Masakazu Hamada 교수

RanBP2/Nup358, the major component of the cytoplasmic filaments of the nuclear pore complex (NPC), is essential for mouse embryogenesis and is implicated in both macromolecular transport and mitosis, but its specific molecular functions are unknown. Using RanBP2 conditional knockout mouse embryonic fibroblasts and a series of mutant constructs, we show that transport, rather than mitotic, functions of RanBP2 are required for cell viability. Cre-mediated RanBP2 inactivation caused cell death with

The large nucleoporin Nup358/RanBP2 forms eight filaments that project from the nuclear pore into the cytoplasm where they function as docking platforms for nucleocytoplasmic transport receptors. RNAi screens have implicated Nup358 in the HIV-1 life cycle. The 164 C-terminal amino acids of this 3,224 amino acid protein are a cyclophilin homology domain (Nup358Cyp), which has potential to bind the HIV-1 capsid and regulate viral progress to integration. Here we examined the virological role of Nu

Head and neck cancer has been treated by a combination of surgery, radiation, and chemotherapy. In recent years, the development of immune checkpoint inhibitors (ICIs) has made immunotherapy a new treatment method. Oncolytic virus (OV) therapy selectively infects tumor cells with a low-pathogenic virus, lyses tumor cells by the cytopathic effects of the virus, and induces anti-tumor immunity to destroy tumors by the action of immune cells. In OV therapy for head and neck squamous cell carcinoma

Safingol, L- threo-dihydrosphingosine, induces cell death in human oral squamous cell carcinoma (SCC) cells through an endonuclease G (endoG) -mediated pathway. We herein determined whether safingol induced apoptosis and autophagy in oral SCC cells. Safingol induced apoptotic cell death in oral SCC cells in a dose-dependent manner. In safingol-treated cells, microtubule-associated protein 1 light chain 3 (LC3)-I was changed to LC3-II and the cytoplasmic expression of LC3, amount of acidic vesicu

Sphingosine kinase 1 (SphK1) overexpressed in head and neck squamous cell carcinoma (SCC) regulates tumor growth. The effects of PF-543, a specific SphK1 inhibitor, on human SCC cells were examined. The proportion of viable cells after PF-543 treatment decreased in a time- and dose-dependent manner, and cell death occurred in SphK1-expressing SCC cells. Flow cytometry analysis revealed that PF-543 induced both necrosis and apoptosis. PF-543 also induced granular accumulation of LC3 and conversio

The bacterium Helicobacter pylori was originally classified in the Campylobacter genus, which contains major periodontopathic bacterial species, and H. pylori DNA has been found in the oral cavity. Although many studies show an association between the presence of periodontal bacteria and an overweight body-mass index (BMI; >25 kg/m²), the relationship between body weight and the presence of H. pylori in the oral cavity has not been demonstrated. Herein, we analysed the relationship be

The tumor microbiome, a relatively new research field, affects tumor progression through several mechanisms. The Cancer Microbiome Atlas (TCMA) database was recently published. In the present study, we used TCMA and The Cancer Genome Atlas and examined microbiome profiling in head and neck squamous cell carcinoma (HNSCC), the role of the intratumoral microbiota in the prognosis of HNSCC patients, and differentially expressed genes in tumor cells in relation to specific bacterial infections. We i

A 12-year-old Japanese boy was referred to our hospital for evaluation of a radiopaque area on the left side of the mandible. Radiographic and computed tomographic examinations revealed a radiopaque lesion located on the lingual side, along with permanent tooth eruption. Several small tooth-like structures were noted within the lesion and the mandibular left second premolar was inclined in a mesial direction. An odontoma was clinically diagnosed and surgical removal by an endoscopic intraoral ap

The discovery that somatic cells are reprogrammable to pluripotency by ectopic expression of a small subset of transcription factors has created great potential for the development of broadly applicable stem-cell-based therapies. One of the concerns regarding the safe use of induced pluripotent stem cells (iPSCs) in therapeutic applications is loss of genomic integrity, a hallmark of various human conditions and diseases, including cancer. Structural chromosome defects such as short telomeres an

<b>Background/Objectives</b>: Generative artificial intelligence (AI) such as ChatGPT has developed rapidly in recent years, and in the medical field, its usefulness for diagnostic assistance has been reported. However, there are few reports of AI use in dental fields. <b>Methods</b>: We created 20 questions that we had encountered in clinical pediatric dentistry, and collected the responses to these questions from three types of generative AI. The responses were evaluated on a 5-point scale by

Bismuth-based-layer-structured ferroelectric films have been formed epitaxially on Nb-doped SrTiO 3 substrates by pulsed laser deposition (PLD). These films show an atomically smooth surface with a wide terrace of 100 nm–200 nm, as observed by atomic force microscopy (AFM) which is ideal for measuring such properties. Crystal growth apparently changes from the step-flow mode to the island-state mode according to the number of perovskite layers sandwiched by bismuth oxide layers. Additionally, th

Autophagy-related genes (ARGs) have been implicated in the initiation and progression of malignant tumor promotion. To investigate the dynamics of expression of genes, including ARGs, head and neck squamous cell carcinoma (HNSCC) cells were placed under serum-free conditions to induce growth retardation and autophagy, and these starved cells were subjected to transcriptome analysis. Among the 21 starvation-induced genes (SIGs) located in the autophagy, cell proliferation, and survival signaling

Safingol, a L-threo-dihydrosphingosine, induced the nuclear translocation of a mitochondrial apoptogenic mediator--endonuclease G (endo G)--and apoptosis of human oral squamous cell carcinoma (SCC) cells. Upstream mediators remain largely unknown. The levels of hydrogen peroxide (H2O2) in cultured oral SCC cells were measured. Treatment with safingol increased intracellular H2O2 levels but not extracellular H2O2 levels, indicating the production of H2O2. The cell killing effect of safingol and H

Hypophosphatasia (HPP) is a rare genetic disorder; affected patients may experience early exfoliation of primary teeth, especially anterior teeth. However, there have been few reports regarding longitudinal follow-up for primary teeth, especially posterior teeth, until their replacement with permanent teeth. Here, we describe a patient with HPP who underwent follow-up from 1 to 9 years of age. A 14-month-old boy was referred to our hospital with the chief complaint of early loss of primary anter