• Proceedings of the Korean Society of Developmental Biology Conference
• /
• 2005.07a
• /
• pp.42-42
• /
• 2005

• Proceedings of the Korean Society of Embryo Transfer Conference
• /
• 2004.10a
• /
• pp.46-46
• /
• 2004

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.17 no.1
• /
• pp.157-164
• /
• 2003

Cervi Parvum Cornu(CPC) is that the young horn of deer family and has been traditionally used as a medicine in Eastern. The purpose of present study was to investigate the effects of CPC on cell cycle progression and its molecular mechanism in human periodontal ligament cells (HPOLC). In cell proliferation assay, 1 ng/ml, 10 ng/ml, 100 ng/ml, 1 ㎍/ml and 10 ㎍/ml of CPC were used, all treatment groups increased the cell growth. Maximal cell proliferation was observed in cells exposed to 100 ng/ml of CPC at 4 day, and 10 ng/ml and 100 ng/ml of CPC at 6 days. S phase was increased and G1 phase was decreased in the group treated with 100 ng/ml of CPC in cell cycle analysis. The protein levels of cyclin D1 were not changed, but the levels of cyclin E, cdk 2, cdk 4 and cdk 6 were increased. The protein levels of p21, pRb were decreased as compared to that of control group, but the levels of p53 was not changed in the cells both treated with CPC Md untreated. These results suggested that CPC increases the cell proliferation and cell cycle progression in HPDLC, which is linked to an increased cellular levels of cyclin E, cdk 2, cdk 4 and cdk 6, and decreased the levels of p53, p21.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.7
• /
• pp.1045-1050
• /
• 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 Physiology & Pathology in Korean Medicine
• /
• v.22 no.5
• /
• pp.1250-1255
• /
• 2008

Onchungeum(OCE), a herbal formula, has been used for treatment of anemia, discharging blood and skin diseases. In the previous study, we investigated the anti-cancer effect of OCE by G1 arrest of the cell cycle in human hepatocarcinoma cells, Hep3B cells. In this study, it was examined that the difference of anti-proliferative mechanisms by change in the ratio of OCE composition (OCE I) in Hep3B cells. Treatment of OCE I exhibited a relatively strong anti-proliferative activity and caused various morphological changes such as membrane shrinkage and cell floating. In addition, OCE-I arrests the cell cycle at G1 phase, which was associated with the down-regulation of cyclin D1 and Cdk6 expressions. The G1 arrest was also associated with the induction of Cdk inhibitors p27 and p21. Moreover, both p21 and p27 were detected by immunoprecipitation with anti-Cdk4 and anti-Cdk2 antibodies in OCE I-treated cells but in case of OCE, p21 did not make any complexes with Cdk4 and Cdk2. These results suggest that the change in the ratio of OCE composition might induce different mechanisms in anti-cancer efficacy of OCE, which may confer characteristic principles in oriental medical formula.

• Journal of Periodontal and Implant Science
• /
• v.32 no.4
• /
• pp.811-825
• /
• 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.

• Proceedings of the Ginseng society Conference
• /
• 2006.05a
• /
• pp.3-12
• /
• 2006

1 The present work was performed to investigate the effects of ginsenoside Rh2 on proliferation, cell cycle-regulation and differentiation of human leukemia HL-60 cells as well as the underlying mechanisms for these effects. 2 Ginsenoside Rh2 potently inhibited the proliferation of HL-60 cells in both a dose- and time-dependent manner with an $IC_{50}$, $20{\mu}M$. 3 DNA flow-cytometry indicated that ginsenoside Rh2 markedly induced a $G_1$ phase arrest of HL-60 cells. 4 Among the $G_1$ phase cell cycle-related proteins, the levels of cyclin-dependent kinase(CDK)4, 6 and cyclin D1, cyclin D2, cyclin D3 were reduced by ginsenoside Rh2, whereas the steadystate levels of CDK2 and cyclin E were unaffected. 5 The protein levels of a CDK inhibitor p16, $p21^{CIP1/WAF1}$ and $p27^{KIP1}$ were markedly increased by ginsenoside Rh2. 6 Ginsenoside Rh2 markedly enhanced the binding of $p21^{CIP1/WAF1}$ and $p27^{KIP1}$ with CDK2 and CDK6, resulting in the reduced activity of both kinases and the hypophosphorylation of Rb protein. 7 We furthermore suggest that ginsenoside Rh2 is a potent inducer of the differentiation of HL-60 cells, based on observations such as a reduction of the nitroblue tetrazolium level, an increase in the esterase activities and phagocytic activity, morphology changes, and the expression of CD11b, CD14, CD64 and CD66b surface antigens. 8 In conclusion, the onset of ginsenoside Rh2-induced the $G_0/G_1$ arrest of HL-60 cells prior to the differentiation is linked to a sharp up-regulation of the $p21^{CIP1/WAF1}$ level and a decrease in the CDK2, CDK4 and CDK6 activities. This is the first report demonstrating that ginsenoside Rh2 potently inhibits the proliferation of human promyelocytic HL-60 cells via the $G_1$ phase cell cycle arrest and differentiation induction.

• Journal of Life Science
• /
• v.28 no.11
• /
• pp.1316-1320
• /
• 2018

The effects of a green tea extract (GTE) were examined using the MCF-7 human breast cancer cell line. Cell viability assays using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays revealed that GTE had a significant cytotoxic effect on MCF-7 cells, depending on the concentration of GTE. Western blotting of p53 and its related proteins, p21/cip1 and CDK2, after GTE treatment revealed that a significant and concentration dependent increase in p53 protein in response to GTE. The levels of p21/cip1 proteins were also increased at low GTE concentrations were significantly increased even at the highest GTE concentrations. However, the level of CDK2 was significantly decreased by treatment with high concentrations of GTE. These results indicate that treatment with GTE increased the p53 level in MCF-7 cells, and this activation of p53 markedly elevated the levels of p21/cip1proteins, which, in turn, inhibited CDK2 expression in the MCF-7 cells. The inhibition of CDK2 expression might then affect cell cycle progression. Subsequent FACS analysis indicated that GTE treatment the gradually increased progression of the MCF-7 to the G1 phase. These results clearly demonstrate that the anti-tumor effect of GTE in MCF-7 cells is regulated by p53 arrest of the MCF-7 cells at the G1 stage of cell cycle.

• Journal of Life Science
• /
• v.24 no.1
• /
• pp.92-97
• /
• 2014

Cordycepin, an active component originally isolated from the traditional medicine Cordyceps militaris, is a derivative of the nucleoside adenosine, which has been shown to possess a number of pharmacological properties, including antioxidant and anti-inflammatory activities, immunological stimulation, and antitumor effects. This study was conducted on cultured human prostate carcinoma LNCap cells to elucidate the possible mechanisms by which cordycepin exerts its anticancer activity, which, until now, has remained poorly understood. Cordycepin treatment of LNCap cells resulted in dose-dependent inhibition of cell growth and the induction of apoptotic cell death as detected by an MTT assay, cleavage of poly ADP-ribose polymerase, and annexin V-FITC staining. Flow cytometric analysis revealed that cordycepin resulted in G2/M arrest in cell cycle progression and downregulation of cyclin B1 and cyclin A expression in a concentration-dependent manner. Moreover, the incubation of cells with cordycepin caused a striking induction in the expression of the cyclin-dependent kinase (CDK) inhibitor p21Waf1/Cip1 without affecting the expression of the tumor suppressor p53. It also resulted in a significant increase in the binding of CDK2 and CDC2 to p21. These findings suggest that cordycepin-induced G2/M arrest and apoptosis in human prostate carcinoma cells is mediated through p53-independent upregulation of the CDK inhibitor p21.

• YAKHAK HOEJI
• /
• v.43 no.3
• /
• pp.378-384
• /
• 1999

Retinoic acid (RA) and dibutyryl cyclic AMP (dbcAMP) induce the differentiation of the multipotent embryonic carcinoma cell line, F9 cells, into parietal endoderm like cell. The F9 cells are highly proliferative doubling approximately 12 hourse. S Phase is predominant, lasting 10 hours and G2/M phase occupies most of the remaining cycle (2 hours) and G1 phase is nearly non-existent. In this study, we showed the effect of RA and dbcAMPon the cell cycle associated molecules (especially around G1 phase) during F9 cell differentiation. Differentiation of F9 cells was induced by the combined addition of RA ($10^{-7}M$) and dbcAMP (0.5mM), and cells were harvested daily up to 4 days. Flow cytometric analysis showed the prolongation of G1 phase around 30 hours after induction. Western blot analysis revealed that the amount of cyclin D1 and cdk2 were increased at day 4. However, histone H1 kinase activity of cdk2 was decreased. These data strongly suggest that RA and dbcAMP induce the growth arrest of F9 cells at G1 phase by decreasing the activity of cdk2, although they have increased the protein contents of cyclin D1 and cdk2. The reason for the discrepancy between the H1 kinase activity and protein contents are not clear yet.