Publications by authors named "Sungwon Shin"

Article Synopsis
  • Manganese porphyrins, particularly MnTnBuOE-2-PyP (BMX-001), show enhanced effects when used with radiotherapy, but the exact immune mechanisms involved are not fully understood.
  • In a study with mice bearing 4T1 tumors, it was found that using MnBuOE alongside radiotherapy led to a significant reduction in cancer-associated fibroblasts and altered interactions between various immune cells.
  • The combination treatment (MnBuOE/RT) resulted in increased maturation markers in dendritic cells and more M1 macrophages, showing promise for better immunomodulation compared to radiotherapy alone.
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  • The study explores whether entinostat, a histone deacetylase inhibitor, enhances the effectiveness of radiotherapy and anti-PD-1 treatment in lung cancer using a mouse model.
  • Results showed that entinostat, combined with radiation, delayed tumor growth and altered immune cell populations, increasing CD8 T cells while decreasing regulatory T-cells (Tregs).
  • The findings suggest entinostat may boost immune responses, potentially leading to improved cancer treatment strategies that integrate ionizing radiation and immunotherapy.
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Intrinsic or acquired radioresistance often limits the efficacy of radiation therapy (RT), thereby leading to local control failure. Cancerous cells have abnormal pH dynamics due to high metabolic demands, but it is unclear how pH dynamics contribute to radioresistance. In this study, we investigated the role of Na-H exchange 1 (NHE1), the major intracellular pH (pH) regulator, in RT response.

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  • This study explores how removing the spleen (splenectomy) affects the growth of lung cancer in mice, particularly how it interacts with radiation treatment.
  • Human and mouse lung cancer cells were injected into different strains of mice, and the researchers analyzed the impact of splenectomy and radiation on tumor growth and immune responses.
  • The findings indicate that splenectomy can hinder tumor growth but does not enhance radiation's effects; however, it alters immune cell activity and improves outcomes when combined with anti-PD-1 therapy.
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Immunomodulation by radiotherapy (RT) is an emerging strategy for improving cancer immunotherapy. Nanomaterials have been employed as innovative tools for cancer therapy. This study aimed to investigate whether mesoporous silica nanoparticles (MSNs) enhance RT-mediated local tumor control and the abscopal effect by stimulating anti-cancer immunity.

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Tumor migration and invasion induced by the epithelial-to-mesenchymal transition (EMT) are prerequisites for metastasis. Here, we investigated the inhibitory effect of a mimic of superoxide dismutase (SOD), cationic Mn(III) -substituted -n-hexylpyridylporphyrin (MnTnHex-2-PyP, MnHex) on the metastasis of breast cancer in cellular and animal models, focusing on the migration of tumor cells and the factors that modulate this behavior. Wound healing and Transwell migration assays revealed that the migration of mouse mammary carcinoma 4T1 cells was markedly reduced during the concurrent treatment of MnHex and radiation therapy (RT) compared with that of the control and RT alone.

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Article Synopsis
  • Research-oriented universities prioritize Responsible Conduct of Research (RCR) training for faculty and students, but current training methods are ineffective in addressing real ethical dilemmas faced in academia.
  • A study involving 50 research stakeholders at a top-tier institution revealed discrepancies between perceptions of unethical issues (like inappropriate relationships and authorship concerns) and what researchers believe are the most critical RCR elements.
  • The findings suggest that previous training has not significantly influenced researchers' judgments on ethics, prompting a call for improved training methods to better equip both current and future researchers.
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We evaluated the effect of manganese ferrite nanoparticles (MFN) on radiosensitization and immunologic responses using the murine hepatoma cell line Hepa1-6 and the syngeneic mouse model. The clonogenic survival of Hepa1-6 cells was increased by hypoxia, while being restricted by ionizing radiation (IR) and/or MFN. Although MFN suppressed HIF-1α under hypoxia, the combination of IR and MFN enhanced apoptosis and DNA damage in Hepa1-6 cells.

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Radiation therapy (RT) is an effective local treatment for unresectable hepatocellular carcinoma (HCC), but there are currently no predictive biomarkers to guide treatment decision for RT or adjuvant systemic drugs to be combined with RT for HCC patients. Previously, we reported that extracts of the marine sponge sp. may contain a natural radiosensitizer for HCC treatment.

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The observation of histopathology using optical microscope is an essential procedure for examination of tissue biopsies or surgically excised specimens in biological and clinical laboratories. However, slide-based microscopic pathology is not suitable for visualizing the large-scale tissue and native 3D organ structure due to its sampling limitation and shallow imaging depth. Here, we demonstrate serial optical coherence microscopy (SOCM) technique that offers label-free, high-throughput, and large-volume imaging of ex vivo mouse organs.

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Due to a superior dose conformity to the target, proton beam therapy (PBT) continues to rise in popularity. Recently, considerable efforts have been directed toward discovering treatment options for use in combination with PBT. This study aimed to investigate the targeting of checkpoint kinase 1 (CHK1), a critical player regulating the G2/M checkpoint, as a promising strategy to potentiate PBT in human triple-negative breast cancer (TNBC) cells.

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Although the concurrent use of a chemotherapeutic agent and radiotherapy improves survival in patients with locally advanced or recurrent cervical cancer, severe side effects related to chemotherapy are frequent and may result in a low quality of life for the patients. In this study, we investigated the effects of a combination of Wee1 inhibitor (AZD1775) and irradiation in cervical cancer. In vitro effects of AZD1775 with irradiation in human cervical cancer cells were assessed by clonogenic survival and apoptosis assays.

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Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) affords stem cell protection and links microbes to intestinal epithelial regeneration. We investigated whether NOD2 status is associated with crypt survival and intestinal epithelial regeneration independent of microbiota-derived molecules. To assess crypt survival, a clonogenic microcolony assay was performed with 15 Gy of X-ray irradiation.

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Recent studies have highlighted the implications of genetic variations in the relative biological effectiveness (RBE) of proton beam irradiation over conventional X-ray irradiation. Proton beam radiotherapy is a reasonable radiotherapy option for hepatocellular carcinoma (HCC), but the impact of genetic difference on the HCC RBE remains unknown. Here, we determined proton RBE in human HCC cells by exposing them to various doses of either 6-MV X-rays or 230-MeV proton beams.

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When radiotherapy is applied to the abdomen or pelvis, normal tissue toxicity in the gastrointestinal (GI) tract is considered a major dose-limiting factor. Proton beam therapy has a specific advantage in terms of reduced doses to normal tissues. This study investigated the fundamental differences between proton- and X-ray-induced intestinal injuries in mouse models.

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This study evaluated the effect of air injection depth in the big-bubble (BB) technique, which is used for corneal tissue preparation in lamellar keratoplasty. The BB technique was performed on ex vivo human corneoscleral buttons using a depth-sensing needle, based on optical coherence tomography (OCT) imaging technology. The needle tip, equipped with a miniaturized OCT depth-sensing probe, was inserted for air injection at a specified depth.

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Recent progress in three-dimensional optical imaging techniques allows visualization of many comprehensive biological specimens. Optical clearing methods provide volumetric and quantitative information by overcoming the limited depth of light due to scattering. However, current imaging technologies mostly rely on the synthetic or genetic fluorescent labels, thus limits its application to whole-body visualization of generic mouse models.

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Tumor hypoxia is a major mechanism of resistance to radiation therapy (RT), which is associated with poor prognosis in affected cancer patients. Various approaches to treat hypoxic and radioresistant cancers, including pancreatic cancer, have shown limited success. Fucoidan, a polysaccharide from brown seaweed, has antitumor and antiangiogenesis activities.

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A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

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Deep anterior lamellar keratoplasty (DALK) is an emerging surgical technique for the restoration of corneal clarity and vision acuity. The big-bubble technique in DALK surgery is the most essential procedure that includes the air injection through a thin syringe needle to separate the dysfunctional region of the cornea. Even though DALK is a well-known transplant method, it is still challenged to manipulate the needle inside the cornea under the surgical microscope, which varies its surgical yield.

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We previously demonstrated that overexpression of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) promotes increased cell proliferation and tumorigenic potential through upregulation of specificity protein 1 (Sp1) and acyl-CoA-binding protein (ACBP). Fatty acid synthase (FASN) is a key enzyme in fatty acid biosynthesis, and its expression in various cancers is associated with survival, poor prognosis and cancer recurrence. In the present study, we evaluated whether PGC-1α regulated FASN expression in human colorectal cancer (SNU-C4 and HT-29) cells.

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Although efficacy of combined histone deacetylase (HDAC) inhibitors and conventional photon radiotherapy is being tested in clinical trials, their combined effect with proton beam radiotherapy has yet to be determined. Here, we compared combined effect of valproic acid (VPA), a class I and II HDAC inhibitor and antiepileptic drug with proton and photon irradiation in hepatocellular carcinoma (HCC) cells in vitro and in vivo. We found that VPA sensitized more Hep3B cells to proton than to photon irradiation.

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Aims: Cationic manganese (Mn)-substituted N-pyridylporphyrin-based potent mimics of the family of superoxide dismutases (SODs) protect normal tissues from injury related to ionizing radiation (IR) by reducing levels of reactive oxygen and nitrogen species (ROS/RNS). Furthermore, Mn-porphyrins have demonstrated antitumor and radiosensitizing effects on cancer cells by promoting IR-induced tumor vasculature damage and apoptotic processes. In this study, we explored the underlying mechanisms of Mn-porphyrin-mediated tumor radiosensitization using murine mammary carcinoma 4T1 and melanoma B16 cells in vitro and in vivo.

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Acute myeloid leukemia (AML) is a heterogeneous myeloid clonal disorder exhibiting the accumulation of immature myeloid progenitors in the bone marrow and peripheral blood. Standard AML therapy requires intensive combination chemotherapy, which leads to significant treatment-related toxicity. The search for new, low toxic marine agents, inducing the generation of ceramide in leukemic cells is a new approach to improve the therapy of leukemia.

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Purpose: This study is to investigate the effect of captopril when combined with irradiation.

Materials And Methods: 4T1 (mouse mammary carcinoma) cells were injected in the right hind leg of Balb/c mice. Mice were randomized to four groups; control (group 1), captopril-treated (group 2), irradiated (group 3), irradiated and captopril-treated concurrently (group 4).

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