Exploring the Expression and Function of T Cell Surface Markers Identified through Cellular Indexing of Transcriptomes and Epitopes by Sequencing

PURPOSE

By utilizing both protein and mRNA expression patterns, we can identify more detailed and diverse immune cells, providing insights into understanding the complex immune landscape in cancer ecosystems.

MATERIALS AND METHODS

This study was performed by obtaining publicly available Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) data of peripheral blood mononuclear cells (PBMCs) from the Gene Expression Omnibus database. A total of 94674 total cells were analyzed, of which 32412 were T cells. There were 228 protein features and 16262 mRNA features in the data. The Seurat package was used for quality control and preprocessing, principal component analysis was performed, and Uniform Manifold Approximation and Projection was used to visualize the clusters. Protein and mRNA levels in the CITE-seq were analyzed.

RESULTS

We observed that a subset of T cells in the clusters generated at the protein level divided better. By identifying mRNA markers that were highly correlated with the CD4 and CD8 proteins and cross-validating CD26 and CD99 markers using flow cytometry, we found that CD4+ and CD8+ T cells were better discriminated in PBMCs. Weighted Nearest Neighbor clustering results identified a previously unobserved T cell subset.

CONCLUSION

In this study, we used CITE-seq data to confirm that protein expression patterns could be used to identify cells more precisely. These findings will improve our understanding of the heterogeneity of immune cells in the future and provide valuable insights into the complexity of the immune response in health and disease.

Case report: Pathological complete response to neoadjuvant brigatinib in stage III non-small cell lung cancer with ALK rearrangement

Purpose

The use of neoadjuvant anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitors (TKIs) has not been extensively explored. The current case report highlights the notable pathological complete response (pCR) achieved following neoadjuvant brigatinib therapy in a patient with stage IIIA ALK-positive non-small cell lung cancer (NSCLC).

Case presentation

A 32-year-old male presented with incidental lung lesions, ultimately diagnosed as clinical stage T3N1M0, IIIA NSCLC with an ALK gene rearrangement. Following a multidisciplinary discussion, the patient opted for neoadjuvant brigatinib therapy, which significantly reduced the tumor size. Subsequently, surgery with curative intent was performed, revealing pCR with no residual tumor cells. The patient remained disease-free during a 13-month follow-up period.

Conclusion

This case report provides compelling evidence of pCR following brigatinib therapy in ALK-positive NSCLC, suggesting that surgery after neoadjuvant therapy with brigatinib may offer a safe and effective approach for patients with ALK-positive NSCLC.

Exploring aryl hydrocarbon receptor expression and distribution in the tumor microenvironment, with a focus on immune cells, in various solid cancer types

Introduction

Aryl hydrocarbon receptor (AhR) is a transcription factor that performs various functions upon ligand activation. Several studies have explored the role of AhR expression in tumor progression and immune surveillance. Nevertheless, investigations on the distribution of AhR expression, specifically in cancer or immune cells in the tumor microenvironment (TME), remain limited. Examining the AhR expression and distribution in the TME is crucial for gaining insights into the mechanism of action of AhR-targeting anticancer agents and their potential as biomarkers.

Methods

Here, we used multiplexed immunohistochemistry (mIHC) and image cytometry to investigate the AhR expression and distribution in 513 patient samples, of which 292 are patients with one of five solid cancer types. Additionally, we analyzed the nuclear and cytosolic distribution of AhR expression.

Results

Our findings reveal that AhR expression was primarily localized in cancer cells, followed by stromal T cells and macrophages. Furthermore, we observed a positive correlation between the nuclear and cytosolic expression of AhR, indicating that the expression of AhR as a biomarker is independent of its localization. Interestingly, the expression patterns of AhR were categorized into three clusters based on the cancer type, with high AhR expression levels being found in regulatory T cells (Tregs) in non-small cell lung cancer (NSCLC).

Discussion

These findings are anticipated to serve as pivotal evidence for the design of clinical trials and the analysis of the anticancer mechanisms of AhR-targeting therapies.

Additional local therapy before disease progression for EGFR-mutated advanced lung cancer: a systematic review and meta-analysis

Background

International guidelines recommend the use of local therapy (LT) to limited progression in patients with epidermal growth factor receptor (EGFR)-mutated advanced non-small cell lung cancer (NSCLC). However, the use of LT before disease progression has not been extensively analyzed. This meta-analysis evaluates the efficacy and safety of administering additional LT in conjunction with first-line EGFR-tyrosine kinase inhibitors (TKIs) before disease progression in patients with EGFR-mutated advanced NSCLC.

Methods

We systematically searched PubMed, Embase, and the Cochrane Library for studies published up until May 31, 2023. The LT group consisted of patients who received first-line EGFR-TKIs in conjunction with additional LT, while the TKI group comprised participants treated with first-line EGFR-TKIs alone. Studies comparing the survival outcomes of the LT and TKI groups were included in this analysis. The primary outcomes were progression-free survival (PFS) and overall survival (OS). This review was registered on PROSPERO (registration number CRD42023439913).

Results

Among the 11 investigated studies covering 1,313 patients, the LT modalities included radiotherapy, surgery, and ablation therapy, which accounted for 91%, 27%, and 27% of the studies, respectively. The pooled hazard ratios of median PFS and OS were 0.34 [95% confidence interval (CI): 0.22-0.53; P<0.001] and 0.42 (95% CI: 0.36-0.48; P<0.001), respectively, which indicated significant benefits for the LT group compared to the TKI group. There was no significant difference between the LT and TKI groups (P=0.473) regarding the incidence of grade 3 or higher adverse events.

Conclusions

This study suggests that the strategic use of additional LT before disease progression is a promising approach for the treatment of EGFR-mutated advanced NSCLC.

CD81 and CD82 expressing tumor-infiltrating lymphocytes in the NSCLC tumor microenvironment play a crucial role in T-cell activation and cytokine production

Introduction

To understand the immune system within the tumor microenvironment (TME) of non-small cell lung cancer (NSCLC), it is crucial to elucidate the characteristics of molecules associated with T cell activation.

Methods

We conducted an in-depth analysis using single-cell RNA sequencing data obtained from tissue samples of 19 NSCLC patients. T cells were classified based on the Tumor Proportion Score (TPS) within the tumor region, and molecular markers associated with activation and exhaustion were analyzed in T cells from high TPS areas.

Results

Notably, tetraspanins CD81 and CD82, belonging to the tetraspanin protein family, were found to be expressed in activated T cells, particularly in cytotoxic T cells. These tetraspanins showed strong correlations with activation and exhaustion markers. In vitro experiments confirmed increased expression of CD81 and CD82 in IL-2-stimulated T cells. T cells were categorized into CD81highCD82high and CD81lowCD82low groups based on their expression levels, with CD81highCD82high T cells exhibiting elevated activation markers such as CD25 and CD69 compared to CD81lowCD82low T cells. This trend was consistent across CD3+, CD8+, and CD4+ T cell subsets. Moreover, CD81highCD82high T cells, when stimulated with anti-CD3, demonstrated enhanced secretion of cytokines such as IFN-γ, TNF-α, and IL-2, along with an increase in the proportion of memory T cells. Bulk RNA sequencing results after sorting CD81highCD82high and CD81lowCD82low T cells consistently supported the roles of CD81 and CD82. Experiments with overexpressed CD81 and CD82 showed increased cytotoxicity against target cells.

Discussion

These findings highlight the multifaceted roles of CD81 and CD82 in T cell activation, cytokine production, memory subset accumulation, and target cell cytolysis. Therefore, these findings suggest the potential of CD81 and CD82 as promising candidates for co-stimulatory molecules in immune therapeutic strategies for cancer treatment within the intricate TME.

A simplified cranial cavity model to understand the relationship between intracranial pressure and dural sinus pressure

Although accurate intracranial pressure (ICP) monitoring is essential for the diagnosis and treatment of severe brain diseases, current methods are performed invasively. Therefore, a safe and less invasive ICP measurement is required. The purpose of our study was to develop a simplified cranial cavity model for a better understanding of the relationship between the ICP and the pressure measurement within the dural venous sinus (DVS) to support the validity of using sinus pressure as the surrogate of the ICP. The in-house cranial cavity model had three components: the brain part, the DVS part, and the subarachnoid space (SAS) part. Pressure in other parts was measured when the pressure in the SAS part and, separately, brain part was increased from 0 (baseline) to 50 mmHg at intervals of 10 mmHg. When the pressure in the SAS part was increased from 10 to 50 mmHg at 10 mmHg interval, pressures of both the brain and DVS parts increased without significant difference (all P > 0.05). However, pressures in both the SAS and DVS parts differed while the pressure in the brain part was increased. The pressures in both parts showed about 70% of the increase in the brain part. Nevertheless, the pressures in the SAS and DVS parts were not significantly different (P > 0.05). A simplified in-house cranial cavity model was developed consisting of three compartments to represent the actual intracranial spaces. The pressure measurement within the DVS was feasible to use as a surrogate for the ICP measurement.

Polo-like Kinase 4: A Multifaceted Marker Linking Tumor Aggressiveness and Unfavorable Prognosis, and Insights into Therapeutic Strategies

(1) Background: This study investigated whether polo-like kinase 4 (PLK4) is a suitable therapeutic target or biomarker for lung adenocarcinoma (LUAD). (2) Methods: We acquired LUAD data from The Cancer Genome Atlas (TCGA) database through the UCSC Xena data portal. Gene expression, clinical, survival, and mutation data from multiple samples were analyzed. Gene enrichment analysis, unsupervised clustering of PLK4-related pathways, and differential gene expression analyses were performed. Additionally, correlations, t-tests, survival analyses, and statistical analyses were performed. (3) Results: PLK4 expression was higher in LUAD tissues than in normal tissues and was associated with poor prognosis for both overall and progression-free survival in LUAD. PLK4 was highly correlated with cell-proliferation-related pathways using Gene Ontology (GO) biological process terms. PLK4 expression and pathways that were highly correlated with PLK4 expression levels were upregulated in patients with LUAD with the TP53 mutation. (4) Conclusions: PLK4 expression affects the survival of patients with LUAD and is a potential therapeutic target for LUAD with TP53 mutations.

Real-world analysis of first-line afatinib in patients with EGFR-mutant non-small cell lung cancer and brain metastasis: survival and prognostic factors

Background

Overall survival (OS) in patients with non-small cell lung cancer (NSCLC) and brain metastases (BMs) is poor. We aimed to identify prognostic factors and ascertain treatment outcomes of first-line afatinib for patients with epidermal growth factor receptor (EGFR)-mutant NSCLC with BM in a real-world setting.

Methods

This retrospective observational study reviewed electronic records of patients with EGFR-mutant NSCLC who received first-line afatinib treatment between October 2014 and October 2019 in 16 hospitals across South Korea. The Kaplan-Meier method estimated time on treatment (TOT) and OS; multivariate analyses were performed using Cox proportional hazards (PH) models.

Results

Among 703 patients who received first-line afatinib, 262 (37.3%) had baseline BM. Of 441 patients without baseline BM, 92 (20.9%) developed central nervous system (CNS) failure. Compared with patients without CNS failure, those with CNS failure during afatinib treatment were younger (P=0.012), had a higher Eastern Cooperative Oncology Group (ECOG) performance status (PS) (P<0.001), increased metastatic site involvement (P<0.001), advanced stage disease (P<0.001), with liver metastasis (P=0.008) and/or bone metastasis (P<0.001) at baseline. Cumulative incidence of CNS failure in years 1, 2 and 3 was 10.1%, 21.5% and 30.0%, respectively. In multivariate analysis, cumulative incidence was significantly higher in patients with ECOG PS ≥2 (P<0.001), uncommon EGFR mutations (P=0.001), and no baseline pleural metastasis (P=0.017). Median TOT was 16.0 months (95% CI: 14.8-17.2) and, in patients with CNS failure, without CNS failure, and with baseline BM was 12.2, 18.9, and 14.1 months, respectively (P<0.001). Median OS was 52.9 months (95% CI: 45.4-60.3) and, in patients with CNS failure, without CNS failure, and with baseline BM was 29.1, 67.3 and 48.5 months, respectively (P<0.001).

Conclusions

First-line afatinib in the real-world setting showed clinically meaningful effectiveness in patients with EGFR-mutant NSCLC and BM. CNS failure was a poor prognostic factor for TOT and OS correlating with younger age, poor ECOG PS, higher metastatic number, advanced disease stage, uncommon EGFR mutations, and baseline liver and/or bone metastases.

Development of a scintillator-based optical soft x-ray (OSXR) diagnostic system for KSTAR tokamak

We have developed a new scintillator-based optical soft x-ray (OSXR) diagnostic system for KSTAR. By utilizing fiber optic faceplates, mm-size lens arrays, and fiber bundles, we have successfully constructed a novel optical system for scintillator-based soft x-ray detection to overcome the limited vacuum-port conditions in KSTAR. P47 (Y2SiO5), which has a fast rise (∼7 ns) and decay (∼100 ns) time sufficient for detecting plasma instabilities observed in the kHz-MHz spectral range, was selected as the scintillator material for the KSTAR OSXR system. Scintillation toward each detection channel is collected by the lens arrays coupled to optical fiber cores, which are connected to the photodetector system. Initial results obtained during the 2022 KSTAR experimental campaign support the validity of the OSXR data through the consistency of OSXR measurement results with other diagnostics. We also observe that the OSXR system can capture magnetohydrodynamic activities, such as sawtooth oscillations, and provide valuable information for disruption mitigation studies using shattered pellet injection.

Abstract 3234: OCT-598, a novel EP2/EP4 dual antagonist, promotes anti-tumor immune responses in syngeneic mouse tumor models in combination with standard-of-care chemo- and immunotherapies

Prostaglandin E2 (PGE2) is widely recognized as one of the major bioactive lipids that, with the striking regenerative potential, promote drug-resistance in cancer cells as well as immune evasion in the tumor microenvironment (TME). Primarily driven by apoptotic cell death, PGE2 is thought to elicit wound-healing responses to help provide an immunosuppressive and proliferative niche that supports cancer stem cell repopulation and thereby therapy-resistance. While COX1/2 inhibitors that attenuate PGE2 production have shown promising anti-cancer effects in various (pre-)clinical settings, the gastrointestinal- and cardiotoxicities precluded their development as anti-cancer agents. It is anticipated that specific targeting of PGE2 signaling via its cognate receptors constitutes a safer and potentially more effective approach. Of the receptor subtypes EP1-4, Gα,s-coupled EP2 and EP4 are believed to be directly involved in immunosuppressive effects of PGE2.OCT-598 is a novel, highly potent and selective EP2/EP4 dual antagonist with Ki values of 23 nM and 0.2 nM vs EP2 and EP4, respectively. PGE2 inhibited normal differentiation of human monocytes into CD1a+CD16- dendritic cells under the presence of GM-CSF and IL-4 and promoted differentiation towards CD1a-CD16+ macrophages in vitro. However, EP2/EP4 dual inhibition by OCT-598 reversed this phenomenon to a greater extent than either EP2- or EP4-specific inhibitor alone. In vivo, OCT-598 effected tumor growth inhibition in multiple syngeneic mouse models as a single agent as well as in combination with an immune checkpoint blocker (ICB). Furthermore, the addition of OCT-598 to the lung cancer standard-of-care regimen (anti-PD-1 plus chemotherapy) in TC-1 mouse lung adenocarcinoma model gave rise to complete tumor regression. In conclusion, dual blockade of EP2 and EP4 by OCT-598 is shown to be a compelling strategy to reinforce antitumor effects by thwarting PGE2-mediated therapy resistance and immune evasion.Findings from this study provide a rationale for clinical development of OCT-598 as a therapeutic option for human malignant cancers.

Citation Format: Youngrae Lee, Sujeong Baek, Dong Kwon Kim, Yeri Lee, Donggeon Kim, Seongin Jo, Sang Kyun Lim, Young Sook Shin, Soonsang Kwon, Seung Min Yang, Young Taek Kim, Seong-San Kang, Chun-Bong Synn, Kwangmin Na, Mi Hyun Kim, Heekyung Han, Yu Jin Han, Sungwoo Lee, Jae Hwan Kim, Mi Ran Yun, Youngseon Byeon, Young Seob Kim, Ji Yun Lee, Jii Bum Lee, Chang Gon Kim, Min Hee Hong, Sun Min Lim, Kyoung-Ho Pyo, Byoung Chul Cho, Taeyoung Yoon. OCT-598, a novel EP2/EP4 dual antagonist, promotes anti-tumor immune responses in syngeneic mouse tumor models in combination with standard-of-care chemo- and immunotherapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3234.

Abstract 5107: A novel AhR inhibitor ‘DA-4505’ improved the anti-cancer efficacy of surgical and chemotherapy via synergistic anti-tumor effects of aPD-1

Background: The Aryl hydrocarbon receptor (AhR) is one of the most predominant regulators of cancer metabolism. The AhR exerts important immunosuppressive functions by activating Treg cells and myeloid-derived suppressor cells and repressing CD8+ effector T cells. Here, we propose that a best-in-class AhR inhibitor, DA-4505, improves anti-tumor efficacy via modulation of tumor immune surveillance compared to BAY2416964, an AHR antagonist drug candidate being studied in the clinical phase.

Methods: To evaluate anti-tumor effects of DA-4505 and BAY2416964, the two AhR inhibitors were dosed at 10 mg/kg once daily alone or in combination with aPD-1 (10 mg/kg) in surgical and chemotherapy models, and a PDX model (YHIM2004). Tumor volume, relapse, and survival were evaluated, and immune profiles were analyzed with IHC, flow cytometry, and scRNAseq.

Results: A significant tumor reduction appeared in the CT26 and 4T1 tumor models after the DA-4505 treatment compared to vehicle group (P&lt;0.05). In contrast, DA-4505 treatment did not induce significant tumor regression compared to vehicle group in tumor-bearing NOG mice, suggesting that anti-tumor effects of DA-4505 were driven by immunologic mechanisms. To evaluate the role of DA-4505 in conjunction with surgery, DA-4505 alone or in combination with anti-PD-1 was given prior to and following resection of the tumors in 4T1 tumor-bearing mice. Survival of mice treated with DA-4505 alone or DA-4505 combined with anti-PD-1 was significantly prolonged after resection compared to aPD-1 treatment group (P&lt;0.05). In addition, there were four mice that did not have a relapse by treating DA-4505 with or without aPD-1 after surgery (4/5). A tumor regression also appeared in the YHIM2004-engrafted humanized mouse study. A tumor reduction was shown by treating DA-4505 alone or in combination with pembrolizumab compared to vehicle group (P&lt;0.05). Next, we co-administered an AhR inhibitor and aPD-1 as a partner to improve the antitumor effects of chemotherapy. The DA-4505 add-on group showed tumor regression when compared with the combination therapy group treated with aPD-1 and chemotherapy (P&lt;0.0001). In addition, a significant increase in survival rate was shown in the group treated with a DA-4505 add-on compared to vehicle group (P&lt;0.001). Analysis of scRNAseq showed that M1 macrophage expressing CCL7 and CCL8 were increased in DA-4505 treated group compared to the vehicle and aPD-1 groups. This suggests that immune modulatory effect of DA-4505 may be due to enhanced recruitment of immune cells into the tumor site by macrophages with high chemotactic activity.

Conclusion: The AhR inhibitor DA-4505 demonstrated an improvement in anti-tumor efficacy. In addition, it has shown a synergistic effect when combined with aPD-1. Discoveries from this study provide a preclinical rationale for future clinical implications in solid tumor.

Citation Format: DongKwon Kim, Sujeong Baek, Seung Min Yang, Yu Jin Han, Seong-san Kang, Chun-Bong Synn, Mi Hyun Kim, Heekyung Han, Kwangmin Na, Young Taek Kim, Sungwoo Lee, Taedong Han, Hyounmie Doh, Jongho Cho, Dajeong Kim, Daewon Cha, Jae Hwan Kim, Youngseon Byeon, Young Seob Kim, Mi Ran Yun, Ji Yun Lee, Jii Bum Lee, Chang Gon Kim, Min Hee Hong, Sun Min Lim, Byoung Chul Cho, Kyoung-Ho Pyo. A novel AhR inhibitor ‘DA-4505’ improved the anti-cancer efficacy of surgical and chemotherapy via synergistic anti-tumor effects of aPD-1. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5107.

Interplay between chronic inflammation and clonal haematopoiesis of indeterminate potential in Behçet's disease

BACKGROUND

Clonal haematopoiesis of indeterminate potential (CHIP) is a predisposition to haematological malignancy whose relationship with chronic inflammatory diseases, such as cardiovascular diseases, has been highlighted. Here, we aimed to investigate the CHIP emergence rate and its association with inflammatory markers in Behçet's disease (BD).

METHODS

We performed targeted next-generation sequencing to detect the presence of CHIP using peripheral blood cells from 117 BD patients and 5004 healthy controls between March 2009 and September 2021 and analysed the association between CHIP and inflammatory markers.

RESULTS

CHIP was detected in 13.9% of patients in the control group and 11.1% of patients in the BD group, indicating no significant intergroup difference. Among the BD patients of our cohort, five variants (DNMT3A, TET2, ASXL1, STAG2, and IDH2) were detected. DNMT3A mutations were the most common, followed by TET2 mutations. CHIP carriers with BD had a higher serum platelet count, erythrocyte sedimentation rate, and C-reactive protein level; older age; and lower serum albumin level at diagnosis than non-CHIP carriers with BD. However, the significant association between inflammatory markers and CHIP disappeared after the adjustment for various variables, including age. Moreover, CHIP was not an independent risk factor for poor clinical outcomes in patients with BD.

CONCLUSIONS

Although BD patients did not have higher CHIP emergence rates than the general population, older age and degree of inflammation in BD were associated with CHIP emergence.

Effect of early hysterectomy on a risk of incident cardiovascular disease in women: a nationwide population-based cohort study

Aim

Women who inevitably underwent surgical hysterectomy before natural menopause may have an earlier increase in hematocrit and storage iron than women who continue menstruation, thereby increasing the risk of cardiovascular disease (CVD) early. We aimed to evaluate the association of women with hysterectomy vs. without hysterectomy before their 50s with the risk of incident CVD.

Methods

This was a retrospective-cohort study, 135,575 women aged 40 to 50 years in 2011–2014 were extracted from the Korean Health Insurance Review and Assessment Service data and after propensity score matching, 55,539 pairs were included in hysterectomy and non-hysterectomy group respectively. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of cardiovascular death, myocardial infarction (MI), stroke, and coronary artery revascularization.

Results

After adjustment for confounding factors, hysterectomy group had an increased risk of MACCE compared with non-hysterectomy group (hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.09–1.44). Regarding individual outcomes, cardiovascular death, MI, and coronary revascularization were comparable between the groups, whereas, the risk of stroke was significantly higher in hysterectomy group than non-hysterectomy group (HR, 1.31; 95% CI, 1.12–1.53). Even after excluding women who underwent oophorectomy, hysterectomy group had a higher risk of MACCE than non-hysterectomy group (HR, 1.24; 95% CI 1.06–1.44).

Conclusions

Early surgical menopause due to hysterectomy, not hormonal menopause, was associated with an increased risk for a composite of CVD, especially stroke. This suggest that the role of “uterus” as well as sex hormones may be important for the sharp increase in the risk of CVD in women after menopause.

Funding Acknowledgement

Type of funding sources: None.

Blunted atrial reverse remodeling a year after catheter ablation for atrial fibrillation and their long-term rhythm outcome

Background

Although active rhythm control by atrial fibrillation (AF) catheter ablation (AFCA) reduces left atrial (LA) dimension, blunted atrial reverse remodeling can be observed in patients with significant atrial myopathy. We explored the characteristics and long-term outcomes of AF patients who showed blunted atrial reverse remodeling despite no AF recurrence within a year after AFCA.

Methods

Among a total of 2,756 patients with AFCA, we included 1,685 patients (74.8% male, 60.2±10.1 years old, 54.5% paroxysmal AF) who underwent both baseline and 1-year follow-up echocardiogram, baseline LA&gt;40mm, and did not recur within a year. We divided them into tertile groups (T1–T3) based on one-year percent change of LA dimension after propensity matching for age, sex, AF type, and baseline LA dimension. We also investigated the patients' genetic characteristics with blunted LA reverse remodeling (T1) using a genome-wide association study (GWAS).

Results

Patients with blunted LA reverse remodeling (T1, n=424) were independently associated with body mass index (OR 1.082 [1.010–1.160], p=0.025), LA peak pressure (OR 1.010 [1.002–1.019], p=0.019), LA wall thickness (OR 0.448 [0.252–0.789], p=0.006), LA voltage (OR 0.651 [0.463–0.907], p=0.012), and pericardial fat volume (OR 1.004 [1.001–1.008], p=0.014). Throughout 65.9±37.4 months of follow-up, the incidence of AF recurrence a year after the procedure was significantly higher in the T1 group than in T2 or T3 groups (Log-rank p&lt;0.001). Among 894 patients with GWAS, ATXN1, XPO7, KRR1_PHLDA1, ZFHX3, and their polygenic risk score were associated with blunted LA reverse remodeling.

Conclusions

Patients with blunted LA reverse remodeling after AFCA were independently associated with low LA voltage, thin wall thickness, high LA pressure, and fat volume, and have a genetic background. Long-term clinical recurrence a year after AFCA was higher in this patient group with suspicious atrial myopathy.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health and WelfareNational Research Foundation of Korea

Clinical outcomes of hyperprogression based on volumetry in non-small cell lung cancer after immune checkpoint inhibitor treatment

BACKGROUND

Hyperprogressive disease (HPD) is a novel pattern of the treatment course after immune checkpoint inhibitor (ICI) therapy in patients with non-small cell lung cancer (NSCLC). This study aimed to investigate the clinical characteristics, outcomes, and associated factors of HPD using a semiautomatic volume measurement.

METHODS

This retrospective study enrolled patients with recurrent and/or metastatic NSCLC treated with ICIs between January 2015 and August 2019 at eight tertiary centers in Korea. HPD was defined according to the tumor growth kinetics and time to treatment failure. Tumor volume was measured using a semiautomatic software.

RESULTS

A total of 219 NSCLC patients with 35 HPD by volumetric measurement (HPDv) (15.9%) were enrolled. The median duration of overall survival (OS) and OS after ICI treatment (ICI-OS) were 34.5 and 18.4 months, respectively. HPDv patients had significantly worse progression-free survival (PFS) than progressive disease patients without HPDv (1.16 vs. 1.82 months, p-value <0.001). ICI-OS did not significantly differ between patients with HPDv and those without HPDv (2.66 vs. 5.4 months, p = 0.105). PD-L1 expression lower than 50%, more than three metastatic sites, neutrophil-to-lymphocyte ratio equal to or higher than 3.3, and hemoglobin level lower than 10 were found to be associated with HPDv.

CONCLUSIONS

There is no standardized definition of HPD. However, defining HPD in NSCLC patients treated with ICI using a semiautomatic volume measurement software is feasible.

Improving Theranostic Gallium-68/Lutetium-177-Labeled PSMA Inhibitors with an Albumin Binder for Prostate Cancer

We developed a novel therapeutic radioligand, [177Lu]1h, with an albumin binding motif and evaluated it in a prostate-specific membrane antigen (PSMA)-expressing tumor xenograft mouse model. Fourteen PSMA target candidates were synthesized, and binding affinity was evaluated with an in vitro competitive binding assay. First, four compound candidates were selected depending on binding affinity results. Next, we selected four compounds ([68Ga]1e, [68Ga]1g, [68Ga]1h, and [68Ga]1k) were screened for tumor targeting efficiency by micro-positron emission tomography/computed tomography (micro-PET/CT) imaging. Finally, [177Lu]1h compound was evaluated the tumor targeting efficiency and therapeutic efficiency by micro-single-photon emission computed tomography/computed tomography (micro-SPECT/CT), biodistribution, and radiotherapy studies. Estimated human effective dose was calculated by biodistribution data. Compound 1h showed a high binding affinity (Ki value = 4.08 ± 0.08 nmol/L), and [177Lu]1h showed extended blood circulation (1 hour = 10.32 ± 0.31, 6 hours = 2.68 ± 1.07%ID/g) compared to [177Lu]PSMA-617 (1 h = 0.17 ± 0.10%ID/g). [177Lu]1h was excreted via the renal pathway and showed high tumor uptake (24.43 ± 3.36%ID/g) after 1 hour, which increased over 72 hours (72 hours = 51.39 ± 9.26%ID/g). Mice treated with 4 and 6 MBq of [177Lu]1h showed a median survival rate of >61 days. In particular, all mice treated with 6 MBq of [177Lu]1h survived for the entire monitoring period. The estimated human effective dose of [177Lu]1h was 0.07 ± 0.01 and 0.03 ± 0.00 mSv/MBq in total body and kidney, respectively. The current study indicates that [177Lu]1h has the potential for further investigation of metastatic castration-resistant prostate cancer (mCRPC) therapy in clinical trials.

Safety and Diagnostic Yield of Radial Probe Endobronchial Ultrasound-Guided Biopsy for Peripheral Lung Lesions in Patients with Idiopathic Pulmonary Fibrosis: A Multicenter Cross-Sectional Study

BACKGROUND

Radial probe endobronchial ultrasound-guided transbronchial lung biopsy (RP-EBUS-TBLB) is widely used for diagnosis of peripheral lung lesions (PLLs). To date, there have been no reports regarding the clinical outcomes of RP-EBUS-TBLB for PLLs in patients with idiopathic pulmonary fibrosis (IPF).

OBJECTIVES

This study was performed between October 2017 and December 2019 to identify the safety and diagnostic performance of RP-EBUS-TBLB in IPF patients.

METHODS

Patients were divided into the usual interstitial pneumonia (UIP) group (n = 39, 4%), the probable UIP group (n = 12, 1%), and the noninterstitial lung disease (non-ILD) group (n = 903, 95%).

RESULTS

The diagnostic yield was significantly lower in the UIP group than in the non-ILD group (62% vs. 76%; p = 0.042), but there were no significant differences between the UIP and probable UIP groups (62% vs. 83%; p = 0.293) or the probable UIP and non-ILD groups (83% vs. 76%; p = 0.741). Multivariate logistic analysis showed that the mean diameter of PLLs, positive bronchus sign on CT, and "within the lesion" status on EBUS were independently associated with success of the procedure. Especially, the presence of the UIP pattern on CT (OR, 0.385; 95% CI: 0.172-0.863; p = 0.020) was independently associated with failed diagnosis. Among patients with UIP, "within the lesion" status on EBUS (OR, 25.432; 95% CI: 2.321-278.666; p = 0.008) was shown to be a factor contributing to a successful diagnosis. Overall, there were no significant differences in complication rates among the 3 study groups.

CONCLUSION

RP-EBUS-TBLB can be performed safely with an acceptable diagnostic yield, even in patients with IPF.

Outer membrane vesicles produced by Burkholderia cepacia cultured with subinhibitory concentrations of ceftazidime enhance pro-inflammatory responses

BURKHOLDERIA CEPACIA

is an opportunistic pathogen that infects patients with debilitating underlying diseases. This study investigated the production of outer membrane vesicles (OMVs) by B. cepacia cultured with sub-minimum inhibitory concentrations (MICs) of antibiotics and examined their pathogenic roles both in vitro and in vivo. B. cepacia ATCC 25416 produced more OMVs under antibiotic stress conditions than controls. OMVs isolated from B. cepacia cultured in Luria-Bertani (LB) broth (OMVs/LB) induced cytotoxicity and the expression of pro-inflammatory cytokine genes in A549 cells in a dose-dependent manner. Host cell cytotoxicity and pro-inflammatory responses were significantly higher in A549 cells treated with B. cepacia OMVs cultured with 1/4 MIC of ceftazidime (OMVs/CAZ) than in the cells treated with OMVs/LB, OMVs cultured with 1/4 MIC of trimethoprim/sulfamethoxazole (OMVs/SXT), or OMVs cultured with 1/4 MIC of meropenem. Intratracheal injection of B. cepacia OMVs also induced histopathology in vivo in mouse lungs. Expressions of IL-1β and TNF-α genes were significantly up-regulatedin the lungs of mice treated with OMVs/CAZ compared to mice administered other OMVs; the expression of the GRO-α gene, however, was significantly up-regulated in OMVs/SXT. In conclusion, OMVs produced by B. cepacia under different antibiotic stress conditions induce different host responses that may contribute to the pathogenesis of B. cepacia.

Preoperative Assessment of Renal Sinus Invasion by Renal Cell Carcinoma according to Tumor Complexity and Imaging Features in Patients Undergoing Radical Nephrectomy

Objective

To identify the association between renal tumor complexity and pathologic renal sinus invasion (RSI) and evaluate the usefulness of computed tomography tumor features for predicting RSI in patients with renal cell carcinoma (RCC).

Materials and Methods

This retrospective study included 276 consecutive patients who underwent radical nephrectomy for RCC with a size of ≤ 7 cm between January 2014 and October 2017. Tumor complexity and anatomical renal sinus involvement were evaluated using two standardized scoring systems: the radius (R), exophytic or endophytic (E), nearness to collecting system or sinus (N), anterior or posterior (A), and location relative to polar lines (RENAL) nephrometry and preoperative aspects and dimensions used for anatomical classification (PADUA) system. CT-based tumor features, including shape, enhancement pattern, margin at the interface of the renal sinus (smooth vs. non-smooth), and finger-like projection of the mass, were also assessed by two independent radiologists. Univariable and multivariable logistic regression analyses were performed to identify significant predictors of RSI. The positive predictive value, negative predictive value (NPV), accuracy of anatomical renal sinus involvement, and tumor features were evaluated.

Results

Eighty-one of 276 patients (29.3%) demonstrated RSI. Among highly complex tumors (RENAL or PADUA score ≥ 10), the frequencies of RSI were 42.4% (39/92) and 38.0% (71/187) using RENAL and PADUA scores, respectively. Multivariable analysis showed that a non-smooth margin and the presence of a finger-like projection were significant predictors of RSI. Anatomical renal sinus involvement showed high NPVs (91.7% and 95.2%) but low accuracy (40.2% and 43.1%) for RSI, whereas the presence of a non-smooth margin or finger-like projection demonstrated comparably high NPVs (90.0% and 91.3% for both readers) and improved accuracy (67.0% and 73.9%, respectively).

Conclusion

A non-smooth margin or the presence of a finger-like projection can be used as a preoperative CT-based tumor feature for predicting RSI in patients with RCC.

Clinical course of asymptomatic malignant pleural effusion in non-small cell lung cancer patients: A multicenter retrospective study

The British Thoracic Society guidelines recommend observation for patients with asymptomatic malignant pleural effusion (MPE). However, asymptomatic MPE can become symptomatic. This study examined the clinical course of asymptomatic MPE in patients with non-small cell lung cancer (NSCLC), including the incidence and timing of symptom development of asymptomatic MPE and the associated factors.Retrospective data of 4822 NSCLC patients between January 2012 and December 2017 were reviewed. Symptom development of asymptomatic MPE was defined as the development of symptoms requiring additional treatment, such as insertion of a chest tube, within 1 year in patients who lacked MPE symptoms at the time of diagnosis. Clinical information, pathological parameters, and radiological characteristics were reviewed. Patient data up to 1 year from the initial diagnosis were reviewed.Of 113 patients with asymptomatic MPE, 46 (41%) became symptomatic within 1 year despite appropriate anticancer treatment. The median time to symptom development was 4 months, and 38 patients (83%) developed symptoms within 6 months. Multivariate logistic regression showed that female sex (odds ratio [OR], 0.256; 95% confidence interval [CI], 0.101-0.649; P = .004) and the depth of pleural effusion on initial computed tomography (CT) (OR, 0.957; 95% CI, 0.932-0.982; P = .001) were independently associated with symptom development of asymptomatic MPE.A fraction of 41% of patients with asymptomatic MPE became symptomatic within 1 year. Female sex and larger MPE on initial CT were independently associated with symptom development of asymptomatic MPE.

Nationwide Surveillance on Antimicrobial Resistance Profiles of Enterococcus faecium and Enterococcus faecalis Isolated from Healthy Food Animals in South Korea, 2010 to 2019

Intestinal commensal bacteria are considered good indicators for monitoring antimicrobial resistance. We investigated the antimicrobial resistance profiles and resistance trends of Enterococcus faecium and Enterococcus faecalis isolated from food animals in Korea between 2010 and 2019. E. faecium and E. faecalis, isolated from chickens and pigs, respectively, presented a relatively high resistance rate to most of the tested antimicrobials. We observed high ciprofloxacin (67.9%), tetracycline (61.7%), erythromycin (59.5%), and tylosin (53.0%) resistance in E. faecium isolated from chickens. Similarly, more than half of the E. faecalis isolates from pigs and chickens were resistant to erythromycin, tetracycline and tylosin. Notably, we observed ampicillin, daptomycin, tigecycline and linezolid resistance in a relatively small proportion of enterococcal isolates. Additionally, the enterococcal strains exhibited an increasing but fluctuating resistance trend (p < 0.05) to some of the tested antimicrobials including daptomycin and/or linezolid. E. faecalis showed higher Multidrug resistance (MDR) rates than E. faecium in cattle (19.7% vs. 8.6%, respectively) and pigs (63.6% vs. 15.6%, respectively), whereas a comparable MDR rate (≈60.0%) was noted in E. faecium and E. faecalis isolated from chickens. Collectively, the presence of antimicrobial-resistant Enterococcus in food animals poses a potential risk to public health.

Observation of Coulomb-Assisted Nuclear Bound State of Ξ^{-}-^{14}N System

In an emulsion-counter hybrid experiment performed at J-PARC, a Ξ^{-} absorption event was observed which decayed into twin single-Λ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as Ξ^{-}+^{14}N→_{Λ}^{10}Be+_{Λ}^{5}He. For the binding energy of the Ξ^{-} hyperon in the Ξ^{-}-^{14}N system a value of 1.27±0.21  MeV was deduced. The energy level of Ξ^{-} is likely a nuclear 1p state which indicates a weak ΞN-ΛΛ coupling.

The role of Zur-regulated lipoprotein A in bacterial morphology, antimicrobial susceptibility, and production of outer membrane vesicles in Acinetobacter baumannii

Background

Zinc uptake-regulator (Zur)-regulated lipoprotein A (ZrlA) plays a role in bacterial fitness and overcoming antimicrobial exposure in Acinetobacter baumannii. This study further characterized the zrlA gene and its encoded protein and investigated the roles of the zrlA gene in bacterial morphology, antimicrobial susceptibility, and production of outer membrane vesicles (OMVs) in A. baumannii ATCC 17978.

Results

In silico and polymerase chain reaction analyses showed that the zrlA gene was conserved among A. baumannii strains with 97–100% sequence homology. Recombinant ZrlA protein exhibited a specific enzymatic activity of D-alanine-D-alanine carboxypeptidase. Wild-type A. baumannii exhibited more morphological heterogeneity than a ΔzrlA mutant strain during stationary phase. The ΔzrlA mutant strain was more susceptible to gentamicin than the wild-type strain. Sizes and protein profiles of OMVs were similar between the wild-type and ΔzrlA mutant strains, but the ΔzrlA mutant strain produced 9.7 times more OMV particles than the wild-type strain. OMVs from the ΔzrlA mutant were more cytotoxic in cultured epithelial cells than OMVs from the wild-type strain.

Conclusions

The present study demonstrated that A. baumannii ZrlA contributes to bacterial morphogenesis and antimicrobial resistance, but its deletion increases OMV production and OMV-mediated host cell cytotoxicity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-020-02083-0.

18 F-labeled 1,2,3-triazole-linked Glu-urea-Lys-based PSMA ligands have good pharmacokinetic properties for positron emission tomography imaging of prostate cancer

BACKGROUND

Prostate-specific membrane antigen (PSMA) is increasingly recognized as an excellent target for prostate cancer imaging and therapy. Finding compounds with a high target-to-nontarget ratio are an important challenge in the development of positron emission tomography (PET) imaging agents. In this study, we attempted to find a suitable compound from a simply-synthesized compound library.

METHOD

¹⁸ F-labeling was achieved in a two-step synthesis consisting of [¹⁸ F]fluorination of azido sulfonates followed by copper(I)-catalyzed click ligation. In vitro binding experiment and in vivo studies were carried out using isogenic PSMA+ PC3-PIP and PSMA- PC3-flu cells and 22RV1 cells. [¹²⁵ I]MIP-1095 was used to measure the binding affinities of compounds through a competitive binding assay, and [¹⁸ F]DCFPyL was used for a comparative assessment of compounds. Radiation dosimetry data were obtained using OLINDA/EXM software.

RESULTS

Nine novel PSMA ligands were synthesized by the combination of three azido compounds and three terminal acetylene-containing Glu-urea-Lys compounds. Among them, compound 6f having a pyridine moiety showed a high binding affinity of 6.51 ± 0.19 nM (K_i ). ¹⁸ F-labeled compounds were obtained at moderate yields within 70 to 75 minutes (including high-performance liquid chromatography purification). Compound [¹⁸ F]6c had the lowest log P of -2.693. MicroPET/computed tomography (CT) images were acquired from 22RV1 cell xenograft mice after injecting [¹⁸ F]6c, [¹⁸ F]6f, and [¹⁸ F]6i. Additional microPET/CT experiments of [¹⁸ F]6c and [¹⁸ F]6f were performed using PSMA+ PC3-PIP and PSMA- PC3-flu cell-bearing mice. [¹⁸ F]6c was selected for further studies because it was found to have high uptake in tumors and rapid renal clearance, resulting in great tumor-to-nontumor ratios and distinct tumor images with very low background activity. Human dosimetry estimation of [¹⁸ F]6c using OLINDA/EXM software was calculated, resulting in an effective dose of 4.35 × 10^-3  mSv/MBq.

CONCLUSIONS

[¹⁸ F]6c showed significant tumor uptake, a high tumor-to-nontumor ratio, and good radiation dosimetry results, suggesting further development as a potential diagnostic PET agent for prostate cancer.

Short communication: First detection of Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus ST30 in raw milk taken from dairy cows with mastitis in South Korea

We identified 199 Staphylococcus aureus isolates from quarter milk samples of 1,289 dairy cattle between 2014 and 2018. About 66% of the isolates were resistant to at least 1 antimicrobial agent; the highest rate of resistance was to penicillin, followed by resistance to ampicillin, erythromycin, and sulfadimethoxine. We obtained 30 methicillin-resistant S. aureus (MRSA) strains from 6 farms in 3 provinces. The MRSA strains exhibited a significantly higher resistance rate to most of the tested antimicrobials than the oxacillin-susceptible strains. The MRSA strains represented 5 genotypes: ST72-t324-SCCmec IV (n = 14), ST30-t1752-SCCmec IV (n = 8), ST188-t189-SCCmec NT (n = 6), ST188-t2284-SCCmec NT (n = 1), and NT-NT-SCCmec IV (n = 1). One of the ST188 MRSA strains represented a novel staphylococcal protein A (spa) type (t2284). In addition, 7 of the 8 ST30 MRSA strains were Panton-Valentine leukocidin (PVL)-positive and carried various staphylococcal enterotoxin encoding genes. This is the first report of PVL-positive ST30 MRSA-t1752-SCCmec IV from bovine mastitis in Korea. All of ST72-t324-SCCmec IV MRSA strains carried staphylococcal enterotoxin and leukotoxin encoding genes. They were also sensitive to most of the tested non-β-lactam antimicrobials. In contrast, ST188-t189 MRSA strains were resistant to multiple antimicrobials and predominantly carried the leukotoxin encoding gene. Taken together, these findings may indicate that dairy cows could be a major source for spreading MRSA strains, and contaminated milk could be a vehicle for transmission. Suitable hygienic measures should be established in dairy farms and processing plants to limit the likelihood of introducing MRSA into the food chain.