• Molecules and Cells
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• 제42권11호
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• pp.773-782
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• 2019

Cellular senescence is an irreversible form of cell cycle arrest. Senescent cells have a unique gene expression profile that is frequently accompanied by senescence-associated heterochromatic foci (SAHFs). Protein kinase CK2 (CK2) downregulation can induce trimethylation of histone H3 Lys 9 (H3K9me3) and SAHFs formation by activating SUV39h1. Here, we present evidence that the PI3K-AKT-mTOR-reactive oxygen species-p53 pathway is necessary for CK2 downregulation-mediated H3K9me3 and SAHFs formation. CK2 downregulation promotes SUV39h1 stability by inhibiting its proteasomal degradation in a p53-dependent manner. Moreover, the dephosphorylation status of Ser 392 on p53, a possible CK2 target site, enhances the nuclear import and subsequent stabilization of SUV39h1 by inhibiting the interactions between p53, MDM2, and SUV39h1. Furthermore, $p21^{Cip1/WAF1}$ is required for CK2 downregulation-mediated H3K9me3, and dephosphorylation of Ser 392 on p53 is important for efficient transcription of $p21^{Cip1/WAF}$. Taken together, these results suggest that CK2 downregulation induces dephosphorylation of Ser 392 on p53, which subsequently increases the stability of SUV39h1 and the expression of $p21^{Cip1/WAF1}$, leading to H3K9me3 and SAHFs formation.

• Molecules and Cells
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• 제42권3호
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• pp.252-261
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• 2019

The omega-3 fatty acid docosahexaenoic acid (DHA) is known to induce apoptosis and cell cycle arrest via the induction of reactive oxygen species (ROS) production and endoplasmic reticulum (ER) stress in many types of cancers. However, the roles of DHA in drug-resistant cancer cells have not been elucidated. In this study, we investigated the effects of DHA in cisplatin-resistant gastric cancer SNU-601/cis2 cells. DHA was found to induce ROS-dependent apoptosis in these cells. The inositol 1,4,5-triphosphate receptor ($IP_3R$) blocker 2-aminoethyl diphenylboninate (2-APB) reduced DHA-induced ROS production, consequently reducing apoptosis. We also found that G-protein-coupled receptor 120 (GPR120), a receptor of long-chain fatty acids, is expressed in SNU-601/cis2 cells, and the knockdown of GPR120 using specific shRNAs alleviated DHA-mediated ROS production and apoptosis. GPR120 knockdown reduced the expression of ER stress response genes, similar to the case for the pre-treatment of the cells with N-acetyl-L-cysteine (NAC), an ROS scavenger, or 2-APB. Indeed, the knockdown of C/EBP homologous protein (CHOP), a transcription factor that functions under ER stress conditions, markedly reduced DHA-mediated apoptosis, indicating that CHOP plays an essential role in the anti-cancer activity of DHA. These results suggest that GPR120 mediates DHA-induced apoptosis by regulating $IP_3R$, ROS, and ER stress levels in cisplatin-resistant cancer cells, and that GPR120 is an effective chemotherapeutic target for cisplatin resistance.

• 대한한방내과학회지
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• 제43권3호
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• pp.344-362
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• 2022

Objective: In this study, the antioxidant activity of Ojayeonjong-hwan extracts was compared, and the following results were obtained. Methods: For hydrothermal and ethanol extracts, DPPH free radical and ABTS cationic radical erasing activity and reducing power using the FRAP method were compared, and the association between the antioxidant power of each extract and total phenol content was investigated. Significant results were obtained through in vitro apoptosis analysis through FFITC staining, mitochondrial membrane potential analysis, and ROS level measurement using C2C12 myoblastoma. Results: 1. In a comparison of DPPH free radical and ABTS cationic radical scavenging activity, water, and 70% ethanol extracts of Ojayeonjong-hwan (WEO and EEO) showed superior radical scavenging ability. 2. In the results of reducing power using the FRAP method, WEO and EEO showed antioxidant activity, which was shown to be dependent on the total phenol content contained in the extracts. 3. In comparison to the protective effect against H₂O₂-induced oxidative stress in C2C12 myoblasts, water extracts had no significant effect, but 70% ethanol extracts inhibited H₂O₂-mediated cytotoxicity in a concentration-dependent manner. 4. The cytotoxic protective effect of EEO against oxidative stress in C2C12 myoblasts was correlated with its inhibitory effects on H₂O₂-induced apoptosis and cell-cycle arrest. 5. In H₂O₂-treated C2C12 myoblasts, the apoptosis inhibitory effects of EEO were associated with the suppression of mitochondrial dysfunction and DNA damage. 6. The protective effects of EEO against H₂O₂-induced oxidative stress in C2C12 myoblasts were directly related to the inhibition of ROS generation. Conclusions: Ojayeonjong-hwan extracts all have protective potential against oxidative stress.

• The Korean Journal of Physiology and Pharmacology
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• 제26권5호
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• pp.367-375
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• 2022

Gastric cancer stem cells (GCSCs) are a major cause of radioresistance and chemoresistance in gastric cancer (GC). Therefore, targeting GCSCs is regarded as a powerful strategy for the effective treatment of GC. Atorvastatin is a widely prescribed cholesterol-lowering drug that inhibits 3-hydroxy-3-methylglutaryl-coenzyme A reductase, a rate-limiting enzyme in the mevalonate pathway. The anticancer activity of atorvastatin, a repurposed drug, is being investigated; however, its therapeutic effect and molecular mechanism of action against GCSCs remain unknown. In this study, we evaluated the anticancer effects of atorvastatin on MKN45-derived GCSCs. Atorvastatin significantly inhibited the proliferative and tumorsphere-forming abilities of MKN45 GCSCs in a mevalonate pathway-independent manner. Atorvastatin induced cell cycle arrest at the G0/G1 phase and promoted apoptosis by activating the caspase cascade. Furthermore, atorvastatin exerted an antiproliferative effect against MKN45 GCSCs by inhibiting the expression of cancer stemness markers, such as CD133, CD44, integrin α6, aldehyde dehydrogenase 1A1, Oct4, Sox2, and Nanog, through the downregulation of β-catenin, signal transducer and activator of transcription 3, and protein kinase B activities. Additionally, the combined treatment of atorvastatin and sorafenib, a multi-kinase targeted anticancer drug, synergistically suppressed not only the proliferation and tumorsphere formation of MKN45 GCSCs but also the in vivo tumor growth in a chick chorioallantoic membrane model implanted with MKN45 GCSCs. These findings suggest that atorvastatin can therapeutically eliminate GCSCs.

• Journal of Microbiology and Biotechnology
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• 제34권2호
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• pp.249-261
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• 2024

New anti-lung cancer therapies are urgently required to improve clinical outcomes. Since ganodermanontriol (GDNT) has been identified as a potential antineoplastic agent, its role in lung adenocarcinoma (LUAD) is investigated in this study. Concretely, lung cancer cells were treated with GDNT and/or mycophenolate mofetil (MMF), after which MTT assay, flow cytometry and Western blot were conducted. Following bioinformatics analysis, carboxylesterase 2 (CES2) was knocked down and rescue assays were carried out in vitro. Xenograft experiment was performed on mice, followed by drug administration, measurement of tumor growth and determination of CES2, IMPDH1 and IMPDH2 expressions. As a result, the viability of lung cancer cells was reduced by GDNT or MMF. GDNT enhanced the effects of MMF on suppressing viability, promoting apoptosis and inducing cell cycle arrest in lung cancer cells. GDNT up-regulated CES2 level, and strengthened the effects of MMF on down-regulating IMPDH1 and IMPDH2 levels in the cells. IMPDH1 and IMPDH2 were highly expressed in LUAD samples. CES2 was a potential target for GDNT. CES2 knockdown reversed the synergistic effect of GDNT and MMF against lung cancer in vitro. GDNT potentiated the role of MMF in inhibiting tumor growth and expressions of CES2 and IMPDH1/2 in lung cancer in vivo. Collectively, GDNT suppresses the progression of LUAD by activating CES2 to enhance the metabolism of MMF.

• 생명과학회지
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• 제24권2호
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• pp.137-147
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• 2014

유근피(Cortex ulmi pumilae)는 항산화, 항염증, 항균, 항암 등 다양한 생리활성이 보고되어 있으며, 뛰어난 소염효과로 예로부터 약재로 사용되어 왔다. 본 연구에서는 3T3-L1 지방전구세포를 이용하여 유근피 추출물의 지방세포 분화에 미치는 영향과 그 기전을 검토하였다. 유근피 추출물을 분화유도제와 동시에 처리한 결과, 3T3-L1 지방전구세포의 세포질 내 triglyceride 생성을 농도의존적으로 감소시켰으며, 지방세포분화 관련 전사인자인 $C/EBP{\alpha}$, $C/EBP{\beta}$ 및 $PPAR{\gamma}$의 발현을 유의적으로 저하시켰다. 다음으로 유근피 추출물을 지방세포 분화 유도 단계별로 처리한 결과, 분화유도제와 동시에 처리한 경우 즉 분화 초기에 처리한 경우가 가장 효과적인 지방세포 분화 억제효능을 보였으며, 이 때 분화초기에 발현되는 $C/EBP{\beta}$의 발현량은 현저하게 감소되었다. 또한 유근피 추출물에 의해 mitotic clonal expansion 단계의 세포증식이 농도의존적으로 억제되는 것을 확인하였으며, 세포주기분석을 통해 G1 arrest를 유발함으로써 증식이 억제 된다는 것을 확인하였다. 또한, G1 arrest는 G1/S 전이 관련 단백질인 p21의 발현 증가, cyclin E의 발현 감소 및 Rb의 인산화 감소에 의한 것임을 확인하였다. 이러한 연구결과들로부터 유근피 추출물은 지방세포 분화 초기 단계에 작용하여 지방세포 분화 관련 전사인자의 발현을 억제하고 mitotic clonal expansion을 저해하여, 지방전구세포의 지방세포로의 분화를 억제하는 항비만 효능을 가지는 천연소재임을 확인하였으며, 따라서 본 연구는 향후 이를 활용한 지속적인 연구를 위한 기초자료로 그 가치가 매우 높을 것이라 생각된다.

• 생명과학회지
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• 제19권9호
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• pp.1314-1320
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• 2009

히스톤 디아세틸라이제 저해제(HDACI)는 최근에 새로운 미래형 항암제로 주목을 받고 있으며 다른 항암요법 및 치료제와의 병용치료에도 효과적으로 적용될 수 있을 것으로 기대하고 있다. HDACI은 다양한 조직기원의 암세포에서 증식억제 및 세포사멸 유도능이 시험되어 왔으나 비소세포폐암 세포에서 그 작용 및 기전이 명확히 조사된 바가 없다. 본 연구는 HDACI 중의 하나인 sodium butyrate (SB)를 비소세포폐암 세포주인 H460에 처리하여 세포생존율, 세포주기 분석, 세포사멸도를 평가하고, 이와 관련하여 세포사멸 관련 단백질, p53, ERK의 변화를 조사하고자 하였다. 3가지 다른 농도(2.5, 7.5, 20 mM)의 SB에 H460 세포가 48시간 노출되었을 때, 세포 생존율은 농도의존적으로 감소되었으나 7.5 mM 이상의 농도에서 대조군에 비해 유의한 생존을 감소를 보였고, 20 mM에서 생존을 50% 전후를 나타냈다. SB노출은 H460 세포의 사멸을 유발하였는데, 세포사의 유형은 아포토시스와 괴사가 동시에 발생함이 Annexin-V 분석으로 확인되었다. H460 세포에서 SB에 의해 유발되는 뚜렷한 세포주기의 변화양상은 G2/M기정지였으며, 이러한 세포주기의 지연현상으로 세포사멸이 초래되는 것으로 생각된다. SB처리는 아포토시스 발생관련 효소인 caspase-3과 caspase-7의 활성화를 유발하였으며, 이에 의한 PARP 단백 질의 분절화도 관찰되었다. 동시에, 항세포사별 단백질인 XIAP의 단백질 함량은 감소함을 보였다. SB 노출에 의한 세포주기의 G2/M기의 정지현상과 관련하여는 p53 단백질의 증가가 주목할 만한 하였다. SB의 H460세포에의 처리는 일반 ERK단백질의 함량 변화를 유도하지 않았으나, 인산화형의 ERK는 SB처리농도에 의존적으로 그 단백질 함량이 감소하였다. 이는 ERK가 비소세포폐암 세포인 H460에서 세포생존 및 유지와 관련된 단백질의 인산화에 계속적으로 관여하고 있다는 사실을 암시한다. 즉, SB의 처리는 ERK의 인산화를 유의하게 억제하는 기전과 관련이 있을 가능성이 높다고 추측된다. 향후 SB의 노출에 의한 PERK 감소 기전에 대한 연구가 추가적으로 진행되면 SB의 더욱 효율적인 암세포 사멸 유도 전략수립에 도움을 줄 수 있을 것이라 예상된다.

• Radiation Oncology Journal
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• 제17권4호
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• pp.314-320
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• 1999

목적 : Paclitaxel(Toxol)은 미소관의 집합을 촉진시키고 분해를 방지하는 미소관 억제제로서 이 작용은 세포주기 중 방사선에 예민한 G2fM 시기에 일어나기 때문에 방사선조사와 병용할 경우 방사선감작제 가능성이 있다. Paclitaxel과 방사선조사를 병용하여 흰쥐의 위점막에서 paclitaxe이 방사선의 효과에 미치는 영향을 파악하기 위하여 본 연구를 시행하였다. 대상 및 방법 : 실험군은 paclitaxel 단독군, 방사선조사 단독군 및 paclitaxel과 방사선조사 병용군의 세 군으로 분류하여 paclltaxel 단독군은 paclitaxel (10 mg/kg)을 복강내 1회 주입하였고, 방사조사 단독군은 8 Gy를 전복부에 단일 조사하였으며, paclitaxel과 방사선조사 병용군은 paclitaxel (10 mg/kg)을 복강내 주입 후 24시간에 방사선조사 단독군과 동일한 방법으로 방사선조사하였다. 실험 완료 후 위점막 내 유사분열수, apoptosis와 기타 점막의 변화를 시간별로(6, 24시간, 3일 및 5일) 비교관찰하였다. 결과 : Paclitaxel 주입 후 위점막 내 유사분열은 증가하지 않았고 apoptosis는 6시간에 $5.75\%$였고 3일까지 비슷하게 지속되었다. Paclitaxel 주입 후 경미한 위선의 확장이 24시간에 관찰되었고, 세포의 비정형이 24시간과 3일에 보였으나 5일에는 정상으로 회복되었다. 방사선조사 단독군에서 apoptosis는 6시간에 $6.0\%$로 가장 많았으며 24시간에 $1.25\%$로 감소되었고 5일까지 지속되었다. 위선의 확장과 세포의 비정형은 방사선조사 후 6시간부터 5일까지 계속해서 경미하게 보였다. Paclltaxei과 방사선조사 병용군은 apoptosis가 6, 24시간, 3일 및 5일에 각각 5.5, 4.5, 4.0, $4.0\%$로 방사선조사 단독군에 비하여 24시간부터 많아졌고 3일에는 통계학적으로 유의한 차이가 있었다. 위선의 확장과 세포의 비정형은 Paclitaxel과 방사선조사 병용군에서 방사선조사 단독군에 비하여 증가되지 않았다. 결론 : 흰쥐의 위점막은 paclitaxel 주입 후 24시간에 방사선조사를 시행한 결과 apoptosis를 종말점으로 볼 때 paclitaxel의 첨가효과만을 보여 주었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권18호
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• pp.7849-7855
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• 2014

Purpose: To investigate the effect of deacetylase inhibitory trichostatin A (TSA) on anti HepG2 liver carcinoma cells and explore the underlying mechanisms. Materials and Methods: HepG2 cells exposed to different concentrations of TSA for 24, 48, or 72h were examined for cell growth inhibition using CCK8, changes in cell cycle distribution with flow cytometry, cell apoptosis with annexin V-FTIC/PI double staining, and cell morphology changes under an inverted microscope. Expression of ${\beta}$-catenin, HDAC1, HDAC3, H3K9, CyclinD1 and Bax proteins was tested by Western blotting. Gene expression for ${\beta}$-catenin, HDAC1and HDAC3 was tested by q-PCR. ${\beta}$-catenin and H3K9 proteins were also tested by immunofluorescence. Activity of Renilla luciferase (pTCF/LEF-luc) was assessed using the Luciferase Reporter Assay system reagent. The activity of total HDACs was detected with a HDACs colorimetric kit. Results: Exposure to TSA caused significant dose-and time-dependent inhibition of HepG2 cell proliferation (p<0.05) and resulted in increased cell percentages in G0/G1 and G2/M phases and decrease in the S phase. The apoptotic index in the control group was $6.22{\pm}0.25%$, which increased to $7.17{\pm}0.20%$ and $18.1{\pm}0.42%$ in the treatment group. Exposure to 250 and 500nmol/L TSA also caused cell morphology changes with numerous floating cells. Expression of ${\beta}$-catenin, H3K9and Bax proteins was significantly increased, expression levels of CyclinD1, HDAC1, HDAC3 were decreased. Expression of ${\beta}$-catenin at the genetic level was significantly increased, with no significant difference in HDAC1and HDAC3 genes. In the cytoplasm, expression of ${\beta}$-catenin fluorescence protein was not obvious changed and in the nucleus, small amounts of green fluorescence were observed. H3K9 fluorescence protein were increased. Expression levels of the transcription factor TCF werealso increased in HepG2 cells following induction by TSA, whikle the activity of total HDACs was decreased. Conclusions: TSA inhibits HDAC activity, promotes histone acetylation, and activates Wnt/${\beta}$-catenin signaling to inhibit proliferation of HepG2 cell, arrest cell cycling and induce apoptosis.

• 동의생리병리학회지
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• 제21권1호
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• pp.158-164
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• 2007

Uterine leiomyoma is the most common tumor in the female genital tract. Although the tumor is benign, it is a matter of paramount importance since it often causes profuse menstrual bleeding, pressure symptoms and infertility. Nevertheless, the etiology and pathophysiology of this abnormality remain poorly understood. The traditional definitive treatment for uterine leiomyomas is hysterectomy and, even today, symptomatic leiomyomas are the leading cause of hysterectomy in Korea. Clearly, the development of a safe, effective, and nonsurgical method of treatment for leiomyoma would be of great benefit to many women. This study demonstrated growth inhibition of uterine leiomyoma cells using Haeohyultang (HT). When human leiomyoma cells were treated with Haeohyultang, cells showed dose-dependent growth inhibitory effect. Cell growth was inhibited by over 40% as determined by both cell counts and MTS assay. Reduction of cellular viability as a consequence of exposure to Haeohyultang resulted from induction of apoptosis, as assessed by DNA fragmentation, PARP cleavage, caspase 9 and caspase 3 assay. Flow cytometry analysis with uterine leiomyoma cells demonstrated sub G1 cell cycle arrest after treatment with drug Haeohyultang. But, the expression levels of p27 and p21 were not changed in Haeohyultang treated cells compared with control. However, the expression levels of clAP1 were reduced by Haeohyultang compared with control. This reduction of clAP1 data means activation of the caspase family, and then induction of PARP cleavage and apoptosis. These results suggest that Haeohyultang may be potential therapeutic approach in the clinical management of uterine leiomyoma.