Somatic cell nuclear transfer (SCNT) has various applications in research, as well as in the medical field and animal husbandry. However, the efficiency of SCNT is low and the accurate mechanism of SCNT in murine embryo development is unreported. In general, the developmental rate of SCNT murine embryos is lower than in vivo counterparts. In previous studies, polo-like kinase 1 (Plk1) was reported to be a crucial element in cell division including centrosome maturation, cytokinesis, and spindle formation. In an initial series of experiments in this study, BI2536, a Plk1 inhibitor, was treated to in vivo-fertilized embryos and the embryos failed to develop beyond the 2-cell stage. This confirmed previous findings that Plk1 is crucial for the first mitotic division of murine embryos. Next, we investigated Plk1's localization and intensity by immunofluorescence analysis. In contrast to normally developed embryos, SCNT murine embryos that failed to develop exhibited two types of Plk1 expressions; a low Plk1 expression pattern and ectopic expression of Plk1. The results show that Plk1 has a critical role in SCNT murine embryos. In conclusion, this study demonstrated that the SCNT murine embryos fail to develop beyond the 2-cell stage, and the embryos show abnormal Plk1 expression patterns, which may one of the main causes of developmental failure of early SCNT murine embryos.
Animal Husbandry ; Cell Division ; Centrosome ; Cytokinesis ; Ectopic Gene Expression ; Embryonic Development ; Embryonic Structures ; Female ; Fluorescent Antibody Technique ; Nuclear Transfer Techniques ; Phosphotransferases ; Pregnancy

Aurora kinase A plays an essential role in mitosis including chromosome separation and cytokinesis. Aberrant expression and activity of Aurora kinase A is associated with numerous malignancies including colorectal cancer followed by poor prognosis. The aim of this study is to determine the inhibitory effects of LDD970, an indirubin derivative, on Aurora kinase A in HT29 colorectal cancer cells. In vitro kinase assay revealed that, LDD970 inhibited levels of activated Aurora kinase A (IC₅₀=0.37 mM). The inhibitory effects of LDD970 on Aurora kinase A, autophosphorylation and phosphorylation of histone H3 (Ser10), were confirmed by immunoblot analysis. Moreover, LDD970 inhibited migration of HT29 cells and upregulated apoptosis-related protein cleaved PARP. In cell viability assay, LDD970 was observed to suppress HT29 cell growth (GI₅₀=4.22 µM). Although further studies are required, results of the present study suggest that LDD970 provide a valuable insight into small molecule indirubin derivative for therapeutic potential in human colorectal cancer.
Aurora Kinase A* ; Cell Survival ; Colorectal Neoplasms* ; Cytokinesis ; Histones ; HT29 Cells ; Humans* ; In Vitro Techniques ; Mitosis ; Phosphorylation ; Phosphotransferases ; Prognosis

PURPOSE: Mefenamic acid (MEF) as a non-steroidal anti-inflammatory drug is used as a medication for relieving of pain and inflammation. Radiation-induced inflammation process is involved in DNA damage and cell death. In this study, the radioprotective effect of MEF was investigated against genotoxicity induced by ionizing radiation in human blood lymphocytes. MATERIALS AND METHODS: Peripheral blood samples were collected from human volunteers and incubated with MEF at different concentrations (5, 10, 50, or 100 microM) for two hours. The whole blood was exposed to ionizing radiation at a dose 1.5 Gy. Lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis blocked binucleated lymphocyte. RESULTS: A significant decreasing in the frequency of micronuclei was observed in human lymphocytes irradiated with MEF as compared to irradiated lymphocytes without MEF. The maximum decreasing in frequency of micronuclei was observed at 100 microM of MEF (38% decrease), providing maximal protection against ionizing radiation. CONCLUSION: The radioprotective effect of MEF is probably related to anti-inflammatory property of MEF on human lymphocytes.
Cell Death ; Cytokinesis ; DNA Damage ; Healthy Volunteers ; Humans* ; Inflammation ; Lymphocytes* ; Mefenamic Acid* ; Micronucleus Tests ; Radiation, Ionizing ; Radiation-Protective Agents

OBJECTIVETo investigate the cytotoxicity of indium chloride (InCl₃) and its effects on micro-nucleus formation in primary human lymphocytes cultured in vitro.

METHODSThe CCK-8 assay was used to evaluate the cytotoxicity of 24 h exposure to different concentrations of InCl₃(4, 40, 80, 200, 500, and 1 000 µmol/L) in lymphocytes cultured in vitro. The cytokinesis-block method was used to determine the micronucleus level in lymphocytes exposed to different concentrations of InCl₃and the effects of anti-oxidant vitamin C on micronucleus frequency.

RESULTSLymphocytes exposed to InCl₃of no less than 500 µmol/L had significantly lower survival rates than those in the control group (P < 0.05). Lymphocytes exposed to 80 µmol/L InCl₃had a significantly higher micronucleus frequency than those in the control group (P < 0.05). However, there was no further increase in micronucleus frequency of lymphocytes exposed to 200 µmol/L InCl₃. Lymphocytes cultured in whole blood and exposed to 500 or 1000 µmol/L InCl₃had a significantly increased micronucleus frequency than those in the control group (P < 0.001). The increase in micronucleus frequency of lymphocytes induced by indium could be partially antagonized by 20 or 100 µmol/L vitamin C.

CONCLUSIONInCl₃can induce an increase in micronucleus frequency of primary human lymphocytes cultured in vitro, which might be associated with DNA damage induced by oxidative stress.

Cell Nucleus ; metabolism ; Cytokinesis ; DNA Damage ; Humans ; In Vitro Techniques ; Indium ; toxicity ; Lymphocytes ; drug effects ; Oxidative Stress

Although it has been suggested that kinesin family member 14 (KIF14) has oncogenic potential in various cancers, including hepatocellular carcinoma (HCC), the molecular mechanism of this potential remains unknown. We aimed to elucidate the role of KIF14 in hepatocarcinogenesis by knocking down KIF14 in HCC cells that overexpressed KIF14. After KIF14 knockdown, changes in tumor cell growth, cell cycle and cytokinesis were examined. We also examined cell cycle regulatory molecules and upstream Skp1/Cul1/F-box (SCF) complex molecules. Knockdown of KIF14 resulted in suppression of cell proliferation and failure of cytokinesis, whereas KIF14 overexpression increased cell proliferation. In KIF14-silenced cells, the levels of cyclins E1, D1 and B1 were profoundly decreased compared with control cells. Of the cyclin-dependent kinase inhibitors, the p27Kip1 protein level specifically increased after KIF14 knockdown. The increase in p27Kip1 was not due to elevation of its mRNA level, but was due to inhibition of the proteasome-dependent degradation pathway. To explore the pathway upstream of this event, we measured the levels of SCF complex molecules, including Skp1, Skp2, Cul1, Roc1 and Cks1. The levels of Skp2 and its cofactor Cks1 decreased in the KIF14 knockdown cells where p27Kip1 accumulated. Overexpression of Skp2 in the KIF14 knockdown cells attenuated the failure of cytokinesis. On the basis of these results, we postulate that KIF14 knockdown downregulates the expression of Skp2 and Cks1, which target p27Kip1 for degradation by the 26S proteasome, leading to accumulation of p27Kip1. The downregulation of Skp2 and Cks1 also resulted in cytokinesis failure, which may inhibit tumor growth. To the best of our knowledge, this is the first report that has identified the molecular target and oncogenic effect of KIF14 in HCC.
Carcinoma, Hepatocellular/*metabolism ; Cyclin-Dependent Kinase Inhibitor p27/genetics/*metabolism ; Cyclins/genetics/metabolism ; *Cytokinesis ; Gene Silencing ; Hep G2 Cells ; Humans ; Kinesin/genetics/*metabolism ; Liver Neoplasms/*metabolism ; Oncogene Proteins/genetics/*metabolism ; Proteasome Endopeptidase Complex/metabolism ; RNA, Messenger/genetics/metabolism ; S-Phase Kinase-Associated Proteins/genetics/metabolism ; *Ubiquitination

BACKGROUND: Aurora kinase A (Aurora-A) plays an important role in the regulation of mitosis and cytokinesis. Dysregulated Aurora-A leads to mitotic faults and results in pathological conditions. No studies on Aurora-A expression in human diabetic skin tissue have been reported. In light of this, we explored the expression of Aurora-A in human diabetic skin tissue. METHODS: Aurora-A protein was evaluated by western blotting in 6 human diabetic skin tissue and 6 normal skin specimens. RESULTS: Increased expression of Aurora-A protein was detected in all diabetic skin tissue samples in both western blot analysis and immunohistochemical staining. However, in the case of the normal skin tissue, no bands of Aurora-A protein were detected in either the western blotting analysis or the immunohistochemical staining. CONCLUSIONS: Thus far, there have been no studies on the expression of Aurora-A in diabetic skin tissue. However, we believe that oxidative DNA damage related to the expression of Aurora-A protein and Aurora-A could be involved inhuman diabetic skin tissue.
Aurora Kinase A* ; Blotting, Western ; Cytokinesis ; Diabetes Mellitus ; DNA Damage ; Humans ; Mitosis ; Skin*

Cytokinesis ; Humans ; Lymphocytes ; pathology ; Micronucleus Tests ; Neoplasms ; genetics ; Risk Factors

Polo-like kinase 1 (Plk1), a well-characterized member of serine/threonine kinases Plk family, has been shown to play pivotal roles in mitosis and cytokinesis in eukaryotic cells. Recent studies suggest that Plk1 not only controls the process of mitosis and cytokinesis, but also, going beyond those previously described functions, plays critical roles in DNA replication and Pten null prostate cancer initiation. In this review, we briefly summarize the functions of Plk1 in mitosis and cytokinesis, and then mainly focus on newly discovered functions of Plk1 in DNA replication and in Pten-null prostate cancer initiation. Furthermore, we briefly introduce the architectures of human and mouse prostate glands and the possible roles of Plk1 in human prostate cancer development. And finally, the newly chemotherapeutic development of small-molecule Plk1 inhibitors to target Plk1 in cancer treatment and their translational studies are also briefly reviewed.
Animals ; Cell Cycle Checkpoints ; Cell Cycle Proteins ; antagonists & inhibitors ; metabolism ; physiology ; Cytokinesis ; DNA Replication ; Humans ; Male ; Mitosis ; Models, Biological ; PTEN Phosphohydrolase ; genetics ; metabolism ; Prostatic Neoplasms ; drug therapy ; enzymology ; pathology ; Protein Kinase Inhibitors ; therapeutic use ; Protein-Serine-Threonine Kinases ; antagonists & inhibitors ; metabolism ; physiology ; Proto-Oncogene Proteins ; antagonists & inhibitors ; metabolism ; physiology ; Substrate Specificity

OBJECTIVETo investigate the relationship between the urinary 1-hydroxypyrene level and cytokinesis-block micronucleus in peripheral blood lymphocyte in coke oven workers.

METHODSOne hundred and fifty-eight workers from a coke plant and 158 referents without occupational PAHs exposure were recruited in this study. Urnary level of 1-hydroxypyrene was measured by alkaline hydrolysis combined with high performance liquid chromatography as an internal exposure dose, and the chromosomal damage of peripheral blood lymphocyte were evaluated with cytokinesis-block micronucleus (CBMN) method. Personal information including occupational history, age, sex, smoking and alcohol drinking, was collected by questionnaire.

RESULTSThe lymphocyte chromosomal damage level expressed as frequency of CBMN in coke oven workers was significantly higher than that of controls (3.32 ± 2.90 vs 0.57 ± 0.88, P < 0.01) after adjusting for sex, age, smoking and alcohol drinking, and correlation between urinary 1-hydroxypyrene concentrations and frequency of CBMN was found (Spearman Partial correlation coefficient = 0.28, P < 0.05) in coke oven workers. Three hundreds and sixteen subjects were divided into three groups by their urine 1-hydroxypyrene level (expressed as 0.11 ∼ 0.70, 0.71 ∼ 4.09 and 4.10 ∼ 24.74 µmol/mol Cr). After adjusting for age, sex, smoking and alcohol drinking by multiple nonparametric analysis of covariance, the frequency of CBMN in the groups of 0.71 ∼ 4.09 and 4.10 ∼ 24.74 µmol/mol C were 1.89 ± 2.37 and 3.29 ± 2.36, significantly higher than that in the group of 0 ∼ 0.70 µmol/mol Cr (0.56 ± 0.89).

CONCLUSIONSUnder present PAHs exposure levels, the Cytokinesis-block micronucleus test could detect PAHs-induced genotoxicity in coke oven workers.

Adult ; Case-Control Studies ; Coke ; toxicity ; Cytokinesis ; DNA Damage ; Female ; Humans ; Lymphocytes ; cytology ; Male ; Micronucleus Tests ; Middle Aged ; Mutagens ; toxicity ; Occupational Exposure ; Pyrenes ; toxicity ; Urinalysis ; Urine ; chemistry

Cytokinesis ; Micronucleus Tests