OS10.6.A What is the initial cell in the subventricular zone for human glioblastoma genesis?

Background

We all have a fundamental question about why glioblastoma (GBM) develops. In order to find the answer to this fundamental question, if you find out what the first cell is, you will get closer to the answer. GBM arises from the subventricular zone (SVZ). GBM is one of the most devastating tumour of human brain as the most optimal treatment barely prolongs the survival, and it does not cure the disease. As the majority of GBM tissues show copy number variations (CNV) of co-altered chromosomal 7 gain and 10 loss, we hypothesized the origin cell (Oc) of SVZ may be traced back with these markers. The cellular identity of the Oc is still unknown and it is different from the tumour-derived progenitor-like cells. We aimed to define these cells from the SVZ that have a potential to get activated into GBM.

Material and Methods

We compared bulk RNA sequencing (RNAseq) data of IDHwt GBM tumor tissue (n=122), tumor free SVZ from GBM patients (n=40), tumor-free control SVZ of non-glial tumor (n=9). Pared single nucleus RNAseq (snRNAseq) or single cell RNAseq (scRNAseq) samples of tumor free SVZ (n=11) and GBM tumor (n=8), were done to see cell specific CNVs. We developed genetically engineered mouse models for GBM genesis introducing three driver mutations (TP53, PTEN, and EGFRviii) into SVZ to isolate mouse Oc (mOc) and mouse cancer cells (mCc). The biological characteristics of separated mOc and mCc were compared. Bulk RNAseq and scRNAseq were performed on these cells (mOc, mCc), and their cellular state was compared with the human gene set.

Results

In this work, we found two types of the Oc in the RNA sequencing of 60 human tumour free-SVZ samples. Furthermore, single-cell level analysis revealed that two Oc types in SVZ harbor ongoing patterns of CNV co-alterations from Oc1 to Oc2, and finally to GBM. The Oc1 type cells contained the CNV signature of Oc2 ancestor with neural progenitor cell (NPC) signature. Oc2 type cells expressed a high level of EGFR than other cells with astrocyte-like cell signature. Both of these cells expressed oligodendrocyte progenitor cell (OPC)-like signatures in the SVZ. We validated the human-based findings by using the P53/PTEN/EGFR-mutant mouse model with EGFR/tdTomato overexpression and P53/PTEN knockout in the SVZ cells. As a result, non-tumourigenic and highly motile Oc-like cell-states are found in the mouse models, supporting the firework-like migration pattern from the SVZ.

Conclusion

Our results demonstrate how members of Oc preoccupy the SVZ, known as the stem cell niche and give rise to the tumour. We anticipate that a new therapy may emerge by targeting the Oc in the SVZ.

P12.04.A Exosomes from glioma associated sphere forming cells induce a transition of invasive phenotype via transfer of EMP2 and CA9

Background

Glioblastoma multiforme (GBM) mostly occurs local recurrence at normal parenchyme adjacent tumor despite of conventional treatment. Glioma stem like cells (GSC) forming intratumoral heterogeneity within the GBM acquired the microenvironmental adaptation by inter-exosomal contents exchange between heterogenic cells. In addition, GSC has an invasive potential as like human GBM. Therefore, we investigate whether exosomal proteins of GSC affect the normal tissue invasion in GBM.

Material and Methods

Exosomes were isolated by Size-Exclusion method from conditioned media and validated by Electron microscope and Immunoblot assay. Exosomal proteomics were examined with Liquid Chromatography-Mass Spectrometry (LC/MS). To produce the fluorescent exosome, bi-cistron vectors were cloned with shRNA and CD63-GFP. To identify the effect of tranfected exosome, the isolated exosomes were treated to recipient cells and examined the invasion by 3D invasion assay and mouse intracranial model.

Results

Firstly, we dichotomized two groups following tumor invasion at matrigel assay and GSC derived orthotopic mouse model. CSC2 and X01 GSCs revealed highly invasive phenotype whereas 83NS and 528NS GSCs did not. Exosome was isolated in each group and identified by CD63 expression or electron microscopy. In proteomics analysis, hypoxia, extracellular matrix organization, GTPase cycle related proteins were enriched in highly invasive cell’s exosome. Among them, we focused the carbonic anhydrase IX (CA9) and the epithelial membrane protein 2 (EMP2) on its permissive role to glioblastoma invasion respectively. CA9 and EMP2 mRNA and protein levels were verified in GSCs and their exosomes and the high expression levels were detected in CSC2 and X01 compared to the low one in 83NS and 528NS GSCs. To evaluate the effects of CA9 and EMP2 on exosome mediated invasion potential, viral bi-cistron vectors was composed with the target gene knockdown and the CD63 fluorescence was used to detect intracellular exosome transfer. Interestingly, the decreased expression of phosphorylated FAK, a key invasive marker, was observed after Lentiviral mediated CA9- and EMP2-knockdown in highly invasive CSC2. To identify whether CA9 and EMP2 proteins are the intracellular effector protein responsible for exosome mediated glioma invasion, the donor exosomes (Exo-CSC2-sh-CA9 and Exo-CSC2-EMP2, after Lentiviral transfection to CSC2s) were isolated and treated to the non invasive 528NS cells as recipient cells. In 3D invasion assay, Exo-CSC2-shCA9 or Exo-CSC2-shEMP2 mediated tumor invasion was significantly decreased at 528NS GSCs compared to Exo-CSC2-shEV. These features were found at mouse intracranial model as well.

Conclusion

Together with these, we conclude that exosome derived from GSCs induces a transition of invasive phenotype via transfer of EMP2 and CA9 proteins.

P10.07.B Differential YAP activity in human glioblastoma tumorspheres

Background

Although glioblastoma (GBM) is the most common primary brain tumor, the best available treatment options are still associated with poor prognosis. Recently, the Hippo/YAP signaling pathway has been emerged as an important driver of GBM. Nevertheless, extensive studies have not yet been focused on the importance of phosphorylation event in regulating endogenous YAP activity in GBM. Here, we sought to elucidate that the modulation and stabilization of YAP/TAZ in Hippo pathway promotes GBM progression.

Material and Methods

Expression patterns of YAP1, TAZ, CTGF, TEAD4 and LATS1 mRNA were confirmed in human normal and GBM tissue, and patient survival according to YAP1 expression was confirmed in TCGA and Severance cohort. The YAP1 expression patterns in several TSs were classified into SOH and AH according to transcriptome analysis and western blot. For each classified TSs, the characteristics of SOH and AH were comparatively analyzed through immunoprecipitation, nucleus fraction, TEAD4 luciferase assay, and confocal analysis. The effect of YAP1 knockdown/out and overexpression in SOH and AH TSs were measured by WST/ATP analysis, 3D invasion and neurosphere formation, and western blot. In addition, the drug reactivity of SOH and AH TSs was examined by treatment with the YAP1 inhibitors Peptide17 and verteporfin, and the effects of Peptide17, verteporfin and YAP1-shRNA were examined in in-vivo xenograft model.

Results

YAP1 mRNA levels including TAZ, CTGF, TEAD4 and LATS1 were higher in GBM than in normal tissues. Through transcriptome analysis and western blot, TS can be divided into SOH and AH groups according to the expression level of CTGF, but not YAP1 level. In the case of SOH TS, the binding of TEAD4 was strong in immunoprecipitation, the ratio of YAP1 was higher in the nucleus in the nucleus fractionation and confocal analysis, and the luciferase activity of TEAD4 was high in the TEAD4 luciferase assay. On the other hand, in the case of TS of AH, the opposite trend was observed. When YAP1 was knocked down or out, the proliferation, invasion, and stemness of TS tended to be decrease more in SOH TS than in AH TS, and SOH TS showed more sensitive drug response even in Peptide17 and Verteporfin treatment. In the case of YAP1 overexpression, the opposite trend was observed in SOH TS. In the in-vivo xenograft model, injection of Peptide17, verteporfin, and YAP1-shRNA showed a tendency to increase the survival rate of mice.

Conclusion

The association of YAP has been described in several cancers, but there has been no study comparing GBM TS by YAP expression and classifying it at the functional level. Now, for the first time, we show that the characteristics of GBM TS can be predicted according to the expression value of YAP, respectively, and YAP is expected to be applied as an important prognostic factor for GBM treatment in the future.

Antidepressant medication and risk of cardiovascular disease in posttraumatic stress disorder patients: application of marginal structural models in Korean National Health Insurance Database

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): - National Research Foundation of Korea (NRF) grant funded by the Ministry of Science and ICT

Introduction

Previous evidence on antidepressant medication and cardiovascular disease (CVD) in posttraumatic stress disorder (PTSD) patients is mixed. We evaluated associations between antidepressant medication and CVD by applying marginal structural model.

Methods

We gathered medical utilization records of 27,170 patients diagnosed with PTSD in years 2004 - 2018 without prior CVD diagnosis from Korean National Health Insurance Database (NHID). PTSD and CVD were characterized in correspondence of ICD-10 diagnostic codes. We acquired information on antidepressant use from medical utilization records and categorized by medication category: selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs) and tricyclic antidepressants (TCAs). Discrete-time survival analysis with marginal structural inverse probability weighting was used to test association between antidepressants and CVDs and were compared to results from traditional time-fixed model and simple time-varying model. We calculated cumulative daily defined doses (DDDs) of each antidepressant categories and conducted polynomial splining to test dose response.

Results

SSRI use was associated with acute coronary syndrome (hazard ratio [HR] 1.53, 95% confidence interval [CI] 1.26 - 1.86) and ischemic stroke (HR 1.33, 95% CI 1.08 - 1.63). SNRI use was associated with acute coronary syndrome (HR 1.52, 95% CI 1.09 - 2.12). TCA use was associated with acute coronary syndrome (HR 1.54, 1.21 - 1.96) and ischemic stroke (HR 1.34, 1.06 - 1.70). Polynomial spline showed positive dose-response in association between antidepressant use and CVD.

Conclusion

Antidepressant use is causally associated with CVD in patients with PTSD. Higher cumulative DDD of antidepressant increases the risk of CVD.

AB0838 The Impact of Comorbidities on Patients with Axial Spondyloarthritis: A Cluster Analysis

Background

Previous study using cluster analysis technique analyzed the association between comorbidities and various outcome measures in patients with axial spondyloarthritis (axSpA). Due to the cross-sectional nature of the study, however, prognostic information about each group were not provided.

Objectives

This study aims to perform cluster analysis to differentiate axSpA patients in terms of comorbidities and to examine the differential treatment outcomes of these groups using the data retrieved from Korean College of Rheumatology Biologics (KOBIO) registry which includes longitudinal data of axSpA patients using anti-TNF agents.

Methods

Clinical characteristics and demographic data of axSpA patients in KOBIO registry were analyzed using an agglomerative hierarchical cluster analysis. The optimum number of clusters was determined by the pseudo-F statistic. After clustering, baseline clinical characteristics and treatment outcomes were compared between isolated axSpA and classified comorbidity groups using multivariable linear models and mixed linear models, respectively.

Results

1,207 patients were included in the study. At least one comorbidity was seen in 464 (38%) axSpA patients. Compared with those with isolated axSpA, patients with comorbidity were older, longer disease duration, and reported higher PtGA (p = 0.019), and BASFI (p <0.001), but did not have significantly different BASDAI, ESR, and CRP levels. The most common comorbidities were hypertension (14.4%), hyperlipidemia (13.0%), and obesity (4.5%). The hierarchical cluster analysis classified patients in 21 groups. We combined clusters 17-21 for further evaluation due to the small size of clusters (<5 patients). In multivariable linear models for baseline clinical characteristics, we found that patients in the hypothyroidism, asthma, and headache clusters reported poorer PtGA, BASDAI, or BASFI, and the weight loss cluster had higher level of CRP, compared with patients with isolated axSpA even after adjustment of patient demographic data. After 1-year treatment of anti-TNF agents, the patients in the hypothyroidism and weight loss clusters decreased greater amounts of BASDAI and BASFI scores and ESR/CRP levels, respectively, compared with patients with isolated axSpA (Table 1). However, the degree of improvement in asthma and headache clusters, which had higher disease activities at baseline, was similar with isolated axSpA. Therefore, they still had higher disease activity scores at the 1-year follow-up.

Table 1.

Comparing each cluster to patients with isolated axSpA (i.e. no comorbidity) using multivariable linear mixed models for each treatment outcome measure at 1-year follow-up as the dependent variable.

Cluster/descriptionPtGABASDAIBASFIESRCRP2isolated axSpA-----3Obesity0.233 (-0.57 - 1.036)0.098 (-0.648 - 0.844)-0.078 (-0.811 - 0.656)9.005 (0.481 - 17.529)†0.358 (-0.553 - 1.269)10Hypothyroidism-1.243 (-3.139 - 0.653)-2.147 (-3.908 - -0.385)†-2.38 (-4.076 - -0.684)†2.234 (-18.11 - 22.578)-0.087 (-2.123 - 1.95)11Weight loss-0.618 (-2.804 - 1.568)-0.901 (-2.932 - 1.131)-1.93 (-3.886 - 0.026)-26.891 (-50.351 - -3.431)†-4.197 (-6.544 - -1.849)†15Asthma0.049 (-2.138 - 2.235)0.833 (-1.199 - 2.864)0.254 (-1.702 - 2.209)-1.058 (-24.517 - 22.402)2.018 (-0.552 - 4.589)16Headache-0.103 (-1.052 - 0.846)0.169 (-0.713 - 1.051)0.463 (-0.387 - 1.312)0.344 (-9.693 - 10.382)-0.046 (-1.132 - 1.04)

† p-value < 0.05

. Only clusters including significant results were shown due to the limitation oft he number of characters.

Conclusion

Comorbidity could affect the treatment outcomes in patients with axSpA in certain subgroups. Thus, we should also pay attention to the comorbidities when treating axSpA.

Disclosure of Interests

None declared

POS0211 ASSOCIATION BETWEEN CARDIOVASCULAR OUTCOME AND RHEUMATOID ARTHRITIS: NATIONWIDE POPULATION-BASED COHORT STUDY

Background

Many studies have shown increased risk of cardiovascular disease (CVD) in patients with rheumatoid arthritis (RA). Despite a growing burden posed by CVD in RA patients, large scale studies which examined the association between characteristic of RA patients and CVD risks, and studies which adjusted for various confounding factors are lacking.

Objectives

This study aimed to investigate the association between CVD risk and RA in large-scale, nationwide cohort of Korean population, and to examine which characteristics of RA patients are associated with increased CVD risk.

Methods

We enrolled 136,469 patients with RA who participated in national health examinations within 2 years of RA diagnosis between 2010 and 2017 and non-RA controls matched by age and sex (n= 682,345). The cohort was followed until the end of 2019. The outcome was occurrence of myocardial infarction (MI) or stroke. MI was defined as one hospitalization or two outpatient visit with ICD-10-CM codes I21 or I22. Stroke was defined as one hospitalization with ICD-10-CM codes I63 or I64 and a claim for brain imaging (CT or MRI). The Cox proportional hazard model and Kaplan Meier curve were used for the analysis.

Results

Mean follow up duration was 4.7 years. The incidence rate of CVD was higher in RA group than control (MI: 3.20 vs 2.08; stroke: 2.84 vs 2.33 per 1,000 person-years). The risk of CVD was higher in RA patients. (MI: adjusted HR 1.54, 95% CI 1.46-1.61; Stroke: adjusted HR 1.22, 95% CI 1.16-1.28). The association between RA and CVD was prominent in female (MI: adjusted HR 1.41 in male, 1.60 in female, p for interaction = 0.0293; Stroke: adjusted HR 1.13 in male, 1.27 in female, p for interaction = 0.03) and younger-age subgroups (MI: adjusted HR 2.9 in <40 years, 1.52 in 40-64 years, 1.51 in ≥65 years, p for interaction<0.0001; Stroke: adjusted HR 2.35 in <40 years, 1.21 in 40-64 years, 1.21 in ≥65 years, p for interaction = 0.0100) after adjusting for confounding variables. The association between RA and risk of MI was significant in those without DM. (adjusted HR 1.30 in DM, 1.61 in non-DM, p for interaction = 0.0005)

Conclusion

RA patients had increased risk of CVD events compared to age- and sex-matched control group, and this association was stronger in female and younger-age subgroups. Therefore appropriate screening for CVD would be important in all RA patients including female and younger patients.

Disclosure of Interests

None declared

POS0803 INCREASED RISK OF MALIGNANCY IN PATIENTS WITH TAKAYASU’S ARTERITIS: A POPULATION-BASED COHORT STUDY IN KOREA

Background

Recent studies have identified neoplasms as the second most common cause of death in patients with Takayasu’s arteritis (TAK) [1,2]. Various autoimmune diseases are related to the increased rates of malignancies. Despite conflicting data, most studies concluded that there is no increase in the risk of malignancies in giant cell arteritis [3]. In the case of TAK, there have been few reports of malignancies [4]. However, only one study compared the risk of malignancies in TAK to that of the general population [5]. Because the previous study only included 180 patients with TAK from single center, no definite conclusion could be drawn. Here, we evaluated the relative risk of malignancies in patients with TAK and compared them with the general population using the medical insurance data of South Korea.

Objectives

This study aimed to evaluate the relative risk of malignancy in patients with TAK compared to that in the general population.

Methods

This retrospective nationwide cohort study used data from the Korean Health Insurance Review and Assessment Service database. All newly diagnosed patients with Takayasu’s arteritis were identified between January 2009 and December 2019. They were observed until the diagnosis of malignancy, death, or end of the observational period, December 2020. The occurrence of malignancy was regarded as the first claim under ICD-10 codes, including C00–97, D46, and D47.1, according to the incidence of malignancy classification published by the National Cancer Registry (NCR). The incidence of malignancy in the general population was retrieved from the 2014 NCR, which collects the annual incidence of malignancies in the entire population of South Korea. The standardized incidence ratios (SIRs) of the overall and site-specific malignancies were estimated and compared with the incidence of cancer in the general population.

Results

We identified 1,449 newly diagnosed patients with Takayasu’s arteritis during the observational period (9,196 person-years). A total of 74, 66, and 8 patients had overall, solid, and hematologic malignancies, respectively. The risks of overall (SIR, 1.62; 95% confidence interval [CI], 1.27–2.03), solid (SIR, 2.04; 95% CI, 1.56–2.61), and hematologic (SIR, 4.05; 95% CI, 3.72–7.98) malignancies were increased compared to those in the general population. In solid malignancies, breast (SIR, 2.07; 95% CI, 1.16–3.42), ovarian (SIR, 4.45; 95% CI, 1.21–11.39), and major salivary gland (SIR, 19.04; 95% CI, 2.31–68.76) cancers had an increased risk. In hematologic malignancies, the risk of myelodysplasia increased (SIR, 18.02; 95% CI, 3.72–52.66). Immunosuppressive agent use was not associated with malignancy. There was no specific period when cancer more frequently occurred.

Conclusion

An increased risk of malignancy was observed in patients with Takayasu’s arteritis compared to that in the general population in this large-scale nationwide population study of Korean health insurance data.

References

[1]Garen T, Lerang K, Hoffmann-Vold A-M, Andersson H, Midtvedt Ø, Brunborg C, et al. Mortality and causes of death across the systemic connective tissue diseases and the primary systemic vasculitides. Rheumatology. 2018;58(2):313-20.

[2]Jang SY, Park TK, Kim D-K. Survival and causes of death for Takayasu’s arteritis in Korea: A retrospective population-based study. International Journal of Rheumatic Diseases. 2021;24(1):69-73.

[3]Hill CL, Cole A, Rischmueller M, Dodd T, Coleman M, Tucker G, et al. Risk of cancer in patients with biopsy-proven giant cell arteritis. Rheumatology (Oxford). 2010;49(4):756-9.

[4]Bicakcigil M, Aksu K, Kamali S, Ozbalkan Z, Ates A, Karadag O, et al. Takayasu’s arteritis in Turkey - clinical and angiographic features of 248 patients. Clin Exp Rheumatol. 2009;27(1 Suppl 52):S59-64.

[5]Park JK, Choi IA, Lee EY, Song YW, Lee EB. Incidence of malignancy in Takayasu arteritis in Korea. Rheumatol Int. 2014;34(4):517-21.

Disclosure of Interests

None declared

Palladium-Catalyzed α-Arylation of Cyclic β-Dicarbonyl Compounds for the Synthesis of CaV1.3 Inhibitors

Cyclic α-aryl β-dicarbonyl derivatives are important scaffolds in medicinal chemistry. Palladium-catalyzed coupling reactions of haloarenes were conducted with diverse five- to seven-membered cyclic β-dicarbonyl derivatives including barbiturate, pyrazolidine-3,5-dione, and 1,4-diazepane-5,7-dione. The coupling reactions of various para- or meta-substituted aryl halides occurred efficiently when Pd(t-Bu₃P)₂, Xphos, and Cs₂CO₃ were used under 1,4-dioxane reflux conditions. Although the couplings of ortho-substituted aryl halides with pyrazolidine-3,5-dione and 1,4-diazepane-5,7-dione were moderate, the coupling with barbiturate was limited. Using the optimized reaction conditions, we synthesized several 5-aryl barbiturates as new scaffolds of Ca_V1.3 Ca²⁺ channel inhibitors. Among the synthesized molecules, 14e was the most potent Ca_V1.3 inhibitor with an IC₅₀ of 1.42 μM.