• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.107-111
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• 2016

Sex cord tumors with annular tubules are known to originate from the sex cord of embryonic gonads that synthesize Sertoli cells, Leydig cells, granulosa cells, and theca cells of the ovarian stroma, while ovarian small cell carcinoma of the hypercalcemic type is a type of neuroendocrine tumor. Both these tumors are uncommon, potentially malignant neoplasms in children. We report the case of a sex cord tumor with annular tubules in an 11-year-old girl and a case of small cell carcinoma of the hypercalcemic type in a 10-year-old girl. We also discuss the prognosis and management of these tumors.

• Nutrition Research and Practice
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• v.4 no.6
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• pp.455-461
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• 2010

The tumor microenvironment, particularly sufficient nutrition and oxygen supply, is important for tumor cell survival. Nutrition deprivation causes cancer cell death. Since apoptosis is a major mechanism of neuronal loss, we explored neuronal apoptosis in various microenvironment conditions employing neuroblastoma (NB) cells. To investigate the effects of tumor malignancy and differentiation on apoptosis, the cells were exposed to poor microenvironments characterized as serum-free, low-glucose, and hypoxia. Incubation of the cells in serum-free and low-glucose environments significantly increased apoptosis in less malignant and more differentiated N-type IMR32 cells, whereas more malignant and less differentiated I-type BE(2)C cells were not affected by those treatments. In contrast, hypoxia (1 % $O_2$) did not affect apoptosis despite cell malignancy. It is suggested that DLK1 constitutes an important stem cell pathway for regulating self-renewal, clonogenicity, and tumorigenicity. This raises questions about the role of DLK1 in the cellular resistance of cancer cells under poor microenvironments, which cancer cells normally encounter. In the present study, DLK1 overexpression resulted in marked protection from apoptosis induced by nutrient deprivation. This in vitro model demonstrated that increasing severity of nutrition deprivation and knock-down of DLK1 caused greater apoptotic death, which could be a useful strategy for targeted therapies in fighting NB as well as for evaluating how nutrient deprived cells respond to therapeutic manipulation.

• BMB Reports
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• v.54 no.2
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• pp.130-135
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• 2021

Voltage-gated potassium (Kv) channels are involved in many important cellular functions and play pivotal roles in cancer progression. The expression level of Kv2.1 was observed to be higher in the highly metastatic prostate cancer cells (PC-3), specifically in their membrane, than in immortalized prostate cells (WPMY-1 cells) and comparatively less metastatic prostate cancer cells (LNCaP and DU145 cells). However, Kv2.1 expression was significantly decreased when the cells were treated with antioxidants, such as N-acetylcysteine or ascorbic acid, implying that the highly expressed Kv2.1 could detect reactive oxygen species (ROS) in malignant prostate cancer cells. In addition, the blockade of Kv2.1 with stromatoxin-1 or siRNA targeting Kv2.1 significantly inhibited the migration of malignant prostate cancer cells. Our results suggested that Kv2.1 plays an important role as a ROS sensor and that it is a promising therapeutic molecular target in metastasis of prostate cancer.

• Korean Journal of Veterinary Service
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• v.30 no.4
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• pp.533-538
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• 2007

A 16-year-old female mixed dog was submitted for examination at the pathology division of national veterinary research and quarantine service (NVRQS). Grossly, white or grayish spherical, multinodular, firm to friable masses were present in the tibiofibula to the pharenge area of the right limb, and dysphagia, breathing difficulties and tachypnea were shown. Various-sized white or grayish black masses were scattered in lungs and diaphragm and one mass was observed in the trachea and in the jejunum, respectively. Histopathologically, the neoplastic cells were composed of polygonal or spindle shaped cells with various sized round to oval nuclei and abundant cytoplasm. These cells formed lobules or nests separated by fine connective tissue and contained little amount of melanin pigments. Melanin pigments were stained dark gray or black with Fontana-Masson method. Melanosomes were also ultrastructurally demonstrable by electron microscopy. Based on above results, the present case was diagnosed as canine malignant melanoma originating from the lower limb and digit.

• Molecules and Cells
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• v.40 no.8
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• pp.567-576
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• 2017

The $Na^+/H^+$ exchanger is responsible for maintaining the acidic tumor microenvironment through its promotion of the reabsorption of extracellular $Na^+$ and the extrusion of intracellular $H^+$. The resultant increase in the extracellular acidity contributes to the chemoresistance of malignant tumors. In this study, the chemosensitizing effects of cariporide, a potent $Na^+/H^+-exchange$ inhibitor, were evaluated in human malignant mesothelioma H-2452 cells preadapted with lactic acid. A higher basal level of phosphorylated (p)-AKT protein was found in the acid-tolerable H-2452AcT cells compared with their parental acid-sensitive H-2452 cells. When introduced in H-2452AcT cells with a concentration that shows only a slight toxicity in H-2452 cells, cariporide exhibited growth-suppressive and apoptosis-promoting activities, as demonstrated by an increase in the cells with pyknotic and fragmented nuclei, annexin V-PE(+) staining, a $sub-G_0/G_1$ peak, and a $G_2/M$ phase-transition delay in the cell cycle. Preceding these changes, a cariporide-induced p-AKT down-regulation, a p53 up-regulation, an ROS accumulation, and the depolarization of the mitochondrial-membrane potential were observed. A pretreatment with the phosphatidylinositol-3-kinase (PI3K) inhibitor LY294002 markedly augmented the DNA damage caused by the cariporide, as indicated by a much greater extent of comet tails and a tail moment with increased levels of the p-histone H2A.X, $p-ATM^{Ser1981}$, $p-ATR^{Ser428}$, $p-CHK1^{Ser345}$, and $p-CHK2^{Thr68}$, as well as a series of pro-apoptotic events. The data suggest that an inhibition of the PI3K/AKT signaling is necessary to enhance the cytotoxicity toward the acidtolerable H-2452AcT cells, and it underlines the significance of proton-pump targeting as a potential therapeutic strategy to overcome the acidic-microenvironment-associated chemotherapeutic resistance.

• Tuberculosis and Respiratory Diseases
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• v.77 no.4
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• pp.188-192
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• 2014

We present a case of an unusual infectious complication of a ruptured mediastinal abscess after endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), which led to malignant pleural effusion in a patient with stage IIIA non-small-cell lung cancer. EBUS-TBNA was performed in a 48-year-old previously healthy male, and a mediastinal abscess developed at 4 days post-procedure. Video-assisted thoracoscopic surgery was performed for debridement and drainage, and the intraoperative findings revealed a large volume pleural effusion that was not detected on the initial radiographic evaluation. Malignant cells were unexpectedly detected in the aspirated pleural fluid, which was possibly due to increased pleural permeability and transport of malignant cells originating in a ruptured subcarinal lymph node from the mediastinum to the pleural space. Hence, the patient was confirmed to have squamous cell lung carcinoma with malignant pleural effusion and his TNM staging was changed from stage IIIA to IV.

• The Korean Journal of Cytopathology
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• v.7 no.1
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• pp.69-74
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• 1996

Malignant rhabdold tumor is a distinct renal tumor in the pediatric age group. It was originally described as a rhabdomyosarcomatold variant of Wilms' tumor. However, subsequent studies fatted to confirm myogenous differentiation, so it is now considered to be a distinct and unique type of highly malignant tumor, histogenetically unrelated. Although extrarenal forms of this tumor are rare, several examples have been described in other sites, especially the liver, prostate, paravertebral area, urinary bladder and soft tissue. We experienced a case of malignant rhabdiod tumor located in the intraabdominal cavity in a 10 month-old boy. Smear of peritoneal fluid showed round, polygonal and irregular shaped cells with large nuclei, ample cytoplasm containing light pink to purple cytoplasmic inclusions, and one or a few prominent nucleoli. Immunocytochemistry revealed positivity to cytokeratin, epithelial membrane antigen and vimentin, and negativity to desmin and neuron-specific enolase. These distinct cytologic appearance and immunophenotypes were most consistent with a diagnosis of extrarenal malignant rhabdoid tumor. The cytoplasmic inclusions were correlated with eosinophilic inclusions seen in histologic section and electron microscopy confirmed this interpretation, showing filamentous aggregations in the cytoplasms of the tumor cells.

• Korean Journal of Head & Neck Oncology
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• v.14 no.2
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• pp.199-205
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• 1998

Objective: Telomerase, a specialized ribonucleoprotein polymerase associated with cellular immortality, is expressed by most malignant cells and is inactive in most normal somatic cells. The assays of telomerase activity in various tumors have provided both diagnostic and prognostic information. This study was carried out to determine whether telomerase activity could be useful in distinguishing benign and malignant thyroid diseasees. Materials & Methods: Telomerase activity was determined using Oncor $TRAP_{EZE}^{TM}ELISA$ Telomerase Detection Kit for performing PCR-based telomeric repeat amplification protocol (TRAP) assay followed by ELISA detection in both normal and tumor tissues of 23 adenomatous hyperplasias, 12 follicular adenomas, 4 follicular carcinomas, 16 papillary carcinomas, 4 Hashimoto's thyroiditises and 3 malignant lymphomas. We also examined all cases microscopically to review the status of lymphoid infiltrate. Results: Of the 62 cases, extensive lymphoid infiltrates were contained in 20 tumor tissues(4 Hashimoto's thyroiditises, 3 malignant lymphomas, 6 adenomatous hyperplasias and 7 papillary carcinomas), all of which showed positive telomerase activity. All the normal tissues without lymphoid infiltrates(n=43) did not express telomerase activity. Of 42 tumor tissues without lymphoid infiltrates, 37(88.0%) showed positive telomerase activity: 13 of 17 adenomatous hyperplasias(76.5%), 11 of 12 follicular adenomas(91.7%), 4 of 4 follicular carcinomas(100.0%) and 9 of 9 papillary carcinomas(100.0%). Conclusions: Our methods showed high sensitivity in the detection of telomerase activity and the exclusion of lymphoid infiltrates may be important in telomerase assay. In our work, the measurement of telomerase activity was not useful in distinguishing benign and malignant thyroid diseases.

• Korean Journal of Head & Neck Oncology
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• v.7 no.2
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• pp.114-119
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• 1991

Malignant oncocytoma(oxyphil cell adenoma) is a extremely rare malignant tumor of the salivary glands and almost occurs in the parotid gland. A case of malignant oncocytoma of the parotid gland occurring in a 63 year old man is reported. Establishing a diagnosis of malignant oncocytoma essentially requires the application of two sets of criteria to the tumor under examination. First, the tumor cells must be identified as oncocyte and second, malignancy must be determined. Histochemical stains are not as useful as generally believed. Electron microscopy confirms the diagnosis by demonstrating an abundance of mitochondria. The diagnosis of malignant oncocytoma depends on several additional criteria in addition to cellular and nuclear pleomorphism, including lack of encapsulation, local infiltration, perineural and intravascular growth, and regional and/or distant metastasis. Satisfactory results from surgical resection and postoperative radiotherapy in our patient serve as additional experience in the treatment of this rare malignancy.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.3
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• pp.89-97
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• 2011

The Human Papilloma Virus (HPV) infection has been strongly associated with pathogenesis of uterine cervix carcinoma. HPV type 16, a causative agent of uterine cervix carcinoma, encodes the E6 and E7 oncogenes, expression of which is pivotal for malignant transformation and maintenance of malignant phenotypes. To develop a gene therapy for HPV-related carcinoma, We investigated the effect of E6 short-interfering RNA (E6 siRNA) on the expression of this oncogene and on the growth of HPV 16-related uterine cervix carcinoma cells. SiHa cells, a uterine cervix carcinoma cell line, which contain a single copy of HPV 16 integrated in the chromosome and express the E6 and E7 oncogenes. Before 24 hr of transfection, cells were seeded and transfected with control plasmid or E6 siRNA-expressing plasmid. The mRNA was analysed by reverse transcriptase polymerase chain reaction (RT-PCR). The cell growth rate was investigated by MTT method. The E6 mRNA level in SiHa cells was decreased in HPV 16 E6 siRNA-expression vector transfected cells and a decrease in the growth of these cells was also observed. From these results. it is evident that E6 siRNA played a role in suppression of growth of SiHa cells and has a fair chance as a candidate for gene specific therapy for HPV related uterine cervix carcinoma.