine, Cytarabine, and G-CSF) for two cycles, which also failed to induce remission. One patient underwent Haploidentical Hematopoietic Stem Cell Transplantation (Haplo-HSCT) and achieved complete molecular remission during a 12-month follow-up period. Regrettably, the other two patients, who did not receive transplantation, passed away. The therapeutic conclusion is that pediatric AML patients with the aforementioned co-expression do not respond to chemotherapy. Non-remission transplantation, supplemented with tailor-made pre- and post-transplant strategies, may enhance treatment outcomes.

"Off-pore" nucleoporins relocalize heterochromatic breaks through phase separation.

Phase separation forms membraneless compartments in the nuclei, including by establishing heterochromatin "domains" and repair foci. Pericentromeric heterochromatin mostly comprises repeated sequences prone to aberrant recombination, and "safe" homologous recombination (HR) repair of these sequences requires the movement of repair sites to the nuclear periphery before Rad51 recruitment and strand invasion. How this mobilization initiates is unknown, and the contribution of phase separation to these dynamics is unclear. Here, we show that Nup98 nucleoporin is recruited to heterochromatic repair sites before relocalization through Sec13 or Nup88 nucleoporins, and downstream from the Smc5/6 complex and SUMOylation. Remarkably, the phase separation properties of Nup98 are required and sufficient to mobilize repair sites and exclude Rad51, thus preventing aberrant recombination while promoting HR repair. Disrupting this pathway results in heterochromatin repair defects and widespread chromosome rearrangements, revealing a novel "off-pore" role for nucleoporins and phase separation in nuclear dynamics and genome integrity in a multicellular eukaryote.

NUP98-BPTF promotes oncogenic transformation through PIM1 upregulation.

INTRODUCTION: Nucleoporin 98 (NUP98) fusion proteins are recurrently found in leukemia and are associated with unfavorable clinical outcomes. They are distributed to the nucleus and contribute to leukemogenesis via aberrant transcriptional regulation. We previously identified NUP98-BPTF (NB) fusion in patients with T-cell acute lymphoblastic leukemia (T-ALL) using next-generation sequencing. The FG-repeat of NUP98 and the PHD finger and bromodomain of bromodomain PHD finger transcription factor (BPTF) are retained in the fusion. Like other NUP98 fusion proteins, NB is considered to regulate genes that are essential for leukemogenesis. However, its target genes or pathways remain unknown. MATERIALS AND METHODS: To investigate the potential oncogenic properties of the NB fusion protein, we lentivirally transduced a doxycycline-inducible NB expression vector into mouse NIH3T3 fibroblasts and human Jurkat T-ALL cells. RESULTS: NB promoted the transformation of mouse NIH3T3 fibroblasts by upregulating the proto-oncogene Pim1, which encodes a serine/threonine kinase. NB transcriptionally regulated Pim1 expression by binding to its promoter and activated MYC and mTORC1 signaling. PIM1 knockdown or pharmacological inhibition of mTORC1 signaling suppressed NB-induced NIH3T3 cell transformation. Furthermore, NB enhanced the survival of human Jurkat T-ALL cells by inactivating the pro-apoptotic protein BCL2-associated agonist of cell death (BAD). CONCLUSION: We demonstrated the pivotal role of NB in cell transformation and survival and identified PIM1as a key downstream target of NB. These findings propose a promising therapeutic strategy for patients with NB fusion-positive leukemia.

Nucleoporin Nup98 is an essential factor for ipo4 dependent protein import.

Nucleocytoplasmic transport of macromolecules is essential in eukaryotic cells. In this process, the karyopherins play a central role when they transport cargoes across the nuclear pore complex. Importin 4 belongs to the karyopherin ß family. Many studies have focused on finding substrates for importin 4, but no direct mechanism studies of its precise transport function have been reported. Therefore, this paper mainly aimed to study the mechanism of nucleoporins in mediating nuclear import and export of importin 4. To address this question, we constructed shRNAs targeting Nup358, Nup153, Nup98, and Nup50. We found that depletion of Nup98 resulted in a shift in the subcellular localization of importin 4 from the cytoplasm to the nucleus. Mutational analysis demonstrated that Nup98 physically and functionally interacts with importin 4 through its N-terminal phenylalanine-glycine (FG) repeat region. Mutation of nine of these FG motifs to SG motifs significantly attenuated the binding of Nup98 to importin 4, and we further confirmed the essential role of the six FG motifs in amino acids 121-360 of Nup98 in binding with importin 4. In vitro transport assay also confirmed that VDR, the substrate of importin 4, could not be transported into the nucleus after Nup98 knockdown. Overall, our results showed that Nup98 is required for efficient importin 4-mediated transport. This is the first study to reveal the mechanism of importin 4 in transporting substrates into the nucleus.

Acute onset of constrictive pericarditis due to acute myelomonocytic leukemia: A case and literature review.

We herein present a fatal case of constrictive pericarditis (CP) due to acute myelomonocytic leukemia (AMML) in a patient who initially complained of an acute onset of chest pain two days after COVID-19 vaccination. An autopsy revealed pericardial infiltration of leukemic cells. CP is rarely associated with leukemia and only 14 cases have been reported in the literature. The etiology of CP in previous reports included leukemic infiltration, graft-versus-host disease, drug-induced, post-radiation, autoimmune, and otherwise unidentified. This case indicates that leukemic infiltration can cause CP and that clinicians should include leukemia in the differential diagnosis of CP.

Rare NUP98::PRRX1 fusion transcript in a therapy-related acute myeloid leukemia associated with del(7q) following chemotherapy for diffuse large B-cell lymphoma.

BACKGROUND: Therapy-related acute myeloid leukemia (t-AML) is increasingly recognized as a treatment complication in patients receiving chemotherapy, radiotherapy, or immunosuppressive agents for primary neoplasms. NUP98::PRRX1 fusion gene, caused by t(1;11)(q23;p15), is a rare recurrent cytogenetic alteration in leukemia, and only seven cases with NUP98::PRRX1 were reported so far. METHODS: A 53-year-old female patient was diagnosed with t-AML after 20 months of complete remission (CR) from diffuse large B-cell lymphoma (DLBCL). Conventional karyotype, fluorescence in situ hybridization (FISH), and DNA/RNA next-generation sequence (NGS) were used to detect genetic abnormalities. RESULTS: Abnormal karyotype of 46, XX, t(1;11)(q25;p15), del(7)(q22) was revealed. NUP98 gene rearrangement and del(7)(q22) were verified by FISH. Further, RNA NGS detected NUP98::PRRX1 fusion transcript, and DNA NGS detected KRAS gene mutation. The patient achieved CR after a combined chemotherapy regimen containing BCL-2 inhibitor and underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), but she died of leukemia recurrence 14 months later. CONCLUSIONS: Novel targeted drugs may provide opportunities for patients with NUP98::PRRX1 to undergo allo-HSCT. However, since the cases of carrying the NUP98::PRRX1 are limited, more patients with this genetic change need to be investigated to elucidate the prognostic significance.

The nuclear pore protein NUP98 impedes LTR-driven basal gene expression of HIV-1, viral propagation, and infectivity.

Nucleoporins (NUPs) are cellular effectors of human immunodeficiency virus-1 (HIV-1) replication that support nucleocytoplasmic trafficking of viral components. However, these also non-canonically function as positive effectors, promoting proviral DNA integration into the host genome and viral gene transcription, or as negative effectors by associating with HIV-1 restriction factors, such as MX2, inhibiting the replication of HIV-1. Here, we investigated the regulatory role of NUP98 on HIV-1 as we observed a lowering of its endogenous levels upon HIV-1 infection in CD4+ T cells. Using complementary experiments in NUP98 overexpression and knockdown backgrounds, we deciphered that NUP98 negatively affected HIV-1 long terminal repeat (LTR) promoter activity and lowered released virus levels. The negative effect on promoter activity was independent of HIV-1 Tat, suggesting that NUP98 prevents the basal viral gene expression. ChIP-qPCR showed NUP98 to be associated with HIV-1 LTR, with the negative regulatory element (NRE) of HIV-1 LTR playing a dominant role in NUP98-mediated lowering of viral gene transcription. Truncated mutants of NUP98 showed that the attenuation of HIV-1 LTR-driven transcription is primarily contributed by its N-terminal region. Interestingly, the virus generated from the producer cells transiently expressing NUP98 showed lower infectivity, while the virus generated from NUP98 knockdown CD4+ T cells showed higher infectivity as assayed in TZM-bl cells, corroborating the anti-HIV-1 properties of NUP98. Collectively, we show a new non-canonical function of a nucleoporin adding to the list of moonlighting host factors regulating viral infections. Downregulation of NUP98 in a host cell upon HIV-1 infection supports the concept of evolutionary conflicts between viruses and host antiviral factors.

Clinical whole-genome sequencing and FISH identify two different fusion partners for NUP98 in a patient with acute myeloid leukemia: A case report.

BACKGROUND: Only rare cases of acute myeloid leukemia (AML) have been shown to harbor a t(8;11)(p11.2;p15.4). This translocation is believed to involve the fusion of NSD3 or FGFR1 with NUP98; however, apart from targeted mRNA quantitative PCR analysis, no molecular approaches have been utilized to define the chimeric fusions present in these rare cases. CASE PRESENTATION: Here we present the case of a 51-year-old female with AML with myelodysplastic-related morphologic changes, 13q deletion and t(8;11), where initial fluorescence in situ hybridization (FISH) assays were consistent with the presence of NUP98 and FGFR1 rearrangements, and suggestive of NUP98/FGFR1 fusion. Using a streamlined clinical whole-genome sequencing approach, we resolved the breakpoints of this translocation to intron 4 of NSD3 and intron 12 of NUP98, indicating NUP98/NSD3 rearrangement as the likely underlying aberration. Furthermore, our approach identified small variants in WT1 and STAG2, as well as an interstitial deletion on the short arm of chromosome 12, which were cryptic in G-banded chromosomes. CONCLUSIONS: NUP98 fusions in acute leukemia are predictive of poor prognosis. The associated fusion partner and the presence of co-occurring mutations, such as WT1, further refine this prognosis with potential clinical implications. Using a clinical whole-genome sequencing analysis, we resolved t(8;11) breakpoints to NSD3 and NUP98, ruling out the involvement of FGFR1 suggested by FISH while also identifying multiple chromosomal and sequence level aberrations.

Circ-NUP98 Promotes Lung Adenocarcinoma Development Through Regulating CBX1 by miR-188-3p.

Lung cancer has a high morbidity and mortality among malignant tumors, and lung adenocarcinoma (LUAD) is the main type of lung cancer. In recent years, circular RNAs (circRNAs) have been confirmed to play an important role in the generation and development of human cancer. However, the specific role and mechanism of circ-NUP98 in LUAD are still unclear and need to be further investigated. Circ-NUP98, microRNA-188-3p (miR-188-3p), and chromobox homolog 1 (CBX1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell-counting Kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, wound healing, and transwell assay were used to observe LUAD cell proliferation, apoptosis, migration, invasion, and cell-cycle progression. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were examined using special assay kits. CyclinD1, Bcl-2-related X protein (Bax), matrix metalloproteinase 9 (MMP9) protein, and CBX1 protein levels were determined using Western blot. The interaction between miR-188-3p and circ-NUP98 or CBX1 was identified by dual-luciferase reporter and RNA immunoprecipitation (RIP) assay. In vivo efficacy of circ-NUP98 was evaluated in a xenograft tumor model. Besides, the expression of CBX1 and KI67 in the tumors was detected by immunohistochemical (IHC) assay. Circ-NUP98 and CBX1 expressions were upregulated in LUAD tissues and cells, and miR-188-3p was decreased. Downregulation of circ-NUP98 could inhibit the proliferation, migration, invasion, and oxidative stress, and promote apoptosis of LUAD cells. Mechanism experiments showed that circ-NUP98 acted as a sponge for miR-188-3p to increase CBX1 expression. Knockdown of circ-NUP98 could inhibit the growth of LUAD tumors in vivo. Circ-NUP98 might promote the malignant development of LUAD via the miR-188-3p/CBX1 axis, which might provide a potential new marker for early diagnosis of LUAD.

Rare Ring Chromosome [r(15)]: Cytogenetic Abnormality in TP53-Mutated De Novo AML-M4 Masked as Gastrointestinal Bleed With Rapidly Progressing Hyperleukocytosis and Leukostasis.

TP53-mutated (TP53m) acute myeloid leukemia (AML) comprises only 5-15% of de novo AML, associated with poor survival outcomes due to its resistance to conventional therapy. Ring chromosomes, an even more rare subset of genetic anomalies, occur in only 2% of cases. We report a unique case of de novo AML with both TP53 and ring chromosome anomalies leading to a catastrophic outcome in a 72-year-old male who initially presented with gastrointestinal bleeding (GIB) and urethral stone status post-cystoscopy with J-stent placement. He had no history of chemotherapy use, radiation, benzene exposure, or any other risk factors except for his age. He was noted to have pancytopenia, for which bone marrow biopsy, flow cytometry, and cytogenetic studies were done. Biopsy reported an interesting next-generation sequenced TP53-mutated AML, which correlates with a low rate of response to standard chemotherapy except for bone marrow transplants. Notably, with a complex aberration of 45 XY with multiple translocations (t), deletions (del), inversions (inv), derivative (der) breakpoints, aneuploidy, and rare ring and maker chromosomes, his case was complicated with rapid-onset and very severe hyperleucostasis, reflecting the prognostic value of this rare cytogenetic configuration. The patient expired within 48 hours of diagnosis, despite the urgent initiation of cytoreductive therapy and the mitigation of tumor lysis syndrome with Rasburicase. To the best of our knowledge, this is one of the first AML-M4 patients with rapid-onset leucostasis and the demise of next-generation sequences (NGS) in a de Novo AML patient with this rare complex combination.

Virus Infection and mRNA Nuclear Export.

Gene expression in eukaryotes begins with transcription in the nucleus, followed by the synthesis of messenger RNA (mRNA), which is then exported to the cytoplasm for its translation into proteins. Along with transcription and translation, mRNA export through the nuclear pore complex (NPC) is an essential regulatory step in eukaryotic gene expression. Multiple factors regulate mRNA export and hence gene expression. Interestingly, proteins from certain types of viruses interact with these factors in infected cells, and such an interaction interferes with the mRNA export of the host cell in favor of viral RNA export. Thus, these viruses hijack the host mRNA nuclear export mechanism, leading to a reduction in host gene expression and the downregulation of immune/antiviral responses. On the other hand, the viral mRNAs successfully evade the host surveillance system and are efficiently exported from the nucleus to the cytoplasm for translation, which enables the continuation of the virus life cycle. Here, we present this review to summarize the mechanisms by which viruses suppress host mRNA nuclear export during infection, as well as the key strategies that viruses use to facilitate their mRNA nuclear export. These studies have revealed new potential antivirals that may be used to inhibit viral mRNA transport and enhance host mRNA nuclear export, thereby promoting host gene expression and immune responses.

Clinical implications of NUP98::NSD1 fusion at diagnosis in adult FLT3-ITD positive AML.

OBJECTIVES: The cryptic fusion oncogene NUP98::NSD1 is known to be associated with FLT3-ITD mutation in acute myeloid leukemia (AML), and an independent poor prognostic factor in pediatric AML. However, there are little data regarding the clinical significance of NUP98::NSD1 in adult cohort. METHODS: We conducted a multicenter retrospective study to investigate the prevalence, clinical characteristics, and prognostic impact of NUP98::NSD1 in adult FLT3-ITD-positive AML patients. RESULTS: In a total of 97 FLT3-ITD-positive AML patients, six cases (6.2%) were found to harbor the NUP98::NSD1 fusion transcript. NUP98::NSD1 positive cases had significantly higher platelet counts and a higher frequency of FAB-M4 morphology than NUP98::NSD1 negative cases. NUP98::NSD1 was found to be mutually exclusive with NPM1 mutation, and was accompanied by the WT1 mutation in three of the six cases. The presence of NUP98::NSD1 fusion at the time of diagnosis predicted poor response to cytarabine-anthracycline-based intensive induction chemotherapy (induction failure rate: 83% vs. 36%, p = .038). Five of the six cases with NUP98::NSD1 underwent allogeneic hematopoietic stem cell transplantation (HSCT). Two of the five cases have successfully maintained remission, with one of them being rescued through a second HSCT. CONCLUSIONS: Detecting NUP98::NSD1 in adult FLT3-ITD-positive AML is crucial to recognizing chemotherapy-resistant group.

Phase-separated nuclear bodies of nucleoporin fusions promote condensation of MLL1/CRM1 and rearrangement of 3D genome structure.

NUP98 and NUP214 form chimeric fusion proteins that assemble into phase-separated nuclear bodies containing CRM1, a nuclear export receptor. However, these nuclear bodies' function in controlling gene expression remains elusive. Here, we demonstrate that the nuclear bodies of NUP98::HOXA9 and SET::NUP214 promote the condensation of mixed lineage leukemia 1 (MLL1), a histone methyltransferase essential for the maintenance of HOX gene expression. These nuclear bodies are robustly associated with MLL1/CRM1 and co-localized on chromatin. Furthermore, whole-genome chromatin-conformation capture analysis reveals that NUP98::HOXA9 induces a drastic alteration in high-order genome structure at target regions concomitant with the generation of chromatin loops and/or rearrangement of topologically associating domains in a phase-separation-dependent manner. Collectively, these results show that the phase-separated nuclear bodies of nucleoporin fusion proteins can enhance the activation of target genes by promoting the condensation of MLL1/CRM1 and rearrangement of the 3D genome structure.

Acute myeloid leukemia with NUP98::RARG resembling acute promyelocytic leukemia accompanying ARID1B gene mutation.

In this study, we present a case of acute myeloid leukemia characterized by the t(11;12)(p15;q13) translocation, exhibiting clinical, immunophenotypical, and morphological features consistent with acute promyelocytic leukemia (APL). The RNA sequencing analysis of the patient's bone marrow samples revealed the presence of the NUP98-retinoic acid receptor gamma (RARG) (NUP98::RARG) gene resulting from the translocation. Furthermore, the presence of a mutation in the ARID1B gene in the patient under study indicates a potential association with resistance to all-trans retinoic acid (ATRA).

[Influence of siRNA complexes on the reproduction of influenza A virus (Orthomyxoviridae: Alphainfluenzavirus) in vivo].

INTRODUCTION: Influenza is one of the most pressing global health problems. Despite the wide range of available anti-influenza drugs, the viral drug resistance is an increasing concern and requires the search for new approaches to overcome it. A promising solution is the development of drugs with action that is based on the inhibition of the activity of cellular genes through RNA interference. AIM: Evaluation in vivo of the preventive potential of miRNAs directed to the cellular genes FLT4, Nup98 and Nup205 against influenza infection. MATERIALS AND METHODS: The A/California/7/09 strain of influenza virus (H1N1) and BALB/c mice were used in the study. The administration of siRNA and experimental infection of animals were performed intranasally. The results of the experiment were analyzed using molecular genetic and virological methods. RESULTS: The use of siRNA complexes Nup98.1 and Nup205.1 led to a significant decrease in viral reproduction and concentration of viral RNA on the 3rd day after infection. When two siRNA complexes (Nup98.1 and Nup205.1) were administered simultaneously, a significant decrease in viral titer and concentration of viral RNA was also noted compared with the control groups. CONCLUSIONS: The use of siRNAs in vivo can lead to an antiviral effect when the activity of single or several cellular genes is suppressed. The results indicate that the use of siRNAs targeting the cellular genes whose expression products are involved in viral reproduction is one of the promising methods for the prevention and treatment of not only influenza, but also other respiratory infections.

The Nup98::Nsd1 fusion gene induces CD123 expression in 32D cells.

The NUP98::NSD1 fusion gene is associated with extremely poor prognosis in patients with acute myeloid leukemia (AML). NUP98::NSD1 induces self-renewal and blocks differentiation of hematopoietic stem cells, leading to development of leukemia. Despite its association with poor prognosis, targeted therapy for NUP98::NSD1-positive AML is lacking, as the details of NUP98::NSD1 function are unknown. Here, we generated 32D cells (a murine interleukin-3 (IL-3)-dependent myeloid progenitor cell line) expressing mouse Nup98::Nsd1 to explore the function of NUP98::NSD1 in AML, including comprehensive gene expression analysis. We identified two properties of Nup98::Nsd1 + 32D cells in vitro. First, Nup98::Nsd1 promoted blocking of AML cell differentiation, consistent with a previous report. Second, Nup98::Nsd1 increased dependence on IL-3 for cell proliferation, due to overexpression of the alpha subunit of the IL-3 receptor (IL3-RA, also known as CD123). Consistent with our in vitro data, IL3-RA was also upregulated in samples from patients with NUP98::NSD1-positive AML. These results highlight CD123 as a potential new therapeutic target in NUP98::NSD1-positive AML.