Publications by authors named "Keon W Kang"

Tamoxifen (TAM) resistance is a main cause of therapeutic failure in breast cancers. Although methionine dependency is a phenotypic characteristic of tumor cells, the role of sulfur amino acid metabolism in chemotherapy resistance remains to be elucidated. This study compared metabolite profiles of sulfur amino acid metabolism from methionine to taurine or glutathione (GSH) between normal MCF-7 and TAM-resistant MCF-7 (TAMR-MCF-7) cells.

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The acquisition of tamoxifen resistance is a major therapeutic problem in breast cancer. We developed a tamoxifen-resistant MCF-7 (TRM-7) cell line to elucidate the molecular mechanisms and factors associated with acquisition of such resistance. We showed that phosphorylation of STAT3 at tyrosine 705 (Y705) and RANTES expression are increased in response to tamoxifen in human breast cancer cells.

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Bioassay-guided fractionation of the EtOAc extract of the root of Erythrina addisoniae (Leguminosae) resulted in the isolation of four new (1-4), along with 2 known prenylated isoflavonoids (5-6). The structures of the isolates were assigned on the basis of spectroscopic data analysis, focusing on interpretation of 1D and 2D NMR, and MS data. All the isolates were evaluated for their inhibitory effects on protein tyrosine phosphatase 1B (PTP1B), as well as their growth inhibition on MCF7, adriamycin-resistant MCF7 (MCF7/ADR), and MDA-MB-231 breast cancer cell lines.

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Background And Purpose: Neointima is considered a critical event in the development of vascular occlusive disease. Nectandrin B from nutmeg functions as a potent AMP-activated protein kinase (AMPK) activators. The present study addressed whether nectandrin B inhibits intimal hyperplasia in guide wire-injured arteries and examined its molecular mechanism.

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Endothelial nitric oxide synthase (eNOS) has important regulatory functions in vascular tone, and impaired endothelium-dependent vasodilatation is a key event in diabetes and atherosclerosis. Vitis amurensis grapes containing resveratrol oligomers are consumed as wine and fruit and have antioxidative and neuroprotective effects. In this study, our goal was identify the most potent eNOS-activating compound among six stilbenes and oligostilbenes found in V.

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Indocyanine green (ICG) is an FDA-approved near infrared (NIR) fluorescent dye used in clinical imaging. However, its applications remain limited due to its short half-life, nonspecific plasma binding, optical instability, and poor aqueous stability. Dye doped silica nanoparticles provide an effective barrier in keeping the dye away from the surrounding environment, but ICG cannot be encapsulated into silica easily by conventional methods.

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Sentinel lymph node (SLN) mapping has been widely used to predict the metastatic spread of primary tumor to regional lymph nodes in clinical practice. In this research, a new near-infrared (NIR)-emitting polymer nanogel (NIR-PNG) having a hydrodynamic diameter of about 30 nm, which is optimal for lymph node uptake, was developed. The NIR-emitting polymer nanoprobes were designed and synthesized by conjugating IRDye800 organic dye to biodegradable pullulan-cholesterol polymer nanogels.

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Acquired resistance to tamoxifen (TAM) is a serious therapeutic problem among estrogen-receptor-positive breast cancer patients. We have previously reported that TAM-resistant MCF-7 (TAMR-MCF-7) cells have elevated angiogenic potential via Pin1-dependent vascular endothelial growth factor (VEGF) production. Vitis amurensis grape consumed as wine and fruit contains several resveratrol-like stilbenes or oligostilbenes.

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Enterocutaneous fistula (ECF) is a communication between the bowel lumen and the skin, which especially occurs post-operatively and is associated with significant morbidity and mortality. Correct diagnosis and anatomical information of ECF are crucial for a patient's management. Here, we present a case of ECF clearly diagnosed by hybrid single-photon emission computed tomography/computed tomography (SPECT/CT).

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Objective: To evaluate the efficacy of post-treatment positron emission tomography (PET)/computed tomography (CT) for identification of tumor recurrence, and to determine whether [(18)F]fluorodeoxyglucose (FDG) uptake measured as the maximum standardized uptake value (SUV(max)) has predictive role regarding survival in patients with uterine cervical cancer.

Methods: Medical records from 276 women with uterine cervical cancer who had post-treatment [(18)F]FDG PET/CT performed were retrospectively reviewed. Results of PET/CT scans were compared with histological or clinical examination.

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Background: Identification of predictive biomarkers is essential for the successful development of targeted therapy. Insulin-like growth factor 1 receptor (IGF1R) has been examined as a potential therapeutic target for various cancers. However, recent clinical trials showed that anti-IGF1R antibody and chemotherapy are not effective for treating lung cancer.

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Objective: To determine whether [(18)F]FDG uptake on PET/CT imaging before surgical staging has prognostic significance in patients with epithelial ovarian cancer (EOC).

Methods: Patients with EOC were imaged with integrated PET/CT before surgical staging. Hypermetabolic lesions were measured as the standardized uptake value (SUV) in primary and metastatic tumors.

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Diabetes is associated with higher incidence of myocardial infarction (MI) and increased propensity for subsequent events post-MI. Here we conducted a temporal analysis of the influence of diabetes on cardiac dysfunction and remodeling after ischemia reperfusion (IR) injury in mice. Diabetes was induced using streptozotocin and IR performed by ligating the left anterior descending coronary artery for 30 min followed by reperfusion for up to 42 days.

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Background: The purpose of this study was to determine the usefulness of sequential FDG PET/CTs for prediction of axillary lymph node (ALN) status after neoadjuvant chemotherapy (NAC).

Methods: Seventy-seven stage II or III breast cancer patients who received 3 cycles of neoadjuvant docetaxel/doxorubicin chemotherapy were enrolled in this prospective study. FDG PET/CTs were acquired before chemotherapy and after the first cycle of chemotherapy for early metabolic response prediction.

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Background: Pulmonary sclerosing hemangioma (PSH) has been reported to show increased FDG uptake and be potential false-positives on 18F-FDG PET/CT examination. However, it is still unclear whether the previously-reported high FDG uptake is a universal characteristic of PSH, and furthermore, there have been no investigations on what kind of radiologic or histologic features may have been related with its FDG uptake values.

Purpose: To investigate the 18F-FDG PET/CT features of pulmonary sclerosing hemangiomas (PSHs), and to evaluate the relating factors with their FDG uptake values.

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Background: Unexpected focal 18F-FDG breast uptakes are occasionally identified on PET/CT due to its increased use for cancer staging and follow-up. The need for their characterization has been suggested.

Purpose: To retrospectively evaluate the diagnostic value of ultrasonography (US) in distinguishing benign from malignant lesions for unexpected focal 18F-FDG uptakes in breast on PET/CT scans.

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Background And Objective: 5-Aminolaevulinic acid (ALA) and its derivatives act as precursors of the photosensitizer protoporphyrin IX (PpIX). In this study, we compared cytotoxic effects of photodynamic therapy (PDT) with the hexenyl ester of ALA (ALA-hx) between MCF-7 human breast cancer cells and adriamycin-resistant MCF-7 (MCF-7/ADR) cells.

Materials And Methods: Cell viability and apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide (MTT), flow cytometry assays.

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Aim: To monitor cells in vivo or to detect the sentinel lymph node, we developed a PET/MRI silica nanoprobe with an enhanced near-infrared fluorescence signal.

Methods: We developed enhanced near-infrared fluorescent (NIRF) magnetic silica nanoparticles, MNP-SiO2(NIR797), that encapsulate NIRF dye in the silica. We applied this probe to visualizing cells in the deep tissue of mice using NIRF imaging.

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(68)Ga labeled NOTA-RGD was a recently developed positron emission tomography (PET) radiotracer for the visualization of angiogenesis, and is regarded as a promising imaging agent for cancer and several other disorders. In this study, we investigated the whole-body distribution and radiation dosimetry of (68)Ga-NOTA-RGD in humans. Ten cancer patients (53.

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Since tenascin C is a factor expressed highly in the tumor-associated matrix, it would be a desirable first step for targeting the tumor-specific microenvironment. In fact, a high level of tenascin C expression has been reported in most solid tumors, including lung cancer, colon cancer and glioblastoma. Therefore, the targeted binding of tenascin C in tumor stroma would inhibit tumor metastasis by modulating cancer cell growth and migration.

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Purpose: Although the three-phase bone scan (TBPS) is one of the widely used imaging studies for diagnosing complex regional pain syndrome type I (CRPS-1), there is some controversy regarding the TPBS image criteria for CRPS-1. In this study, we modified the image criteria using image pattern and quantitative analysis in the patients diagnosed using the most recent consensus clinical diagnostic criteria.

Materials And Methods: The study included 140 patients with suspected CRPS-1 (CRPS-1, n = 79; non-CRPS, n = 61; mean age 39 ± 15 years) who underwent TPBS.

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Thyroid cancer is one of the most rapidly increasing cancers in many countries. Although most thyroid cancers are differentiated cancers and easily treated with radioiodine (RI), a portion of differentiated and undifferentiated cancers is refractory not only to RI therapy, but also to radiotherapy and chemotherapy. Thus, various alternative therapies have been tested in RI-refractory thyroid cancers.

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Cellular MRI with a reporter gene offers the opportunity to track small numbers of tumor cells and to study metastatic processes in their earliest developmental stages in the target organs of interest. This study demonstrates the feasibility of using the MR reporter ferritin for the noninvasive imaging and quantification of metastatic melanoma cells in the lymph nodes (LNs) of living mice. A B16F10 murine melanoma cell line expressing human ferritin heavy chain (hFTH) and green fluorescent protein (GFP) was constructed to allow the detection of cells by MRI and fluorescence imaging.

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Purpose: Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) are measures of metabolic activity of tumors determined by fluorine-18 fluorodeoxyglucose ([(18)F]FDG) uptake on PET/CT images. The purpose of this study was to investigate the relationship between functional tumor parameters (MTV and TLG) and clinical outcomes in patients with epithelial ovarian cancer (EOC).

Methods: Fifty-five patients with EOC who had undergone [(18)F]FDG PET/CT before surgical staging were included in this retrospectively study.

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