• International Journal of Oncology
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• v.54 no.5
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• pp.1875-1883
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• 2019

Reversine, a 2,6-diamino-substituted purine analogue, has been reported to be effective in tumor suppression via induction of cell growth arrest and apoptosis of cancer cells. However, it remains unclear whether reversine exerts anticancer effects on human colorectal cancer cells. In the present study, in vitro experiments were conducted to investigate the anticancer properties of reversine in human colorectal cancer cells. The effect of reversine on human colorectal cancer cell lines, SW480 and HCT-116, was examined using a WST-1 cell viability assay, fluorescence microscopy, flow cytometry, DNA fragmentation, small interfering RNA (siRNA) and western blotting. Reversine treatment demonstrated cytotoxic activity in human colorectal cancer cells. It also induced apoptosis by activating poly(ADP-ribose) polymerase, caspase-3, -7 and -8, and increasing the levels of the pro-apoptotic protein second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI. The pan-caspase inhibitor Z-VAD-FMK attenuated these reversine-induced apoptotic effects on human colorectal cancer cells. Additionally, reversine treatment induced cell cycle arrest in the subG1 and G2/M phases via increase in levels of p21, p27 and p57, and decrease in cyclin D1 levels. The expression of Fas and death receptor 5 (DR5) signaling proteins in SW480 and HCT116 cells was upregulated by reversine treatment. Reversine-induced apoptosis and cell cycle arrest were suppressed by inhibition of Fas and DR5 expression via siRNA. In conclusion, Reversine treatment suppressed tumor progression by the inhibition of cell proliferation, induction of cell cycle arrest and induction of apoptosis via upregulation of the Fas and DR5 signaling pathways in human colorectal cancer cells. The present study indicated that reversine may be used as a novel anticancer agent in human colorectal cancer.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.282-287
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• 2009

Ochnaflavone is a natural biflavonoid and mainly found in the caulis of Lonicera japonica (Caprifoliaceae). Biological activities such as anti-inflammatory and anti-atherogenic effects have been previously reported. The anticancer activity of ochnaflavone, however, has been poorly elucidated yet. In the present study, we investigated the effect of ochnaflavone on the growth inhibitory activity in cultured human colon cancer cell line HCT-15. Ochnaflavone inhibited the proliferation of the cancer cells with an $IC_{50}$ value of $4.1{\mu}M$. Flow cytometric analysis showed that ochnaflavone arrested cell cycle progression in the G2/M phase, and induced the increase of sub-G1 peak in a concentration-dependent manner. Induction of cell cycle arrest was correlated with the modulation of the expression of cell cycle regulating proteins including cdc2 (Tyr15), cyclin A, cyclin B1 and cyclin E. The increase of sub-G1 peak by the higher concentrations of ochnaflavone (over $20{\mu}M$) was closely related to the induction of apoptosis, which was evidenced by the induction of DNA fragmentation, activation of caspase-3, -8 and -9, and cleavage of poly-(ADP-ribose) polymerase. These findings suggest that the cell cycle arrest and induction of apoptosis might be one possible mechanism of actions for the anti-proliferative activity of ochnaflavone in human colon cancer cells.

• Journal of Food Hygiene and Safety
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• v.24 no.3
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• pp.267-272
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• 2009

The trace element nutrient selenium discharges its well-known nutritional anti-tumor activity. Converging data from epidemiological, ecological and clinical studies have shown that selenium can decrease the risk for some types of human cancers, especially those of the prostate, lung, and colon. Mechanistic studies have indicated that selenium has many desirable attributes of chemoprevention targeting cancer cells through DNA single strand breaks, the induction of reactive oxygen species. However, there is no reports about the relationship between methylseleninic acid (MSeA), one of methylselenol metabolites and cell cycle arrest in LNCaP human prostate cancer cells. Our data showed that MSeA arrested G1/S pahse of cell cycle arrest and inhibited DNA synthesis in LNCaP cells and those cellular events by MSeA were due to the induction ofp27 protein which is a well-known cyclin-dependent kinase inhibitor. Taken together, cell cycle arrest occurred by MSeA may contribute to the growth-inhibition of prostate cancer cells.

• BMB Reports
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• v.42 no.11
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• pp.725-730
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• 2009

Cyclin E1 (CCNE1), a positive regulator of the cell cycle, controls the transition of cells from G1 to S phase. In numerous human tumors, however, CCNE1 expression is frequently dysregulated, while the mechanism leading to its dysregulation remains incompletely defined. Herein, we showed that CCNE1 expression was subject to post-transcriptional regulation by a microRNA miR-16-1. This was evident at protein level of CCNE1 as well as its mRNA level. Further evident by dual luciferase reporter assay revealed that two evolutionary conserved binding sites on 3' UTR of CCNE1 were the direct functional target sites. Moreover, we showed that miR-16-1 induced G0/G1 cell cycle arrest by targeting CCNE1 and siRNA against CCNE1 partially phenocopied miR-16-1-induced cell cycle phenotype whereas substantially rescued anti-miR-16-1- induced phenotype. Together, all these results demonstrate that miR-16-1 plays a vital role in modulating cellular process in human cancers and indicate the therapeutic potential of miR-16-1 in cancer therapy.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.2
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• pp.205-213
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• 2017

Quercetin, a plant-derived flavonoid found in fruits, vegetables and tea, has been known to possess bioactive properties such as anti-oxidant, anti-inflammatory and anti-cancer. In this study, anti-cancer effect of quercetin and its underlying mechanisms in triple-negative breast cancer cells was investigated. MTT assay showed that quercetin reduced breast cancer cell viability in a time and dose dependent manner. For this, quercetin not only increased cell apoptosis but also inhibited cell cycle progression. Moreover, quercetin increased FasL mRNA expression and p51, p21 and GADD45 signaling activities. We also observed that quercetin induced protein level, transcriptional activity and nuclear translocation of Foxo3a. Knockdown of Foxo3a caused significant reduction in the effect of quercetin on cell apoptosis and cell cycle arrest. In addition, treatment of JNK inhibitor (SP 600125) abolished quercetin-stimulated Foxo3a activity, suggesting JNK as a possible upstream signaling in regulation of Foxo3a activity. Knockdown of Foxo3a and inhibition of JNK activity reduced the signaling activities of p53, p21 and GADD45, triggered by quercetin. Taken together, our study suggests that quercetin induces apoptosis and cell cycle arrest via modification of Foxo3a signaling in triple-negative breast cancer cells.

• International Journal of Oral Biology
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• v.43 no.2
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• pp.61-68
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• 2018

Codium fragile (Suringar) Hariot is an edible green seaweed that belong to the Codiaceae family and has been used in Oriental medicine for the treatment of enterobiasis, dropsy, and dysuria. Methanol extract of codium fragile has anti-oxidant, anti-inflammatory and anti-cancer properties, although the anti-cancer effect on oral cancer has not yet been reported. In this study, we investigated the anti-cancer activity and the mechanism of cell death by methanol extracts of Codium fragile (MeCF) on human FaDu hypopharyngeal squamous carcinoma cells. Our data showed that MeCF inhibits cell viability in a dose-dependent manner, and markedly induced apoptosis, as determined by the MTT assay, Live/Dead assay, and DAPI stain. In addition, MeCF induced the proteolytic cleavage of procaspase -3, -7, -9 and poly(ADP-ribose) polymerase(PARP), and upregulated or downregulated the expression of mitochondrial-apoptosis factor, Bax(pro-apoptotic factor), and Bcl-2(anti-apoptotic factor). Futhermore, MeCF induced a cell cycle arrest at the G1/S phase through suppressing the expression of the cell cycle cascade proteins, p21, CDK4, CyclinD1, and phospho-Rb. Taken together, these results indicated that MeCF inhibits cell growth, and this inhibition is mediated by caspase- and mitochondrial-dependent apoptotic pathways through cell cycle arrest at the G1/S phase in human FaDu hypopharyngeal squamous carcinoma cells. Therefore, methanol extracts of Codium fragile can be provided as a novel chemotherapeutic drug due to its growth inhibition effects and induction of apoptosis in human oral cancer cells.

• Journal of Life Science
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• v.16 no.5
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• pp.828-833
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• 2006

Maize (Zea mays L.) pistil cell death and stamen cell arrest are pivotal process on the sex determination, which diverges from bisexual state of floral meristem to unisexual state in staminate or pistillate floret. We investigated the temporal and spatial distribution of cell cycle gene expression during maize sex determination. The positive regulatory genes of cell cycle, cyclin A, cyclin B, cyclin dependent kinase (CDK) and Mad2 were highly expressed in the developing pistil and stamen but the expression was disappeared in the dying pistil and arresting stamens. In contrast, the negative regulatory genes of cell cycle, Wee1 and CDK inhibitor (CKI) were expressed in the arresting stamens in the wild-type ear and tasselseed2 mutant tassel, however, these genes were not detected in dying pistil although the cyclin B gene expression was disappeared. These results suggest that both the pistil cell death and stamen cell arrest process in maize sex determination are involved in cell cycle regulation, but the different expression patterns of negative regulatory cell cycle genes in the arresting stamens and aborting pistils suggest that the two processes may have distinctive modes of action.

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

• Environmental Mutagens and Carcinogens
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• v.24 no.3
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• pp.113-120
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• 2004

Chromium compounds are known human and animal carcinogens. In this study, the effects of sodium chromate on apoptosis and cell cycle were investigated in order to unveil the elements of early cellular responses to the metal. Using Chinese hamster ovary cells(CHO-K1-BH4), we found taht chromium (VI) treatment induced apoptosis in these cells, as signified by nuclear fragmentation, DNA laddering on agarose gel electrophoresis, and an increased proportionof cells with hypodiploid DNA. Preceding these changes, chromium (VI) treatment increased caspase 3 pritease activity and also increased expression of p53 protein, while the level of bcl2 protein was not changed. Coincubation with caspase inhibitor, Z-DEVD-FMK, inhibited chromium-induced apoptosis. In the flow cytometric analysis using propidium iodide fluorescence, an increase of cell population in G2/M phase was shown in cells exposed to at least 160 $\mu\textrm{m}$ of sodium chromate for 72h, form 9.8% for 0$\mu\textrm{m}$ chromium (VI) to 26.4% for 320$\mu\textrm{m}$ chromium(VI). Taken together, these findings suggest that chromium(VI)-induced apoptosis is accompanied by G2/M cell cycle arrest, and that p53-mediated pathway may be involved in positive regulation of G2/M arrest and a concurred apoptosis in CHO cells.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5189-5193
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• 2016

Objective: Dorema glabrum Fisch. & C.A. Mey is a perennial plant that has several curative properties. Anti-proliferative activity of seeds of this plant has been demonstrated in a mouse fibrosarcoma cell line. The aim of the present study was to evaluate cytotoxicity of D. glabrum root extracts in a human gastric adenocarcinoma (AGS) cell line and explore mechanisms of apoptosis induction, cell cycle arrest and altered gene expression in cancer cells. Materials and Methods: The MTT assay was used to evaluate IC50 values, EB/AO staining to analyze the mode of cell death, and flow cytometry to assess the cell cycle. Quantitative real-time polymerase chain reaction (qRT-PCR) amplification was performed with apoptosis and cell cycle-related gene primers, for cyclin D1, c-myc, survivin, VEGF, Bcl-2, Bax, and caspase-3 to determine alteration of gene expression. Results: Our results showed that n-hexane and chloroform extracts had greatest toxic effects on gastric cancer cells with IC50 values of $6.4{\mu}g/ml$ and $4.6{\mu}g/ml$, respectively, after 72 h. Cell cycle analysis revealed that the population of treated cells in the G1 phase was increased in comparison to controls. Cellular morphological changes indicated induction of apoptosis. In addition, mRNA expression levels of Bax and caspase-3 were increased, and of bcl-2 survivin, VEGF, c-myc and cyclin D1 were decreased. Conclusion: Our study results suggest that D. glabrum has cytotoxic effects on AGS cells, characterized by enhanced apoptosis, reduced cell viability and arrest of cell cycling.