ABSTRACT
The objective of this study was to determine the effect of ionizing radiation (IR) exposure of parents on carcinogenesis of the next generation focusing on the epigenetic perspective to clarify the relationship between radiation dose and carcinogenesis in F1 generation SD rats. F1 generations from pregnant rats (F0) who were exposed to gamma rays were divided into three groups according to the dose of radiation: 10 rad, 30 rad, and untreated. They were intraperitoneally injected with 50 mg/kg of diethylnitrosamine (DEN). Carcinogenesis was analyzed by examining expression levels of tumor suppressor genes (TSG) and other related genes by methylation-specific polymerase chain reaction (MSP). DNA methylation in liver tissues was evaluated to discern epigenetic regulation of transgenerational carcinogenesis vulnerability following IR exposure. Numerous studies have proved that transcriptional inactivation due to hypermethylation of TSG preceded carcinogenesis. Results of this study revealed hypermethylation of tumor suppressor gene SOCS1 in group treated with 30 rad. In addition, genes related to DNA damage response pathway (GSTP1, ATM, DGKA, PARP1, and SIRT6) were epigenetically inactivated in all DEN treated groups. In the case of proto-oncogene c-Myc, DNA hypermethylation was identified in the group with low dose of IR (10 rad). Results of this study indicated that each TSG had different radiation threshold level (dose-independent way) and DEN treatment could affect DNA methylation profile irrelevant of ionizing radiation dose.
Subject(s)
Animals , Humans , Rats , Carcinogenesis , Diethylnitrosamine , DNA , DNA Damage , DNA Methylation , Epigenomics , Family Characteristics , Gamma Rays , Genes, Tumor Suppressor , Liver , Parents , Polymerase Chain Reaction , Proto-Oncogenes , Radiation, IonizingABSTRACT
BACKGROUND AND OBJECTIVES: Various chemicals can affect the function of olfaction and steroids have been used for the treatment of olfactory dysfunction. In this study, we investigated the effect of chronic dexamethasone treatment on olfactory epithelium injured by 3-methylindole (3-MI). SUBJECTS AND METHODS: 0.75 mg/kg of dexamethasone and 0.15 mL of normal saline were administered to each of the 12 mice belonging to the experimental and control group respectively every other day from 1 week, before a single intraperitoneal administration of 175 mg/kg 3-MI, to 4 weeks after 3-MI injection. Three mice from each group were sacrificed every week, and olfactory epithelium was examined after H & E and immunohistochemical staining. RESULTS: On H & E staining, the height of the olfactory epithelium and the polarity of the cells showed no difference between the two groups. On olfactory marker protein (OMP) staining, the number of OMP-immunoreactive (IR) olfactory receptor cells was significantly increased in the experimental groups from 2 and 4 weeks after 3-MI injection compared with the control group. On proliferating cell nuclear antigen (PCNA) staining, PCNA-IR basal cells were significantly reduced in groups that received dexamethasone from 2 weeks to 3 weeks after injection compared with the control group. CONCLUSION: Dexamethasone shows no protective effect in early necrosis of olfactory epithelium by 3-MI, but showed positive effect on the regeneration of the olfactory receptor cells of olfactory epithelium.
Subject(s)
Animals , Mice , Dexamethasone , Necrosis , Olfactory Marker Protein , Olfactory Mucosa , Proliferating Cell Nuclear Antigen , Regeneration , Skatole , Smell , SteroidsABSTRACT
Malignant tumors of the external auditory canal (EAC) are very rare. Squamous cell carcinoma, adenoid cystic carcinoma and basal cell carcinoma on the decreasing frequency are the most common pathologic forms of EAC malignancy. Mucoepidermoid carcinoma (MEC) of the EAC is extremely rare. Only three cases of MEC occurring in EAC were reported to date in the English literature. We present a case of MEC occurring in the EAC with the review of related literatures.
Subject(s)
Aminocaproates , Carcinoma, Adenoid Cystic , Carcinoma, Basal Cell , Carcinoma, Mucoepidermoid , Carcinoma, Squamous Cell , Ear CanalABSTRACT
Extramedullary plasmacytoma (EMP) is a rare plasma cell neoplasm occurring anywhere in the body. Paranasal sinus is the most commonly involved site of head and neck region, and then nasal cavity, oropharynx on the decreasing frequency. EMP of larynx is quite rare and only two cases of EMP were reported to have occurred in the epiglottis and the false cord of larynx, respectively, in the Korean literature. We report an unusual case of EMP occurring in the arytenoid that was treated by surgical excision.