• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3539-3548
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• 2012

The Nm23 gene is a metastatic suppressor identified in a melanoma cell line and expressed in different tumors where their levels of expression are associated with reduced or increased metastatic potential. Nm23 is one of the over 20 metastasis suppressor genes (MSGs) confirmed in vivo. It is highly conserved from yeast to human, implying a critical developmental function. Tumors with alteration of the p53 gene and reduced expression of the Nm23 gene are more prone to metastasis. Nm23-H1 has 3'-5' exonuclease activity. This review focuses on the role of Nm23 in cancer progression and also a potential novel target for cancer therapy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.6
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• pp.984-991
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• 1997

New tumor suppressor gene, snm23, homologous to human nm23/NDP kinase (human nucleoside diphosphate kinase) gene whose product has a tumor metastasis inhibitory activity, was first cloned from Korean tiger shark (Scyliorhinus forazame) skin cDNA library constructed by using a $\lambda$ ZAP-II cDNA synthesis kit. About $1\times10^5$ plaques were screened and several positive plaques were isolated and confirmed by second screening. The phagemid containing a positive clone from the Uni-Zap XR vector was excised in vivo and the gene containing the tumor metastasis suppressor protein was named as snm23. Cloned gene, snm23, was sequenced with ABI-PRISM 310 Genetic Analyzer. The nucleotide and deduced amino acid sequences of snm23 have shown an open reading frame consisting of 450 base pairs that correspond to a protein of 150 amino acid residues, with a calculated molecular mass of 16.8 kDa. Sequence comparison of snm23 with human nm23/NDP kinase was performed by using Blast protein data base of National Center for Biotechnology Information. In order to determine tissue specificity, reverse transcription-polymerase chain reaction (RT-PCR) was used. Good expression level of snm23/NDP kinase was detected at the tissues from skin, cartilage, and liver of Korean tiger shark.

• Korean Journal of Head & Neck Oncology
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• v.20 no.2
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• pp.147-155
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• 2004

Objectives: Head and neck squamous cell carcinoma (HNSCC) is the most common head and neck malignant tumor. The molecular genetic changes involving both oncogenes and tumor suppressor genes are known to be involved in head and neck squamous cell carcinogenesis, but the roles of the known tumor suppressor genes in carcinogenesis are not fully elucidated. The objectives of this study are to demonstrate the genetic alterations including the loss of heterozygosity (LOH) , amplification, and microsatellite instability of known tumor suppressor genes in HNSCC and to evaluate the relationship between genetic alterations of tumor suppressor genes and clinicopathologic features. Materials and Methods: Genetic alterations of 10 micro satellite markers of the 6 known tumor suppressor genes (APC, EXT1, DPC4, p16, FHIT, and PTEN) were analysed by DNA-PCR in paraffin-embedded histologically confirmed HNSCC specimens. Results: The genetic alterations of tumor suppressor genes were found frequently. Among the genetic alterations, LOH was most frequently found one. LOH was found frequently in APC (45.4%), EXT1 (36.4%), DPC4 (54.5%), and p16 (50%), but not found in FHIT. Also, the author found that abnormalities of APC gene was related to cervical lymph node metastasis and recurrence and that abnormalities of EXT1 gene were coexisted with those of APC gene or DPC4 gene. But these coexistences had no correlation with clinical features. Conclusion: These results suggested that APC, EXT1, p16, and DPC4 genes might play important roles and multiple tumor suppressor genes may participate dependently or independently in the carcinogenesis of HNSCC. These results also suggested that APC gene might relate to prognosis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9059-9064
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• 2014

MicroRNAs (miRNAs) are ubiquitously expressed small, non-coding RNAs that negatively regulate gene expression at a post transcriptional/translational level. They have emerging as playing crucial roles in cancer at all stages ranging from initiation to metastasis. As a tumor suppressor miRNA, aberrant expression of microRNA-29b (miR-29b) has been detected in various types of cancer, and its disturbance is related with tumor development and progression. In this review, we summarize the latest findings with regard to the tumor suppressor signatureof miR-29b and its regulatory mechanisms. Our review highlights the diverse relationships between miR-29b and its target genes in malignant tumors.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.346.1-347
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• 1998

• Toxicological Research
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• v.23 no.3
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• pp.197-205
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• 2007

Cancer metastasis is a major determinant of cancer patient mortality. Mounting evidence favors a strong positive role for $TGF-{\beta}$ in human cancer progression. The complex pattern on cross-talk of $TGF-{\beta}$ and the related other signaling pathways is an important area of investigation that will ultimately contribute to understanding of the bifunctional role of $TGF-{\beta}$ in cancer progression. This review summarizes some of the current understanding of $TGF-{\beta}$ signaling with a major focus in its contribution to the tumor cell invasion and metastasis. Five issues are addressed in this review: (1) $TGF-{\beta}$ signaling, (2) $TGF-{\beta}$ and EMT, (3) $TGF-{\beta}$ and MMP, (4) $TGF-{\beta}$ and Ras, and (5) Role of $TGF-{\beta}$ in invasion and metastasis. Due to the bifunctional cellular effects of $TGF-{\beta}$, as a tumor promoter and a tumor suppressor, more precisely defined $TGF-{\beta}$ signaling pathways need to be elucidated. According to the current literature, $TGF-{\beta}$ is clearly a major factor stimulating tumor progression through a complex spectrum of the interplay and cross-talk between various signaling molecules. Understanding the role of $TGF-{\beta}$ in invasion and metastasis will provide valuable information on establishing strategies to manipulate $TGF-{\beta}$ signaling which should be a high priority for the development of anti-metastatic therapeutics.

• Biomedical Science Letters
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• v.17 no.3
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• pp.261-265
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• 2011

Parkin is a putative tumor suppressor protein and its expression is frequently reduced or absent in several types of tumors. In this study, we examined the role of Parkin in mRNA expression of monocyte chemotactic protein-1 (MCP-1) in the breast cancer cell line MCF7. Expression of MCP-1 mRNA increased after TNF-${\alpha}$ treatment. However, overexpression of Parkin induced a decrease in expression of MCP-1 mRNA in TNF-${\alpha}$-stimulated MCF7. This decrease in MCP-1 mRNA by Parkin overexpression occurred in a dose- and time-dependent manner. Using a wound scratch assay, we found that Parkin overexpression in MCF7 cells also resulted in a decrease in cell migration. These results suggest that Parkin down-regulates MCP-1 synthesis leading to decreased migration of tumor cells. We suggest that one possible mechanism by which Parkin acts as a tumor suppressor is by inhibiting migration or metastasis of cancer cells.

• IMMUNE NETWORK
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• v.21 no.3
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• pp.21.1-21.22
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• 2021

Myeloid-derived suppressor cells (MDSCs) have strong immunosuppressive activity and are morphologically similar to conventional monocytes and granulocytes. The development and classification of these cells have, however, been controversial. The activation network of MDSCs is relatively complex, and their mechanism of action is poorly understood, creating an avenue for further research. In recent years, MDSCs have been found to play an important role in immune regulation and in effectively inhibiting the activity of effector lymphocytes. Under certain conditions, particularly in the case of tissue damage or inflammation, MDSCs play a leading role in the immune response of the central nervous system. In cancer, however, this can lead to tumor immune evasion and the development of related diseases. Under cancerous conditions, tumors often alter bone marrow formation, thus affecting progenitor cell differentiation, and ultimately, MDSC accumulation. MDSCs are important contributors to tumor progression and play a key role in promoting tumor growth and metastasis, and even reduce the efficacy of immunotherapy. Currently, a number of studies have demonstrated that MDSCs play a key regulatory role in many clinical diseases. In light of these studies, this review discusses the origin of MDSCs, the mechanisms underlying their activation, their role in a variety of clinical diseases, and their function in immune response regulation.

• Journal of Gastric Cancer
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• v.17 no.4
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• pp.363-373
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• 2017

Purpose: The aims of this study were to evaluate the expression of the large tumor suppressor (LATS) genes LATS1 and LATS2 by immunohistochemical staining of gastric cancer, and to evaluate the clinicopathological significance of LATS expression and its correlation with overall survival (OS). Materials and Methods: LATS1 and LATS2 expression in a tissue microarray was detected by immunohistochemistry, using 264 gastric cancer specimens surgically resected between July 2006 and December 2009. Results: Low expression of LATS1 was significantly associated with more advanced American Joint Committee on Cancer (AJCC) stage (P=0.001) and T stage (P=0.032), lymph node (LN) metastasis (P=0.040), perineural invasion (P=0.042), poor histologic grade (P=0.007), and diffuse-type histology by the Lauren classification (P=0.033). Low expression of LATS2 was significantly correlated with older age (${\geq}65$, P=0.027), more advanced AJCC stage (P=0.001) and T stage (P=0.001), LN metastasis (P=0.004), perineural invasion (P=0.004), poor histologic grade (P<0.001), and diffuse-type histology by the Lauren classification (P<0.001). Kaplan-Meier survival analysis revealed significantly poor OS rates in the groups with low LATS1 (P=0.037) and LATS2 (P=0.037) expression. Conclusions: Expression of LATS1 or LATS2 is a significant marker for a good prognosis in patients with gastric cancer.

• IMMUNE NETWORK
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• v.9 no.4
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• pp.122-126
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• 2009

Transforming growth factor-$\beta$ (TGF-$\beta$) is a highly pleiotropic cytokine playing pivotal roles in immune regulation. TGF-$\beta$ facilitates tumor cell survival and metastasis by targeting multiple cellular components. Focusing on its immunosuppressive functions, TGF-$\beta$ antagonists have been employed for cancer treatment to enhance tumor immunity. TGF-$\beta$ antagonists exert anti-tumor effects through #1 activating effector cells such as NK cells and cytotoxic $CD8^+$ Tcells (CTLs), #2 inhibiting regulatory/suppressor cell populations, #3 making tumor cells visible to immune cells, #4 inhibiting the production of tumor growth factors. This review focuses on the effect of TGF-$\beta$ on T cells, which are differentiated into effector T cells or newly identified tumor-supporting T cells.