Oral cancer take up 2-6% of all carcinomas and squamous cell carcinoma, which is the most common type in oral cancer, has a poor prognosis due to its high metastasis and recurrence rates. In treating oral cancer, chemotherapy to the primary, metastasized and recurrent lesion is a very important and useful treatment, even though its widespread usage is limited due to high general toxicity and local toxicity to other organs. Taxol, a microtubule stabilizing agent, is an anticancer drug that induces cell apoptosis by inhibiting depolymerization of microtubules in between the metaphase and anaphase of the cell mitosis. Recently, its effectiveness and mechanism on various tumor has been reported. However, not much research has been done on the application of Taxol to oral squamous cell carcinoma. Cyclosporin A, which is an immunosuppressant, is being used on cancers and when co-administered with Taxol, effectiveness of Taxol is enhanced by inhibition of Taxol induced multidrug resistance. In this study, Cyclosporin A with different concentration of Taxol was co-administered to HN22, the oral squamous cell carcinomacell line. To observe the cell apoptosis and the mechanisms that take part in this process, mortality evaluation of tumor cell using wortmannin, c-DNA microarray, RT-PCR analysis, cytometry analysis and western blotting were used, and based upon the observation on the effect and mechanism of the agent, the following results were obtained: 1. The HN22 cell line viability was lowest when 100micrometer of Wortmannin and 5microgram/ml of Taxol were co-administered, showing that Taxol participates in P13K-AKT1 pathway. 2. In c-DNA microarray, where 1microgram/ml of cyclosporine A and 3mg/ml of Taxol were co-administered, no up regulation of AKT1, PTEN and BAD c-DNA that participate in cell apoptosis was observed. 3. When 1microgram/ml of Cyclosporin A was applied alone to HN22 cell line,no difference was found in AKT1, PTEN and BAD mRNA expression. 4. Increased AKT1, mRNA expression was observed when 3microgram/ml of Taxol was applied alone to HN22 cell line. 5. When 1microgram/ml of Cyclosporin A and Taxol (3microgram/ml and 5microgram/ml) were co-administered to HN22 cell line, PTEN mRNA expression increased, whereas AKT1 and BAD mRNA decreased. 6. As a result of cytometry analysis, in the group of Cyclosporin A(1microgram/ml) and Taxol(3microgram/ml) co-administration, increased Annxin V was observed, which shows that apoptosis occurred by deformation of plasma membrane. However, no significant difference was observed with varying concentration. 7. In western blot analysis, no caspase 3 was observed in the group of Cyclosporin A(1microgram/ml) and Taxol(3microgram/ml) co-administration. From the results of this study, it can be concluded that synergistic effect can be observed in combination therapy of Taxol and Cyclosporin A on oral squamous cell carcinoma cell line, where decreased activity of the cell line was observed. This resulted in decreased AKT1 and BAD mRNA and increased PTEN mRNA expression and when wortmannin and Taxol were co-administered, the viability decreased which confirms that Taxol decreases the viability of tumor cell line. Hence, when Taxol and cyclosporine A are co-administered, it can be assumed that cell apoptosis occurs through AKt1 pathway.
Anaphase ; Apoptosis ; Blotting, Western ; Carcinoma, Squamous Cell* ; Caspase 3 ; Cell Line* ; Cell Line, Tumor ; Cell Membrane ; Cyclosporine* ; Drug Resistance, Multiple ; Drug Therapy ; Metaphase ; Microtubules ; Mitosis ; Mortality ; Mouth Neoplasms ; Neoplasm Metastasis ; Oligonucleotide Array Sequence Analysis ; Paclitaxel* ; Prognosis ; Recurrence ; RNA, Messenger ; Up-Regulation

Sec13p has been known as an endoplasmic reticulum-Golgi transport protein. Recently, it has also been shown to be required for the formation of septation in the fission yeast Schizosaccharomyces pombe. In the present study, we focused on the role of a human homolog of Saccharomyces cerevisiae SEC13, Sec13 protein during mitosis in U2OS cells. We found that the expression of Sec13 was constant throughout the cell cycle, and localized to the kinetochores at metaphase during mitosis. By using green fluorescent protein technology, we observed that Sec13 is required for evasion of mitotic arrest in response to spindle damage, leading to G1-like phase and apoptotic cell death. In addition, cells expressing exogenous Sec13 showed giant nuclei compared to endogenous ones in the absence of nocodazole. These results demonstrate that Sec13 is involved in the regulation of the metaphase/anaphase transition and may be functionally associated with mitotic machinery to maintain genomic stability during mitosis.
Anaphase ; Antineoplastic Agents/pharmacology ; Cell Line, Tumor/drug effects/metabolism/pathology ; *G1 Phase ; *Genomic Instability ; Green Fluorescent Proteins/metabolism ; Humans ; Kinetochores/metabolism ; Membrane Proteins/*genetics/metabolism ; Metaphase ; Mitosis/*physiology ; *Mitotic Spindle Apparatus ; Nocodazole/pharmacology ; Osteosarcoma/genetics/metabolism/pathology ; Research Support, Non-U.S. Gov't

CUE domain-containing 2 (CUEDC2) is a protein involved in the regulation of the cell cycle, inflammation, and tumorigenesis and is highly expressed in many types of tumors. CUEDC2 is phosphorylated by Cdk1 during mitosis and promotes the release of anaphase-promoting complex or cyclosome (APC/C) from checkpoint inhibition. CUEDC2 is also known to interact with IkB kinase α (IKKα) and IKKβ and has an inhibitory role in the activation of transcription factor nuclear factor-κB. Moreover, CUEDC2 plays an important role in downregulating the expression of hormone receptors estrogen receptor-α and progesterone receptor, thereby impairing the responsiveness of breast cancer to endocrine therapies. In this review, current knowledge on the multi-functions of CUEDC2 in normal processes and tumorigenesis are discussed and summarized.
Anaphase-Promoting Complex-Cyclosome ; Breast Neoplasms ; pathology ; Carrier Proteins ; metabolism ; Cell Cycle Proteins ; metabolism ; Cell Transformation, Neoplastic ; pathology ; Estrogen Receptor alpha ; metabolism ; Female ; Humans ; I-kappa B Kinase ; metabolism ; Inflammation ; pathology ; M Phase Cell Cycle Checkpoints ; Membrane Proteins ; metabolism ; Mitosis ; NF-kappa B p50 Subunit ; metabolism ; Receptor-Interacting Protein Serine-Threonine Kinases ; metabolism ; Signal Transduction ; Ubiquitin-Protein Ligase Complexes ; metabolism ; Ubiquitination

Chfr, a mitotic stress checkpoint gene, regulates a prophase delay in cells exposed to agents that disrupt microtubules, such as nocodazole and taxol. Chfr expression was ubiquitious in normal human tissues. It is very high conserved between human and mice. Preliminary sutdies indicated that Chfr expression was cell cycle regulated and it dependent on its ubiqitin ligase activity. The direct target of the Chfr pathway was Polo-like kinase 1 (Plk1). Ubiquitination of Plk1 by Chfr delayed the activation of the Cdc25C phosphatase and the inactivation of the Weel kinase, leading to a delay in Cdc 2 activation. The chfr gene was inactivated owing to lack of expression or by mutation in some human cancer cell lines examined. Normal primary cells and tumour cell lines that express wild-type chfr exhibited delayed entry into metaphase when centrosome separation was inhibited by mitotic stress. In contrast, the tumour cell lines that had lost chfr function entered metaphase without delay. Ecotopic expression of wild-type chfr restored the cell cycle delay and increased the ability of the cells to survive mitotic stress. Thus, chfr defines a checkpoint that delays entry into metaphase in response to mitotic stress. The progress of research on structure of Chfr gene and effects of Chfr protein was reviewed.
Cell Cycle ; genetics ; physiology ; Cell Cycle Proteins ; genetics ; metabolism ; physiology ; Humans ; Metaphase ; genetics ; physiology ; Mitosis ; genetics ; physiology ; Neoplasm Proteins ; genetics ; physiology ; Neoplasms ; genetics ; metabolism ; pathology ; Poly-ADP-Ribose Binding Proteins ; Prophase ; genetics ; physiology ; Protein-Serine-Threonine Kinases ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Proto-Oncogene Proteins ; metabolism ; Ubiquitin-Protein Ligases

BACKGROUND: The KCl hypotonic treatment is important for swelling the cells and adequate spreading of chromosomes on the slide. Cytogenetic laboratory usually use 0.075M KCl solution. Sometimes, it is difficult to obtain enough and good quality of metaphase cells, because of inadequate hypotonic treatment. The purpose of this study was to evaluate the mitotic index and band resolution according to the different KCl concentration. METHODS: The group I included blood specimens obtained from 14 newborns (median age 1 day, range 1-8 days) and 4 cord blood. The group II included 16 persons whose median age was 28 years (1-37 years). The blood was cultured in RPMI 1640 medium with fetal calf serum and phytohemagglutinin for 72 hours. Mitosis was arrested by adding colcemid (100 ng/mL). The hypotonic treatment was done by adding different KCl concentration such as 0.075M, 0.068M and 0.057M for 30 minutes at 37 degrees C. The mitotic index was calculated as the number of metaphase cells per total 1,000 cells. The band resolution was evaluated by 2 persons independently. RESULTS: For group I, the mitotic index was not different according to the KCl concentration; 0.075M, 18.8 (5.5~31.5); 0.068M, 22.3 (11~32.5); 0.057M, 20.5 (2.5~29), (P=0.137). The proportion of cells with 400 or more band resolution was significantly higher in specimens treated with 0.068M KCl than those treated with 0.075M KCl; 0.075M, 67.8% (56~92.5); 0.068M, 73.6% (46.1~84.6); 0.057M, 71.6% (63~89.2), (P=0.027). For group II, the results were similar to those of group I. The mitotic index was as follows; 0.075M, 22.3 (5~28); 0.068M, 26 (4~34.5); 0.057M, 21.5 (2.5~36.5), (P=0.568). The proportion of cells with 400 or more band resolution was as follows; 0.075M, 66.6% (42.8~83.3); 0.068M, 69.7% (54.3~87.5); 0.057M, 68.2% (50~78.6) (P=0.04). CONCLUSIONS: For 0.068M or 0.057M KCl treatment, band resolution was improved, while the mitotic index was similar to that of 0.075M KCl. We suggest use of 0.068M or 0.057M KCl hypotonic treatment in addition to 0.075M KCl for chromosome preparation of peripheral blood.
Cytogenetics ; Demecolcine ; Fetal Blood ; Humans ; Infant, Newborn ; Metaphase ; Mitosis ; Mitotic Index*

A recently identified protein, FAN1 (FANCD2-associated nuclease 1, previously known as KIAA1018), is a novel nuclease associated with monoubiquitinated FANCD2 that is required for cellular resistance against DNA interstrand crosslinking (ICL) agents. The mechanisms of FAN1 regulation have not yet been explored. Here, we provide evidence that FAN1 is degraded during mitotic exit, suggesting that FAN1 may be a mitotic substrate of the anaphase-promoting cyclosome complex (APC/C). Indeed, Cdh1, but not Cdc20, was capable of regulating the protein level of FAN1 through the KEN box and the D-box. Moreover, the up- and down-regulation of FAN1 affected the progression to mitotic exit. Collectively, these data suggest that FAN1 may be a new mitotic substrate of APC/CCdh1 that plays a key role during mitotic exit.
Anaphase-Promoting Complex-Cyclosome ; Bone Neoplasms ; metabolism ; pathology ; Cadherins ; genetics ; metabolism ; Cdc20 Proteins ; Cell Cycle Proteins ; genetics ; metabolism ; Cell Line, Tumor ; Exodeoxyribonucleases ; genetics ; metabolism ; HEK293 Cells ; Humans ; Mitosis ; Osteosarcoma ; metabolism ; pathology ; Ubiquitin-Protein Ligase Complexes ; genetics ; metabolism

OBJECTIVE: To evaluate the clinicopathological implication of poly (ADP-ribose) polymerase (PARP) expression in epithelial ovarian cancer. METHODS: Retrospectively, slide samples (n=72) were analyzed. PARP expression was analyzed using immunohistochemical staining. RESULTS: Of 72 cases, positive PARP expression were 27 cases (37.5%). PARP expression showed negative correlation with FIGO stage (p=0.004) and mitotic count (p=0.010), but showed no correlation with grade (p=0.053), tumor size (p=0.301), Ki-67 LIs (p=0.986), p53 positivity (p=0.414), and bcl-2 positivity (p=0.413). CONCLUSION: PARP expression showed negative correlation with advanced stage and mitoses in epithelial ovarian cancer. Therefore PARP expression could be a new prognostic factor in epithelial ovarian cancer.
Mitosis ; Ovarian Neoplasms* ; Retrospective Studies

There is no definite histological criteria which can predict the biologic behavior of meningiomas, although resectability is the most important factor in terms of recurrence. For grading meningiomas, various factors have been studied, such as hypercellularity, nuclear pleomorphism, small cells with high N/C ratio, prominent nucleoli (PN), frequent mitosis, loss of architecture, focal necrosis (FN). We investigated 116 meningiomas to evaluate the correlation between the factors and the proliferative activity using AgNORs and MIB-1 labelling index (LI). They were divided into 3 groups: Group A includes meningiomas with none of the factors; group B with one of the factors; group C with two or more factors. MIB-1 LI was correlated with each factor, but AgNORs was not. There was a statistical difference among group A (<1.28%), B (2.7%) and C (5.1%) (p<0.05) using MIB-1 LI. FN was the most frequently associated with other factors, and it had the highest MIB-1 LI (6.31%). MIB-1 LI of group B was 5.1 2.3%. In group B, the most frequent combination was FN and PN, and it showed the highest MIB-1 LI (5.74%). This study indicates that FN and PN are important for diagnosis of atypical meningioma, and MIB-1 LI appears to be a useful method for estimating the proliferative activity of meningiomas, and 5% or more of MIB-1 LI could help in making a diagnosis of atypical meningioma.
Diagnosis ; Meningioma* ; Mitosis ; Necrosis ; Recurrence

Humans ; Meiosis/physiology* ; Mitosis/physiology*

Malignant Leydig cell tumor of the testis is a very rare condition. A case of the malignant Leydig cell tumor arised from the right testis of seventy-year-old man is reported. The patient presented painless, 4 x 8 x 5 cm sized, mass without endocrinological manifestations and the mass was removed and diagnosed as a malignant Leydig cell tumor histologically showing frequent mitosis, pleomorphic cells in trabecular pattern with nuclear atypia, clear cells with foamy cytoplasm, and vascular invasion of tumor emboli in tumor capsule. No Reinke`s crystalloid was seen. The patient is now being followed in disease free state.
Cytoplasm ; Humans ; Leydig Cell Tumor* ; Mitosis ; Testis