• Asian Pacific Journal of Cancer Prevention
• /
• 제15권9호
• /
• pp.4101-4107
• /
• 2014

Protein phosphatase 1 (PP1) is a major serine/threonine phosphatase that controls gene expression and cell cycle progression. The active mutant IPP5 ($8-60hIPP5^m$), the latest member of the inhibitory molecules for PP1, has been shown to inhibit the growth of human cervix carcinoma cells (HeLa). In order to elucidate the underlying mechanisms, the present study assessed overexpression of $8-60hIPP5^m$ in HeLa cells. Flow cytometric and biochemical analyses showed that overexpression of $8-60hIPP5^m$ induced G2/M-phase arrest, which was accompanied by the upregulation of cyclin B1 and phosphorylation of G2/M-phase proteins ATM, p53, $p21^{cip1/waf1}$ and Cdc2, suggesting that $8-60hIPP5^m$ induces G2/M arrest through activation of the ATM/p53/$p21^{cip1/waf1}$/Cdc2/cyclin B1 pathways. We further showed that overexpression of $8-60hIPP5^m$ led to delayed nuclear translocation of cyclin B1. $8-60hIPP5^m$ also could translocate to the nucleus in G2/M phase and interact with $pp1{\alpha}$ and Cdc2 as demonstrated by co-precipitation assay. Taken together, our data demonstrate a novel role for $8-60hIPP5^m$ in regulation of cell cycle in HeLa cells, possibly contributing to the development of new therapeutic strategies for cervix carcinoma.

• Journal of the Korean Wood Science and Technology
• /
• 제46권2호
• /
• pp.166-177
• /
• 2018

Plant essential oils are defined as fragrant volatile oils extracted from leaves, stems, fruits, flowers, and roots of a plant. Such oils are composed of multiple components and multiple functions. By accumulation of inductive information, various plant essential oils have been studied for using in therapeutic medicine for various diseases. Despite of the apparent advantages of essential oils as a source of therapeutic medicines, plant essential oils have many limitations, including cytotoxic side effects. Therefore, it is necessary to evaluate the toxicity and the mechanisms of cytotoxicity of such oils. In this study, we evaluated the cytotoxicity to human-derived cell lines of 10 plant essential oils provided by National Institute of Forest Science (i.e., Larix kaempferi; Abies holophylla; Zanthoxylum ailanthoides; Pinus parviflora; Tsuga sieboldti; Chamaecyparis pisifera; Cryptomeria japonica; Pinus densiflora; Illicium anisatum; Pinus thunbergii). Cytotoxicity evaluations were accomplished by using CCK-assays and PCR-based cytotoxicity-related marker gene analyses with A549 cell line, and the Detroit551 cell line which are lung and skin cell line. The genes were analyzed included caspase-3 has a role in cell apoptosis, and the other cyclinA, cyclinB, cyclinD, and cyclinE regulated cell cycling for the cell proliferation. By examining the five cytotoxicity-related marker genes by performing real-time PCR and examined the cytostatic gene regulation associated with the various essential oils. The results of this study showed that the degree of cytotoxicity and the cytostatic gene regulation which could give precious information for using the plant essential oil for the clinical usages.

• Journal of Periodontal and Implant Science
• /
• 제29권3호
• /
• pp.593-607
• /
• 1999

치주인대세포는 치주인대의 유지와 개조에 있어서 중요한 역할을 담당하는 섬유아세포성 세포로서, 세포에 가해진 여러가지 조건에 따라 다양한 표현형의 변화를 나타내는 것으로 알려져 있다. 기계적 응력은 치주인대세포의 세포증 식과 밀접히 연관되어 있는 것으로 알려져 있으며, 이는 세포주기 조절인자들의 발현을 증가 시킴으로써 이루어질 것으로 생각되나 그 자세 한 작용기전은 알려져 있지 않다. 그러므로 이 연구의 목적은 기계적 응력이 사람 치주인대세 포의 세포증식과 세포주기 조절인자의 발현에 미치는 영향을 연구하기 위하여 사람 치주인대 세포에 기계적 응력을 가한 후 세포증식을 관찰하고 , 세포주기조절인자들인 p 53 , $p21^{WAF1/CIP1}$ cyclin-dependent kinases(cdks), cyclins 및 proliferating cell nuclear antigen(PCNA)의 단백질 발현 변화를 연구하였다. 본 연구에 사용한 사람 치주인 대세포는 교정치료를 목적으로 발거한 건전한 사람 소구치의 치주인대로부터 explantation culture하여 얻은 후 계대배양을 시행하여 제6 계대의 세포를 사용하였다. 배양한 사람 치주인 대세포를 55-mm Petriperm dish당 $1{\times}10^4$ 개를 분주하고, dish당 1kg의 기계적 응력을 가하면서 12일동안 세포배양을 시행하였다. 사람 치주인대세포의 세포증식은 기계적 응력을 가한 후 8-12일 사이에 현저히 증가하였으며, PCNA 단백질의 발현은 기계적 응력을 가한 후 6-10일 사이에 현저히 증가하였다. 또한 기계적 응력은 사람 치주 대세포의 cdk4, cdk6, cdk2 및 cyclin D1 단백질의 발현을 다소 증가 시켰으나, p53 및 $p21^{WAF1/CIP1}$ 단백질의 발현은 큰 변화가 없었다. 이상의 결과 서 기계적 응력은 사람 치주인대세포 의 p53 및 $p21^{WAF1/CIP1}$ 단백질 발현의 변화 없이 cdks 단백질 발현을 증가시킴으로써 세포증식을 증가시키는 것으로 생각된다.

• Natural Product Sciences
• /
• 제18권1호
• /
• pp.16-21
• /
• 2012

Honokiol, a naturally occurring neolignan mainly found in Magnolia species, has been shown to have the anti-angiogenic, anti-invasive and cancer chemopreventive activities, but the molecular mechanism of actions has not been fully elucidated yet. In the present study, we investigated the effect of honokiol on the growth inhibitory activity in cultured SNU-638 human gastric cancer cells. We found that honokiol exerted potent antiproliferative activity against SNU-638 cells. Honokiol also arrested the cell cycle progression at the G0/G1 phase and induced the apoptotic cell death in a concentration-dependent manner. The cell cycle arrest was well correlated with the downregulation of Rb, cyclin D1, cyclin A, cyclin E, and CDK4 expression, and the induction of cyclin-dependent kinase inhibitor p27. The increase of sub-G1 peak by honokiol was closely related to the induction of apoptosis, which was evidenced by the induction of DNA fragmentation, the cleavage of poly(ADPribose) polymerase, and the sequential activation of caspase cascade. These findings suggest the cell cycle arrest and induction of apoptosis might be one possible mechanism of actions for the anti-proliferative activity of honokiol in human gastric cancer cell.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권17호
• /
• pp.7575-7582
• /
• 2015

Cyclin E, a key coordinator of the G1 to S transition in the cell cycle, may be deregulated in several malignancies, including breast cancer. The most significant aberration in cyclin E is its elastase mediated proteolytic cleavage into tumor specific low molecular weight isoforms (LMW-Es). LMW-Es are biochemically hyperactive and biologically drive tumorigenesis in transgenic mouse models. Additionally, expression of LMW-Es has been correlated with poor survival in breast cancer cases. Here we determine whether expression of LMW-Es in a breast cancer cell line that is naturally devoid of these deregulated forms would alter their progression through each phase of the cell cycle. The results revealed that LMW-Es expression resulted in an increased doubling time, concomitant with a predominant increase in the population in the S phase of the cell cycle. Moreover, downregulation of p53 in LMW-Es cells resulted in additional shortening of the doubling time and enrichment of cells in the S and G2/M phases of the cell cycle. Furthermore, expression of LMW-Es sensitized cells to ${\beta}$-estradiol (E2) mediated growth and changed expression patterns of estrogen receptor and Bcl-2. Intriguingly, expression of LMW-Es could surpass anti-apoptotic effects raised by p53 upregulation. Taken together these studies suggest that overexpression of LMW-Es in collaboration with p53 loss results in altered g rowth properties of MCF-7 cells, enhancing the oncogenic activity of these ER positive breast cancer cells.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권15호
• /
• pp.6417-6421
• /
• 2015

Viscum album var (VAV) also known as mistletoe, has long been categorized as a traditional herbal medicine in Asia. In addition to its immunomodulating activities, mistletoe has also been used in the treatment of chronic hepatic disorders in China and Korea. There are numerous reports showing that VAV possesses anti-cancer effects, however influence on human hepatocarcinoma has never been elucidated. In the present study, hot water extracts of VAV was evaluated for its potential anti-cancer effect in vitro. SK-Hep1 cells were treated with VAV (50-400ug/ml) for both 24 and 48 hours then cell viability was measured by cell counting kit-8 (CCK-8). Flow cytometry analysis was used to measure the proportion of SK-Hep1 in the different stages of cell cycle. RT-PCR and Western blot analysis were conducted to measure expression of cell cycle arrest related genes and proteins respectively. VAV dose dependently inhibited the proliferation of SK-Hep1 cells without any cytotoxicity with normal Chang liver cell (CCL-13). Flow cytometry analysis showed that VAV extract inhibited the cell cycle of SK-Hep1 cells via G1 phase arrest. RT-PCR and Western blot analysis both revealed that cyclin dependent kinase 2 (Cdk2) and cyclin D1 gene expression were significantly down regulated while p21 was upregulated dose dependently by VAV treatment. Combined down regulation of Cdk2, Cyclin D1 and up regulation of p21 can result in cell death. These results indicate that VAV showed evidence of anti-cancer activity through G1 phase cell cycle arrest in SK-Hep1 cells.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권12호
• /
• pp.6349-6355
• /
• 2012

Previous studies showed that Math1 homologous to human Hath1 can cause mouse goblet cells to differentiate. In this context it is important that the majority of colon cancers have few goblet cells. In the present study, the potential role of Hath1 in colon carcinogenesis was investigated. Sections of paraffin-embedded tissues were used to investigate the goblet cell population of normal colon mucosa, mucosa adjacent colon cancer and colon cancer samples from 48 patients. Hath1 and Muc2 expression in these samples were tested by immunohistochemistry, quantitative real-time reverse transcription -PCR and Western blotting. After the recombinant plasmid, pcDNA3.1(+)-Hath1 had been transfected into HT29 colon cancer cells, three clones were selected randomly to test the levels of Hath1 mRNA, Muc2 mRNA, Hath1, Muc2, cyclin D1 and p27 by quantitative real-time reverse transcription-PCR and Western blotting. Moreover, the proliferative ability of HT29 cells introduced with Hath1 was assessed by means of colony formation assay and xenografting. Expression of Hath1, Muc2, cyclin D1 and p27 in the xenograft tumors was also detected by Western blotting. No goblet cells were to be found in colon cancer and levels of Hath1 mRNA and Hath1, Muc2 mRNA and Muc2 were significantly down-regulated. Hath1 could decrease cyclin D1, increase p27 and Muc2 in HT29 cells and inhibit their proliferation. Hath1 may be an anti-oncogene in colon carcinogenesis.

• Journal of Ginseng Research
• /
• 제31권1호
• /
• pp.1-13
• /
• 2007

We found that the main bacterial metabolite M1 is an active component of orally administered protopanxadiol-type ginsenosides, and that the anti-metastatic effect by oral administration of ginsenosides may be primarily mediated through the inhibition of tumor invasion, migration and growth of tumor cells by their metabolite M1. Pharmacokinetic study after oral administration of ginsenoside Rb1 revealed that M1 was detected in serum for 24 h by HPLC analysis but Rb1 was not detected. M1, with anti-metastatic property, inhibited the proliferation of murine and human tumor cells in a time- and concentration-dependent manner in vitro, and also induced apoptotic cell death (the ladder fragmentation of the extracted DNA). The induction of apoptosis by M1 involved the up-regulation of the cyclin-dependent kinase(CDK) inhibitor $p27^{Kip1}$ as well as the down-regulation of a proto-oncogene product c-Myc and cyclin D1 in a time-dependent manner. Thus, M1 might cause the cell-cycle arrest (G1 phase arrest) in honor cells through the up/down-regulation of these cell-growth related molecules, and consequently induce apoptosis. The nucleosomal distribution of fluorescence-labeled M1 suggests that the modification of these molecules is induced by transcriptional regulation. Tumor-induced angiogenesis (neovascularization) is one of the most important events concerning tumor growth and metastasis. Neovascularization toward and into tumor is a crucial step for the delivery of nutrition and oxygen to tumors, and also functions as the metastatic pathway to distant organs. M1 inhibited the tube-like formation of hepatic sinusoidal endothelial (HSE) cells induced by the conditioned medium of colon 26-L5 cells in a concentration-dependent manner. However, M1 at the concentrations used in this study did not affect the growth of HSE cells in vitro.

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

• BMB Reports
• /
• 제41권10호
• /
• pp.716-721
• /
• 2008

To explore the effects of deregulated expression of the EBNA1 binding protein 2 (EBP2) on cell growth, we generated human HEK293 stable clones constitutively expressing an EBP2-EGFP fusion protein. We found both RNA and protein levels of cyclin E1, a dominant oncoprotein, were elevated in the EBP2- EGFP stable clones. These findings were confirmed by flow cytometry bivariate analysis of cyclin expression versus DNA content. Moreover, the increase in p21 expression and the specific phosphorylation at Ser1981 of ATM and Ser15 of p53 were also observed in these stable clones, and these observations may explain the failure to observe an increase in Cdk2 kinase activity. In addition, after one year of passage culture, the EBP2-EGFP stable clones tended to lose 4 to 5 chromosomes per cell when compared to that of control cells. All of these findings provide a possible link between deregulated expression of EBP2 and tumor development.