• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.867-870
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• 2001

All-trans-retinoic acid (RA) plays essential roles in the regulation of differentiation and proliferation. It has been proved that RA is effective in the treatments of epithelial and hematologic malignancies. However, in spite of its pronounced effects, the clinical applications of RA are limited due to the retinoid acute resistance. Although RA induces complete remission in a high proportion of the patients of acute promyelocytic leukemia (APL), the cancer was relapsed in many patients after a brief remission in spite of a continued RA treatment. Patients who relapsed from remission that was initially induced by RA had clinically resistant to further RA treatment. That is, specific cytochrome P450 enzymes in the liver were induced by the continuous oral administration of RA, thereby accelerating the metabolism of RA. To overcome this problem, biodegradable microspheres were proposed by us, previously. And, several microsphere formulations for RA delivery have been prepared and studied on their effectiveness. Recently, poly(D,L-lactide) (PDLLA) microsphere formulation was optimized, And, from the animal studies by using a mouse and a rat, it have appeared to be effective on both the inhibition of tumor growth and chemoprevention of a carcinogenesis. In this study, subacute toxicities of the PDLLA microsphere formulation have been investigated as a preclinical test. For the test, the microspheres was injected subcutaneously into the back site of rats, and body weight change, clinical signs, hematological changes, blood biochemistry were evaluated. As a result, severe toxicities such as mortality were observed at the dose of 100mg RA/kg, and toxicities were not observed at the dose of 50mg RA/kg, which is the effective dose against carcinogenesis. Bone fracture, observed at several rats, might be inhibited by treating them with anti-inflammatory drugs.

• Applied Microscopy
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• v.32 no.4
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• pp.411-419
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• 2002

Metallothionein (MT) is a family of ubiquitous, low molecular weight ($6,000{\sim}7,000D$), cysteine-rich ($30{\sim}35%$) inducible protein with a high affinity to metal ions and has no aromatic amino acids and histidine. Some of the known functions of MT include detoxification of heavy metals and alkylating agents and neutralization of free radicals. Also, this protein has been reported to involve in tumor pathophysiology and therapy resistance. MT expression may affect a number of cellular processes including gene expression, apoptosis, proliferation and differentiation. Many reports on the physiological and biochemical properties of MT have been published, but ultrastructural reports on the localization of MT in human gastric cancer tissues are extremely rare. The present study was undertaken to examine the ultrastructural features and the localization of MT within the gastric adenocarcinoma. Ultrastructures of gastric cancer cells were characterized by the high nuclear cytoplasmic ratio, the interdigitation between cells, the irregular nucleus containing much heterochromatin and the wide distribution of free ribosomes in the cytoplasm. Immunohistochemical reaction for MT was prominent in the gastric adenocarcinoma. And the immunogold labellings were more prominent within the nucleus than the cytoplasm. Particularly, immunogold particles were numerously seen at nulcleolus or nucleolar associated heterochromatin. These results suggest that MT expression by gastric cancer cells is associated with cell proliferative activity and is possibly synthesized in the cytoplasm, and then the protein is transported into the nucleus to participate in any transcriptional steps.

• Korean Journal of Food Science and Technology
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• v.50 no.4
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• pp.437-443
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• 2018

Activation of macrophages plays an important role in the host-immune system. In this study, we investigated the functional roles and related signaling mechanism of hot-water extracts of bee pollen (BPW) in RAW 264.7 macrophages. Since BPW did not exert cytotoxicity at concentrations ranging from 62.5 to $250{\mu}g/mL$ in macrophage cells, a concentration of $250{\mu}g/mL$ was used as the maximum dose of BPW throughout subsequent experiments. BPW increased inducible nitric oxide synthase-mediated nitric oxide production in a concentration-dependent manner. Additionally, BPW was found to induce macrophage activation by augmenting the expression of cell surface molecules (cluster of differentiation; CD80/86, and major histocompatibility complex; MHC class I/II) and production of pro-inflammatory cytokines (tumor necrosis $factor-{\alpha}$, interleukin-6, and $IL-1{\beta}$) through mitogen-activated protein kinase and nuclear $factor-{\kappa}B$ signaling pathways in RAW 264.7 macrophages. Taken together, our results indicate that BPW could potentially be used as an immunomodulatory agent.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2277-2281
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• 2015

Objectives: To explore the expression of astrocyte elevated gene-1 (AEG-1) in cervical cancer and analyze its correlation with microvascular density (MVD), nuclear factor kappaB (NF-kB p65) and vascular endothelial growth factor (VEGF). Materials and Methods: Immunohistochemical MaxVision method was adopted to detect the expression level of AEG-1, NF-kB p65 and VEGF in 45 samples of invading cervical cancer and 12 samples of cervicitis from The First Affiliated Hospital of Wenzhou Medical University. Tumor microvascular endothelial marker CD34 combined with Weidner was used to determine the MVD in cervical cancer tissue. The positive expression and staining conditions of AEG-1, NF-kB p65 and VEGF in cervical cancer tissues were observed under a light microscope. Correlations between expression of AEG-1 protein and those of NF-Kb p65 and VEGF, as well as MVD, were analyzed using Pearson correlation. Results: The expression levels of AEG-1 were $0.186{\pm}0.043$ in cervical cancer and $0.051{\pm}0.002$ in chronic cervicitis (p<0.01). Moreover, expression of AEG-1 was related to vascular invasion and lymphatic metastasis of cervical cancer (p<0.01), but not with age of the patients, differentiation degree, tumour size, pathological type and parametrial infiltration (p>0.05). Pearson correlation analysis showed that the expression of AEG-1 was linked with NF-kB p65 (r=0.501, p=0.000), VEGF (r=0.718, p=0.000) as well as MVD in cervical cancer tissue (r=0.815, p=0.000). Conclusions: AEG-1 is highly expressed in cervical cancer and promotes angiogenesis, which might be related to the fact that AEG-1 activating the signal pathway of NF-kB could up-regulate the level of VEGF expression.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.6
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• pp.581-590
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• 2000

Alterations in the cellular genome affecting the expression or function of genes controlling cell growth and differentiation are considered to be the main cause of cancer. Over 30 oncogenes can be activated by insertional mutagenesis, single point mutations, chromosomal translocations and gene amplification. The ras oncogenes have been detected in $15{\sim}20%$ of human tumors that include some of the most common forms of human neoplasia and are known to acquire their transforming properties by single point mutations in two domains of their coding sequences, most commonly in codons 12 and 61. The ras gene family consists of three functional genes, N-ras, K-ras and H-ras which encode highly similar proteins of 188 or 189 amino acid residues generically known as P21. ras proteins have been shown to bind GTP and GTP, and possess intrinsic GTPase activity. Experimental study was performed to observe the mutational change of the ras gene family and apply the results to the clinical activity. 36 Golden Syrian Hamster each weighing $60{\sim}80g$ were used and painted with 0.5% DMBA by 3 times weekly on the right buccal cheek(experimental side) for 6, 8, 10, 12, 14 and 16 weeks. Left buccal cheek (control side) was treated with mineral oil as the same manner of the right side. The hamsters were sacrificed on the 6, 8, 10, 12, 14 & 16 weeks. Normal and tumor tissues from paraffin block were completely dissected by microdissection and DNA from both tissue were isolated by proteinase K/phenol/chloroform extraction. Segments of the K-ras and H-ras gene were amplified by PCR using the oligonucleotide primers corresponding to the homologous region (codon 12 and 61) of the hamster gene, and then confirmational change of ras genes was observed by SSCP and autosequencing analysis. The results were as follows : 1. Malignant lesion could be found in the experimental side from the experimental six weeks. 2. One hamster among six showed point mutation of the H-ras codon 12($G{\rightarrow}A$ transition) at the experimental 10 and 14 weeks. 3. One of six at 6 weeks, two of six at 8 weeks and one of six at 12 weeks revealed the confirmational change of the H-ras codon 61($A{\rightarrow}T$ transversion). 4. The incidence of point mutation of H-ras codon 12 and 61 were 5.5%(2 of 36) and 11%(4 of 36) respectively. 5. Point mutation of the K-ras could not be seen during the whole experimental period. Form the above results, these findings strongly support the concept that H-ras oncogenes may have the influence of the DMBA induced carcinoma of hamster buccal pouch.

• Environmental Mutagens and Carcinogens
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• v.22 no.2
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• pp.112-124
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• 2002

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been reported to exert detrimental toxicities on various organ systems including reproductive, cardiovascular, nervous, or dermal system. Immunomodulatory effects of TCDD is thymic atrophy, downregulation of cytotoxic T or B lymphocyte differentiation and activation, which were demonstrated using experimental animals, whereas immunotoxicity in human has not been investigated well. This study was proceeded to evaluate general immunologic spectrum of the Korean Vietnam War veterans exposed to TCDD during their operation, and compare with that of the non-exposed control subjects with similar age. Regarding composition and quantity, immune cells in peripheral blood collected from the TCDD-exposed was not much different from those of the control except decreased red blood cell, hemoglobin and hematocrit level. Furthermore, plasma IgG2, G3, and G4 isotype distribution was similar between two groups, but IgG1 level was significantly lowered in the TCDD-exposed, indicating a TCDD-mediated functional alteration of B cells. Significantly enhanced level of IgE in plasma, a hallmark of dermal or respiratory allergic response, was also observed in the TCDD-exposed compared with that of the control. Elevated generation of IL-4 and IL-10 was resulted from in vitro stimulation of T cells with PMA plus ionomycin or PHA, respectively, from the TCDD-exposed in comparison to those of the control, suggesting a skewed type-2 response. In addition, the level of IFN${\gamma}$, a multifunctional cytokine for T cell-mediated immunity, was lowered in the TCDD-exposed with upregulation of tumor necrosis factor $\alpha$. The present study suggests that TCDD exposure disturbs immunohomeostasis in humans observed as an aberrant plasma IgE and IgG1 levels and dysregulation of T cell activities.

• Journal of Yeungnam Medical Science
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• v.15 no.2
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• pp.359-370
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• 1998

Eight cases of chonproblastoma were studied by analyzing the clinical and pathologic findings. The age of eight cases ranged from 17 to 38 years old(median age, 22.7 years old). The tumors developed in the femur(3 cases), patella(2 cases), tibia(1 case), fibula(l case), and ulna(1 case). The mean diameter of tumors was 4.0cm (range, 1.5 to 8.0cm). Grossly, tumors showed grayish brown solid area with foci of secondary aneurysmal bone cyst. Histologically, the tumor cells were round or polygonal in shape with nuclear groove. And there were chondroid differentiation(7 cases), mitosis(3 cases), calcific deposits(3 cases), secondary aneurysmal bone cyst(4 cases), hemosiderin deposits(4 cases), necrosis(3 cases), vascular invasion(1 caes), and foamy histiocytes and cholesterol cleft(l cases). All cases showed no metastasis to lymph node and distant organ. Seven cases (87.5%) were immunoreactive for S-100 protein. None was immunoreactive for cytokeratin.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6447-6453
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• 2012

Background: The mucin components of the gastric gel layer function as a protective and lubricating factor against luminal acid and proteolytic enzymes. Alteration of mucin expression in gastric preneoplastic and neoplastic lesions has suggested potential roles in neoplastic processes. This study aimed to assess the clinicopathological and prognostic significance of MUC-2, MUC-4 and MUC-5AC in Japanese gastric cancer. Methods: Expression of MUC-2, -4 and -5AC was evaluated on tissue microarrays of gastric carcinomas and adjacent non-cancerous mucosa specimens by immunohistochemistry and compared with clinicopathological parameters and survival time of the patients. Results: The three mucins were found to be expressed to a lesser extent in gastric carcinomas in comparison with non-cancerous mucosa (p<0.05). MUC-2 expression was negatively correlated with tumor size, depth of invasion, and TNM staging of gastric cancer (p<0.05), while that of MUC-5AC was negatively associated with the depth of invasion, venous invasion, lymph node metastasis and TNM staging (p<0.05), but positively with MUC-4 and MUC-2 expression (p<0.05). There was higher MUC-2 expression in intestinal- than diffuse-type carcinomas (p<0.05). Kaplan-Meier analysis indicated no relationship between expression of the three mucins and the cumulative survival rate of patients, even stratified according to the depth of invasion (p>0.05). Conclusion: Down-regulated expression of MUC-2, -4 and -5AC may be involved in pathogenesis, invasion, metastasis or differentiation of gastric carcinoma. Their altered expression might therefore be employed as an indicator of pathobiological behavior.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.5773-5777
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• 2015

Background: Oral squamous cell carcinoma (OSCC) is thought to develop from precancerous dysplastic lesions through multistep processes of carcinogenesis involving activation of oncogenes and loss of tumor suppressor genes. The human epidermal growth factor receptor 2 (Her-2/neu [erbB-2]), a cell membrane glycoprotein, is a growth factor receptor that has receptor tyrosine kinase activity. Her2/neu activation plays a central role in cell proliferation and survival. It has been shown that overexpression of Her2/neu increases the rate of cell division and growth, leading to precancerous changes. The aim of the present study was to compare the serum and salivary Her2/neu levels between cases with premalignant and malignant oral lesions. Materials and Methods: Fasting blood samples and unstimulated saliva by passive drooling were collected from three groups of healthy control (n=20), premalignant disorder (PMD) (n=20) and OSCC (n=25) subjects. The HER2 extracellular domain (HER2 ECD) levels were measured using ELISA. Results: The levels of serum Her2/neu showed no significant differences between any of the groups but on the other hand salivary Her2/neu levels were found to be significantly (p<0.05) higher when compared between control (median 68.7 pg/ml, range: 21.5 - 75.8) and OSCC (median 145.6 pg/ml, range: 45.1-191.1). A similar trend was observed when comparing between PMD (median 43.3, range: 22.1 -94.7) and OSCC with a statistical significance of p<0.05. Conclusions: Our study provided evidence of increased salivary Her2/neu in OSCC when compared to PMD and control which was not the case for serum levels. This suggests that probably Her2/neu is not highly amplified as in breast cancer so as to be reflected in serum. Since saliva is in local vicinity of the OSCC, even a mild increase might be mirrored. On the whole, this study proposes Her2/neu as marker for distinguishing premalignant and malignant conditions.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3173-3178
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• 2012

The enhancer of zeste homolog 2 (EZH2) methyl transferase and histone 3 lysine 27 (H3K27me3) protein can repress gene transcription, and their aberrant expression has been observed in various human cancers. This study determined their expression levels in gastric cancer tissues with reference to clinicopathological features and patient survival. We collected 117 gastric cancer and corresponding normal tissues for immunohistochemistry analysis. In gastric cancers, 82/117 (70.1%) were positive for EZH2 and 66/117 (56.4%) for H3K27me3 proteins in contrast to only 5.41% and 7.25% of normal gastric mucosa specimens, respectively. Kaplan-Meier survival data showed the average overall and disease-free survival of EZH2 high expression patients was 25.2 and 20.2 months, respectively, shorter than that with EZH2 low expression (40.5 and 35.9 months). The average overall survival and disease-free survival of high H3K27me3 expression patients was 23.4 and 17.4 months, shorter than without H3K27me3 expression (37.6 and 34.5 months). The average overall survival and disease-free survival of patients with both EZH2 and H3K27me3 expression was 18.8 and 12.9 months, respectively, shorter than that with either alone (34.7 and 31.2 months) or with low levels of both (43.9 and 39.9 months). Multivariate Cox regression analysis showed that H3K27me3 and EZH2 expression, tumor size differentiation and clinical stage were all independent prognostic factors for predicting patient survival. This study demonstrated that detection of both EZH2 and H3K27me3 proteins can predict poor survival of gastric cancer patients, superior to single protein detection. In addition, H3K27me3 and EZH2 protein expression could predict lymph node metastasis.