• Genomics & Informatics
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• 제11권4호
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• pp.245-253
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• 2013

A radioresistant cell line was established by fractionated ionizing radiation (IR) and assessed by a clonogenic assay, flow cytometry, and Western blot analysis, as well as zymography and a wound healing assay. Microarray was performed to profile global expression and to search for differentially expressed genes (DEGs) in response to IR. H460R cells demonstrated increased cell scattering and acidic vesicular organelles compared with parental cells. Concomitantly, H460R cells showed characteristics of increased migration and matrix metalloproteinase activity. In addition, H460R cells were resistant to IR, exhibiting reduced expression levels of ionizing responsive proteins (p-p53 and ${\gamma}$-H2AX); apoptosis-related molecules, such as cleaved poly(ADP ribose) polymerase; and endoplasmic reticulum stress-related molecules, such as glucose-regulated protein (GRP78) and C/EBP-homologous protein compared with parental cells, whereas the expression of anti-apoptotic X-linked inhibitor of apoptosis protein was increased. Among DEGs, syntrophin beta 2 (SNTB2) significantly increased in H460R cells in response to IR. Knockdown of SNTB2 by siRNA was more sensitive than the control after IR exposure in H460, H460R, and H1299 cells. Our study suggests that H460R cells have differential properties, including cell morphology, potential for metastasis, and resistance to IR, compared with parental cells. In addition, SNTB2 may play an important role in radioresistance. H460R cells could be helpful in in vitro systems for elucidating the molecular mechanisms of and discovering drugs to overcome radioresistance in lung cancer therapy.

• Biomolecules & Therapeutics
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• 제27권6호
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• pp.591-602
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• 2019

Human breast cancer cell line, MDA-MB-231, is highly invasive and aggressive, compared to less invasive cell line, MCF-7. To explore the genes that might influence the malignancy of MDA-MB-231, DNA microarray analysis was performed. The results showed that G0/G1 switch 2 (G0S2) was one of the most highly expressed genes among the genes upregulated in MDA-MB-231. Although G0S2 acts as a direct inhibitor of adipose triglyceride lipase, action of G0S2 in cancer progression is not yet understood. To investigate whether G0S2 affects invasiveness of MDA-MB-231 cells, G0S2 expression was inhibited using siRNA, which led to decreased cell proliferation, migration, and invasion of MDA-MB-231 cells. Consequently, G0S2 inhibition inactivated integrin-regulated FAK-Src signaling, which promoted Hippo signaling and inactivated ERK1/2 signaling. In addition, G0S2 downregulation decreased ${\beta}$-catenin expression, while E-cadherin expression was increased. It was demonstrated for the first time that G0S2 mediates the Hippo pathway and induces epithelial to mesenchymal transition (EMT). Taken together, our results suggest that G0S2 is a major factor contributing to cell survival and metastasis of MDA-MB-231 cells.

• Molecules and Cells
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• 제42권11호
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• pp.810-819
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• 2019

For physiological or pathological understanding of bone disease caused by abnormal behavior of osteoclasts (OCs), functional studies of molecules that regulate the generation and action of OCs are required. In a microarray approach, we found the suppression of tumorigenicity 5 (ST5) gene is upregulated by receptor activator of nuclear $factor-{\kappa}B$ ligand (RANKL), the OC differentiation factor. Although the roles of ST5 in cancer and ${\beta}-cells$ have been reported, the function of ST5 in bone cells has not yet been investigated. Knockdown of ST5 by siRNA reduced OC differentiation from primary precursors. Moreover, ST5 downregulation decreased expression of NFATc1, a key transcription factor for osteoclastogenesis. In contrast, overexpression of ST5 resulted in the opposite phenotype of ST5 knockdown. In immunocytochemistry experiments, the ST5 protein is colocalized with Src in RANKL-committed cells. In addition, ST5 enhanced activation of Src and Syk, a Src substrate, in response to RANKL. ST5 reduction caused a decrease in RANKL-evoked calcium oscillation and inhibited translocation of NFATc1 into the nucleus. Taken together, these findings provide the first evidence of ST5 involvement in positive regulation of osteoclastogenesis via Src/Syk/calcium signaling.

• Molecules and Cells
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• 제42권3호
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• pp.237-244
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• 2019

Understanding the mechanisms of cancer drug resistance is a critical challenge in cancer therapy. For many cancer drugs, various resistance mechanisms have been identified such as target alteration, alternative signaling pathways, epithelial-mesenchymal transition, and epigenetic modulation. Resistance may arise via multiple mechanisms even for a single drug, making it necessary to investigate multiple independent models for comprehensive understanding and therapeutic application. In particular, we hypothesize that different resistance processes result in distinct gene expression changes. Here, we present a web-based database, CDRgator (Cancer Drug Resistance navigator) for comparative analysis of gene expression signatures of cancer drug resistance. Resistance signatures were extracted from two different types of datasets. First, resistance signatures were extracted from transcriptomic profiles of cancer cells or patient samples and their resistance-induced counterparts for >30 cancer drugs. Second, drug resistance group signatures were also extracted from two large-scale drug sensitivity datasets representing ~1,000 cancer cell lines. All the datasets are available for download, and are conveniently accessible based on drug class and cancer type, along with analytic features such as clustering analysis, multidimensional scaling, and pathway analysis. CDRgator allows meta-analysis of independent resistance models for more comprehensive understanding of drug-resistance mechanisms that is difficult to accomplish with individual datasets alone (database URL: http://cdrgator.ewha.ac.kr).

• Biomolecules & Therapeutics
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• 제27권1호
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• pp.107-116
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• 2019

The global obesity epidemic and associated metabolic diseases require alternative biological targets for new therapeutic strategies. In this study, we show that a phytochemical sulfuretin suppressed adipocyte differentiation of preadipocytes and administration of sulfuretin to high fat diet-fed obese mice prevented obesity and increased insulin sensitivity. These effects were associated with a suppressed expression of inflammatory markers, induced expression of adiponectin, and increased levels of phosphorylated ERK and AKT. To elucidate the molecular mechanism of sulfuretin in adipocytes, we performed microarray analysis and identified activating transcription factor 3 (Atf3) as a sulfuretin-responsive gene. Sulfuretin elevated Atf3 mRNA and protein levels in white adipose tissue and adipocytes. Consistently, deficiency of Atf3 promoted lipid accumulation and the expression of adipocyte markers. Sulfuretin's but not resveratrol's anti-adipogenic effects were diminished in Atf3 deficient cells, indicating that Atf3 is an essential factor in the effects of sulfuretin. These results highlight the usefulness of sulfuretin as a new anti-obesity intervention for the prevention of obesity and its associated metabolic diseases.

• BMB Reports
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• 제54권10호
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• pp.497-504
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• 2021

EGR1 (early growth response 1) is dysregulated in many cancers and exhibits both tumor suppressor and promoter activities, making it an appealing target for cancer therapy. Here, we used a systematic multi-omics analysis to review the expression of EGR1 and its role in regulating clinical outcomes in breast cancer (BC). EGR1 expression, its promoter methylation, and protein expression pattern were assessed using various publicly available tools. COSMIC-based somatic mutations and cBioPortal-based copy number alterations were analyzed, and the prognostic roles of EGR1 in BC were determined using Prognoscan and Kaplan-Meier Plotter. We also used bc-GenEx-Miner to investigate the EGR1 co-expression profile. EGR1 was more often downregulated in BC tissues than in normal breast tissue, and its knockdown was positively correlated with poor survival. Low EGR1 expression levels were also associated with increased risk of ER+, PR+, and HER2- BCs. High positive correlations were observed among EGR1, DUSP1, FOS, FOSB, CYR61, and JUN mRNA expression in BC tissue. This systematic review suggested that EGR1 expression may serve as a prognostic marker for BC patients and that clinicopathological parameters influence its prognostic utility. In addition to EGR1, DUSP1, FOS, FOSB, CYR61, and JUN can jointly be considered prognostic indicators for BC.

• Journal of Korean Neurosurgical Society
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• 제66권6호
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• pp.642-651
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• 2023

Objective : Endothelial colony-forming cells (ECFCs) have been reported to play an important role in the pathogenesis of moyamoya disease (MMD). We have previously observed stagnant growth in MMD ECFCs with functional impairment of tubule formation. We aimed to verify the key regulators and related signaling pathways involved in the functional defects of MMD ECFCs. Methods : ECFCs were cultured from peripheral blood mononuclear cells of healthy volunteers (normal) and MMD patients. Low-density lipoproteins uptake, flow cytometry, high content screening, senescence-associated β-galactosidase, immunofluorescence, cell cycle, tubule formation, microarray, real-time quantitative polymerase chain reaction, small interfering RNA transfection, and western blot analyses were performed. Results : The acquisition of cells that can be cultured for a long time with the characteristics of late ECFCs was significantly lower in the MMD patients than the normal. Importantly, the MMD ECFCs showed decreased cellular proliferation with G1 cell cycle arrest and cellular senescence compared to the normal ECFCs. A pathway enrichment analysis demonstrated that the cell cycle pathway was the major enriched pathway, which is consistent with the results of the functional analysis of ECFCs. Among the genes associated with the cell cycle, cyclin-dependent kinase inhibitor 2A (CDKN2A) showed the highest expression in MMD ECFCs. Knockdown of CDKN2A in MMD ECFCs enhanced proliferation by reducing G1 cell cycle arrest and inhibiting senescence through the regulation of CDK4 and phospho retinoblastoma protein. Conclusion : Our study suggests that CDKN2A plays an important role in the growth retardation of MMD ECFCs by inducing cell cycle arrest and senescence.

• 생명과학회지
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• 제22권1호
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• pp.49-54
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• 2012

이소플라본 genistein이 마우스 전지방 3T3-L1세포주의 성장과 지방세포형성과정에 미치는 영향을 연구하였다. 그 결과, 마우스 전지방 3T3-L1 세포주의 성장이 처리한 genistein 농도 의존적으로 저해되었다. 또한, Oil Red O 염색에 의하여 50 ${\mu}M$ genistein 처리에 의해 지방세포형성과정이 억제됨을 확인하였다. 이러한 genistein에 의한 지방세포성장 억제효과의 분자생물학적 기전을 연구하기 위하여, oligo DNA 마이크로어레이 실험을 수행하였다. 발현이 증가된 유전자 중 항비만, 항염증 활성과 관련이 있는 것으로 알려져 있는 sirtuin-1 유전자를 선택하여 발현변화를 확인하였다. 처리한 네종류의 파이토케미칼(resveratrol, capsaicin, daidzein, genistein)에 의해 sirtuin-1의 발현이 증가됨을 확인하였고, 이 중 genistein에 의한 sirtuin-1 유전자의 발현이 가장 높았다. 또한, sirtuin-1-siRNA에 의한 sirtuin-1 유전자의 발현 감소에 의해 지방세포형성 억제과정이 복구됨을 확인하였다. 이러한 연구결과는, genistein에 의한 전지방세포의 성장 저해와 지방세포형성의 저해과정을 이해하는데 도움을 줄 것으로 기대된다.

• Nutrition Research and Practice
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• 제11권2호
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• pp.105-113
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• 2017

BACKGROUND/OBJECTIVES: A high-fat diet (HFD) induces obesity, which is a major risk factor for cardiovascular disease and cancer, while a calorie-restricted diet can extend life span by reducing the risk of these diseases. It is known that health effects of diet are partially conveyed through epigenetic mechanism including DNA methylation. In this study, we investigated the genome-wide hepatic DNA methylation to identify the epigenetic effects of HFD-induced obesity. MATERIALS AND METHODS: Seven-week-old male C57BL/6 mice were fed control diet (CD), calorie-restricted control diet (CRCD), or HFD for 16 weeks (after one week of acclimation to the control diet). Food intake, body weight, and liver weight were measured. Hepatic triacylglycerol and cholesterol levels were determined using enzymatic colorimetric methods. Changes in genome-wide DNA methylation were determined by a DNA methylation microarray method combined with methylated DNA immunoprecipitation. The level of transcription of individual genes was measured by real-time PCR. RESULTS: The DNA methylation statuses of genes in biological networks related to lipid metabolism and hepatic steatosis were influenced by HFD-induced obesity. In HFD group, a proinflammatory Casp1 (Caspase 1) gene had hypomethylated CpG sites at the 1.5-kb upstream region of its transcription start site (TSS), and its mRNA level was higher compared with that in CD group. Additionally, an energy metabolism-associated gene Ndufb9 (NADH dehydrogenase 1 beta subcomplex 9) in HFD group had hypermethylated CpG sites at the 2.6-kb downstream region of its TSS, and its mRNA level was lower compared with that in CRCD group. CONCLUSIONS: HFD alters DNA methylation profiles in genes associated with liver lipid metabolism and hepatic steatosis. The methylation statuses of Casp1 and Ndufb9 were particularly influenced by the HFD. The expression of these genes in HFD differed significantly compared with CD and CRCD, respectively, suggesting that the expressions of Casp1 and Ndufb9 in liver were regulated by their methylation statuses.

• 생명과학회지
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• 제22권11호
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• pp.1500-1506
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• 2012

Transforming growth factor-${\beta}$ (TGF-${\beta}$)에 의해 유도되는 세포사멸 과정은 간에서 손상 받은 조직이나 비정상적인 조직을 제거하는데 중요한 역할을 담당한다. 간세포에서 TGF-${\beta}$에 의해 유도되는 세포사멸 과정 동안 중요한 기능을 담당하는 유전자를 탐색하고자 쥐의 간세포인 AML12 세포를 이용하여 TGF-${\beta}$ 처리 전후에 발현이 변화되는 유전자를 microarray analysis를 통해 확인하였다. TGF-${\beta}$에 의해 여러 가지 유전자들의 발현이 변화됨을 확인하였는데, 그 가운데 여러 가지 세포사멸 인자들의 활성을 억제하여 세포사멸을 억제한다고 알려져 있는 SGK1의 발현 감소를 확인하였다. TGF-${\beta}$에 의해 SGK1의 mRNA와 단백질 level이 모두 감소함을 확인하였고, 항상 active한 형태의 SGK1 (CA-SGK1)을 발현시켰을 때 TGF-${\beta}$에 의한 세포사멸이 억제됨을 확인하였다. 이러한 결과들은 간세포에서 SGK1의 발현 감소가 TGF-${\beta}$에 의한 세포사멸을 유도하는데 중요한 기능을 담당할 가능성이 높음을 의미하는 것이다.