• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.154.2-154.2
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• 2003

Mammalian cell cycles are tightly regulated by cyclins, cyclin dependent kinase (CDK), Retinoblatoma (Rb) protein, and cellular CDK inhibitors (CDKI). Cyelin dependent kinases (CDK) are key enzymes regulating eukaryotic cell cycle. And also it is recognized that the abnormal increase of CDK activities is one of the common events in human cancer and CDK inhibitors have therapeutic values in cancer treatment. Until now it is known that over 10 different CKDs participate in cell cycle regulation. (omitted)

• 대한의생명과학회지
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• 제16권2호
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• pp.71-74
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• 2010

Cell proliferation is governed by precise and orderly process the regulation of which involves many different proteins. The key enzyme for cell growth and arrest is cyclin dependent kinases (cdks). In human cells, several cdks orchestrate four distinct cell cycle phases (M, $G_1$, S and $G_2$ ) and they sequentially operate in an order of cdc1, cdk4, cdk6 and cdk2. The regulatory components of cdks consist of cyclins and two family of cdk inhibitors, INK4 (inhibitors of cdk4) and KIP (kinase inhibitor protein). $G_1$ regulatory molecules for cdk mainly respond to environmental cues of mitogenic and anti-mitogenic stimuli and therefore influence activities of $G_1$ cdks, namely, cdk4/6 and cdk2. $G_1$ inhibitors include $p21^{CIP}$ and $p27^{KIP1}$. Between them, $p27^{KIP1}$ has attracted attentions of many researchers because of its characteristic regulatory features and diverse functions. Besides, the role of $p27^{KIP1}$ in cancer development warrants further studies in the future. Therefore, this review will focus on the recent findings and especially on the complexity of regulatory mechanisms of $p27^{KIP1}$.

• 생명과학회지
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• 제19권7호
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• pp.871-877
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• 2009

대표적인 histone deacetylase inhibitor 저해제의 일종일 sodium butyrate에 의한 인체백혈병 U937세포의 증식 억제에 관한 기전 연구를 세포주기 조절 측면에서 조사하였다. MTT assay 및 flow cytometry 분석을 통하여 sodium butyrate의 처리 농도 증가에 따른 U937 세포의 증식억제는 세포주기 G1 arrest 및 apoptosis 유발에 의한 것임을 확인하였다. RT-PCR및 Western blotting 결과에서 sodium butrate에 의한 G1 arrest는 세포주기 G1기에서 S기로의 진입에 중요한 역할을 하는 cyclin D1, E, A, cyclin-dependent kinase (Cdk) 4 및 Cdk6발현의 저해와 p21 및 p27과 같은 Cdk inhibitor의 발현 증가와 연관성이 있었다. Sodium butyrate는 또한 retinoblastoma protein (pRB)및 p130 단백질의 인산화를 저해시켰으나, S기 진행에 중요한 전사조절인자인 E2F-1 및 E2F-4의 의 발현에는 큰 영향이 없었다. 그러나 sodium butyrate에 의한 pRB 및 p130단백질의 인산화 저해는 pRB와 E2F-1및 p130과 E2F-4와의 결합력을 증사시켰다. 본 연구의 결과는 U937세포의 증식억제에 pRB/p130 인산화 억제 및 Cdk inhibitors의 발현 증가가 중요한 역할을 하고있음을 보여주는 것으로, sodium butyrate의 항암기전 이해에 중요한 자료가 될 것이다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2006년도 Spring Conference
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• pp.95-105
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• 2006

Alzheimer's disease (AD) is an irreversible, progressive brain disorder that is characterized by dementia. Amounts of p25 and cdk5 kinase activity are specifically upregulated in AD patient's brain samples. Considerable evidence now points importance of p25/cdk5 in generation of A$\beta$ peptides and hyperphosphorylation of tau linking amyloid plaques and neurofibrillary tangles, two major pathological hallmarks of AD. We demonstrated that P25/CDK5 phosphorylates BACE1, the first step protease to produce A$\beta$. P25/CDK5 inhibitors to reduce BACE1 phosphorylation and the secretion of A$\beta$ are screened through in silica, in vitro, and cell-based assays. Out of 4.3 million chemicals we finally selected two compounds to have IC50 of 10 microM in cell-based assays. The inhibitors block Tau phosphrorylation as well as BACE1 phosphorylation. In conclusion P25 should be one of the best targets for AD therapeutics.

• Journal of Microbiology and Biotechnology
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• 제17권10호
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• pp.1712-1716
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• 2007

To generate new scaffold candidates as highly selective and potent cyelin-dependent kinase (CDK) inhibitors, structure-based drug screening was performed utilizing 3D pharmacophore conformations of known potent inhibitors. As a result, CR229 (6-bromo-2,3,4,9-tetrahydro-carbolin-1-one) was generated as the hit-compound. A computational docking study using the X-ray crystallographic structure of CDK2 in complex with CR229 was evaluated. This predicted binding mode study of CR229 with CDK2 demonstrated that CR229 interacted effectively with the Leu83 and Glu81 residues in the ATP-binding pocket of CDK2 for the possible hydrogen bond formation. Furthermore, biochemical studies on inhibitory effects of CR229 on various kinases in the human cervical cancer HeLa cells demonstrated that CR229 was a potent inhibitor of CDK2 ($IC_{50}:\;3\;{\mu}M$), CDKI ($IC_{50}:\;4.9\;{\mu}M$), and CDK4 ($IC_{50}:\;3\;{\mu}M$), yet had much less inhibitory effect ($IC_{50}:>20\;{\mu}M$) on other kinases, such as casein kinase 2-${\alpha}1$ (CK2-${\alpha}1$), protein kinase A (PKA), and protein kinase C (PKC). Accordingly, these data demonstrate that CR229 is a potent CDK inhibitor with anticancer efficacy.

• Reproductive and Developmental Biology
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• 제31권2호
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• pp.71-76
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• 2007

Previous studies have shown that BMI-1026 is a potent inhibitor of the cyclin-dependent kinases (cdk). In cell culture, the compound also arrests G2/M strongly and G1/S and S weakly. Two key kinases, cdk1 (p34cdc2 kinase) and mitogen-activated protein (MAP) kinase (erk1 and 2), perform crucial roles during oocyte maturation and, later, metaphase II (MII) arrest. In mammalian oocytes, both kinases are activated gradually around the time of germinal vesicle breakdown (GVBD) and maintain high activity in eggs arrested at metaphase II. In this study, we examined the effects of BMI-1026 on GVBD and MII arrest in mouse oocytes. BMI-1026 inhibited GVBD of immature oocytes and activated MII-arrested oocytes in a concentration-dependent manner, with more than 90% of oocytes exhibiting GVBD inhibition and MII activation at 100 nM This is approximately 500$\sim$1,000 times more potent than the activity reported for the cdk inhibitors roscovitine (${\sim}50{\mu}M$) and butyrolactone (${\sim}100{\mu}M$). Based on the results of previous in vitro kinase assays, we expected BMI-1026 to inhibit only cdk1 activation in oocytes and eggs, not MAP kinase. However, in our cell-based system, it inhibited the activity of both kinases. We also found that the effect of BMI-1026 is reversible. Our results suggest that BMI-1026 inhibits GVBD and activates MII-arrested oocytes efficiently and reversibly and that it also inhibits both cdk1/histone HI kinase and MAP kinase in mouse oocytes.

• Biomolecules & Therapeutics
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• 제20권1호
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• pp.81-88
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• 2012

Histone deacetylases (HDACs) are enzymes involved in the remodelling of chromatin, and have a key role in the epigenetic regulation of gene expression. Histone deacetylase (HDAC) inhibitors are emerging as an exciting new class of potential anti-cancer agents. In recent years, a number of structurally diverse HDAC inhibitors have been identifi ed and these HDAC inhibitors induce growth arrest, differentiation and/or apoptosis of cancer cells in vitro and in vivo. However, the underlying molecular mechanisms remain unclear. This study aimed at investigating the anti-tumor activity of various HDAC inhibitors, IN-2001, using T47D human breast cancer cells. Moreover, the possible mechanism by which HDAC inhibitors exhibit anti-tumor activity was also explored. In estrogen receptor positive T47D cells, IN-2001, HDAC inhibitor showed anti-proliferative effects in dose-and time-dependent manner. In T47D human breast cancer cells showed anti-tumor activity of IN-2001 and the growth inhibitory effects of IN-2001 were related to the cell cycle arrest and induction of apoptosis. Flow cytometry studies revealed that IN-2001 showed accumulation of cells at $G_2$/M phase. At the same time, IN-2001 treatment time-dependently increased sub-$G_1$ population, representing apoptotic cells. IN-2001-mediated cell cycle arrest was associated with induction of cdk inhibitor expression. In T47D cells, IN-2001 as well as other HDAC inhibitors treatment significantly increased $p21^{WAF1}$ and $p27^{KIP1}$ expression. In addition, thymidylate synthase, an essential enzyme for DNA replication and repair, was down-regulated by IN-2001 and other HDAC inhibitors in the T47D human breast cancer cells. In summary, IN-2001 with a higher potency than other HDAC inhibitors induced growth inhibition, cell cycle arrest, and eventual apoptosis in human breast cancer possibly through modulation of cell cycle and apoptosis regulatory proteins, such as cdk inhibitors, cyclins, and thymidylate synthase.

• Environmental Analysis Health and Toxicology
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• 제27권
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• pp.10.1-10.7
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• 2012

Objectives: In recent years, a number of structurally diverse Histone deacetylase (HDAC) inhibitors have been identified and these HDAC inhibitors induce growth arrest, differentiation and/or apoptosis of cancer cells in vitro and in vivo. This study aimed at investigating the antitumor activity of newly synthesized HDAC inhibitor, 3-(4-dimethylamino phenyl)-N-hydroxy-2-propenamide (IN-2001) using human breast cancer cells. Methods: We have synthesized a new HDAC inhibitor, IN-2001, and cell proliferation inhibition assay with this chemical in estrogen receptor-positive human breast cancer MCF-7 cells. Cell cycle analysis on MCF-7 cells treated with IN-2001 was carried out by flow cytometry and gene expression was measured by RT-PCR. Results: In MCF-7 cells IN-2001 showed remarkable anti-proliferative effects in a dose- and time-dependent manner. In MCF-7 cells, IN-2001 showed a more potent growth inhibitory effect than that of suberoylanilide hydroxamic acid. These growth inhibitory effects were related to the cell cycle arrest and induction of apoptosis. IN-2001 showed accumulation of cells at $G_2$/M phase and of the sub-$G_1$ population in a time-dependent manner, representing apoptotic cells. IN-2001-mediated cell cycle arrest was associated with HDAC inhibitor-mediated induction of CDK inhibitor expression. In MCF-7 cells, IN-2001 significantly increased $p21^{WAF1}$ expression. Conclusions: In summary, cyclin-dependent kinase (CDK) induced growth inhibition, possibly through modulation of cell cycle and apoptosis regulatory proteins, such as CDK inhibitors, and cyclins. Taken together, these results provide an insight into the utility of HDAC inhibitors as a novel chemotherapeutic regime for hormone-sensitive and insensitive breast cancer.

• 대한한방내과학회지
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• 제25권4호
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• pp.9-17
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• 2004

Objective : Mesangial cell proliferation and excessive accumulation of extracellular matrix (ECM) proteins is the common pathologic feature of glomerulosclerosis, and platelet-derived growth factor (PDGF) BB-chain, transforming growth factor betal $(TGF-{\beta}1)$, cyclin dependent kinases (CDK) and CDK inhibitors mediated in these pathophysiological processes. Bupleurum falcatum which is one of the most widely used components in traditional oriental medicines, has multiple pharmacological effects, such as antipyretic, analgesic, immune modulating, anti-inflammatory, anti-allergic, anti-thrombotic, anti-atherosclerotic, and antitussive effects. Methods : In this study, we evaluated the influence of Bupleurum falcatum on mesangial cell proliferation, DNA synthesis and expression of PDGF-BB chain, $TGF-{\beta}1$, CDKI, CDK2, CDK4, p21 and p27 in fetal bovine serum (FBS)-activated human mesangial cell. Results : Bupleurum falcatum reduced the mesangial cell proliferation and DNA synthesis more than control and captopril. And in the ELISA analysis of $TGF-{\beta}1$, and RT-PCR of PDGF-BB chain, CDK1, CDK2, CDK4, p21, and p27, Bupleurum falcatum inhibited the expression of $TGF-{\beta}1$ protein and PDGF-BB, CDK1, CDK2 gene and promoted that of p21 gene in a dose-dependent manner in comparing with control and captopril. Conclusions: These results suggest that Bupleurum falcatum may inhibit the mesangial cell proliferation and DNA synthesis by regulation of PDGF-BB and $TGF-{\beta}1$ expressions, and by modulation of CDK1, CDK2 and p21 expression.

• 한국임상약학회지
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• 제30권1호
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• pp.1-10
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• 2020

Objective: The aim of the study was to perform a meta-analysis of randomized clinical trials to compare the clinical efficacy and safety between combination of cyclin-dependent kinase (CDK) 4/6 inhibitors with aromatase inhibitors (AIs) and AIs alone in patients with hormone receptor+/human epidermal growth factor receptor type2-(HR+/HER2-) advanced breast cancer. Methods: Published clinical studies were identified through electronic database searches until February 2019. Literature qualities were assessed by the Scottish Intercollegiate Guidelines Network Checklist. Key endpoints of efficacy were progression-free survival (PFS), objective response rate (ORR), and clinical benefit (CB). Endpoints of safety were adverse events (AEs) (neutropenia, leukopenia, any grade 3/4 AEs, and serious AEs) and on-treatment death. Meta-analysis was performed using the RevMan 5.3 software. Results: The selected five studies were evaluated as "good" in quality assessment. Compared to AIs alone, the combination therapy significantly improved PFS (pooled hazard ratio=0.55; 95% confidence interval (CI) 0.49-0.62), ORR (odds ratio=1.78; 95% CI=1.49-2.13), and CB (odds ratio=1.86; 95% CI=1.51-2.28). The prevalence of AEs was significantly higher in the combination group than in the AIs alone group. On-treatment death was greater in the combination group than in the AIs alone group, although insignificant. Conclusion: The combination therapy of CDK4/6 inhibitors with AIs was more effective for the treatment of HR+/HER2- advanced breast cancer, but less safe than AIs alone. The combination therapy should be effectively managed through patient monitoring, and further studies are needed to reduce AEs in the combination therapy of CDK4/6 inhibitors with AIs.