Publications by authors named "Ha Ra Jun"

One of the major challenges in modern biogerontology is understanding the accumulation of molecular damage and the manifestation of phenotypic heterogeneity during aging. Notably, genomic instability caused by impaired DNA damage repair along with telomere attrition are primary drivers of aging. However, how these aging-related characteristics differ in individuals who age healthily without developing major age-associated diseases remains unclear.

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ObjectiveDNA methylation is a key regulator of gene expression and plays a crucial role in cancer development. However, the mechanisms driving gene-specific methylation remain unclear. This study investigates the role of microRNAs (miRNAs) in regulating promoter methylation of specific genes, aiming to uncover miRNA-driven modulation of gene methylation in cancer.

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Purpose: This study aimed to conduct a comprehensive genetic analysis of patients with Langerhans cell histiocytosis (LCH), focusing on the frequency of mitogen-activated protein kinase (MAPK) pathway mutations, detailed mutation profiles of MAPK pathway genes, and their correlation with clinical features and prognosis in Korean LCH patients.

Materials And Methods: We performed targeted next-generation sequencing, capable of capturing exons from 382 cancer-related genes, on genomic DNA extracted from formaldehyde-fixed and paraffin-embedded samples of 45 pathologically confirmed LCH patients.

Results: The majority of patients (91.

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The prevalence and dynamics of circulating tumor DNA (ctDNA) in patients with breast cancer recurrence or de novo metastatic cancer were examined in a retrospective analysis of a prospective observational cohort. Twenty-three recurrent/metastatic breast cancer cases (8 locoregional, 15 distant metastasis) were enrolled, and sequential plasma samples were obtained. Anchor mutations were selected from the target sequencing of each patient's primary and/or metastatic tumor.

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Purpose: Circulating cell-free DNA (cfDNA) has great potential in clinical oncology. The prognostic and predictive values of cfDNA in non-small cell lung cancer (NSCLC) have been reported, with epidermal growth factor receptor (EGFR), KRAS, and BRAF mutations in tumor-derived cfDNAs acting as biomarkers during the early stages of tumor progression and recurrence. However, extremely low tumor-derived DNA rates hinder cfDNA application.

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This study aimed to investigate the feasibility of blood-based biomarkers, including blood tumor mutation burden (bTMB), to predict atezolizumab efficacy in relapsed and advanced non-small cell lung cancer (NSCLC). Stage IV NSCLC patients who had previously received platinum-doublet chemotherapy were recruited and received 1200 mg of atezolizumab every three weeks. Blood was collected to obtain plasma cell-free DNA (cfDNA) before the first cycle (C0) and at the fourth cycle (C4).

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Purpose: Biliary tract cancers (BTCs) are rare and show a dismal prognosis with limited treatment options. To improve our understanding of these heterogeneous tumors and develop effective therapeutic agents, suitable preclinical models reflecting diverse tumor characteristics are needed. We established and characterized new patient-derived cancer cell cultures and patient-derived xenograft (PDX) models using malignant ascites from five patients with BTC.

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