Plasmacytoid Dendritic Cells and Type I Interferon Promote Extrafollicular B Cell Responses to Extracellular Self-DNA.

Class-switched antibodies to double-stranded DNA (dsDNA) are prevalent and pathogenic in systemic lupus erythematosus (SLE), yet mechanisms of their development remain poorly understood. Humans and mice lacking secreted DNase DNASE1L3 develop rapid anti-dsDNA antibody responses and SLE-like disease. We report that anti-DNA responses in Dnase1l3-/- mice require CD40L-mediated T cell help, but proceed independently of germinal center formation via short-lived antibody-forming cells (AFCs) localized to extrafollicular regions. Type I interferon (IFN-I) signaling and IFN-I-producing plasmacytoid dendritic cells (pDCs) facilitate the differentiation of DNA-reactive AFCs in vivo and in vitro and are required for downstream manifestations of autoimmunity. Moreover, the endosomal DNA sensor TLR9 promotes anti-dsDNA responses and SLE-like disease in Dnase1l3-/- mice redundantly with another nucleic acid-sensing receptor, TLR7. These results establish extrafollicular B cell differentiation into short-lived AFCs as a key mechanism of anti-DNA autoreactivity and reveal a major contribution of pDCs, endosomal Toll-like receptors (TLRs), and IFN-I to this pathway.

The deficiency of DNASE1L3 does not affect systemic sclerosis pathogenesis in two inducible murine models of the disease.

We induced systemic sclerosis (SSc)-like disease in both wild-type and Dnase1l3-deficient mice using two distinct approaches involving bleomycin and hypochlorous acid injections. Our observations revealed that the deficiency in DNASE1L3 did not affect tissue fibrosis or inflammation caused by these treatments. Despite the association of single nucleotide polymorphisms in humans with SSc pathogenesis, our study demonstrates that DNASE1L3 is dispensable in two inducible murine models of SSc-like pathogenesis.

The Nexus of cfDNA and Nuclease Biology.

Cell-free DNA (cfDNA) is a widely used noninvasive biomarker for diagnosis and prognosis of multiple disease states. Emerging evidence suggests that cfDNA might not just be passive waste products of cell death but could have a physiological and pathological function in inflammation and autoimmunity. The balance of cfDNA generation and clearance may thus be vital in health and disease. In particular, plasma nuclease activity has been linked to multiple pathologies including cancer and systemic lupus erythematosus (SLE) and associated with profound changes in the nonrandom fragmentation of cfDNA. Lastly, in this review, we explore the effects of DNA fragmentation factor B (DFFB), DNASE1L3, and DNASE1 on cfDNA levels and their fragmentomic profiles, and what these recent insights reveal about the biology of cfDNA.

Lupus Nephritis Patterns and Response to Type I Interferon in Patients With DNASE1L3 Mutations: Report of Three Cases.

DNASE1L3 is an extracellular nuclease that digests chromatin released from apoptotic cells. DNASE1L3 mutations impair the enzyme function, enhance autoantibody production and type I interferon (IFN-I) responses, and cause different autosomal recessive phenotypes ranging from hypocomplementemic urticarial vasculitis syndrome to full-blown systemic lupus erythematosus (SLE). Kidney involvement in patients with DNASE1L3 mutations is poorly characterised. Herein, we describe the clinical course of three children with monogenic SLE due to DNASE1L3 mutations who developed refractory glomerulonephritis leading to kidney failure. They had different renal histopathological patterns (i.e., membranous, endo- and extra-capillary glomerulonephritis and thrombotic microangiopathy), all belonging to the lupus nephritis (LN) spectrum. One patient had a mixed phenotype, showing an overlap between SLE and ANCA-associated vasculitis. Using immunofluorescence, we detected glomerular expression of the IFN I-induced human myxovirus resistance protein 1 (MXA), which was particularly evident in glomerular endothelial cells. 2/3 patients had increased expression of interferon-stimulated genes in the peripheral blood and all three patients had reduced serum DNAse activity. Our findings suggest that DNASE1L3-related glomerulonephritis can be included in the spectrum of IFN I-mediated kidney disorders, and provide the rationale for IFN I-directed therapies in order to improve the poor outcome of this rare condition.

Deoxyribonuclease 1-like 3 inhibits colorectal malignancy through antagonizing NEDD4-triggered CDKN1A ubiquitination.

Deoxyribonuclease 1-like 3 (DNASE1L3) has been shown to play nonnegligible roles in several types of carcinomas. Nevertheless, the biological function, clinical relevance, and influence of DNASE1L3 in colorectal cancer (CRC) remain obscure. Immunohistochemistry was adopted to examine DNASE1L3 and CDKN1A expression in CRC tissue, and the clinical significance of DNASE1L3 was assessed. Cell counting kit-8, colony formation, and transwell assays were employed for assessing tumor proliferation and migration. The mechanisms underlying the impact of DNASE1L3 were explored via western blot analysis, co-immunoprecipitation, and ubiquitination assay. It was observed that DNASE1L3 was downregulated in CRC tissues and was tightly associated with patient prognosis. DNASE1L3 impaired CRC cell proliferation and migration through elevating CDKN1A via suppressing CDKN1A ubiquitination. Meanwhile, DNASE1L3 was positively related to CDKN1A. In mechanism, DNASE1L3 and CDKN1A interacted with the E3 ubiquitin ligase NEDD4. Moreover, DNASE1L3 was competitively bound to NEDD4, thus repressing NEDD4-mediated CDKN1A ubiquitination and degradation. These discoveries implied the potential mechanisms of DNASE1L3 during tumorigenesis, suggesting that DNASE1L3 may serve as a new potential therapeutic agent for CRC.

The Biology of Cell-free DNA Fragmentation and the Roles of DNASE1, DNASE1L3, and DFFB.

Cell-free DNA (cf.DNA) is a powerful noninvasive biomarker for cancer and prenatal testing, and it circulates in plasma as short fragments. To elucidate the biology of cf.DNA fragmentation, we explored the roles of deoxyribonuclease 1 (DNASE1), deoxyribonuclease 1 like 3 (DNASE1L3), and DNA fragmentation factor subunit beta (DFFB) with mice deficient in each of these nucleases. By analyzing the ends of cf.DNA fragments in each type of nuclease-deficient mice with those in wild-type mice, we show that each nuclease has a specific cutting preference that reveals the stepwise process of cf.DNA fragmentation. Essentially, we demonstrate that cf.DNA is generated first intracellularly with DFFB, intracellular DNASE1L3, and other nucleases. Then, cf.DNA fragmentation continues extracellularly with circulating DNASE1L3 and DNASE1. With the use of heparin to disrupt the nucleosomal structure, we also show that the 10 bp periodicity originates from the cutting of DNA within an intact nucleosomal structure. Altogether, this work establishes a model of cf.DNA fragmentation.

Reduced digestion of circulating genomic DNA in systemic sclerosis patients with the DNASE1L3 R206C variant.

OBJECTIVES: Polymorphism in a coding region of deoxyribonuclease I-like III (DNASE1L3), causing amino acid substitution of Arg-206 to Cys (R206C), is a robustly replicated heritable risk factor for SSc and other autoimmune diseases. DNASE1L3 is secreted into the circulation, where it can digest genomic DNA (gDNA) in apoptosis-derived membrane vesicles (AdMVs). We sought to determine the impact of DNASE1L3 R206C on digestion of circulating gDNA in SSc patients and healthy controls (HCs). METHODS: The ability of DNASE1L3 to digest AdMV-associated gDNA was tested in vitro. The effect of R206C substitution on extracellular secretion of DNASE1L3 was determined using a transfected cell line and primary monocyte-derived dendritic cells from SSc patients. Plasma samples from SSc patients and HCs with DNASE1L3 R206C or R206 wild type were compared for their ability to digest AdMV-associated gDNA. The digestion status of endogenous gDNA in plasma samples from 123 SSc patients and 74 HCs was determined by measuring the proportion of relatively long to short gDNA fragments. RESULTS: The unique ability of DNASE1L3 to digest AdMV-associated gDNA was confirmed. Extracellular secretion of DNASE1L3 R206C was impaired. Plasma from individuals with DNASE1L3 R206C had reduced ability to digest AdMV-associated gDNA. The ratio of long: short gDNA fragments was increased in plasma from SSc patients with DNASE1L3 R206C, and this ratio correlated inversely with DNase activity. CONCLUSION: Our results confirm that circulating gDNA is a physiological DNASE1L3 substrate and show that its digestion is reduced in SSc patients with the DNASE1L3 R206C variant.

DNASE1L3 deficiency, new phenotypes, and evidence for a transient type I IFN signaling.

BACKGROUND: Deoxyribonuclease 1 like 3 (DNASE1L3) is a secreted enzyme that has been shown to digest the extracellular chromatin derived from apoptotic bodies, and DNASE1L3 pathogenic variants have been associated with a lupus phenotype. It is unclear whether interferon signaling is sustained in DNASE1L3 deficiency in humans. OBJECTIVES: To explore interferon signaling in DNASE1L3 deficient patients. To depict the characteristic features of DNASE1L3 deficiencies in human. METHODS: We identified, characterized, and analyzed five new patients carrying biallelic DNASE1L3 variations. Whole or targeted exome and/or Sanger sequencing was performed to detect pathogenic variations in five juvenile systemic erythematosus lupus (jSLE) patients. We measured interferon-stimulated gene (ISG) expression in all patients. We performed a systematic review of all published cases available from its first description in 2011 to March 24th 2022. RESULTS: We identified five new patients carrying biallelic DNASE1L3 pathogenic variations, including three previously unreported mutations. Contrary to canonical type I interferonopathies, we noticed a transient increase of ISGs in blood, which returned to normal with disease remission. Disease in one patient was characterized by lupus nephritis and skin lesions, while four others exhibited hypocomplementemic urticarial vasculitis syndrome. The fourth patient presented also with early-onset inflammatory bowel disease. Reviewing previous reports, we identified 35 additional patients with DNASE1L3 deficiency which was associated with a significant risk of lupus nephritis and a poor outcome together with the presence of anti-neutrophil cytoplasmic antibodies (ANCA). Lung lesions were reported in 6/35 patients. CONCLUSIONS: DNASE1L3 deficiencies are associated with a broad phenotype including frequently lupus nephritis and hypocomplementemic urticarial vasculitis with positive ANCA and rarely, alveolar hemorrhages and inflammatory bowel disease. This report shows that interferon production is transient contrary to anomalies of intracellular DNA sensing and signaling observed in Aicardi-Goutières syndrome or STING-associated vasculitis in infancy (SAVI).

Jagged Ends on Multinucleosomal Cell-Free DNA Serve as a Biomarker for Nuclease Activity and Systemic Lupus Erythematosus.

BACKGROUND: Jagged ends of plasma DNA are a recently recognized class of fragmentomic markers for cell-free DNA, reflecting the activity of nucleases. A number of recent studies have also highlighted the importance of jagged ends in the context of pregnancy and oncology. However, knowledge regarding the generation of jagged ends is incomplete. METHODS: Jaggedness of plasma DNA was analyzed based on Jag-seq, which utilized the differential methylation signals introduced by the DNA end-repair process. We investigated the jagged ends in plasma DNA using mouse models by deleting the deoxyribonuclease 1 (Dnase1), DNA fragmentation factor subunit beta (Dffb), or deoxyribonuclease 1 like 3 (Dnase1l3) gene. RESULTS: Aberrations in the profile of plasma DNA jagged ends correlated with the type of nuclease that had been genetically deleted, depending on nucleosomal structures. The deletion of Dnase1l3 led to a significant reduction of jaggedness for those plasma DNA molecules involving more than 1 nucleosome (e.g., size ranges 240-290 bp, 330-380 bp, and 420-470 bp). However, less significant effects of Dnase1 and Dffb deletions were observed regarding different sizes of DNA fragments. Interestingly, the aberration in plasma DNA jagged ends related to multinucleosomes was observed in human subjects with familial systemic lupus erythematosus with Dnase1l3 deficiency and human subjects with sporadic systemic lupus erythematosus. CONCLUSIONS: Detailed understanding of the relationship between nuclease and plasma DNA jaggedness has opened up avenues for biomarker development.

Cell-free DNA in blood circulation is generated by DNase1L3 and caspase-activated DNase.

Cell-free DNA (cfDNA) (e.g. fetal- or tumor-derived DNA) is DNA found in the blood circulation. It is now widely investigated as a biomarker for prenatal screening, tumor diagnosis, and tumor monitoring as "liquid biopsies". However, the biological and biochemical aspects of cfDNA remain unclear. Although cfDNA is considered to be mainly derived from dead cells, information is scarce as to whether it is apoptotic or necrotic and what kinds of endonucleases or DNases are involved. We induced in vivo hepatocyte necrosis and apoptosis in mice deficient in DNase1L3 (also named DNase γ) and/or caspase-activated DNase (CAD) genes with acetaminophen overdose and anti-Fas antibody treatments. We found that (i) DNase1L3 was the endonuclease responsible for generating cfDNA in acetaminophen-induced hepatocyte necrosis and (ii) CAD and DNase1L3 cooperated in producing cfDNA for anti-Fas mediated hepatocyte apoptosis.

An autosomal recessive DNASE1L3-related autoimmune disease with unusual clinical presentation mimicking systemic lupus erythematosus.

We describe the third family in the world, after Arabian and Turkish ones, displaying an autosomal recessive autoimmune disease (AID), mimicking systemic lupus erythematosus (SLE), with unusual manifestations due to a homozygous frame-shift variant in DNASE1L3. SLE is a complex AID characterized by multiple organ involvement. Genetic risk variants identified account for only 15% of SLE heritability. Rare Mendelian forms have been reported, including DNASE1L3-related SLE. Through specific genetic tests we identified a homozygous 2 bp-deletion c.289_290delAC (NM_004944.2) in DNASE1L3, predicting frameshift and premature truncation (p.Thr97Ilefs*2). The same mutation was previously reported in three sisters, born from consanguineous parents and affected with hypocomplementemic urticarial vasculitis syndrome (HUVS). As approximately 50% of individuals affected with HUVS develop SLE, it is still unclear whether it is a SLE sub-phenotype or a separate condition.

Neutrophil Extracellular Traps: A Crucial Factor in Post-Surgical Abdominal Adhesion Formation.

Post-surgical abdominal adhesions, although poorly understood, are highly prevalent. The molecular processes underlying their formation remain elusive. This review aims to assess the relationship between neutrophil extracellular traps (NETs) and the generation of postoperative peritoneal adhesions and to discuss methods for mitigating peritoneal adhesions. A keyword or medical subject heading (MeSH) search for all original articles and reviews was performed in PubMed and Google Scholar. It included studies assessing peritoneal adhesion reformation after abdominal surgery from 2003 to 2023. After assessing for eligibility, the selected articles were evaluated using the Critical Appraisal Skills Programme checklist for qualitative research. The search yielded 127 full-text articles for assessment of eligibility, of which 7 studies met our criteria and were subjected to a detailed quality review using the Critical Appraisal Skills Programme (CASP) checklist. The selected studies offer a comprehensive analysis of adhesion pathogenesis with a special focus on the role of neutrophil extracellular traps (NETs) in the development of peritoneal adhesions. Current interventional strategies are examined, including the use of mechanical barriers, advances in regenerative medicine, and targeted molecular therapies. In particular, this review emphasizes the potential of NET-targeted interventions as promising strategies to mitigate postoperative adhesion development. Evidence suggests that in addition to their role in innate defense against infections and autoimmune diseases, NETs also play a crucial role in the formation of peritoneal adhesions after surgery. Therefore, therapeutic strategies that target NETs are emerging as significant considerations for researchers. Continued research is vital to fully elucidate the relationship between NETs and post-surgical adhesion formation to develop effective treatments.

Deficiency of macrophage-derived Dnase1L3 causes lupus-like phenotypes in mice.

Systemic lupus erythematosus (SLE) is an autoimmune disease caused by environmental factors and loss of key proteins, including the endonuclease Dnase1L3. Dnase1L3 absence causes pediatric-onset lupus in humans, while reduced activity occurs in adult-onset SLE. The amount of Dnase1L3 that prevents lupus remains unknown. To genetically reduce Dnase1L3 levels, we developed a mouse model lacking Dnase1L3 in macrophages (conditional knockout [cKO]). Serum Dnase1L3 levels were reduced 67%, though Dnase1 activity remained constant. Homogeneous and peripheral antinuclear antibodies were detected in the sera by immunofluorescence, consistent with anti-double-stranded DNA (anti-dsDNA) antibodies. Total immunoglobulin M, total immunoglobulin G, and anti-dsDNA antibody levels increased in cKO mice with age. The cKO mice developed anti-Dnase1L3 antibodies. In contrast to global Dnase1L3-/- mice, anti-dsDNA antibodies were not elevated early in life. The cKO mice had minimal kidney pathology. Therefore, we conclude that an intermediate reduction in serum Dnase1L3 causes mild lupus phenotypes, and macrophage-derived DnaselL3 helps limit lupus.

Systemic Lupus Erythematosus Patients with DNASE1L3·Deficiency Have a Distinctive and Specific Genic Circular DNA Profile in Plasma.

Cell-free (cf) extrachromosomal circular DNA (eccDNA) has a potential clinical application as a biomarker. Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with a complex immunological pathogenesis, associated with autoantibody synthesis. A previous study found that SLE patients with deoxyribonuclease 1-like 3 (DNASE1L3) deficiency exhibit changes in the frequency of short and long eccDNA in plasma compared to controls. Here, using the DifCir method for differential analysis of short-read sequenced purified eccDNA data based on the split-read signal of the eccDNA on circulomics data, we show that SLE patients with DNASE1L3 deficiency have a distinctive profile of eccDNA excised by gene regions compared to controls. Moreover, this profile is specific; cf-eccDNA from the top 93 genes is detected in all SLE with DNASE1L3 deficiency samples, and none in the control plasma. The top protein coding gene producing eccDNA-carrying gene fragments is the transcription factor BARX2, which is involved in skeletal muscle morphogenesis and connective tissue development. The top gene ontology terms are 'positive regulation of torc1 signaling' and 'chondrocyte development'. The top Harmonizome terms are 'lymphopenia', 'metabolic syndrome x', 'asthma', 'cardiovascular system disease', 'leukemia', and 'immune system disease'. Here, we show that gene associations of cf-eccDNA can serve as a biomarker in the autoimmune rheumatic diseases.

Integrative analysis of deoxyribonuclease 1-like 3 as a potential biomarker in renal cell carcinoma.

Background: Clear cell renal cell carcinoma (ccRCC), the most common subtype of renal cell carcinoma (RCC), is insensitive to radiotherapy and chemotherapy after surgery. Deoxyribonuclease 1-like 3 (DNASE1L3), an endonuclease that cleaves both membrane-encapsulated single- and double-stranded DNA, suppresses cell cycle progression, proliferation and metabolism in hepatocellular carcinoma cells. There is currently no established link between DNASE1L3 and RCC inhibition. We are gonging to explored the mechanism underlying the relationship between DNASEL1L3 and RCC. Methods: RNA sequencing data for RCC tissue and peritumoral tissue were downloaded from The Cancer Genome Atlas database and analyzed. The expression levels of DNASE1L3 in RCC and normal samples were verified using the Gene Expression Omnibus (GEO) database, Human Protein Atlas database and western blotting. The role and potential mechanism of DNASE1L3 were investigated by analysis of immune-related databases and wound healing, invasion, cell counting kit 8 and immunofluorescence assays. Results: We revealed that DNASE1L3 expression was downregulated in RCC group compared with control group [The Cancer Genome Atlas (TCGA): 7.98 vs. 10.87, P<0.001]. Meanwhile, DNASE1L3 expression correlated with the clinical characteristics of patients. Patients with low DNASE1L3 expression had worse survival (P<0.001) and larger (r=-0.32, P<0.001) and heavier tumors (r=-0.17, P<0.001). DNASE1L3 overexpression inhibited the proliferation (786-O: 0.135±0.014 vs. 0.322±0.027, P<0.001) and invasion (786-O: 1,479±134 vs. 832±67, P<0.05) of RCC cells. The expression of DNASE1L3 was significantly correlated with the tumor immune microenvironment and drug sensitivity in ccRCC. Moreover, the level of the key phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway protein P-AKT was decreased in the group of cells transfected with DNASE1L3. Conclusions: This study strongly suggest that DNASE1L3 may be a promising potential biomarker for the diagnosis and treatment of ccRCC patients.

Cell-Free Genic Extrachromosomal Circular DNA Profiles of DNase Knockouts Associated with Systemic Lupus Erythematosus and Relation with Common Fragile Sites.

Cell-free extrachromosomal circular DNA (cf-eccDNA) has been proposed as a promising early biomarker for disease diagnosis, progression and drug response. Its established biomarker features are changes in the number and length distribution of cf-eccDNA. Another novel promising biomarker is a set of eccDNA excised from a panel of genes specific to a condition compared to a control. Deficiencies in two endonucleases that specifically target DNA, Dnase1 and Dnase1l3, are associated with systemic lupus erythematosus (SLE). To study the genic eccDNA profiles in the case of their deficiencies, we mapped sequenced eccDNA data from plasma, liver and buffy coat from Dnase1 and Dnase1l3 knockouts (KOs), and wild type controls in mouse. Next, we performed an eccDNA differential analysis between KO and control groups using our DifCir algorithm. We found a specific genic cf-eccDNA fingerprint of the Dnase1l3 group compared to the wild type controls involving 131 genes; 26% of them were associated with human chromosomal fragile sites (CFSs) and with a statistically significant enrichment of CFS-associated genes. We found six genes in common with the genic cf-eccDNA profile of SLE patients with DNASE1L3 deficiency, namely Rorb, Mvb12b, Osbpl10, Fto, Tnik and Arhgap10; all of them were specific and present in all human plasma samples, and none of them were associated with CFSs. A not so distinctive genic cf-eccDNA difference involving only seven genes was observed in the case of the Dnase1 group compared to the wild type. In tissue-liver and buffy coat-we did not detect the same genic eccDNA difference observed in the plasma samples. These results point to a specific role of a set of genic eccDNA in plasma from DNase KOs, as well as a relation with CFS genes, confirming the promise of the genic cf-eccDNA in studying diseases and the need for further research on the relationship between eccDNA and CFSs.

DNASE1L3 inhibits hepatocellular carcinoma by delaying cell cycle progression through CDK2.

PURPOSE: Dysregulated cell cycle targeting is a well-established therapeutic strategy against hepatocellular carcinoma (HCC). Dissecting the underlying mechanism may improve the efficacy of HCC therapy. METHODS: HCC data from TCGA and new clinical samples were used for DNASE1L3 expression analysis and for assessing its correlation with HCC development. The in vitro function of DNASE1L3 in HCC cell proliferation, colony formation, migration and invasion was assessed using RTCA, CCK-8 and transwell assays and the in vivo function in subcutaneous tumor formation in a xenograft nude mouse model. The role of DNASE1L3 in HCC tumorigenesis was further verified in AKT/NRASV12-induced and DEN/CCl4-induced primary liver cancers in wildtype and Dnase1l3-/- mice. Finally, RNA-Seq analysis followed by biochemical methods including cell cycle, immunofluorescence, co-immunoprecipitation and Western blotting assays were employed to reveal the underlying mechanism. RESULTS: We found that DNASE1L3 was significantly downregulated and served as a favorable prognostic factor in HCC. DNASE1L3 dramatically attenuated HCC cell proliferation, colony formation, migration and invasion in vitro and reduced subcutaneous tumor formation in nude mice in vivo. Furthermore, DNASE1L3 overexpression dampened AKT/NRASV12-induced mouse liver cancer in wildtype mice and DNASE1L3 deficiency worsened DEN/CCl4-induced liver cancer in Dnase1l3-/- mice. Systemic analysis revealed that DNASE1L3 impaired HCC cell cycle progression by interacting with CDK2 and inhibiting CDK2-stimulated E2F1 activity. C-terminal deletion (DNASE1L3ΔCT) diminished the interaction with CDK2 and abrogated the inhibitory function against HCC. CONCLUSION: Our study unveils DNASE1L3 as a novel HCC cell cycle regulator and tumor suppressor. DNASE1L3 impairs HCC tumorigenesis by delaying cell cycle progression possibly through disrupting the positive E2F1-CDK2 regulatory loop. DNASE1L3 may serve as a target for the development of novel therapeutic strategies against HCC.

Deoxyribonuclease 1-like 3 Inhibits Hepatocellular Carcinoma Progression by Inducing Apoptosis and Reprogramming Glucose Metabolism.

HCC has remained one of the challenging cancers to treat, owing to the paucity of drugs targeting the critical survival pathways. Considering the cancer cells are deficient in DNase activity, the increase of an autonomous apoptisis endonuclease should be a reasonable choice for cancer treatment. In this study, we investigated whether DNASE1L3, an endonuclease implicated in apoptosis, could inhibit the progress of HCC. We found DNASE1L3 was down-regulated in HCC tissues, whereas its high expression was positively associated with the favorable prognosis of patients with HCC. Besides, serum DNASE1L3 levels were lower in HCC patients than in healthy individuals. Functionally, we found that DNASE1L3 inhibited the proliferation of tumor cells by inducing G0/G1 cell cycle arrest and cell apoptosis in vitro. Additionally, DNASE1L3 overexpression suppressed tumor growth in vivo. Furthermore, we found that DNASE1L3 overexpression weakened glycolysis in HCC cells and tissues via inactivating the rate-limiting enzymes involved in PTPN2-HK2 and CEBPß-p53-PFK1 pathways. Finally, we identified the HBx to inhibit DNASE1L3 expression by up-regulating the expression of ZNF384. Collectively, our findings demonstrated that DNASE1L3 could inhibit the HCC progression through inducing cell apoptosis and weakening glycolysis. We believe DNASE1L3 could be considered as a promising prognostic biomarker and therapeutic target for HCC.

DNASE1L3 arrests tumor angiogenesis by impairing the senescence-associated secretory phenotype in response to stress.

Hepatocellular carcinoma (HCC) is one of the most challenging and aggressive cancers with limited treatment options because of tumor heterogeneity. Tumor angiogenesis is a hallmark of HCC and is necessary for tumor growth and progression. DNA damage stress and its associated deoxyribonuclease1-like 3 (DNASE1L3) are involved in HCC progression. Here, we explored the influence mechanism of DNASE1L3 on tumor angiogenesis under DNA damage stress in vitro and in vivo. DNASE1L3 was found downregulated and negatively correlated with poor prognosis of resectable and unresectable HCC patients. The tissue microarray of HCC revealed the negative association between DNASE1L3 and cancer vasculature invasion. Mechanistically, DNASE1L3 was found to relieve cytoplasmic DNA accumulation under DNA damage stress in HCC cell lines, in turn cell senescence and senescence-associated secretory phenotype were arrested via the p53 and NF-κB signal pathway, and hence, tumor angiogenesis was impaired. Furthermore, we found that DNASE1L3 excised these functions by translocating to the nucleus and interacting with H2BE under DNA damage stress using co-immunoprecipitation and fluorescence resonance energy transfer assay. In conclusion, DNASE1L3 inhibits tumor angiogenesis via impairing the senescence-associated secretory phenotype in response to DNA damage stress.