The phenotypic and functional plasticity of adipose tissue macrophages during obesity play a crucial role in orchestration of adipose and systemic inflammation. Tonicity-responsive enhancer-binding protein (TonEBP, also called NFAT5) is a stress protein that mediates cellular responses to a range of metabolic insults. Here, we show that myeloid cell-specific TonEBP depletion reduced inflammation and insulin resistance in mice with high-fat diet-induced obesity, but did not affect adiposity. This phenotype was associated with a reduced accumulation and a reduced pro-inflammatory phenotype of metabolically activated macrophages; decreased expression of inflammatory factors related to insulin resistance; and enhanced insulin sensitivity. TonEBP expression was elevated in the adipose tissue macrophages of obese mice, and Sp1 was identified as a central regulator of TonEBP induction. TonEBP depletion in macrophages decreased induction of insulin resistance-related genes and promoted induction of insulin sensitivity-related genes under obesity-mimicking conditions, and thereby improved insulin signaling and glucose uptake in adipocytes. mRNA expression of TonEBP in peripheral blood mononuclear cells was positively correlated with blood glucose levels in mice and humans. These findings suggest that TonEBP in macrophages promotes obesity-associated systemic insulin resistance and inflammation, and downregulation of TonEBP may induce a healthy metabolic state during obesity.

Lack of coordination between the DNA replication and transcription machineries can increase the frequency of transcription-replication conflicts, leading ultimately to DNA damage and genomic instability. A major source of these conflicts is the formation of R-loops, which consist of a transcriptionally generated RNA-DNA hybrid and the displaced single-stranded DNA. R-loops play important physiological roles and have been implicated in human diseases. Although these structures have been extensively studied, many aspects of R-loop biology and R-loop-mediated genome instability remain unclear. We found that in cancer cells, tonicity-responsive enhancer-binding protein (TonEBP, also called NFAT5) interacted with PARP1 and localized to R-loops in response to DNA-damaging agent camptothecin (CPT), which is associated with R-loop formation. PARP1-mediated PARylation was required for recruitment of TonEBP to the sites of R-loop-associated DNA damage. Loss of TonEBP increased levels of R-loop accumulation and DNA damage, and promoted cell death in response to CPT. These findings suggest that TonEBP mediates resistance to CPT-induced cell death by preventing R-loop accumulation in cancer cells.

Abstract R-loops are three-stranded, RNA–DNA hybrid, nucleic acid structures produced due to inappropriate processing of newly transcribed RNA or transcription-replication collision (TRC). Although R-loops are important for many cellular processes, their accumulation causes genomic instability and malignant diseases, so these structures are tightly regulated. It was recently reported that R-loop accumulation is resolved by methyltransferase-like 3 (METTL3)-mediated m6A RNA methylation under physiological conditions. However, it remains unclear how R-loops in the genome are recognized and induce resolution signals. Here, we demonstrate that tonicity-responsive enhancer binding protein (TonEBP) recognizes R-loops generated by DNA damaging agents such as ultraviolet (UV) or camptothecin (CPT). Single-molecule imaging and biochemical assays reveal that TonEBP preferentially binds a R-loop via both 3D collision and 1D diffusion along DNA in vitro. In addition, we find that TonEBP recruits METTL3 to R-loops through the Rel homology domain (RHD) for m6A RNA methylation. We also show that TonEBP recruits RNaseH1 to R-loops through a METTL3 interaction. Consistent with this, TonEBP or METTL3 depletion increases R-loops and reduces cell survival in the presence of UV or CPT. Collectively, our results reveal an R-loop resolution pathway by TonEBP and m6A RNA methylation by METTL3 and provide new insights into R-loop resolution processes.

BackgroundHigh recurrence and chemoresistance drive the high mortality in hepatocellular carcinoma (HCC). Although cancer stem cells are considered to be the source of recurrent and chemoresistant tumors, they remain poorly defined in HCC. Tonicity-responsive enhancer binding protein (TonEBP) is elevated in almost all HCC tumors and associated with recurrence and death. We aimed to identify function of TonEBP in stemness and chemoresistance of liver cancer.MethodsTumors obtained from 280 HCC patients were analyzed by immunohistochemical analyses. Stemness and chemoresistance of liver CSCs (LCSCs) were investigated using cell culture. Tumor-initiating activity was measured by implanting LCSCs into BALB/c nude mice.FindingsExpression of TonEBP is higher in LCSCs in HCC cell lines and correlated with markers of LCSCs whose expression is significantly associated with poor prognosis of HCC patients. TonEBP mediates ATM-mediated activation of NF-κB, which stimulates the promoter of a key stem cell transcription factor SOX2. As expected, TonEBP is required for the tumorigenesis and self-renewal of LSCSs. Cisplatin induces the recruitment of the ERCC1/XPF dimer to the chromatin in a TonEBP-dependent manner leading to DNA repair and cisplatin resistance. The cisplatin-induced inflammation in LSCSs is also dependent on the TonEBP-ERCC1/XPF complex, and leads to enhanced stemness via the ATM-NF-κB-SOX2 pathway. In HCC patients, tumor expression of ERCC1/XPF predicts recurrence and death in a TonEBP-dependent manner.InterpretationTonEBP promotes stemness and cisplatin resistance of HCC via ATM-NF-κB. TonEBP is a key regulator of LCSCs and a promising therapeutic target for HCC and its recurrence.

Dendritic cells (DCs) are potent antigen-presenting cells that link the innate and adaptive immune responses; as such they play pivotal roles in initiation and progression of rheumatoid arthritis (RA). Here, we report that the tonicity-responsive enhancer-binding protein (TonEBP or NFAT5), a Rel family protein involved in the pathogenesis of autoimmune disease and inflammation, is required for maturation and function of DCs. Myeloid cell-specific TonEBP deletion reduces disease severity in a murine model of collagen-induced arthritis; it also inhibits maturation of DCs and differentiation of pathogenic Th1 and Th17 cells in vivo. Upon stimulation by TLR4, TonEBP promotes surface expression of major histocompatibility complex class II and co-stimulatory molecules via p38 mitogen-activated protein kinase. This is followed by DC-mediated differentiation of pro-inflammatory Th1 and Th17 cells. Taken together, these findings provide mechanistic basis for the pathogenic role of TonEBP in RA and possibly other autoimmune diseases.

TonEBP is a key transcriptional activator in macrophages with an M1 phenotype. High expression of TonEBP is associated with many inflammatory diseases. Heme oxygenase-1 (HO-1), a stress-inducible protein, is induced by various oxidative and inflammatory signals, and its expression is regarded as an adaptive cellular response to inflammation and oxidative injury. Here, we show that TonEBP suppresses expression of HO-1 by blocking Nrf2 binding to the HO-1 promoter, thereby inducing polarization of macrophages to the M1 phenotype. Inhibition of HO-1 expression or activity significantly reduced the inhibitory responses on M1 phenotype and stimulatory effects on M2 phenotype by TonEBP knockdown. Additional experiments showed that HO-1 plays a role in the paracrine anti-inflammatory effects of TonEBP knockdown in macrophages. Identification of HO-1 as a downstream effector of TonEBP provides new possibilities for improved therapeutic approaches to inflammatory diseases.

Tonicity-responsive enhancer binding protein (TonEBP or NFAT5) is a regulator of cellular adaptation to hypertonicity, macrophage activation and T-cell development. Here we report that TonEBP is an epigenetic regulator of thermogenesis and obesity. In mouse subcutaneous adipocytes, TonEBP expression increases > 50-fold in response to high-fat diet (HFD) feeding. Mice with TonEBP haplo-deficiency or adipocyte-specific TonEBP deficiency are resistant to HFD-induced obesity and metabolic defects (hyperglycemia, hyperlipidemia, and hyperinsulinemia). They also display increased oxygen consumption, resistance to hypothermia, and beiging of subcutaneous fat tissues. TonEBP suppresses the promoter of β3-adrenoreceptor gene, a critical regulator of lipolysis and thermogenesis, in ex vivo and cultured adipocytes. This involves recruitment of DNMT1 DNA methylase and methylation of the promoter. In human subcutaneous adipocytes TonEBP expression displays a correlation with body mass index but an inverse correlation with β3-adrenoreceptor expression. Thus, TonEBP is an attractive therapeutic target for obesity, insulin resistance, and hyperlipidemia.

Tonicity-responsive enhancer binding protein (TonEBP), also known as nuclear factor of activated T cells 5 (NFAT5), belongs to the Rel family of transcriptional factors which include NF-κB and NFAT. TonEBP is a key regulator in chronic inflammatory diseases such as rheumatoid arthritis, atherosclerosis, diabetic nephropathy and hepatocellular carcinoma. TonEBP is a rate-limiting component of “pro-inflammatory enhanceosome” in which TonEBP provides a physical tether between activated transcription factors NF-κB and AP-1 to p300 and RNA polymerase II. Assembled in response to inflammatory signals, the pro-inflammatory enhanceosome drives the transcription of TNF-α, IL-1β, IL-6, MCP-1, iNOS, and COX-2. We discovered a class of compounds (CXs) targeting TonEBP. CXs blocked the assembly of the pro-inflammatory enhancesome and potently suppressed the inflammation-induced expression of TNF-α, IL-1β, IL-6, MCP-1, iNOS, and COX-2. Orally administered CXs exhibited remarkable therapeutic activities in mouse models of inflammatory arthritis. Using an alkynyl derivative of a CX and click reaction, we found that CX was covalently attached to TonEBP by alkylation but not to other components of the enhanceosome. Cells harboring a site-directed mutant TonEBP molecule whose amino acid residues for the alkylation were removed exhibited a markedly reduced sensitivity to CXs. These data demonstrate that CXs are a new class of anti-inflammatory agents with a novel mode of action. Citation Format: Byeongjin YE, Hyug Moo Kwon, Soo Youn Choi, Jun Ho Lee, Hyun Je Kang, Cheol-Min Park. Development of anti inflammatory agents targeting TonEBP for treatment of chronic inflammatory diseases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1290.

Objectives Hepatocellular carcinoma (HCC) is a common cancer with high rate of recurrence and mortality. Diverse aetiological agents and wide heterogeneity in individual tumours impede effective and personalised treatment. Tonicity-responsive enhancer-binding protein (TonEBP) is a transcriptional cofactor for the expression of proinflammatory genes. Although inflammation is intimately associated with the pathogenesis of HCC, the role of TonEBP is unknown. We aimed to identify function of TonEBP in HCC. Design Tumours with surrounding hepatic tissues were obtained from 296 patients with HCC who received completion resection. TonEBP expression was analysed by quantitative reverse transcription-quantitative real-time PCR (RT-PCR) and immunohfistochemical analyses of tissue microarrays. Mice with TonEBP haplo deficiency, and hepatocyte-specific and myeloid-specific TonEBP deletion were used along with HCC and hepatocyte cell lines. Results TonEBP expression is higher in tumours than in adjacent non-tumour tissues in 92.6% of patients with HCC regardless of aetiology associated. The TonEBP expression in tumours and adjacent non-tumour tissues predicts recurrence, metastasis and death in multivariate analyses. TonEBP drives the expression of cyclo-oxygenase-2 (COX-2) by stimulating the promoter. In mouse models of HCC, three common sites of TonEBP action in response to diverse aetiological agents leading to tumourigenesis and tumour growth were found: cell injury and inflammation, induction by oxidative stress and stimulation of the COX-2 promoter. Conclusions TonEBP is a key component of the common pathway in tumourigenesis and tumour progression of HCC in response to diverse aetiological insults. TonEBP is involved in multiple steps along the pathway, rendering it an attractive therapeutic target as well as a prognostic biomarker.

NFκB is a central mediator of inflammation. Present inhibitors of NFκB are mostly based on inhibition of essential machinery such as proteasome and protein kinases, or activation of nuclear receptors; as such, they are of limited therapeutic use due to severe toxicity. Here we report an LPS-induced NFκB enhanceosome in which TonEBP is required for the recruitment of p300. Increased expression of TonEBP enhances the NFκB activity and reduced TonEBP expression lowers it. Recombinant TonEBP molecules incapable of recruiting p300 do not stimulate NFκB. Myeloid-specific deletion of TonEBP results in milder inflammation and sepsis. We discover that a natural small molecule cerulenin specifically disrupts the enhanceosome without affecting the activation of NFκB itself. Cerulenin suppresses the pro-inflammatory activation of macrophages and sepsis without detectable toxicity. Thus, the NFκB enhanceosome offers a promising target for useful anti-inflammatory agents.

TonEBP is a key transcriptional activator of M1 phenotype in macrophage, and its high expression is associated with many inflammatory diseases. During the progression of the inflammatory responses, the M1 to M2 phenotypic switch enables the dual role of macrophages in controlling the initiation and resolution of inflammation. Here we report that in human and mouse M1 macrophages TonEBP suppresses IL-10 expression and M2 phenotype. TonEBP knockdown promoted the transcription of the IL-10 gene by enhancing chromatin accessibility and Sp1 recruitment to its promoter. The enhanced expression of M2 genes by TonEBP knockdown was abrogated by antagonism of IL-10 by either neutralizing antibodies or siRNA-mediated silencing. In addition, pharmacological suppression of TonEBP leads to similar upregulation of IL-10 and M2 genes. Thus, TonEBP suppresses M2 phenotype via downregulation of the IL-10 in M1 macrophages.

TonEBP is a key transcription factor in cellular adaptation to hypertonic stress and also in macrophage activation. Since TonEBP is involved in inflammatory diseases such as rheumatoid arthritis and atherosclerosis, we asked whether TonEBP played a role in adipogenesis and insulin resistance. Here we report that TonEBP suppresses adipogenesis and insulin signaling by inhibiting expression of the key transcription factor PPARγ2. TonEBP binds to the PPARγ2 promoter and blocks the epigenetic transition of the locus which is required for the activation of the promoter. When TonEBP expression is reduced, the epigenetic transition and PPARγ2 expression are markedly increased leading to enhanced adipogenesis and insulin response while inflammation is reduced. Thus, TonEBP is an independent determinant of adipose insulin sensitivity and inflammation. TonEBP is an attractive therapeutic target for insulin resistance in lieu of PPARγ agonists.

Abstract Background Systemic inflammatory factors such as C-reactive protein (CRP), ¥â2-microglobulin (B2MG), and ferritin were documented an prognostic factor in patients with hematologic malignancies including lymphoma. The purpose of this study was to find the significance of systemic inflammatory factors for predicting survival outcome in patients with diffuse large B cell lymphoma (DLBCL). Methods A total of 188 patients who newly diagnosed DLBCL and received an rituximab combined chemotherapy at the South Korea between September 2004 and April 2012 were enrolled retrospectively in the current study. Pretreatment serum CRP, B2MG, and ferritin were measured within 4 weeks before the beginning of first line chemotherapy. Results The median age of patients was 58 years (range, 14-84 years) and the mean level of serum CRP, B2MG, and ferritin at pre-treatment were 2.37 mg/dL (range: 0.01 – 29.80), 2.64 mg/L (range: 0.71 – 24.01), and 285.01 ng/ml (range: 5.34-4872.40). Systemic inflammatory factors score were given 1 point if serum levels were more than normal range (CRP; 0.8 mg/dL, B2MG; 2.5 mg/L and ferritin; 220 ng/ml). Systemic inflammatory risk were divided into three groups according to systemic inflammatory factors scores ; low risk was 0 score, intermediate risk was 1 or 2 score, and high risk was 3 score respectively. 5-year progression free survival rates (PFS) were 66.9%, 65.0% and 10.6% in risk groups respectively (p < 0.001). 5-year overall survival rates (OS) were 74.4%, 48.8% and 19.8% in risk groups respectively (p < 0.001). Conclusions Systemic inflammatory factor (CRP, B2MG and ferritin) score were associated with survival outcomes in patients with DLBCL treated by R-CHOP. However, further studies are needed to confirm prognostic value of systemic factors such as CRP, B2MG and ferritin. IPI, international prognostic index; LDH, lactate dehydrogenase; ECOG, Eastern Cooperative Oncology Group (ECOG) performance status; CRP, C-reactive protein; BM, bone marrow; ALC, absolute lymphocyte counts; CHOP-like (cyclophosphamide, adriamycin, vincristine, prednisolone); RCHOP (rituximab plus CHOP) Systemic inflammatory factor (normal range); ¥â2-microglobulin (2.5mg/L), CRP (0.8mg/dL), ferritin (220 ng/mL) Systemic inflammatory factor score : given 1 point if more than normal range Low risk ; 0, Intermediate risk ; 1 or 2, High risk ; 3 Disclosures: No relevant conflicts of interest to declare.

The aim of this study was to investigate predictive factors for rapid engraftment after allogeneic peripheral blood stem cell transplantation (alloPBSCT) in patients with acute leukemia. Two hundred sixty-two patients receiving alloPBSCT were analyzed. Subset analyses of donor stem cells were conducted using a flow cytometric method. The correlation between rapid engraftment of neutrophils, platelets, and donor stem cells doses, as well as other recipient and donor clinical factors, was analyzed. In univariate analysis, factors correlated with neutrophil engraftment (≥0.5 × 10(9)/L) by day 12 were achievement of complete remission (CR) after induction chemotherapy (CR1) before hematopoietic cell transplantation (HCT) and high numbers of CD34+ cells, CD3+ T cells, and CD3+/CD4+ T cells. Factors correlated with platelet engraftment (≥20 × 10(9)/L) by day 12 were achievement of CR1 before HCT, donor and recipient sex mismatch, and high numbers of mononuclear cells, CD34+ cells, CD3+ T cells, CD3+/CD4+ T cells, CD3+/CD8+ T cells, and CD56+ NK cells. In multivariate analysis, independent predictive factors for rapid neutrophil and platelet engraftment were CR1 before HCT (p < 0.001 and p = 0.002, respectively), high number of donor CD34+ cells (p = 0.005 and p < 0.001, respectively), and high number of CD3+ T cells (p = 0.005 and p = 0.001, respectively). In conclusion, achieving CR1 before HCT, as well as larger quantities of donor CD34+ and CD3+ T cells, may predict rapid neutrophil and platelet engraftment after PBSCT.

Objectives: The herpesviridae family includes, among others, herpes simplex virus, varicella zoster virus, Epstein-Barr virus, and cytomegalovirus. Herpesviridae viral infections (HVIs) can lead to serious complications in lymphoma patients undergoing chemotherapy. There is no consensus on the dose and duration of antiviral prophylaxis in these patients. We retrospectively analyzed the incidence and risk factors for HVI in lymphoma patients undergoing chemotherapy.Methods: We reviewed the records of 266 patients who were newly diagnosed with lymphoma and received chemotherapy without acyclovir prophylaxis between June 1996 and August 2009.Results: The cumulative incidence rate of HVI was 20.16% for 5 years from the start of chemotherapy. Independent predictive factors for HVI in lymphoma patients were: female sex [hazard ratio (HR) 2.394; 95% confidence interval (CI): 1.245-4.607; P = 0.009], cumulative dose of steroids per body surface area of at least 2500 mg/m(2) (HR 7.717; 95% CI: 3.814-18.703; P < 0.001), and history of neutropenic fever (HR 0.297; 95% CI: 0.150-0.588; P < 0.001).Conclusions: Female sex, high dose of steroids per body surface area, and neutropenic fever were risk factors for HVI in patients with lymphoma undergoing chemotherapy without acyclovir prophylaxis.

OBJECTIVES:There is no confirmed treatment strategy for primary intestinal diffuse large B-cell lymphoma (DLBL). In this retrospective study, the purpose is to find an appropriate treatment strategy in patients with primary intestinal DLBL undergoing surgery followed by chemotherapy or chemotherapy alone.METHODS:Seventy-six patients were newly diagnosed with DLBL and received treatment between March 2004 and June 2011. Forty-seven patients were treated with surgical resection followed by rituximab combined with cyclophosphamide, adriamycin, vincristine, and prednisolone (R-CHOP), and 29 patients were treated with R-CHOP chemotherapy alone.RESULTS:The characteristics of the patients were as follows: the median age was 56.5 years (range, 15 to 85 y) with a female to male ratio of 1.00:1.45. There was no significant difference in patient characteristics between the 2 groups. The estimated 3-year progression-free survival rates (PFS) and overall survival rates (OS) of surgery followed by R-CHOP (surgery/R-CHOP) and R-CHOP alone (R-CHOP) groups were 92.2% and 74.8% (P=0.009) and 94.2% and 80.7% (P=0.049), respectively. In univariate analysis, significant differences were seen in estimated PFS and OS rates when comparing Lugano stages I and II1 with II2 and IIE (P=0.006 and 0.036), low and low-intermediate risk with high-intermediate risk (P=0.004 and 0.000), and surgery/R-CHOP group with R-CHOP group (P=0.009 and 0.049), respectively. In multivariate analysis, there were no independent predictive factors for survival.CONCLUSIONS:Patients treated with surgery followed by R-CHOP seemed to have a higher survival rate than those treated with R-CHOP alone. There were no significant prognostic factors for survival, but there were possible prognostic factors such as Lugano stage, International Prognostic Index risk, and treatment modality for PFS and OS.

Abstract Abstract 1627 Abstract Background: Gastrointestinal tract is the most commonly involved extranodal site and is represented 10–15% of all non-Hodgkin¡&hibar;s lymphoma (NHL) cases and 30–40% of all extranodal sites. In this retrospective studies, the purpose is finding appropriate treatment strategy according to comparing the efficacy of treatment in patients with primary intestinal diffuse large B cell lymphoma (DLBL) undergoing surgery followed chemotherapy or chemotherapy alone. Method: Seventy six patients were newly diagnosed with DLBL and received chemotherapy between March 2004 and June 2011. Primary intestinal lymphoma which had predominant intestinal lesions was diagnosed by specialized hemato-oncologist. All patients were treated with rituximab combined cyclophosphamide, adriamycin, vincristine, and prednisolone (R-CHOP). Patients were divided into two groups. One included patients who were undertaken surgery followed by R-CHOP (surgery group). The other included patients who were undertaken R-CHOP alone (CT group). Results: The characteristics of the patients were as follows: the median age was 56.5 years (range 15–85 years) with a female-to-male ratio of 45: 31. Patients characteristics had no significant difference between two groups. The estimated 3 years progrression free survival rates (PFS) and overall survival rates (OS) of surgery and CT group were 92.2% and 74.8%, (p=0.009) and 94.2% and 80.7%, (p=0.049) respectively. In univariate analysis, PFS and OS were estimated in Lugano stage I, II1 and II2, IIE (p=0.006 and p=0.036), Low, Low-intermediate, and high-intermediate risk (p=0.004 and p=0.000), and surgery and CT alone, (p=0.009 and p=0.049), respectively. In multivariate analysis, there was no independent predictive factors for survival. Conclusion: Patients treated with surgery followed by R-CHOP were seemed to have higher survival rate than R-CHOP alone although there was no significant differences for survival rate. There was no significant prognostic factors for survival but there were possible prognostic factors such as Lugano stage, IPI risk, and treatment modality for PFS and OS. Figure. The superior survival rates were shown in surgery group than those in R-CHOP chemotherapy group. Disclosures: No relevant conflicts of interest to declare.

BACKGROUND:Essential thrombocythemia (ET) is classified as a Philadelphia chromosome-negative classic myeloproliferative neoplasm. ET is a clonal stem cell disorder that is often associated with JAK2 mutations and shares phenotypic and pathogenetic similarities with other myeloproliferative neoplasms. Hemorrhagic complications and arterial and venous thrombosis are common in patients with ET. The aim of this retrospective analysis was to assess the cumulative incidence rate and risk factors for thrombohemorrhagic events in patients with ET based on a multicenter study in Korea. PATIENTS AND METHODS:A total of 239 patients with ET, from February 1995 to April 2011, were retrospectively analyzed from 4 Korean academic institutions. Data were collected through the review of medical records, and vascular events were confirmed by diagnostic procedures for establishing thrombosis and hemorrhagic complications. RESULTS:Of the patients (median age, 61 years; median follow-up, 51.8 months), 32 (13.4%) experienced thrombohemorrhagic complications. The 10-year cumulative incidence rate showed a 20.6% incidence of thrombohemorrhagic events. In univariate analysis, the presence of JAK2 mutations, high-risk group, previous thrombohemorrhagic events, and >60 years old were shown to have higher incidences of vascular events than any other factors. In multivariate analysis, previous thrombotic events and JAK2 mutations were independent risk factors for vascular events (hazard ratio, 2.907 [95% CI, 1.142-7.406], P =.025; and 4.146 [95% CI 1.227-14.018], P = 0.022). CONCLUSION:Previous thrombotic history and the JAK2 V617F mutation were associated with a higher 10-year cumulative incidence rate of thrombohemorrhagic events.