• Korean Journal of Clinical Laboratory Science
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• v.55 no.1
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• pp.16-28
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• 2023

Lung adenocarcinoma accounts for about 40% of all lung cancers. With the recent development of gene profiling technology, studies on mutations in oncogenes and tumor suppressor genes, which are important for the development and growth of tumors, have been actively conducted. Companion diagnosis using next-generation sequencing helps improve survival with targeted therapy. In this study, formalin-fixed paraffin-embedded tissues of non-small cell lung cancer patients were subjected to hematoxylin and eosin staining for detecting genetic mutations that induce lung adenocarcinoma in Koreans. Immunohistochemical staining was also performed to accurately classify lung adenocarcinoma tissues. Based on the results, next-generation sequencing was applied to analyze the types and patterns of genetic mutations, and the association with smoking was established as the most representative cause of lung cancer. Results of next-generation sequencing analysis confirmed the single nucleotide variations, copy number variations, and gene rearrangements. In order to validate the reliability of next-generation sequencing, we additionally performed the existing genetic testing methods (polymerase chain reaction-epidermal growth factor receptor, immunohistochemistry-anaplastic lymphoma kinase (D5F3), and fluorescence in situ hybridiation-receptor tyrosine kinase 1 tests) to confirm the concordance rates with the next-generation sequencing test results. This study demonstrates that next-generation sequencing of lung adenocarcinoma patients simultaneously identifies mutation.

• Tuberculosis and Respiratory Diseases
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• v.54 no.6
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• pp.610-620
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• 2003

Background : 3p deletion has been shown to be the most frequently occurring change in lung cancers, suggesting the presence of a tumor suppressor gene in this region. Recent attention has focused on a candidate 3p14.2 tumor suppressor gene, FHIT. Therefore, the association of the expression of FHIT, with apoptosis, cell proliferation cycle and the clinicopathological features, including survival, were investigated Materials and Methods : 83 patients with non-small cell lung cancer, who underwent curative operation, between Jan. 1996 and Aug. 2000, at the Wonkwang university hospital, were analyzed. The expression of the FHIT was identified by immunohistochemical staining, and rate of apoptosis and cell proliferation cycle by flow cytometry. Results : 43% (36/83) of patients exhibited no FHIT expression. The rates of FHIT loss were 52% (28/54), 22% (5/23), 50% (3/6); 30% (11/37), 48% (16/33), 69% (9/13); 54% (30/56) and 22% (6/27), in squamous cell cancers, adenocarcinomas, large cell cancers, TNM stages I, II and III, smokers and non-smokers, respectively. All the differences in FHIT loss rates, according to the histopathology, TNM stages and smoking habits, were statistically significant. The median survival time and 2-year survival rate of the FHIT(-) group were 24 months and 44%, and those of the FHIT(+) group were 25 months and 51% (p>0.05), respectively. The apoptotic rate of the FHIT(-) and FHIT(+) groups were 50.72 (${\pm}13.93$) and 59.38 (${\pm}14.33$)%, respectively (p=0.01). The S- and G1-phase fractions of the FHIT(-) and FHIT(+) groups were 13.93 (${\pm}7.35$) and $51.50({\pm}23.15$)% and 15.65(${\pm}6.59$) and 54.16 (${\pm}20.25$)%, respectively (p>0.05). Conclusion : The loss of FHIT expression was increased to a greater extent with advancing TNM stage, smoking habits and squamous cell cancer compared to the adenocarcinomas. However, no survival differences were found according to the expression of FHIT. The apoptotic rate of the FHIT(+) group was greater than in the FHIT(-) group, but differences in the S- and G1-phase fractions, according to the expression of the FHIT, were not found.

• Korean Journal of Head & Neck Oncology
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• v.22 no.1
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• pp.8-14
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• 2006

Objectives: The p53 tumor suppressor gene has a key role in cellular control mechanisms involving apoptosis and DNA repair, leading to the G1 arrest following DNA damage. Its mutation is one of the most frequent alterations in human cancers. Ki-67 is identified in replicating cells of both benign and malignant lesions, so it can be the predictor of proliferative activity. The aim of this study is to evaluate the expression of p53 and Ki-67 in salivary gland tumors. Materials and Methods: Immunohistochemical analysis was used to detect expression of p53 and Ki-67 in paraffin-embedded samples from 31 benign and 27 malignant salivary gland tumors. Results were analyzed between benign and malignant tumors and compared with the clinical parameters such as stage and recurrence in malignant tumors. Results: p53 overexpression was detected in 19.6% of benign tumors and 40.7% of malignant tumors, but there was no statistical significance. p53 was significantly expressed in Warthin's tumor(45.5%) compared with pleomorphic adenoma(5.9%). Only 5.9% of pleomorphic adenoma were positive for p53, while 60% of carcinoma ex pleomorphic adenoma were positive for p53. Ki-67 was expressed in 3.2% of benign tumors and 51.9% of malignant tumors, which showed significant higher expression in malignant tumors. In malignant tumors, p53 and Ki-67 expressions bore no correlation to stage and recurrence. Conclusion: p53 overexpression is not associated with the progression of malignant tumors, and Ki-67 overexpression can be used as biologic indicator of malignant salivary gland tumors.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.726-733
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• 2005

Histone deacetylase (HDAC) inhibitors target key steps of tumor development. They inhibit proliferation, induce differentiation and/or apoptotic cell death, and exhibit potent antimetastatic and antiangiogenic properties in cancer cells in vitro and in vivo. Although they are emerging as a promising new treatment strategy in malignancy, how they exert their effect on human non-small cell lung cancer cells is as yet unclear. The present study was undertaken to investiate the underlying mechanism of a HDAC inhibitor trichostatin A (TSA)-induced growth arrest and its effect on the cell cycle control gene products in a human lung carcinoma cell line A549. TSA treaoent induced the growth inhibition and morphological changes in a concentration-dependent manner. Treatment of A549 cells with TSA resulted in a concentration-dependent increased G1 (under 100 ng/ml) and/or G2/M (200 ng/ml) cell population of the cell cycle as determined by flow cytometry Moreover, 200 ng/ml TSA treatment significantly induced the population of sub-G1 cells (23.0 fold of control). This anti-proliferative effect of TSA was accompanied by a marked inhibition of cyclins, positive regulators of cell cycle progression, and cyclin-dependent kinases (Cdks) expression and concomitant induction of tumor suppressor p53 and Cdk inhibitors such as p21 and p27 Although further studies are needed, these findings provide important insights into the possible molecular mechanisms of the anti-cancer activity of TSA in human lung carcinoma cells.

• Journal of Gastric Cancer
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• v.4 no.3
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• pp.169-175
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• 2004

Purpose: The tumor suppressor gene p53 has been shown to be a factor in the carcinogenesis or progression of gastric cancer. The mutant p53 has been reported to cause a higher risk of lymph-node metastasis. Futhermore, mutation of the p53 has been linked to a poor prognosis for gastric cancer. The heat shock protein-27 (HSP27), a stress protein, has also been reported to be a poor prognostic factor in ovarian and breast cancers. However, in gastric-cancer patients, controversies exist as to its influence on the prognosis. In the present study, we used an immunohistochemical stain to observe the effects of p53 and HSP27 on the clinicopathological factors and on the prognosis for gastric-cancer patients. Materials and Methods: To evaluate the significance of p53 and HSP27 in gastric cancer patients, we analyzed 212 cases of gastric cancer (stage I.IV). Tissue samples of 212 patients were stained immunohistochemically for the mutant p53 protein and for HSP27. The correlations between protein expression and the clinicopathological factors were investigated. Results: The overall expression rates for p53 and HSP27 were $36.9\%\;and\;27.8\%$, respectively. p53 and HSP27 were correlated to each other because the HSP27 expression rate was higher in the p53-positive group (P=0.046). Statistically, the p53 and the HSP27 expression rates were significantly increased in the case of tumor invasiveness, lymphatic metastasis and vessel involvement. Therefore, they play a role in cancer progression. The 5-year survival rates of the p53-positive and the p53-negative groups were $62.8\%\;and\;60.1\%$, respectively (P=0.793) while the 5-year survival rates for the HSP27-positive and HSP27-negative groups were $54.2\%\;and\;63.1\%$, respectively (P=0.090). Conclusion: p53 and HSP27 were correlated to each other in our immunohistochemical study of gastric carcinomas and they were not independent prognostic factors in gastric- cancer patients. However, further studies are needed to determine their prognostic values for gastric-cancer patients.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3667-3671
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• 2015

Invasion and metastasis is the major cause of tumor recurrence, difficulty for cure and low survival rate. Excavating key transcription factors, which can regulate tumor invasion and metastasis, are crucial to the development of therapeutic strategies for cancers. PU.1 is a master hematopoietic transcription factor and a vital regulator in life. Here, we report that, compared to adjacent non-cancerous tissues, expression of PU.1 mRNA in metastatic hepatocellular carcinoma (HCC), but not primary HCC, was significantly down-regulated. In addition, levels of PU.1 mRNA in metastatic hepatoma cell lines MHCC97L and MHCC97H were much lower than in non-metastatic Hep3B cells. Transwell invasion assays after PU.1 siRNA transfection showed that the invasion of hepatoma cell lines was increased markedly by PU.1 knockdown. Oppositely, overexpression of PU.1 suppressed the invasion of these cells. However, knockdown and overexpression of PU.1 did not influence proliferation. Finally, we tried to explore the potential mechanism of PU.1 suppressing hepatoma cell invasion. ChIP-qPCR analysis showed that PU.1 exhibited a high binding capacity with miR-615-5p promoter sequence. Overexpression of PU.1 caused a dramatic increase of pri-, pre- and mature miR-615-5p, as well as a marked decrease of miR-615-5p target gene IGF2. These data indicate that PU.1 inhibits invasion of human HCC through promoting miR-615-5p and suppressing IGF2. These findings improve our understanding of PU.1 regulatory roles and provided a potential target for metastatic HCC diagnosis and therapy.

• Tuberculosis and Respiratory Diseases
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• v.45 no.2
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• pp.333-340
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• 1998

Background: Lung cancer is the leading cause of cancer over the world. P53 alteration is by far the most common genetic defect in lung cancer. The mutation of p53 protein involves the loss of inhibitory function of p53 related tumor suppressor gene and resultant oncogenesis. The analysis of p53 alterations consists of immunohistochemical stain, PCR based assay, or serologic ELISA (enzyme-linked immunosorbent assay). Methods : Serum levels of p53 mutant protein were measured in 69 cases of lung cancer (adenocarcinoma n=29, epidermoid n=16, small cell n=13, large cell n=1, undifferentiated n=1, undetermined n=9) and 42 controls of respiratory disorders using ELISA. Immunohistochemical stain in tissue was performed using monoclonal antibody of p53 in lung cancer subjects. Results: Both serum p53s in nonsmall cell cancer ($0.28{\pm}0.44ng/ml$) and in small cell cancer ($0.20{\pm}0.14ng/ml$) were not different from controls ($0.34{\pm}0.20ng/ml$). Also there was no significant difference in serum p53 according to tumor stages. P53 immunohistochemical stain showed 50% positivity overall in lung cancer. There were no close correlation between serologic level and positivity of immunohistochemical stain. Conclusion: The serologic determination of p53 mutant protein is thought to have no diagnostic role in lung cancer. Immunohistochemical stain in lung cancer specimen shows 50% positivity.

• Journal of Life Science
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• v.32 no.4
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• pp.271-278
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• 2022

The detailed mechanism by which cancer upregulated gene 2 (CUG2) overexpression induces cancer stem cell-like phenotypes is not fully understood. The downregulation of FBXW7 E3 ligase, a tumor suppressor known for its proteolytic regulation of oncogenic proteins such as cyclin E, c-Myc, Notch, and Yap1, has been frequently reported in several types of tumor tissues, including those in the large intestine, cervix, and stomach. Therefore, we investigated whether FBXW7 is involved in CUG2-induced oncogenesis. In this study, the decreased expression of FBXW7 was examined in human lung adenocarcinoma A549 (A549-CUG2) and human bronchial BEAS-2B cells (BEAS-CUG2) overexpressing CUG2 and compared with control cells stably expressing an empty vector (A549-Vec or BEAS-Vec). Treatment with MG132 (a proteosome inhibitor) prevented the degradation of FBXW7 and Yap1 proteins, which are substrates of the FBXW7 E3 ligase. To address the role of Fbxw7 in the development of cancer stem cell (CSC) phenotypes, we suppressed Fbxw7 protein levels using its siRNA. We observed that decreased levels of FBXW7 enhanced cell migration, invasion, and spheroid size and number in A549-Vec and BEAS-Vec cells. The enforced expression of FBXW7 produced the opposite results in A549-CUG2 and BEAS-CUG2 cells. Furthermore, the downregulation of FBXW7 elevated the activities of EGFR, Akt, and ERK1/2 and upregulated β-catenin, Yap1, and NEK2, while the enforced expression of FBXW7 generated the opposite results. We thus propose that FBXW7 downregulation induced by CUG2 confers CSC-like phenotypes through the upregulation of both the EGFR-ERK1/2 and β-catenin-Yap1-NEK2 signaling pathways.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2291-2295
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• 2014

Although nucleolar protein nucleostemin (NS) is essential for cell proliferation and early embryogenesis and expression has been observed in some types of human cancer and stem cells, the molecular mechanisms involved in mediation of cell proliferation and cell cycling remains largely elusive. The aim of the present study was to evaluate NS as a potential target for gene therapy of human breast carcinoma by investigating NS gene expression and its effects on SKBR-3 cell proliferation and apoptosis. NS mRNA and protein were both found to be highly expressed in all detected cancer cell lines. The apoptotic rate of the pcDNA3.1-NS-Silencer group ($12.1-15.4{\pm}3.8%$) was significantly higher than those of pcDNA3.1-NS ($7.2-12.0{\pm}1.7%$) and non-transfection groups ($4.1-6.5{\pm}1.8%$, P<0.01). MTT assays showed the knockdown of NS expression reduced the proliferation rate of SKBR-3 cells significantly. Matrigel invasion and wound healing assays indicated that the number of invading cells was significantly decreased in the pcDNA3.1-NS-siRNA group (P<0.01), but there were no significant difference between non-transfected and over-expression groups (P>0.05). Moreover, RNAi-mediated NS down-regulation induced SKBR-3 cell G1 phase arrest, inhibited cell proliferation, and promoted p53 pathway-mediated cell apoptosis in SKBR-3 cells. NS might thus be an important regulator in the G2/M check point of cell cycle, blocking SKBR-3 cell progression through the G1/S phase. On the whole, these results suggest NS might be a tumor suppressor and important therapeutic target in human cancers.

• Journal of Life Science
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• v.25 no.1
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• pp.1-7
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• 2015

Cyclin D is a member of the cyclin protein family, which plays a critical role as a core member of the mammalian cell cycle machinery. D-type cyclins (D1, D2, and D3) bind to and activate the cyclin-dependent kinases 4 and 6, which can then phosphorylate the retinoblastoma tumor suppressor gene products. This phosphorylation in turn leads to release or derepression of E2F transcription factors that promote progression from the G1 to S phase of the cell cycle. Among the D-type cyclins, cyclin D3 encoded by the CCND3 gene is one of the least well studied. In the present study, we have investigated the biochemistry of the proteolytic mechanism that leads to loss of cyclin D3 protein. Treatment of human prostate carcinoma PC-3-M cells with lovastatin and actinomycin D resulted in a loss of cyclin D3 protein that was completely reversible by the peptide aldehyde calpain inhibitor, LLnL. Additionally, using inhibitors for various proteolytic systems, we show that degradation of cyclin D3 protein involves the $Ca^{2+}$-activated neutral protease calpain. Moreover, the half-life of cyclin D3 protein half-life increased by at least 10-fold in PC-3M cells in response to the calpain inhibitor. We have also demonstrated that the transient expression of the calpain inhibitor calpastatin increased cyclin D3 protein in serum-starved NIH 3T3 cells. These data suggested that the function of cyclin D3 is regulated by $Ca^{2+}$-dependent protease calpain.