Carcinogenesis ; Carcinoma, Squamous Cell ; Cell Cycle ; Cell Line ; CpG Islands ; Cyclins ; Discrimination (Psychology) ; DNA ; DNA Methylation ; Epigenomics ; G1 Phase ; Genes, p16 ; Genes, Regulator ; Head ; Humans ; Immunohistochemistry ; Incidence ; Intention ; Methylation ; Mouth ; Neck ; Oncogenes ; Paraffin ; Phosphotransferases ; Polymerase Chain Reaction ; Regulatory Sequences, Nucleic Acid ; Research Personnel ; S Phase ; Sodium

Tumor hypoxia contributes to the progression of a malignant phenotype and resistance to ionizing radiation and anticancer drug therapy. Many of these effects in hypoxic tumor cells are mediated by expression of specific set of genes whose relation to therapy resistance is poorly understood. In this study, we revealed that DNA-dependent protein kinase (DNA-PK), which plays a crucial role in DNA double strand break repair, would be involved in regulation of hypoxia inducible factor-1 (HIF-1). HIF-1beta-deficient cells showed constitutively reduced expression and DNA-binding activity of Ku, the regulatory subunit of DNA-PK. Under hypoxic condition, the expression and activity of DNA- PK were markedly induced with a concurrent increase in HIF-1alpha expression. Our result also demonstrated that DNA-PK could directly interact with HIF- and especially DNA-PKcs, the catalytic subunit of DNA-PK, could be involved in phosphorylation of HIF-1alpha, suggesting the possibility that the enhanced expression of DNA- PK under hypoxic condition might attribute to modulate HIF-1alpha stabilization. Thus, the correlated regulation of DNA-PK with HIF-1 could contribute to therapy resistance in hypoxic tumor cells, and it provides new evidence for developing therapeutic strategies enhancing the efficacy of cancer therapy in hypoxic tumor cells.
Antibodies/immunology ; Cell Hypoxia ; Cell Line, Tumor ; DNA Helicases/immunology/metabolism ; DNA-Binding Proteins/genetics/*metabolism/*physiology ; Deferoxamine/pharmacology ; Drug Resistance, Neoplasm/*physiology ; Humans ; Immunoprecipitation ; Neoplasms/enzymology/*metabolism ; Nuclear Proteins/genetics/*metabolism/physiology ; Phosphorylation ; Protein-Serine-Threonine Kinases/metabolism/*physiology ; Research Support, Non-U.S. Gov't ; Transcription Factors/genetics/*metabolism/physiology ; Up-Regulation

Advanced gastric cancer with skeletal muscle metastasis is a rare occurrence. Here, we report a rare case of gastric carcinoma with psoas muscle metastasis. This patient had advanced gastric carcinoma and complained of inability to extend the left hip joint due to pain. Because magnetic resonance imaging (MRI) revealed an iliopsoas mass showing heterogeneous signal intensity with fluid collection and enhancement around the mass, we speculated that the mass was an intramuscular metastatic tumor from primary gastric carcinoma as well as an intramuscular abscess. Histopathologically, the patient had a metastasis from primary gastric adenocarcinoma. Therefore, the patient was treated with radiotherapy and subsequent chemotherapy.
Abscess ; Adenocarcinoma ; Hip Joint ; Humans ; Magnetic Resonance Imaging ; Muscle, Skeletal ; Muscles ; Neoplasm Metastasis ; Psoas Muscles ; Stomach Neoplasms

Advanced gastric cancer with skeletal muscle metastasis is a rare occurrence. Here, we report a rare case of gastric carcinoma with psoas muscle metastasis. This patient had advanced gastric carcinoma and complained of inability to extend the left hip joint due to pain. Because magnetic resonance imaging (MRI) revealed an iliopsoas mass showing heterogeneous signal intensity with fluid collection and enhancement around the mass, we speculated that the mass was an intramuscular metastatic tumor from primary gastric carcinoma as well as an intramuscular abscess. Histopathologically, the patient had a metastasis from primary gastric adenocarcinoma. Therefore, the patient was treated with radiotherapy and subsequent chemotherapy.
Abscess ; Adenocarcinoma ; Hip Joint ; Humans ; Magnetic Resonance Imaging ; Muscle, Skeletal ; Muscles ; Neoplasm Metastasis ; Psoas Muscles ; Stomach Neoplasms

Background/Aims: We developed a new endoscopic submucosal dissection (ESD) simulator and evaluated its efficacy and realism for use training endoscopists. Methods: An ESD simulator was constructed using polyvinyl alcohol hydrogel sheets and compared to a previous ESD simulator. Between March 1, 2020, and December 30, 2021, eight expert endoscopists from three different centers analyzed the procedure-related factors of the simulator. Five trainees performed gastric ESD exercises under the guidance of these experts. Results: Although the two ESD simulators provided overall favorable outcomes in terms of ESD-related factors, the new simulator had several benefits, including better marking of the target lesion’s limits (p<0.001) and overall handling (p<0.001). Trainees tested the usefulness of the new ESD simulator. The complete resection rate improved after 3 ESD training sessions (9 procedures), and the perforation rate decreased after 4 sessions (12 procedures). Conclusions We have developed a new ESD simulator that can help beginners achieve a high level of technical experience before performing real-time ESD procedures in patients.

Posttransplant lymphoproliferative disease (PTLD) represents a diverse lymphoproliferative disorder ranging from nonspecific reactive hyperplasia to malignant immunoblastic sarcoma developed in a setting of immunosuppression following organ or cellular transplantation. It is often associated with Epstein-Barr virus (EBV) infection and high dose immunosuppression. PTLD after renal transplantation was reported at first in adult in Korea in 1997. In children there have been several cases of PTLD after liver transplantation but PTLD after renal transplantation has not been reported. This is a case report of PTLD developed 4 months after renal transplantation in a 9-year-old boy. The major clinical manifestations were fever, multiple lymph nodes enlargement and blood-tinged stool. EBV was detected by in-situ hybridization in the enlarged cervical lymph node and the colonic tissue. Histological examination revealed B-cell lineage. Use of ganciclovir and reduction of the immunosuppression level resulted in complete remission of PTLD. This is the first pediatric case report of PTLD following renal transplantation in Korea.
Adult ; B-Lymphocytes ; Child* ; Colon ; Fever ; Ganciclovir ; Herpesvirus 4, Human ; Humans ; Hyperplasia ; Immunosuppression ; Kidney Transplantation* ; Korea ; Liver Transplantation ; Lymph Nodes ; Lymphoma, Large-Cell, Immunoblastic ; Lymphoproliferative Disorders ; Male