• Journal of Ginseng Research
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• v.18 no.2
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• pp.95-101
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• 1994

Saponin of Panax ginseng (C.A. Meyer) is composed of Protopanaxatriol (PT) and Protopanaxa- diol (PD). We investigated the effects of PT and PD on the contractility and $^{45}Ca$ uptake in the pig coronary artery. Isometric tension in the helical strips and $^{45}Ca$ uptake in the ring strips were measured in the presence or absence of PT and PD. PT and PD did not affect the high K+ (40 mM)-induced contraction but relaxed the ACh-induced contraction in a dose4ependent manner (1~10 mg/dl). The vasorelaxing effect of PT on the ACh-induced contraction was more potent than that of PD. Those relaxations were partially suppressed by the rubbing of endothelium removal. ACh-induced contraction in the $Ca^{2+}$-free Tyrode's solution was suppressed by the pretreatment of PT or PD. Following the depletion of ACh-sensitive intracellular $Ca^{2+}$ pool, ACh-induced contraction was suppressed by the pratreatment of PT or PD. With the pretreatment of PT or PD, $^{45}Ca$ uptake by high K+ (43 mM) was not changed but that by ACh was suppressed in the pig coronary artery. From the above results, we suggested that the vasorelaxing effect of PT and PD of Panax ginseng was due to inhibition of intracellular $Ca^{2+}$ release, inhibition of $Ca^{2+}$ uptake via receptor-operated $Ca^{2+}$ channels and in part a release of vasorelaxing factor from endothelium in pig coronary artery.

• Biomolecules & Therapeutics
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• v.3 no.1
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• pp.21-27
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• 1995

The only compounds with antagonistic activity via AT$_1$receptor, one of two subtypes of angiotensin II (AII) receptor, have been demonstrated to block the vasoconstriction effects of AII and thereby provide therapeutic potential. This initiated the search for compounds with high specific affinity to AT$_1$receptor and their effective screening methods. The radioligand binding assay for the AII receptor is regarded as the primary method for the evaluation of AT$_1$receptor antagonists for their activity. In this paper, we characterized the liver AT$_1$receptor and describe the efficient method of the radioligand binding assay using rat liver as a source of AT$_1$receptor. Equilibrium binding studies with rat adrenal cortex, adrenal medulla, liver and bovine adrenal showed that the specific bindings of [$^3$H] AII were saturable in all tissues and the Scatchard plots of those data were linear, suggesting a single population of binding sites. Hill slopes were very near to the unity in all tissues. Kinetic studies of [$^3$H) AII binding in rat liver homogenates yielded two association rate constants, 4.10$\times$10$^{7}$ M$^{-1}$ min$^{-1}$ and 4.02$\times$10$^{9}$ M$^{-1}$ min$^{-1}$ , with a single dissociation rate constant, 7.07$\times$10$^{-3}$ min-$^{-1}$ , possibly due to the partial dissociation phenomenon. The rank order of inhibition potencies of [$^3$H] AII binding in rat liver was AII>Sarile>Losartan>PD 123177. Rat liver homogenates revealed to have very high density of homogeneous population of the AT$_1$receptor subtype, as the specifically bound [$^3$H] AII was not inhibited by PD 123177, the nonpeptide antagonist of AT$_2$. The results of this study demonstrated that the liver homogenates from rats could be the best receptor preparation for the AT$_1$receptor binding assay and provide an efficient system for the screening of newly synthesized candidate compounds of AT$_1$receptor antagonist.

• Journal of Yeungnam Medical Science
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• v.38 no.4
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• pp.308-317
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• 2021

Cancer is the leading cause of death and is on the rise worldwide. Until 2010, the development of targeted treatment was mainly focused on the growth mechanisms of cancer. Since then, drugs with mechanisms related to tumor immunity, especially immune checkpoint inhibitors, have proven effective, and most pharmaceutical companies are striving to develop related drugs. Programmed cell death-1 and programmed cell death ligand-1 inhibitors have shown great success in various cancer types. They showed durable and sustainable responses and were approved by the U.S. Food and Drug Administration. However, the response to inhibitors showed low percentages of cancer patients; 15% to 20%. Therefore, combination strategies with immunotherapy and conventional treatments were used to overcome the low response rate. Studies on combination therapy have typically reported improvements in the response rate and efficacy in several cancers, including non-small cell lung cancer, small cell lung cancer, breast cancer, and urogenital cancers. The combination of chemotherapy or targeted agents with immunotherapy is one of the leading pathways for cancer treatment.

• Journal of Gastric Cancer
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• v.24 no.1
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• pp.29-56
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• 2024

In recent years, remarkable progress has been made in the molecular profiling of gastric cancer. This progress has led to the development of various molecular classifications to uncover subtype-specific dependencies that can be targeted for therapeutic interventions. Human epidermal growth factor receptor 2 (HER2) is a crucial biomarker for advanced gastric cancer. The recent promising results of novel approaches, including combination therapies or newer potent agents such as antibody-drug conjugates, have once again brought attention to anti-HER2 targeted treatments. In HER2-negative diseases, the combination of cytotoxic chemotherapy and programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) inhibitors has become the established standard of care in first-line settings. In the context of gastric cancer, potential biomarkers such as PD-L1 expression, Epstein-Barr virus, microsatellite instability, and tumor mutational burden are being considered for immunotherapy. Recently, promising results have been reported in studies on anti-Claudin18.2 and fibroblast growth factor receptor 2 treatments. Currently, many ongoing trials are aimed at identifying potential targets using novel approaches. Further investigations will be conducted to enhance the progress of these therapies, addressing challenges such as primary and acquired resistance, tumor heterogeneity, and clonal evolution. We believe that these efforts will improve patient prognoses. Herein, we discuss the current evidence of potential targets for systemic treatment, clinical considerations, and future perspectives.

• Tuberculosis and Respiratory Diseases
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• v.83 no.1
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• pp.51-60
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• 2020

Background: Programmed death-ligand 1 (PD-L1) expression is tested by immunohistochemistry (IHC)-22C3, SP263, and SP142. The aim of this study is to evaluate the correlation among the three methods of PD-L1 IHC in non-small cell lung cancer (NSCLC) and clinical significance of PD-L1 expression in lung adenocarcinoma with an epidermal growth factor receptor (EGFR)-tyrosine kinase domain mutation. Methods: The results of 230 patients who were pathologically confirmed as having NSCLC; tested using PD-L1 IHC 22C3, SP263, and SP142 methods; and evaluated via the peptide nucleic acid clamping method to confirm EGFR mutation, were analyzed in this study. Results: 164 patients underwent both the SP263 and 22C3 tests. There was a significant positive correlation between the outcomes of the two tests (Spearman correlation coefficient=0.912, p<0.001), with a derived regression equation as follows: 22C3=15.2+0.884×SP263 (R²=0.792, p<0.001). There was no relationship between the expression of PD-L1 and clinical parameters, including EGFR-tyrosine kinase inhibitor (TKI) mutation. The PD-L1 expression in patients treated with EGFR-TKI yielded a 2-month-shorter progression period than that in the PD-L1-negative group. However, this did not reach statistical significance (PD-L1<1% vs. PD-L1≥1%, 10 months vs. 8 months). Conclusion: The results of the 22C3 and those of SP263 methods were in good correlation with one another. Since the PD-L1 expression is not influenced by the EGFR mutation, it is necessary to perform a PD-L1 test to set the treatment direction in the patients with EGFR-mutant NSCLC.

• Journal of Breast Cancer
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• v.21 no.4
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• pp.406-414
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• 2018

Purpose: T-cell immunoglobulin and mucin domain-containing molecule 3 (TIM-3) is an emerging immune response molecule related to T-cell anergy. There has been tremendous interest in breast cancer targeting immune checkpoint molecules, especially in the triple-negative breast cancer (TNBC). This study was designed to investigate TIM-3 expression on tumor infiltrating lymphocytes (TILs), its relationships with clinicopathological parameters and expression of programmed death receptor 1 (PD-1)/programmed death receptor ligand 1 (PD-L1), and its prognostic role. Methods: Immunohistochemistry on tissue microarray blocks produced from 109 samples of invasive ductal carcinoma type TNBC was performed with antibodies toward TIM-3, PD-1, PD-L1 and breast cancer-related molecular markers. Associations between their expression and clinicopathological parameters as well as survival analyses were performed. Results: TIM-3 was expressed in TILs from all 109 TNBCs, consisting of 17 cases (<5%), 31 cases (6%-25%), 48 cases (26%-50%), and 13 cases (>51%). High TIM-3 was significantly correlated with younger patients (p=0.0101), high TILs (p=0.0029), high tumor stage (p=0.0018), high PD-1 (p=0.0001) and high PD-L1 (p=0.0019), and tended to be associated with higher histologic grade, absence of extensive in situ components and microcalcification. High TIM-3 expression was significantly associated with a combinational immunophenotype group of high PD-L1 and high PD-1 (p<0.0001). High TIM-3 demonstrated a significantly better disease-free survival (DFS) (p<0.0001) and longer overall survival (OS) (p=0.0001), together with high TILs and high PD-1. In univariate survival analysis, high TIM-3 showed reduced relapse risk (p<0.0001) and longer OS (p=0.0003), together with high PD-1 expression. In multivariate analysis, high TIM-3 was statistically significant in predicting prognosis, showing better DFS (hazard ratio [HR], 0.0994; 95% confidence interval [CI], 0.0296-0.3337; p=0.0002) and longer OS (HR, 0.1109; 95% CI, 0.0314-0.3912; p=0.0006). Conclusion: In this study, we demonstrate that TIM-3 expression is an independent positive prognostic factor in TNBC, despite its association with poor clinical and pathologic features.

• Molecules and Cells
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• v.41 no.8
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• pp.742-752
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• 2018

Parkinson's disease (PD) is a neurodegenerative disease characterized by progressive degeneration of dopaminergic (DAergic) neurons, particularly in the substantia nigra (SN). Although circadian dysfunction has been suggested as one of the pathophysiological risk factors for PD, the exact molecular link between the circadian clock and PD remains largely unclear. We have recently demonstrated that $REV-ERB{\alpha}$, a circadian nuclear receptor, serves as a key molecular link between the circadian and DAergic systems. It competitively cooperates with NURR1, another nuclear receptor required for the optimal development and function of DA neurons, to control DAergic gene transcription. Considering our previous findings, we hypothesize that $REV-ERB{\alpha}$ may have a role in the onset and/or progression of PD. In the present study, we therefore aimed to elucidate whether genetic abrogation of $REV-ERB{\alpha}$ affects PD-related phenotypes in a mouse model of PD produced by a unilateral injection of 6-hydroxydopamine (6-OHDA) into the dorsal striatum. $REV-ERB{\alpha}$ deficiency significantly exacerbated 6-OHDA-induced motor deficits as well as DAergic neuronal loss in the vertebral midbrain including the SN and the ventral tegmental area. The exacerbated DAergic degeneration likely involves neuroinflammation-mediated neurotoxicity. The $REV-erb{\alpha}$ knockout mice showed prolonged microglial activation in the SN along with the over-production of interleukin $1{\beta}$, a pro-inflammatory cytokine, in response to 6-OHDA. In conclusion, the present study demonstrates for the first time that genetic abrogation of $REV-ERB{\alpha}$ can increase vulnerability of DAergic neurons to neurotoxic insults, such as 6-OHDA, thereby implying that its normal function may be beneficial for maintaining DAergic neuron populations during PD progression.

• Biomolecules & Therapeutics
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• v.26 no.6
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• pp.539-545
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• 2018

4-Hydroxy-2-(4-hydroxyphenethyl)isoindoline-1,3-dione (PD1) is a synthetic phthalimide derivative of a marine compound. PD1 has peroxisome proliferator-activated receptor (PPAR) ${\gamma}$ agonistic and anti-inflammatory effects. This study aimed to investigate the effect of PD1 on allergic asthma using rat basophilic leukemia (RBL)-2H3 mast cells and an ovalbumin (OVA)-induced asthma mouse model. In vitro, PD1 suppressed ${\beta}$-hexosaminidase activity in RBL-2H3 cells. In the OVA-induced allergic asthma mouse model, increased inflammatory cells and elevated Th2 and Th1 cytokine levels were observed in bronchoalveolar lavage fluid (BALF) and lung tissue. PD1 administration decreased the numbers of inflammatory cells, especially eosinophils, and reduced the mRNA and protein levels of the Th2 cytokines including interleukin (IL)-4 and IL-13, in BALF and lung tissue. The severity of inflammation and mucin secretion in the lungs of PD1-treated mice was also less. These findings indicate that PD1 could be a potential compound for anti-allergic therapy.

• The Korean Journal of Pain
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• v.34 no.1
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• pp.58-65
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• 2021

Background: Supraspinal delivery of neurotensin (NTS), which may contribute to the effect of a systemically administered agonist, has been reported to be either pronociceptive or antinociceptive. Here, we evaluated the effects of systemically administered NTSR1 agonist in a rat model of neuropathic pain and elucidated the underlying supraspinal mechanism. Methods: Neuropathic pain was induced by L5 and L6 spinal nerve ligation in male Sprague-Dawley rats. The effects of intraperitoneally administered NTSR1 agonist PD 149163 was assessed using von Frey filaments. To examine the role of 5-HT neurotransmission, a serotonin (5-HT) receptor antagonist dihydroergocristine was pretreated intrathecally, and spinal microdialysis studies were performed to measure the change in extracellular level of 5-HT in response to PD 149163 administration. To investigate the supraspinal mechanism, NTSR1 antagonist 48692 was microinjected into the rostral ventromedial medulla (RVM) prior to systemic PD 149163. Additionally, the effect of intrathecal DHE on intra-RVM PD 149163 was assessed. Results: Intraperitoneally administered PD 149163 exhibited a dose-dependent attenuation of mechanical allodynia. This effect was partially reversed by intrathecal pretreatment with dihydroergocristine and was accompanied by an increased extracellular level of 5-HT in the spinal cord. The PD 149163-produced antinociception was also blocked by intra-RVM SB 48692. Direct injection of PD 149163 into the RVM mimicked the maximum effect of the same drug delivered intraperitoneally, which was reversed by intrathecal dihydroergocristine. Conclusions: These observations indicate that systemically administered NTSR1 agonist produces antinociception through the NTSR1 in the RVM, activating descending serotonergic projection to release 5-HT into the spinal dorsal horn.

• Biomolecules & Therapeutics
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• v.30 no.5
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• pp.418-426
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• 2022

Chimeric antigen receptor T (CAR-T) cell therapy is one of the promising anticancer treatments. It shows a high overall response rate with complete response to blood cancer. However, there is a limitation to solid tumor treatment. Additionally, this currently approved therapy exhibits side effects such as cytokine release syndrome and neurotoxicity. Alternatively, bispecific antibody is an innovative therapeutic tool that simultaneously engages specific immune cells to disease-related target cells. Since programmed death ligand 1 (PD-L1) is an immune checkpoint molecule highly expressed in some cancer cells, in the current study, we generated αCD3xαPD-L1 bispecific antibody (BiTE) which can engage T cells to PD-L1⁺ cancer cells. We observed that the BiTE-bound OT-1 T cells effectively killed cancer cells in vitro and in vivo. They substantially increased the recruitment of effector memory CD8⁺ T cells having CD8⁺CD44⁺CD62L^low phenotype in tumor. Interestingly, we also observed that BiTE-bound polyclonal T cells showed highly efficacious tumor killing activity in vivo in comparison with the direct intravenous treatment of bispecific antibody, suggesting that PD-L1-directed migration and engagement of activated T cells might increase cancer cell killing. Additionally, BiTE-bound CAR-T cells which targets human Her-2/neu exhibited enhanced killing effect on Her-2-expressing cancer cells in vivo, suggesting that this could be a novel therapeutic regimen. Collectively, our results suggested that engaging activated T cells with cancer cells using αCD3xαPD-L1 BiTE could be an innovative next generation anticancer therapy which exerts simultaneous inhibitory functions on PD-L1 as well as increasing the infiltration of activated T cells having effector memory phenotype in tumor site.