• 생명과학회지
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• 제13권5호
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• pp.642-650
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• 2003

인체 신경아세포종의 성장에 미치는 cAMP의 영향을 조사하기 위하여 Ewing's sarcoma 세포주인 CHP-100 세포에 dibutyry1-cAMP 및 8-bromo-cAMP를 처리하였다. 두 종류의 cAMP analog처리 시간 증가에 따라 CHP-100 세포의 증식이 처리 시간 의존적으로 억제되었으며, 이는 핵의 형태변화 및 DNA 단편화 현상을 수반한 apoptosis 유발과 연관성이 있었다. 또한 DNA flow cytometry 분석결과 cAMP는 세포주기 G1기 특이적 arrest를 유발하였다. cAMP 처리에 의하여 retinoblastoma 단백질(pRB)의 인산화가 억제되었으며, 전사조절인자 E2F-1과의 결합이 증대되었다. cAMP는 cyclin-dependent kinase (Cdk) 2 및 cyclin E 단백질의 발현변화에는 영향을 미치지 않았으나, 그들의 kinase 활성은 처리시간 의존적으로 매우 감소되었다. 또한 cAMP 처리에 의하여 Cdk inhibitor인 $p21^{WAF1/CIP1$의 발현이 증가되었으며, 증가된 p21 단백질은 Cdk2와 강한 결합을 형성하고 있었다. 이상의 결과에서 cAMP의 암세포 성장억제 효과에 pRB 및 p21이 매우 중요한 역할을 함을 알 수 있었다.

• 생명과학회지
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• 제20권7호
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• pp.977-982
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• 2010

본 연구에서는 오미자에서 분리된 dibenzocyclooctadiene lignan의 일종인 gomisin A와 gomisin N에 대한 항암효능을 U937 인체혈구암세포를 대상으로 조사하였다. Gomisin N은 처리농도의 증가에 따라 U937 세포의 증식을 억제하였으나 동일조건에서 gomisin A는 세포독성 효과를 나타내지 못하였으며, gomisin N에 의한 U937 세포의 증식억제는 세포주기 G1 arrest 유발에 의한 것이었다. Gomisin N에 의한 G1 arrest는 cyclin E, cyclin-dependent kinase (Cdk) 2 및 Cdk4의 발현 억제와 Cdk inhibitor인 p16 (INK4A) 및 p21 (WAF1/CIP1)의 발현 증가와 연관성이 있었으나, gomisin A는 세포주기 인자들의 발현에 유의적인 변화를 유발하지 않았다. 또한 gomisin N은 retinoblastoma 단백질군인 pRB 및 p130의 인산화를 억제하였으며, 전사조절인자인 E2F 단백질들의 발현을 억제하였다. 본 연구의 결과에서 gomisin N에 의한 U937 세포의 증식억제는 세포주기 조절인자들의 발현 변화를 통한 G1 arrest 유발에 의한 것임을 알 수 있었으며, gomisin N은 암예방 및 항암활성 후보불질로서의 개발 가능성이 있음을 알 수 있었다.

• Journal of Periodontal and Implant Science
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• 제49권3호
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• pp.138-147
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• 2019

Purpose: Several studies have shown that the oral cavity is a secondary location for Helicobacter pylori colonization and that H. pylori is associated with the severity of periodontitis. This study investigated whether H. pylori had an effect on the periodontium. We established an invasion model of a standard strain of H. pylori in human periodontal ligament fibroblasts (hPDLFs), and evaluated the effects of H. pylori on cell proliferation and cell cycle progression. Methods: Different concentrations of H. pylori were used to infect hPDLFs, with 6 hours of co-culture. The multiplicity of infection in the low- and high-concentration groups was 10:1 and 100:1, respectively. The Cell Counting Kit-8 method and Ki-67 immunofluorescence were used to detect cell proliferation. Flow cytometry, quantitative real-time polymerase chain reaction, and western blots were used to detect cell cycle progression. In the high-concentration group, the invasion of H. pylori was observed by transmission electron microscopy. Results: It was found that H. pylori invaded the fibroblasts, with cytoplasmic localization. Analyses of cell proliferation and flow cytometry showed that H. pylori inhibited the proliferation of periodontal fibroblasts by causing G2 phase arrest. The inhibition of proliferation and G2 phase arrest were more obvious in the high-concentration group. In the low-concentration group, the G2 phase regulatory factors cyclin dependent kinase 1 (CDK1) and cell division cycle 25C (Cdc25C) were upregulated, while cyclin B1 was inhibited. However, in the high-concentration group, cyclin B1 was upregulated and CDK1 was inhibited. Furthermore, the deactivated states of tyrosine phosphorylation of CDK1 (CDK1-Y15) and serine phosphorylation of Cdc25C (Cdc25C-S216) were upregulated after H. pylori infection. Conclusions: In our model, H. pylori inhibited the proliferation of hPDLFs and exerted an invasive effect, causing G2 phase arrest via the Cdc25C/CDK1/cyclin B1 signaling cascade. Its inhibitory effect on proliferation was stronger in the high-concentration group.

• Asian-Australasian Journal of Animal Sciences
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• 제15권7호
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• pp.1045-1050
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• 2002

The aims of this study were to detect spontaneously occurring apoptosis in cultured porcine ovarian cells, to examine the role of growth hormone (GH), tyrosine kinase (TK), protein kinase G (PKG) and cyclin-dependent kinase (CDK) in the control of this process, and to determine whether the effect of GH on apoptosis is mediated by TK-, PKG- and cdc2-dependent intracellular mechanisms. We studied the action of pGH (10 ng/ml), blockers of TK (genistein, lavendustin, both 100 ng/ml), PKG (Rp-Br-PET-cGMPS, 50 nM; KT5823, 100 ng/ml) and CDK (olomoucine, $1{\mu}g/ml$), as well as combinations of GH with these blockers, on the onset of apoptosis in cultured granulosa cells isolated from antral (3-6 mm) porcine follicles. The functional characteristics of an early apoptotic event, DNA fragmentation, were determined using terminal deoxynucleotidyltransferase (TdT)-mediated dUTP nick end labelling (TUNEL), whilst morphological signs of advanced apoptosis such as pyknosis, chromatin marginalization, shrinkage and fragmentation of nucleus, were detected using routine light microscopy. After culture, some ovarian granulosa cells exhibited DNA fragmentation, which in some cases was associated with morphological apoptosis-related changes (pyknosis, shrinkage and fragmentation of the nucleus). GH significantly reduced the proportion of TUNEL-positive cells. Neither TK nor CDK blockers when given alone, significantly affected the percentage of TUNEL-positive cells although both PKG blockers significantly increased this index. Furthermore, TK and PKG blockers given together with GH, prevented or reversed the inhibitory effect of GH on apoptosis, whilst the CDK blocker olomoucine promoted it. These observations demonstrate apoptosis in porcine ovaries and suggest the involvement of GH, TK, PKG and CDK in the control of this process. They also suggest that the effect of GH on ovarian apoptosis is mediated or regulated by multiple signalling pathways including TK-, PKG- and CDK-dependent intracellular mechanisms.

• Journal of Periodontal and Implant Science
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• 제32권4호
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• pp.811-825
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• 2002

Recently, many natural medicines, whose advantages are less side effects and possibility of long-term use, have been studied for their capacity, their anti-bacterial and anti-inflammatory effects and regenerative potential of periodontal tissues. Cervi Parvum Comu(CPC) have been traditionally study as an hale, growth. hematogenous, anti-aging, hack pain in Eastern medicine. The purpose of present study was to investigate the effects of CPC extract on cell cycle progression and its molecular mechanism in human fetal osteoblasts. CPC extracts (10 ${\mu}g/ml$) increased cell proliferation in the human fetal osteoblasts compared to non-supplemented control. There was no significant change in the G1 and S phase, hut a increase in the G2/M phase in 10 ${\mu}g/ml$ and 100 ${\mu}g/ml$ of CPC extracts group as compared to non-supplemented control. The protein expression of cyclin E, cdk 2, cycln D, cdk 4, and cdk 6 was higher than that of control group. The level of p21 was lower than that of control. But that of pRb and pl6 was not distinguished from control. These results indicate that the increase of cell proliferation by CPC extracts may be due t o the increased expression of cyclin E, cdk 2, cyclin D, cdk 4 and cdk 6, and the decreased expression of p21 in human fetal osteoblasts.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 2004년도 제56차 추계 학술대회 연제집
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• pp.40.1-40.1
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• 2004

• Asian Pacific Journal of Cancer Prevention
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• 제15권15호
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• pp.6437-6441
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• 2014

Background: Oridonin isolated from Rabdosia rubescens, a plant used to treat cancer in Chinese folk medicine, is one of the most important antitumor active ingredients. Previous studies have shown that oridonin has antitumor activities in vivo and in vitro, but little is known about cell cycle effects of oridonin in gastric cancer. Materials and Methods: MTT assay was adopted to detect the proliferation inhibition of SGC-7901 cells, the cell cycle was assessed by flow cytometry and protein expression by Western blotting. Results: Oridonin could inhibit SGC-7901 cell proliferation, the $IC_{50}$ being $15.6{\mu}M$, and blocked SGC-7901 cell cycling in the $G_2/M$ phase. The agent also decreased the protein expression of cyclinB1 and CDK1. Conclusions: Oridonin may inhibit SGC-7901 growth and block the cells in the $G_2/M$ phase by decreasing Cdk1 and cyclinB1 proteins.

• Journal of Periodontal and Implant Science
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• 제35권1호
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• pp.87-98
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• 2005

The purpose of present study was to investigate the effects of physiologically active compound (SD62-122) from Phlomidis Radix on the cell cycle progression and its molecular mechanism in human gingival fibroblasts(HGFs). For this purpose, fibroblasts were isolated and cultured from excisioned gingiva during crown lengthening procedure in healthy adult. The following parameter were evaluated that there are cell number counting, MIT assay, cell cycle progression, western blot analysis. The cell number and MIT assay of primary cultured fibroblast was not increased at 2 days but significant increased compare to negative control at 3days(p<0.05). S phase was increased and G1 phase decreased in both $10^{-8}M$ and $10^{-9}M$ of SD62-122 in cell cycle analysis. The cell cycle regulation protein levels of Cyclin $D_1$, Cyclin E, cdk 2, cdk 4 and cdk 6 were increased compare to control in both $10^{-8}M$ and $10^{-9}M$ of SD62-122. The protein levels of p21 and p53 were decreased compare to control, but the level of pRb was not changed compare to control in $10^{-9}M$ of SD2-122. These results suggested that physiologically active compound (SD62-122) isolated from Phlomidis Radix increases the cell proliferation and cell cycle progression in HGFs, which is linked to increased cell cycle regulation protein levels of Cyclin $D_1$, Cyclin E, cdk 2, cdk 4 and cdk 6, and decreased the levels of p21, p53.

• International Journal of Oral Biology
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• 제41권3호
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• pp.113-118
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• 2016

An FDA approved drug for the treatment of type II diabetes, Troglitazone (TRO), a peroxisome proliferator-activated receptor gamma agonist, is withdrawn due to severe idiosyncratic hepatotoxicity. In the search for new applications of TRO, we investigated the cellular effects of TRO on YD15 tongue carcinoma cells. TRO suppressed the growth of YD15 cells in the MTT assay. The inhibition of cell growth was accompanied by the induction of cell cycle arrest at $G_0/G_1$ and apoptosis, which are confirmed by flow cytometry and western blotting. TRO also suppressed the expression of cell cycle proteins such as cyclin D1, cdk2, cdk4, cyclin B1, cdk1(or cdc2), cyclin E1 and cyclin A. The inhibition of cell cycle proteins was coincident with the up-regulation of $p21^{CIP1/WAF1}$ and $p27^{KIP1}$. In addition, TRO induces the activation of caspase-3 and caspase-7, as well as the cleavage of PARP. Further, TRO suppressed the expressions of Bcl-2 without affecting the expressions of Bad and Bax. Overall, our data supports that TRO induces cell cycle arrest and apoptosis on YD15 cells.

• Tuberculosis and Respiratory Diseases
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• 제44권4호
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• pp.796-805
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• 1997

연구배경 : 세포주기의 활성화, 그 중에서도 특히 $G_1$/S 이행에 관여하는 세포주기관련 단백질들은 암발생에 있어서 매우 중요한 역할을 하는 것으로 알려져 있다. $G_1$ 세포주기 관련 단백질 중의 하나인 cdk4 (cyclin dependent kinase 4)의 억제제로 알려져 있는 p16 유전자는 최근에 밝혀진 종양억제유전자중의 하나로서 MTS1 (multiple tumor suppressor 1)이라고도 불린다. p16 유전자는 지금까지 알려진 어느 종양관련 유전자보다도 유전자변이의 빈도가 높은 암억제유전자인데, 특히 비소세포폐암인 경우는 70% 이상의 세포주에서 p16 단백질의 발현이 없는 것으로 밝혀져 있어 p16 유전자는 비소세포폐암 발생에 매우 중요한 역할을 할 것이라고 알려져 있다. 본 연구에서는 비소세포폐암에서 p16을 이용한 유전자치료의 타당성을 입증하기 위하여 다음과 같은 연구를 시행하였다. 방 법 : p16이 결여된 비소세포폐암 세포주 (NCI-H441)에, 정상섬유아세포에서 총 RNA를 추출하여 역전사효소 및 DNA 중합효소반응으로 증폭된 p16 cDNA를 유핵세포 발현 vector인 pRC-CMV plasmid에 subcloning하여 구축된 pRC-CMV-p16 plasmid vector를 lipofectin을 이용하여 유전자 이입한 후, 단백질을 추출하여 Western blot 분석과 면역침전법으로 $G_1$ 세포주기관련 단백질의 변동을 관찰하고, colony 형성능을 비교함으로써 암억제효과를 확인하였다. 결 과 : p16이 유전자주입된 NCI-H441 세포주에서 p16과 cdk4가 복합체를 형성하고 있고 인산화 Rb가 대조 세포주에 비해 감소되어 있음을 확인할 수 있어, p16이 cdk4와 결합함으로써 cdk4에 의한 Rb의 인산화를 방해하고 이에 따른 $G_1$ 세포주기 정체에 의해 종양억제효과가 나타난다는 설명을 뒷받침할 수 있었다. Clonogenic assay 결과는 p16 유전자주입된 NCI-H441 세포주의 colony 형성능이 대조 세포주에 비하여 현격히 감소함을 관찰하였다. 결 론 : 이상의 결과로 p16(MTS1) 유전자를 p16 단백질을 발현하지 못하는 비소세포폐암 세포주에 주입할 경우, 주입한 유전자에서 생성되는 p16 단백질이 cdk와 결합하여 Rb 단백질의 인산화를 저하시켜 궁극적으로 암억제 효과를 일으킬 수 있음이 확인되었고, 이는 향후 비소세포폐암의 유전자치료에 있어서 p16 유전자의 이용 가능성을 확인한 기초자료가 된다고 생각된다.