• Asian Pacific Journal of Cancer Prevention
• /
• 제13권3호
• /
• pp.931-935
• /
• 2012

Cdc25 phosphatases are important regulators of the cell cycle. Their abnormal expression detected in a number of tumors implies that their dysregulation is involved in malignant transformation. However, the role of Cdc25B in renal cell carcinomas remains unknown. To shed light on influence on renal cell carcinogenesis and subsequent progression, Cdc25B expression was examined by real-time RT-PCR and western blotting in renal cell carcinoma and normal tissues. 65 kDa Cdc25B expression was higher in carcinomas than in the adjacent normal tissues (P<0.05), positive correlations being noted with clinical stage and histopathologic grade (P<0.05). To additionally investigate the role of Cdc25B alteration in the development of renal cell carcinoma, Cdc25B siRNA was used to knockdown the expression of Cdc25B. Down-regulation resulted in slower growth, more G2/M cells, weaker capacity for migration and invasion, and induction of apoptosis in 769-P transfectants. Reduction of 14-3-3 protein expression appeared related to Cdc25B knockdown. These findings suggest an important role of Cdc25B in renal cell carcinoma development and provide a rationale for investigation of Cdc2B-based gene therapy.

• Bulletin of the Korean Chemical Society
• /
• 제29권9호
• /
• pp.1659-1660
• /
• 2008

• Asian-Australasian Journal of Animal Sciences
• /
• 제23권4호
• /
• pp.530-536
• /
• 2010

Cdc25B is a mitotic regulator that might act as a starter phosphatase to initiate the positive feedback loop at the entry into mitotic (M) phase. In the present study, distribution of Cdc25B mRNA in duodenal mucosa of the chicken was demonstrated by means of in situ hybridization histochemistry (ISHH) using sense and antisense digoxigenin (DIG)-labeled RNA probes. The results showed that there were many labeled cells distributing in the duodenal mucosa of the adult chicken. Of these labeled cells, 81.60${\pm}$9.63% of Cdc25B mRNA positive cells was distributed in the basilar part and mid-portion of the intestinal gland and 36.21${\pm}$8.81% in the middle and basilar portion of villi of the small intestine of the chicken, respectively. Most of these labeled cells were positive in the regions of the stem cell and proliferation. The signals of ISHH decreased from basilar to upper part in the crypt of Lieberkuhn and weakened in the inferior villi of the duodenum. Moreover, the positive signals were both in the cytoplasm and cell nucleus. However, the labeled cells were negative in both the lamina muscularis mucosae and muscular layer. The results of ISHH suggested the existence of Cdc25B mRNA and vigorous proliferation activities in the duodenal mucosa of adult chicken, replenishing the cells which had sloughed off from the superior part of the villus. Our results provide some molecular evidence for a regular pattern of avian intestinal epitheliosis and functional partition and provide an approach to further study of the locations of Cdc25B in the chicken.

• Bulletin of the Korean Chemical Society
• /
• 제30권4호
• /
• pp.924-926
• /
• 2009

• 대한임상검사과학회지
• /
• 제38권1호
• /
• pp.72-81
• /
• 2006

Wee1 is a kinase regulator of the M-phase promoting factor (MPF; a complex of cdc2 and cyclin B1). The present study was undertaken to determine the role(s) of wee1 in the early stages of mouse ovarian follicles. The expression of wee1 and the correlated cell-cycle components, namely cdc2, cyclin B1, and cdc25C, were evaluated by immunohistochemistry. In addition, the expression of Tyr15-phosphorylated cdc2 (cdc2-p) was also examined to determine whether wee1 kinase phosphorylates cdc2 existed. Each component except cdc25C was found cytoplasmic in the oocytes at all stages of follicles, while cdc25C was not detected in primordial follicles. It was found primarily in ovarian somatic cells and to a small extent in granulosa cells of the growing follicles. To further confirm the expression of cell-cycle components in the primordial follicular oocytes, day1 ovaries were enzymatically and mechanically dissociated, then oocytes were isolated from somatic including pre-granulosa cells, and we confirmed that cdc2-p was expressed in oocytes of primordial follicles. From the results of the present study, we concluded wee1, without the counteracting cdc25C, would cause meiotic arrest of oocytes by the inhibitory phosphorylation of cdc2. The expression of all these proteins in the granulosa cells of growing follicles may regulate their mitosis concurrently with the growth of oocytes and follicles.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권6호
• /
• pp.781-787
• /
• 2009

The sense and antisense digoxigenin-labeled RNA probes of four genes, Cdc25A, Cdc25B, Sox2 and Mnb, were produced by using SP6 and T7 RNA polymerases, respectively, and in vitro transcription. Expression patterns of the four genes were detected by in situ hybridization in HH (Hamburger and Hamilton) stage 10 chick embryos. In general, expression patterns of the four genes were similar. mRNA of the four genes was mostly restricted to the entire CNS (central nervous system). All were confined to an identical region, neural tube, neural groove and caudal neural plate, corresponding to the notochord or spinal cord, but there was some distinction in specific region or in concentration, for example in somites. The overlap in expression at the same developmental stage in the CNS suggests that the four genes may be functional similar or related in CNS development. Expression patterns of the four genes support specific roles of these regulators in the developing CNS.

• 한국발생생물학회:학술대회논문집
• /
• 한국발생생물학회 2003년도 전기 한국발생생물학회 제16차 학술대회논문집
• /
• pp.21-23
• /
• 2003

Mechanisms regulate the arrest and growth of the resting primordial follicles are very poorly understood. To elucidate genes involved in the early folliculogenesis, we conducted suppression subtractive hybridization using mRNA from day1 and day5 ovaries and selected weel for further analysis, since it was most frequent gene in the day1-subtracted cDNA library (1). Expression of weel and correlated components of the cell cycle machinery, such as cdc2, cyclin B1, cdc25C, and phosphorylated cdc2 was evaluated by immunohistochemistry. In primordial follicles, expression of weel, cdcw, and cyclin B1 was cytoplasmic in oocytes, but phosphorylated cdc2 was weakly expressed in oocytes. While cdc25C expression was in ovarian somatic and in some theca cells. None of components was expressed in the pre-granulosa cells of the primordial follicles, while weel weakly, and cdc2 and cyclin B1 was strongly expressed in the granulosa cells of the growing follicles. Results from the present study suggest that 1) the mejotic arrest of the oocytes may not due to of cell cycle machinery, and 2) the weel may arrest meiosis by sequestering cdc2 and cyclin B1 in the cytoplasm by protein-protein interactions and/or by inhibitory phosphorylation.

• Bulletin of the Korean Chemical Society
• /
• 제30권6호
• /
• pp.1313-1316
• /
• 2009

Cdc25 phosphatases have been considered as attractive drug targets for anticancer therapy due to the correlation of their overexpression with a wide variety of cancers. We have been able to identify five novel Cdc25 phosphatase inhibitors with micromolar activity by means of a structure-based de novo design method with a known inhibitor scaffold. Because the newly discovered inhibitors are structurally diverse and have desirable physicochemical properties as a drug candidate, they deserve further investigation as anticancer drugs. The differences in binding modes of the identified inhibitors in the active sites of Cdc25A and B are addressed in detail.

• BMB Reports
• /
• 제44권8호
• /
• pp.553-557
• /
• 2011

We previously reported that CDK2/Cyclin A can phosphorylate and activate the transcription factor NF-Y. In this study, we investigated a potential regulatory role for NF-Y in the transcription of Cyclin A and other cell cycle regulatory genes. Gel-shift assays demonstrate that NF-Y binds to CCAAT sequences in the Cyclin A promoter, as well as to those in the promoters of cell cycle G2 regulators such as CDC2, Cyclin B and CDC25C. Furthermore, expression of Cyclin A increases NF-Y's affinity for CCAAT sequences in the CDC2 promoter; however, Cyclin A's induction of CDC2 transcription is antagonized by p21, an inhibitor of CDK2/Cyclin A. These results suggest a model wherein NF-Y binds to and activates transcription from the Cyclin A promoter, increasing cellular levels of Cyclin A/CDK2 and potentiating NF-Y's capacity for transcriptional transactivation, and imply a positive feedback loop between NF-Y and Cyclin A/CDK2. Our findings are additionally indicative of a role for Cyclin A in activating Cyclin B/CDK1 through promoting NF-Y dependent transcription of Cyclin B and CDC2; NF-Y mediated crosstalk may therefore help to orchestrate cell-cycle progression.

• Journal of Periodontal and Implant Science
• /
• 제49권3호
• /
• pp.138-147
• /
• 2019

Purpose: Several studies have shown that the oral cavity is a secondary location for Helicobacter pylori colonization and that H. pylori is associated with the severity of periodontitis. This study investigated whether H. pylori had an effect on the periodontium. We established an invasion model of a standard strain of H. pylori in human periodontal ligament fibroblasts (hPDLFs), and evaluated the effects of H. pylori on cell proliferation and cell cycle progression. Methods: Different concentrations of H. pylori were used to infect hPDLFs, with 6 hours of co-culture. The multiplicity of infection in the low- and high-concentration groups was 10:1 and 100:1, respectively. The Cell Counting Kit-8 method and Ki-67 immunofluorescence were used to detect cell proliferation. Flow cytometry, quantitative real-time polymerase chain reaction, and western blots were used to detect cell cycle progression. In the high-concentration group, the invasion of H. pylori was observed by transmission electron microscopy. Results: It was found that H. pylori invaded the fibroblasts, with cytoplasmic localization. Analyses of cell proliferation and flow cytometry showed that H. pylori inhibited the proliferation of periodontal fibroblasts by causing G2 phase arrest. The inhibition of proliferation and G2 phase arrest were more obvious in the high-concentration group. In the low-concentration group, the G2 phase regulatory factors cyclin dependent kinase 1 (CDK1) and cell division cycle 25C (Cdc25C) were upregulated, while cyclin B1 was inhibited. However, in the high-concentration group, cyclin B1 was upregulated and CDK1 was inhibited. Furthermore, the deactivated states of tyrosine phosphorylation of CDK1 (CDK1-Y15) and serine phosphorylation of Cdc25C (Cdc25C-S216) were upregulated after H. pylori infection. Conclusions: In our model, H. pylori inhibited the proliferation of hPDLFs and exerted an invasive effect, causing G2 phase arrest via the Cdc25C/CDK1/cyclin B1 signaling cascade. Its inhibitory effect on proliferation was stronger in the high-concentration group.