• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.174-180
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• 2011

Experiments were carried out to determine the role of Raf-1 kinase in the development of drug resistance to paclitaxel in v-H-ras transformed NIH 3T3 fibroblasts (Ras-NIH 3T3). We established a multidrug-resistant cell line (Ras-NIH 3T3/Mdr) from Ras-NIH 3T3 cells by stepwise increases in paclitaxel. Drug sensitivity assays indicated that the $IC_{50}$ value for drug-resistant Ras-NIH 3T3/Mdr cells was more than 1 ${\mu}M$ paclitaxel, 10- or more-fold higher than for the parental Ras-NIH 3T3 cells. Western blot and RT-PCR analysis showed that the drug efflux pump a P-glycoprotein were highly expressed in Ras-NIH 3T3/Mdr cells, while not being detectable in Ras-NIH 3T3 cells. Additionally, verapamil, which appears to inhibit drug efflux by acting as a substrate for P-glycoprotein, completely reversed resistance to paclitaxel in Ras-NIH 3T3/Mdr cell line, indicating that resistance to paclitaxel is associated with overexpression of the multidrug resistance gene. Interestingly, Ras-NIH 3T3/Mdr cells have higher basal Raf-1 activity compared to Ras-NIH 3T3 cells. Unexpectedly, however, the colocalization of Raf-1 and its negative regulator Spry2 was less observed in cytoplasm of Ras-NIH 3T3/Mdr cells due to translocation of Spry2 around the nucleus in the perinuclear zone, implying that Raf-1 may be released from negative feedback inhibition by interacting with Spry2. We also showed that shRNA-mediated knockdown of Raf-1 caused a moderate increase in cell susceptibility to paclitaxel. Thus, the results presented here suggest that a Raf-1-dependent pathway plays an important role in the development of acquired drug-resistance.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.2
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• pp.186-198
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• 2006

Purpose : The purpose of this study is to demonstrate the direct inhibitory effect of Hyulbuchukeotang on the proliferation of uterine leiomyoma cells through an experiment treating uterine leiomyoma cells cultivated by explantation with indicated concentrations of Hyulbuchukeotang and to research the gene expression related to cell cycle ill order to discover the connection with apoptosis and its mechanism by analyzing cell cycle. Methods : After primary culture of uterine leiomyoma cells, the cultivated uterine leiomyoma cells were treated with indicated concentrations of Hyulbuchukeotang for 24 hours. The inhibitory effect on the cell proliferation was determined by the cell count assay. The value of a cell count assay represent the percentage of cells in a phase of the cell cycle compared with total cells. In addition, a link between Hyulbuchukeotang and apoptosis was examined through flow cytometric analysis by FACS and DNA fragmentation analysis. Finally, the degree of gene expression related to cell cycle was evaluated by Western blot analysis. Results : The inhibitory effect of Hyulbuchukeotang increase of uterine leiomyoma cells treated with indicated concentrations of Hyulbuchkeotang increases. The result of gene expression related to G1 phase after treating with 100, 250, 500, 1,000 ${\mu}g/ml$ concentrations of Hyulbuchukeotang. on uterine leiomyoma cells is that the gene expression of p27 was increased but that of p53 an p21 remained unchanged and the gene of pRB, pro-caspase 3 was decreased. Conclusion Through the mentioned experiments, it is demonstrated that Hyulbuchkeotang is effective in inhibiting Proliferation of uterine leiomyoma cells by extending cell cycle G1. However it is not considered that the inhibitory effect results from the aptoposis.

• Journal of Chest Surgery
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• v.36 no.12
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• pp.952-960
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• 2003

It has been reported that p53 regulates the G2-M checkpoint transition through cyclin Bl, and it has been suggested that p53 plays an important role in the development and progression of various malignancies. The aim of this study is to clarify the role of the cell cycle regulators, cyclin B1 and p53 in patients with esophageal squamous cell carcinoma (ESCC). Material and Method: Tissue samples from 46 patients with ESCC were included in this study. Expression levels of cyclin Bl and p53 in samples of normal squamous epithelium, dysplasia, and tumor cells from patients with ESCC were analyzed by immunohistochemical study Result: Several cells in the basement layer of normal epithelium expressed cyclin B1. The number of cyclin B1 positive cells tended to increase as the degree of dysplasia increased from low grade to high grade. More than 10% of tumor cells were cyclin B1 positive in 19 patients (41.3%). Several clinicopathologic parameters, including tumor stage (p<0.05), pathologic Iymph node status (p<0.05) and invasion of Iymphatic vessels (p<0.05), were correlated with the overexpression of cyclin B1. Elevated expression levels of cyclin B1 also correlated with a poor prognosis in patient with ESCC in univariate analysis (p<0.05) and multivariate analysis (p<0.05), In contrast, p53 expression exhibited significant correlation with the level of cyclin B1 expression, but was not associated with prognostic parameters in patients with ESCC. Conclusion: These findings suggest that cyclin B1 is involved in the pathogenesis of carcinoma of the esophagus and that elevated levels of cyclin B1 expression, but not p53 expression, may indicate a poor prognosis for patients with ESCC.

• The Korean Journal of Cytopathology
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• v.13 no.1
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• pp.1-7
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• 2002

The significance of endometrial cells on cervicovaginal smears is underestimated. The aim of this study is to evaluate the detection rate of endometrial cells on cervicovaginal smears. The materials consisted of two groups. Group I was 701 cervicovaginal smears from patients with no gynecological problems. Group II was 208 cervicovaginal smears from patients with abnormal uterine bleeding followed by endometrial curettage; 31 cases of endometrial adenocarclnoma(CA), 19 cases of endometrial hyperplasia(HP), 83 cases of dysfunctional uterine bleeding(DUB), and 75 cases of normal endometrium. Cervicovaginal smears were reviewed according to the criteria of The Bethesda System. Endometrial cells were identified in 15 of 701 cases(2.1%) in group I and 64 of 208 cases(30.8%) in group II. Among group II, detection rate of endometrial cells was the highest in CA (51.6%) compared to HP(26.3%), DUB(41.0%), and normal endometrium(12.0%) (p<0.05). Cytologic atypia of endometrial cells was not found In group I, but was more frequently identified in CA(87.5%) than in HP(10.5%) or DUB(14.7%) (p<0.05). Exfollatlon of endometrial cells might be related to abnormal endometrial lesion, and reporting of endometrial cells in the cervicovaginal smear may increase a chance to detect endometrial lesions especially in patients with abnormal uterine bleeding.

• Journal of Life Science
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• v.19 no.7
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• pp.871-877
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• 2009

We investigated the effects of sodium butyrate, a histone deacetylase inhibitor, on the cell cycle progression in human monocytic leukemia U937 cells. Exposure of U937 cells to sodium butyrate resulted in growth inhibition, G1 arrest of the cell cycle and induction of apoptosis in a dose-dependent manner as measured by MTT assay and flow cytometry analysis. The increase in G1 arrest was associated with the down-regulation in cyclin D1, E, A, cyclin-dependent kinase (Cdk) 4 and 6 expression, and up-regulation of Cdk inhibitors such as p21 and p27. Sodium butyrate treatment also inhibited the phosphorylation of retinoblastoma protein (pRB) and p130, however, the levels of transcription factors E2F-1 and E2F-4 were not markedly modulated. Furthermore, the down-regulation of phosphorylation of pRB and p130 by this compound was associated with enhanced binding of pRB and E2F-1, as well as p130 and E2F-4, respectively. Overall, the present results demonstrate a combined mechanism involving the inhibition of pRBjp130 phosphorylation and induction of Cdk inhibitors as targets for sodium butyrate that may explain some of its anti-cancer effects in U937 cells.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.143-147
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• 2008

The sodium bicarbonate cotransporter (NBC) protein is functionally expressed in salivary glands. In this experiment, we examined the role of NBC in $HCO_3^-$ formation in human parotid gland acinar cells. Intracellular pH (pHi) was measured in 2'-7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF)-loaded cells. Acetazolamide (0.1 mM) and 4,4'-diisothio cyanatostilbene-2,2'-disulphonic acid (DIDS, 0.5 mM) were used as specific inhibitors of carbonic anhydrase and NBC, respectively. The degree of inhibition was assessed by measuring the pHi recovery rate (${\Delta}pHi$/min) after cell acidification using an ammonium prepulse technique. In control experiments, ${\Delta}pHi$/min was $1.40{\pm}0.06$. Treatment of cells with 0.5 mM DIDS or 0.1 mM acetazolamide significantly reduced ${\Delta}pHi$/min to $1.14{\pm}0.14$ and $0.74{\pm}0.15$, respectively. Simultaneous application of DIDS and acetazolamide further reduced ${\Delta}pHi$/min to $0.47{\pm}0.10$. Therefore, DIDS and acetazolamide reduced ${\Delta}pHi$/min by 19% and 47%, respectively, while simultaneous application of both DIDS and acetazolamide caused a reduction in ${\Delta}pHi$/min of 67%. These results suggest that in addition to carbonic anhydrase, NBC also partially contributes to $HCO_3^-$ formation in human parotid gland acinar cells.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.5
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• pp.38-42
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• 1982

N+-P/P+solar cells were fabricated by using the polycrystalline silline wafer with the resistivity of 3-6 ohm-cm. minority carrier lifetimes, measured by Nd: YAG laser, were from 100ns up to 150ns. Conversion efficiency measured under AM 1 irradiation, were about 4%.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.789-795
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• 2004

A promoter-probe shuttle vector pSK1Cat was constructed for the isolation of transcriptional signal sequences from Corynebacterium glutamicum. Besides conferring resistance to kanamycin in Escherichia coli and C. glutamicum, the vector carried a promoterless cat gene to confer resistance to chloramphenicol upon insertion of the appropriate transcriptional signals in the multiple cloning site. By utilizing the vector, a series of transcriptionally active fragments were isolated from the genome of C. glutamicum. The clones, ranging from 200 bp to 1 kb in size, were grouped into 3 classes of strong, medium, and weak, based on the chloramphenicol acetyltransferase (CAT) activity and sensitivity to the chloramphenicol of the clone-carrying C. glutamicum cells. C. glutamicum cells carrying the $P_{19}$ clone, a representative in the strong class, were able to grow on minimal agar plates containing over $40 mg/mell$ chloramphenicol, and showed CAT activity of 10 m㏖/mgㆍmin, performing slightly better than the cells carrying $P_{tac}$ , a strong E. coli promoter. Subcloning analysis of the $P_{19}$ clone identified a 180 bp intergenic fragment ($P_{180}$), which was located upstream of a gene encoding a hypothetical membrane protein. The expression conferred by $P_{180}$ was not affected by either the kinds of carbon sources or changes in temperature. These properties make the $P_{180}$ clone useful for the deregulated expression of biosynthetic genes in C. glutamicum during amino acid fermentation.

• Korean Journal of Animal Reproduction
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• v.20 no.3
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• pp.251-258
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• 1996

This study was designed to evaluate the potential inhibitory effects of glucose (5.56 mM vs. 0 mM) and/or phosphate (potassium phosphate, 1.19 mM vs. 0 mM) on the in vitro devel-opment of rat 8-cell embryos (n=345 embryos from 36 mature rats). Evaluation of embryos at 48 h for developmental stage (STG) indicated that 37% (31/84), 70% (64/91), 69% (59/85), and 77% (67/85) developed to the blastocyst stage in media with glucose+phosphate, glucose only, phosphate only, and no glucose or phosphate, respectively. Embryo development (2.90${\pm}$0.097 for STG) in medium with glucose + phosphate was significantly reduced (P<0.001), while no significant differences were observed between all other media (3.4~3.5${\pm}$0.093-0.097 for STG). Evaluation of embryos for final cell number (FCN) indicated that the greatest number of cells (nuclei) resulted in medium with glucose alone (29.3${\pm}$0.97 cells, P<0.001). No significant differences were observed for FCN for the remaining three media (l7.5${\pm}$1, 04 cells, 18.6${\pm}$1.Ol cells, and 19.8${\pm}$1.01 cells for glucose+phosphate, phosphate only, and no glucose or phosphate, respectively). Our results suggest that glucose and phosphate together exert an inhibitory effect on 8-cell rat embryo development, while glucose alone was beneficial, yielding greater numbers of cells per embryo.

• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.308-314
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• 2011

It has been shown that circadian genes not only play an important role on circadian rhythms, but also participate in other physiological and pathological activities, such as drug dependence, cancer development and radiation injury. The Per2, an indispensable component of the circadian clock, not only modulates circadian oscillations, but also regulates organic function. In the present study, we applied mPER2-upregulated NIH3T3 cells to reveal the relationship of mPer2 and the cells damaged by ultraviolet C (UVC). NIH3T3 cells at the peak of the expression of mPer2 induced by phorbol 12-myristate 13-acetate (PMA) demonstrated little damage by UVC evaluated by MTT assay, cell growth curves and cell colony-forming assay, compared with that at the nadir of the expression of mPer2. Overexpression of mPER2, accompanied p53 upregulated, also demonstrated protective effect on NIH3T3 cells damaged by UVC. These results suggest that mPer2 plays a protective effect on cells damaged by UVC, whose mechanism may be involved in upregulated p53.