Publications by authors named "Hyun An"

Conventional chemotherapy- and radiotherapy-induced cancer senescence, which is characterized by poor proliferation, drug resistance, and senescence-associated secretory phenotype, has gained attention as contributing to cancer relapse and the development of an immunosuppressive tumor microenvironment. However, the association between cancer senescence and anti-tumor immunity is not fully understood. Here, we demonstrate that senescent cancer cells increase the level of PD-L1 by promoting its transcription and glycosylation.

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  • Gangliosides in the brain are essential for maintaining the integrity of the central nervous system, but their complex structures have not been fully understood, limiting our insight into their function.
  • This study employs a glycolipidomic method to analyze ganglioside isomers in specific brain regions of mice, revealing both unique and shared profiles across different areas.
  • The findings indicate significant biological implications of gangliosides' abundance and interaction networks, which could lead to identifying new therapeutic targets for brain diseases.
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Early-life immune exposures can profoundly impact lifelong health. However, functional mechanisms underlying fetal immune development remain incomplete. Erythrocytes are not typically considered active immune mediators, primarily because erythroid precursors discard their organelles as they mature, thus losing the ability to alter gene expression in response to stimuli.

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  • Impaired ion channels in the Golgi apparatus are linked to structural issues like fragmentation, which occurs alongside cognitive deficits in Alzheimer's disease.
  • Researchers identified a new protein called GolpHCat, crucial for regulating Golgi pH and memory, demonstrating unique electrical properties and inhibition by gluconate.
  • Studies involving GolpHCat-knockout mice showed that the absence of this protein leads to altered Golgi structure and impaired memory, highlighting it as a potential target for treating Golgi-related diseases and cognitive issues.
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Efforts to cure BCR::ABL1 B cell acute lymphoblastic leukemia (Ph+ ALL) solely through inhibition of ABL1 kinase activity have thus far been insufficient despite the availability of tyrosine kinase inhibitors (TKIs) with broad activity against resistance mutants. The mechanisms that drive persistence within minimal residual disease (MRD) remain poorly understood and therefore untargeted. Utilizing 13 patient-derived xenograft (PDX) models and clinical trial specimens of Ph+ ALL, we examined how genetic and transcriptional features co-evolve to drive progression during prolonged TKI response.

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Clinical trials with single-agent venetoclax/ABT-199 (anti-apoptotic BCL2 inhibitor) revealed that diffuse large B-cell lymphoma (DLBCL) is not solely dependent on BCL2 for survival. Gaining insight into pathways/proteins that increase venetoclax sensitivity or unique vulnerabilities in venetoclax-resistant DLBCL would provide new potential treatment avenues. Therefore, we generated acquired venetoclax-resistant DLBCL cells and evaluated these together with intrinsically venetoclax-resistant and -sensitive DLBCL lines.

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  • The study investigates producing therapeutic monoclonal antibodies (mAbs) in transgenic plants, highlighting benefits like large-scale production and reduced risk of animal contaminants.
  • It focuses on modifying the mAb SO57 using Fc-engineering with an ER-retention signal to improve its binding to the human neonatal Fc receptor (hFcRn), which influences the antibody's lifespan in circulation.
  • Results showed that engineered variants of mAbK SO57 maintained similar glycan structures and neutralizing activity against the rabies virus, indicating enhanced effectiveness without compromising their function.
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The limited proliferative capacity of erythroid precursors is a major obstacle to generate sufficient numbers of in vitro-derived red blood cells (RBC) for clinical purposes. We and others have determined that BMI1, a member of the polycomb repressive complex 1 (PRC1), is both necessary and sufficient to drive extensive proliferation of self-renewing erythroblasts (SREs). However, the mechanisms of BMI1 action remain poorly understood.

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  • Scientists studied how red blood cells (RBCs) are made during development, focusing on two main types: primitive and definitive RBCs.
  • They used special lab-made cells called iPSCs to create both types of RBCs from the same genetic background.
  • Their research showed that primitive RBCs are different in size and function compared to definitive RBCs, which helps understand blood diseases better and could lead to better blood products for transfusions.
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Rapid, sensitive, inexpensive point-of-care molecular diagnostics are crucial for the efficient control of spreading viral diseases and biosecurity of global health. However, the gold standard, polymerase chain reaction (PCR) is time-consuming and expensive and needs specialized testing laboratories. Here, we report a low-cost yet fast, selective, and sensitive Plasmonic Optical Wells-Based Enhanced Rate PCR: POWER-PCR.

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The cAMP response element-binding protein (CREB) and CREB-regulated transcription coactivators (CRTCs) cooperate in the transcriptional activation of microphthalmia-associated transcription factor subtype M (MITF-M) that is a master regulator in the biogenesis, pigmentation and transfer of melanosomes at epidermal melanocytes. Here, we propose the targeting of phosphorylation circuits on CREB and CRTCs in the expression of MITF-M as the rationale to prevent skin hyperpigmentation by elucidating the inhibitory activity and mechanism of yakuchinone A (Yaku A) on facultative melanogenesis. We employed human epidermal melanocyte cell, mouse skin, and mouse melanoma cell, and applied Western blotting, reverse transcription-polymerase chain reaction, immunoprecipitation and confocal microscopy to conduct this study.

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Introduction: Ovarian cancer, characterized by metastasis and reduced 5-year survival rates, stands as a substantial factor in the mortality of gynecological malignancies worldwide. The challenge of delayed diagnosis originates from vague early symptoms and the absence of efficient screening and diagnostic biomarkers for early cancer detection. Recent studies have explored the intricate interplay between ovarian cancer and protein glycosylation, unveiling the potential significance of glycosylation-oriented biomarkers.

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Patients with Down syndrome (DS), or trisomy 21 (T21), are at increased risk of transient abnormal myelopoiesis (TAM) and acute megakaryoblastic leukemia (ML-DS). Both TAM and ML-DS require prenatal somatic mutations in GATA1, resulting in the truncated isoform GATA1s. The mechanism by which individual chromosome 21 (HSA21) genes synergize with GATA1s for leukemic transformation is challenging to study, in part due to limited human cell models with wild-type GATA1 (wtGATA1) or GATA1s.

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Cyclic imines (CIs) produced by microalgae species and accumulating in the food chain of marine organisms are novel biotoxins that do not belong to the classical group of marine biotoxins. In the past, CIs were found only in limited areas, but in recent years, rapid changes in marine ecosystems have led to widespread CIs, increasing exposure to toxic risks. Monitoring of CIs is therefore required, but still analytically challenging due to the presence of high levels of analogues and interference from other lipophilic substances.

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The Coronavirus Disease 2019 (COVID-19) is transitioning into the endemic phase. Nonetheless, it is crucial to remain mindful that pandemics related to infectious respiratory diseases (IRDs) can emerge unpredictably. Therefore, we aimed to develop and validate a severity assessment model for IRDs, including COVID-19, influenza, and novel influenza, using CT images on a multi-centre data set.

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Polymerase chain reaction (PCR) in small fluidic systems not only improves speed and sensitivity of deoxyribonucleic acid (DNA) amplification but also achieves high-throughput quantitative analyses. However, air bubble trapping and growth during PCR has been considered as a critical problem since it causes the failure of DNA amplification. Here we report bubble-free diatom PCR by exploiting a hierarchically porous silica structure of single-celled algae.

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Glycosylation is a crucial attribute for biotherapeutics with significant impacts on quality, stability, safety, immunogenicity, pharmacokinetics, and efficacy. Therefore, to ensure consistent glycosylation, a systematic review of biotherapeutics is absolutely required including the variable glycan structure (micro-heterogeneity) and different occupancy at individual site (macro-heterogeneity) from drug design to upstream and downstream bioprocesses. Various methods have been used for glyco-characterization of biotherapeutics at the glycan, glycopeptide, and intact protein levels.

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Microscopy of mummified visceral tissue from a Medici family member in Italy identified a potential blood vessel containing erythrocytes. Giemsa staining, atomic force microscopy, and immunohistochemistry confirmed Plasmodium falciparum inside those erythrocytes. Our results indicate an ancient Mediterranean presence of P.

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Sialyllactose (SL) is the most abundant acidic oligosaccharide in human breast milk and plays a primary role in various biological processes. Recently, SL has attracted attention as an excellent dietary supplement for arthritis because it is effective in cartilage protection and treatment. Despite the superior function of SL, there are few pharmacological studies of SL according to blood concentrations in arthritis models.

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Unlabelled: Pollutant exposure due to industrial development increases oxidative stress in human bodies. Dietary intake of antioxidant shows a protective effect against oxidative damage induced by oxidative stress. Therefore, the development of natural antioxidants is needed.

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The optimal use of many biotherapeutics is restricted by Anti-drug antibodies (ADAs) and hypersensitivity responses which can affect potency and ability to administer a treatment. Here we demonstrate that Re-surfacing can be utilized as a generalizable approach to engineer proteins with extensive surface residue modifications in order to avoid binding by pre-existing ADAs. This technique was applied to Asparaginase (ASN) to produce functional mutants with up to 58 substitutions resulting in direct modification of 35% of surface residues.

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Characterization of therapeutic monoclonal antibodies (mAbs) represents a major challenge for analytical sciences due to their heterogeneity associated with post-translational modifications (PTMs). The protein glycosylation requires comprehensive identification, which could influence on the mAbs' structure and their function. Here, we demonstrated high-resolution tandem mass spectrometry with an ultra-high-performance liquid chromatography for characterization and comparison between biologics and biosimilar of infliximab at an advanced level.

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