• Microbiology and Biotechnology Letters
• /
• v.29 no.3
• /
• pp.181-185
• /
• 2001

The naturally occurring chemical indole-3-carbinol (13C), found in vegetables of the Brassica genus, is a promising anticancer agent that was shown previ- ously to induce a Gl cell cycle arrest of human breast cancer cell lines, independent of estrogen receptor signaling. The anticancer activity of 13C and the possible mechanisms of its action were explored in a human hepatocellular carcinoma cell line, HepG2. Treatment of HepG2 cells with 13C suppressed the growth of the cells. The growth sup- pression caused by 13C ($IC_{50}$/: 444$\mu$M) was found to be partially due to its ability to stop the cell cycle in HepG2 cells. Western blot analysis for the Gl phase artiest demonstrated that the expression-levels of cyclin-dependent kinase (Cdk4, Cdk6) and cyclic D were reduced strongly after treatment of Hep72 cells with 13C (4007M) for 24- 72 hrs. Furthermore, I3C selectively abolished the expression of Cdk6 in a dose- and time-dependent manner, and accordingly, inhibited the phosphorylation of retinoblastoma. Interestingly, after the HepG2 cells reached their max- imal growth arrest, the level of the p21, a well-known Cdk inhibitor, increased significantly. Therefore, it could be considered that the Gl arrest of HepG2 cells treated with 13C was due to the indirect inhibition of Cdk4/6 activities by p21 Western blot analysis for G2/M phase arrest of demonstrated the levels of Cdc2 and cyclin Bl werer reduced dramatically after the treatment of HepG2 cells with 13C ($40\mu$M) for 24-72 hrs. flow cytometry of propidium iodide-stained HepG2 cells revealed that 13C induces a Gl (53%,72hr incubation) and G2 (25%,24hr incubation) cell cycle arrest. Thus, our observations have uncovered a previously undefined antiproliferative pathway for r3C that implicates Cdk4/6 and Cdc2 as a target for cell cycle control in human HepG2 cells. However, the 13C-medi- ated cell cycle arrest and repression of Cdk4/6 production did not affect the apoptotic induction of HepG2 cell.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.23 no.1
• /
• pp.199-205
• /
• 2009

It is unclear whether Fructus ligustri Lucidi (FLL) extract anti-proliferative effect in human glioma cells. The present study was therefore undertaken to examine the effect of FLL on cell viability and to determine the underlying mechanism in A172 human glioma cells. Cell viability and cell death were estimated by MTT assay and trypan blue exclusion assay, respectively. Apoptosis was measured by Annexin-V binding assay and cell cycle analysis. Activation of kinases and caspase-3 was estimated by Western blot analysis. FLL resulted in apoptotic cell death in a dose- and time-dependent manner. FLL-induced cell death was not associated with reactive oxygen species generation. Western blot analysis showed that FLL treatment caused down-regulation of PI3K/Akt pathway, but not ERK. The PI3K/Akt inhibitor LY984002 sensitized the FLL-induced cell death and overexpression of Akt prevented the cell death. FLL induced caspase-3 activation and the FLL-induced cell death was prevented by caspase inhibitors. These findings indicate that FLL results in a caspase-dependent cell death through a P13K/Akt pathway in human glioma cells. These data suggest that FLL may serve as a potential therapeutic agent for malignant human gliomas.

• Tuberculosis and Respiratory Diseases
• /
• v.67 no.4
• /
• pp.303-310
• /
• 2009

Background: Elevated expression of cyclooxygenase-2 (COX-2) and Polo-like kinase-1 (PLK-1) is observed in a wide variety of cancers. Augmented expression of COX-2 and enhanced production of prostaglandin $E_2(PGE_2)$ are associated with increased tumor cell survival and malignancy; COX-2 has been implicated in the control of human non-small cell lung carcinoma (NSCLC) cell growth. PLK-1 siRNA induced the cell death of lung cancer cells and the systemic administration of PLK-1 siRNA/atelocollagen complex inhibited the growth of lung cancer in a liver metastatic murine model. COX-2 and PLK-1 are involved in proliferation and in cell cycle regulation, and there is a significant correlation between their interaction in prostate carcinoma. Methods: In this study, we investigated the pattern of COX-2 and PLK-1 expression in NSCLC, after treatment with IL-1$\beta$, COX-2 inhibitor and PLK-1 siRNA. Results: Expression of PLK-1 was decreased in A549 COX-2 sense cells, and was increased in A549 COX-2 anti-sense cells. Knock out of PLK-1 expression by PLK-1 siRNA augmented COX-2 expression in A549 and NCl-H157 cells. When A549 and NCI-H157 cells were treated with COX-2 inhibitor on a dose-dependent basis, PLK-1 and COX-2 were reduced. However, when the expression of COX-2 was induced by IL-1$\beta$, the production of PLK-1 decreased. Conclusion: These results demonstrate that COX-2 and PLK-1 are regulated and inhibited by each other in NSCLC, and suggest that these proteins have a reverse relationship in NSCLC.

• Journal of Acupuncture Research
• /
• v.23 no.2
• /
• pp.91-102
• /
• 2006

Objectives : Ulmus davidiana Planch (UD) has long been known to have anti-inflammatory and protective effects on damaged tissue, inflammation and bone among other functions. Methods : This study was undertaken to address whether the water extract of the bark of UD could modulate proliferation of mouse osteoclasts in vitro and to investigate its effect on cyclooxygenase-2 (COX-2), which converts arachidonic acid to prostaglandin E2 (PGE2) and is highly expressed in osteoclasts. Mouse osteoclasts were tested in vitro for growth inhibition, proliferation cell nuclear antigen expression, and COX-2 activity and expression after treatment with UD extract. Results : Its effects were compared with those of indomethacin (a nonselective COX inhibitor) and celecoxib (a selective COX-2 inhibitor) by Cell viability assay, Cell cycle analysis, Immunohistochemical analysis of PCNA expression, Western blot analysis and PGE2 Enzyme immunoassay (EIA). UD demonstrated a strong growth inhibitory action in both tested osteoclasts cells. The IC50s were $10\;{\mu}g/ml$ for UD, $6\;{\mu}M$ for celecoxib and $42\;{\mu}M$ for indomethacin. UD, as well as celecoxib and indomethacin, suppressed proliferation cell nuclear antigen expression and PGE2 synthesis in osteoclasts. UD inhibited COX-2 expression, whereas celecoxib inhibited COX-2 activity directly. Conclusion : UD selectively and effectively inhibits osteoclasts cell growth in vitro. Inhibitory action of PGE2 synthesis via suppression of COX-2 expression may be responsible for its anti-inflammatory activity.

• Journal of Veterinary Science
• /
• v.25 no.1
• /
• pp.1.1-1.15
• /
• 2024

Background: Axitinib, a potent and selective inhibitor of vascular endothelial growth factor (VEGF) receptor (VEGFR) tyrosine kinase 1,2 and 3, is used in chemotherapy because it inhibits tumor angiogenesis by blocking the VEGF/VEGFR pathway. In veterinary medicine, attempts have been made to apply tyrosine kinase inhibitors with anti-angiogenic effects to tumor patients, but there are no studies on axitinib in canine mammary gland tumors (MGTs). Objectives: This study aimed to confirm the antitumor activity of axitinib in canine mammary gland cell lines. Methods: We treated canine MGT cell lines (CIPp and CIPm) with axitinib and conducted CCK, wound healing, apoptosis, and cell cycle assays. Additionally, we evaluated the expression levels of angiogenesis-associated factors, including VEGFs, PDGF-A, FGF-2, and TGF-β1, using quantitative real-time polymerase chain reaction. Furthermore, we collected canine peripheral blood mononuclear cells (PBMCs), activated them with concanavalin A (ConA) and lipopolysaccharide (LPS), and then treated them with axitinib to investigate changes in viability. Results: When axitinib was administered to CIPp and CIPm, cell viability significantly decreased at 24, 48, and 72 h (p < 0.001), and migration was markedly reduced (6 h, p < 0.05; 12 h, p < 0.005). The apoptosis rate significantly increased (p < 0.01), and the G2/M phase ratio showed a significant increase (p < 0.001). Additionally, there was no significant change in the viability of canine PBMCs treated with LPS and ConA. Conclusion: In this study, we confirmed the antitumor activity of axitinib against canine MGT cell lines. Accordingly, we suggest that axitinib can be applied as a new treatment for patients with canine MGTs.

• Molecules and Cells
• /
• v.24 no.3
• /
• pp.441-444
• /
• 2007

Despite the importance of cell fate decisions regulated by epigenetic programming, no experimental model has been available to study transdifferentiation from myoblasts to smooth muscle cells. In the present study, we show that myoblast cells can be induced to transdifferentiate into smooth muscle cells by modulating their epigenetic programming. The DNA methylation inhibitor, zubularine, induced the morphological transformation of C2C12 myoblasts into smooth muscle cells accompanied by de novo synthesis of smooth muscle markers such as smooth muscle ${\alpha}$-actin and transgelin. Furthermore, an increase of p21 and decrease of cyclinD1 mRNA were observed following zebularine treatment, pointing to inhibition of cell cycle progression. This system may provide a useful model for studying the early stages of smooth muscle cell differentiation.

• Archives of Pharmacal Research
• /
• v.28 no.1
• /
• pp.87-92
• /
• 2005

The cyclin-dependent kinase inhibitor$p27^{kip1}$(p27) has been implicated in the regulation of cell cycle and apoptosis. Recently, we have demonstrated that ceramide induces apoptotic cell death associated with increase in the level of p27 in HL-60 cells. In the present study, we showed that overexpression of p27 increases ceramide-induced apoptotic cell death in HL-60 cells. Furthermore, overexpression of p27 accelerated DNA fragmentation, PARP cleavage and cytochrome c release induced by ceramide. In addition, ceramide induced Sax expression independent of p27. These findings indicate that enhanced effect on apoptosis by p27 is associated with mitochondrial signaling which involves cytochrome c release.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.11
• /
• pp.6791-6795
• /
• 2013

Apoptotic and cytotoxic activity of plant extracts obtaining from naturally growing Cynara syriaca in Turkey and cultivated C cardunculus against DLD1 colorectal cancer cells was determined. Extracts from wild and cultivated Cynara species were obtained from their vegetative parts and receptacles using hexane and applied with five different dose (0.1-1 mg/ml) as well as apigenin for MTT tests for three time periods (24, 48 and 72 hours). After cells were treated with $IC_{50}$ doses for each extract total DNA and RNA were isolated for determination of the cause of cell death. From isolated RNAs, cDNA were synthesized and amplification of p21, BCL-2 and BAX gene regions was carried out. Consequently, we found that pro-apoptotic (BAX) gene expression and a cell cycle inhibitor (p21) were induced in the presence of our artichoke extracts. In contrast, anti-apoptotic BCL-2 gene expression was reduced compared to the control group. In addition DNA fragmentation results demonstrated DLD1 cell death via apoptosis.

• Journal of Life Science
• /
• v.23 no.6
• /
• pp.832-837
• /
• 2013

In this study, it was investigated the possible mechanisms by which glutamine deprivation exerts its anti-proliferative action in cultured human prostate carcinoma PC3 cells. Glutamine deprivation resulted in inhibition of growth and G2/M arrest of the cell cycle in a time-dependent manner without apoptosis induction, as determined by MTT assay, DAPI staining and flow cytometry analyses. The induction of G2/M arrest by glutamine deprivation was associated with the inhibition of expression of Cdc2, cyclin A and cyclin B1, and up-regulation of the expression of cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1) in both transcriptional and translational levels. Moreover, glutamine deprivation increased the phosphorylation of checkpoint kinase (Chk)1 and Chk2; however, the levels of Cdc25C phosphorylation were decreased in response to glutamine deprivation in a time-dependent manner. Our data provide a first biochemical evidence that glutamine deprivation suppresses cell viability through G2/M phase arrest without induction of apoptosis in PC3 cells.

• Molecules and Cells
• /
• v.43 no.8
• /
• pp.739-748
• /
• 2020

Stringent regulation of the chondrocyte cell cycle is required for endochondral bone formation. During the longitudinal growth of long bones, mesenchymal stem cells condense and differentiate into chondrocytes. Epiphyseal chondrocytes sequentially differentiate to form growth-plate cartilage, which is subsequently replaced with bone. Although the importance of nuclear factor 1C (Nfic) in hard tissue formation has been extensively studied, knowledge regarding its biological roles and molecular mechanisms in this process remains insufficient. Herein, we demonstrated that Nfic deficiency affects femoral growth-plate formation. Chondrocyte proliferation was downregulated and the number of apoptotic cell was increased in the growth plates of Nfic^-/- mice. Further, the expression of the cell cycle inhibitor p21 was upregulated in the primary chondrocytes of Nfic^-/- mice, whereas that of cyclin D1 was downregulated. Our findings suggest that Nfic may contribute to postnatal chondrocyte proliferation by inhibiting p21 expression and by increasing the stability of cyclin D1 protein.