이 연구는 제주연안 해역에서 갯녹음의 확산동향과 기후변화로 인한 동계 수온변화(수온상승)가 갯녹음 확산에 미치는 영향을 알아보고 갯녹음 원인생물인 무절석회조류의 번식과 생장을 파악하기 위해 연구되었다. 제주연안의 갯녹음 발생면적은 1998년에는 2,931ha였으나, 2003년에는 4,541ha로 증가하였다. 발생해역도 1998년은 제주도 남부 해역에서 주로 발생했으나, 2003년에는 조천읍, 구좌읍을 제외한 제주도 전역으로 확산되었다. 1992년부터 2004년까지 관측된 2월 평균수온은 갯녹음 해역 15.1℃, 해중림 해역 13.9℃로 갯녹음 해역이 1.2℃가 높게 나타나 두 해역 간 뚜렷한 차이를 보였으나, 8월 수온은 두 해역 간 차이가 없었다. 수온의 장기변동(37년)에서도 갯녹음 해역이 평균 15.3℃인데 비하여 해중림 해역은 평균 14.1℃로 갯녹음 해역이 해중림 해역보다 1.2℃가 높게 나타났다. 연간 수온 증가 값은 갯녹음 해역이 매년 0.038℃씩 증가하고 있는 반면, 해중림 해역은 0.024℃씩 증가하여 장기 수온변동은 갯녹음 해역이 해중림 해역보다 높았다. 이와 같이 기후변화로 인한 지속적인 동계 수온상승은 제주도 갯녹음을 확대시 키고 있음을 시사하고 있다.

As diethylnitrosamine (DEN) effect on cell proliferation, DNA damage and stem cell marker(s) expression have been largely unknown in mouse normal hepatocytes (AML-12 cells) cultured over a short-term period, this study was conducted to examine the cell proliferation, Ataxia telangiectasia mutated (ATM) and epithelial cell adhesion molecule (EpCAM) and Neighbor of Punc E 11 (Nope) expression in AML-12 cells treated with DEN for 24 and 48 h. Cells were treated with DEN (25-800 μg/mL) and cell phenotype was determined, and the MTT assay was used to quantify the proliferation of cells treated with DEN. Expression and distribution of ATM in AML-12 cells were determined by indirect immunofluorescence microscopy. And Western blot analysis of EpCAM and Nope was performed. Cell viability was significantly increased in response to all doses of DEN treatment compared to control at 24 h (p<0.05 or p<0.01). However, there was no significant increase at 48 h, even though it showed increased trend. Immunofluorescence staining of ATM showed that there was an increase of ATM expression at doses of 50, 100 and 200 μg/mL of DEN treatment, showing strong nuclear staining. Furthermore, Western blot analysis showed that DEN treatment showed increased trend of EpCAM and Nope expression. Taken together, DEN treatment increased cell proliferation in AML- 12 cells, and it was associated with increased ATM expression.

Coffee is one of the most familiar beverages to modern human adults, but its bio-physiological effect has not been clearly elucidated. It was known that more than one thousand chemicals were included in the ordinary coffee extract. Among them, the caffein and chlorogenic acid (caffeoylquinic acids) are most abundant and have been investigated by many authors so far. In order to know the real cellular effect of whole coffee extract elements, the dialyzed coffee extract (DCE)1) was made to get coffee elements less than 1000 Da molecular weight, which are freely absorable through gastrointestinal tract. It was directly treated in the culture of RAW 264.7 cells, a murine macrophage lineage. RAW 264.7 cells were treated with DCE equivalent to 2.5 cups of coffee (DCE-2.5), DCE-5, and DCE-10 for 12 hours, and their protein extracts were examined by histological observation and immunoprecipitation high performance liquid chromatography (IP-HPLC). RAW 264.7 cells differently expressed the proliferation-related proteins depending on the dose of DCE. DCE-2.5 and DCE-5 enhanced the cellular growth of RAW 264.7 cells by increasing the expression of β-actin, PCNA, Ki-67, MPM2, MAX, cMyc, E2F-1, and Rb-1, and by decreasing the expression of MAD and p21. These proliferation-related proteins were rarely affected by DCE-10. DCE-2.5 and DCE-5 induced the cellular proliferation of RAW 264.7 cells by the signaling of E2F-1 and cMyc, respectively, but these cellular effects almost disappeared in DCE-10. Therefore, it was presumed that the low dose of coffee, DCE-2.5 and DCE-5 might be effective for the proliferation of murine macrophages, RAW264.7 cells, contrast to the high dose of coffee, DCE-10. It was also suggested that the low dose of DCE-2.5 and DCE-5 be helpful to increase the innate immunity in vivo by increasing the cell number of macrophages in contrast to the high dose of DCE-10.

To investigated the mechanism, induced pluripotent stem cells(iPSC) is important for clinical application and stem cell research. It is well known that hMAGEA2 expression pattern and effect on differentiation in embryonic stem cell but their specific role in iPS cells are unclear. The present study was schemed to understand the function of hMAGEA2 gene in iPS cells and to elucidate its characteristic. Although overexpression of hMAGEA2 in iPS cells are not different on morphology, their pluripotency and self-renewal capacity are significantly strengthened. And hMAGEA2 contributed to promote the cell cycle progression, this cell cycle changes induced proliferation acceleration. Through embryoid body formation in vitro and teratoma formation in vivo, we found that hMAGEA2 critically decreases the differentiation ability in iPS cells. Our results demonstrate that hMAGEA2 intensified the self-renewal, pluripotency, proliferation degree but efficiency of differentiaton is significantly repressed. Our findings provided that hMAGEA2 play a key role of iPS cells.

Aneurysmal bone cyst (ABC) in maxilla is a rare and benign lesion but shows extensive bony destruction, occasionally accompanied with secondary osseous lesions, i.e., central giant cell granuloma, ossifying fibroma, fibrous dysplasia, etc. As the pathogenesis of ABC has not been clearly defined, ABC is diagnostically challenged due to its variable histological features. A 17-year-old boy showed a huge radiolucent lesion at right anterior maxilla, which was accidentally found in routine dental-radiological examination for orthodontic treatment. He had no medical history of systemic disease, and did not remember any traumatic experience on his right anterior maxilla. The radiolucent lesion involved periapical area from right central incisor to right first premolar, and was clinically diagnosed as odontogenic keratocyst. During surgical operation a cyst-like sac was enucleated with severe hemorrhage. In the histological observation the thick fibrous sac showed no lining epithelium, and its luminal side disclosed multiple aneurysmal spaces which were shrunken and almost obliterated. The fibrous sac itself was hyperplastic with abundant vascular channels, and produced fibromatous thickening associated with ossifying trabecular bones. This fibro-osseous tissue was hamartomatous, which was not directly connected and organized with marrow bone of maxilla. Finally, the present case was diagnosed as secondary type ABC differentially from traumatic bone cyst (TBC), odontogenic cyst, and central reparative granuloma. And it was presumed that the hamartomatous proliferation of fibro-osseous tissue in the cystic sac of ABC could produce the swelling pressure effect in the bone marrow similar to the overgrowth of central giant cell granuloma, ossifying fibroma, fibrous dysplasia, etc., in the secondary type ABC.

해양생물을 포함한 천연물질은 신약개발의 원천 소재로서 매력적이며, 특히 무수한 미지의 해양생물들의 연구가 관심을 받고 있다. 기존의 연구에서 미크로네시아에서 채취한 해면동물 40여종에 대하여 항증식 효과를 다양한 암세포주에서 검색한 바 있다. 본 연구에서는 그 중 Cos-cinoderma sp.의 작용 및 그 기전을 살펴보았다. 특히, 암억제유전자 p53의 발현을 억제시킨 세포주(HCT116 p53KO 과 RKO-E6)에서의 차이점을 비교하였다. 세포생존률 시험에서 Coscinoderma sp. 추출물은 p53의 유무와 상관없이 암세포의 증식을 억제하였음을 확인하였다. 이 암세포증식 억제 효과가 p53 존재에 따라 다르게 나타나는지 알아보기 위하여 세포사멸 관련 단백질 발현양을 Coscinoderma sp. 처리한 각 세포주에서 비교하였다. 그 결과, Coscinoderma sp.를 HCT16 세포주에 처리하였을 때, p53과 Noxa의 발현이 증가하는 것을 관찰하였고, caspase-9이 분절되면서 감소하는 것으로부터 apoptosis를 일으킨다고 여겨진다. 반면, p53이 결핍된 HCT116세포주에서는 Coscinoderma sp. 에 의하여 p21과 mTOR의 발현이 증가되는 것을 확인하였고, 이는 senescence를 야기할 수 있다고 여겨진다. 본 연구로부터 Coscinoderma sp.는 p53의 존재여부에 따라 상이한 작용기전을 매개하여 대장암 세포주의 증식을 억제한다는 것을 알 수 있었다. 이는 새로운 항암제의 개발 가능성을 제시하는 것으로, Coscinoderma sp.의 활성 성분에 대한 지속적인 연구가 이루어 져야 할 것으로 보인다.

Skin-derived precursors (SKPs) have potential to differentiate to various cell types including osteoblasts, adipocytes and neurons. SKPs are a candidate for cell-based therapy since they are easily accessible and have multipotency. Most mammalian cells are exposed to a low oxygen environment with 1 to 5% O2 concentration in vivo, while 21% O2 concentration is common in in vitro culture. The difference between in vitro and in vivo O2 concentration may affect to the behavior of cultured cells. In this report, we investigated the effect of hypoxic condition on stemness and proliferation of SKPs. The results indicated that SKPs exposed to hypoxic condition for 5 days showed no change in proliferation. In terms of mRNA expression, hypoxia maintained expression of stemness markers; whereas, oncogenes, such as Klf4 and c-Myc, were downregulated, and the expression of Nestin, related to cancer migration, was also downregulated. Thus, SKPs cultured in hypoxia may reduce the risk of cancer in SKP cell-based therapy.

The PHBV nonofibrous membrane fabricated by electron-spinning method for tissue engineered bone regeneration scaffold was evaulated in terms of cellular prolieration and cryopreservation efficiency. The rat calvarial periosteum derived primary cells were cultured with PHBV nanofibrous membranes and analyzed the cellular proliferation and differention fashion and cryopreservation potential by in vitro MTT assay as well as ALP staining and Alizarine red staining with or without cryopreservation for 2 weeks. The rat calvarial periosteum derived primary cells cultured with PHBV nonofibrous membrane showed favorable proliferation and alkaline phosphatase activity with numerous mineral nodule formation regardless of cryopreservation, even though its efficiency was slightly decreased in cryopreserved condition. These findings suggest that PHBV nanofibrous membrane can be applicable as an efficient cell engineered membrane for guided bone regeneration or scaffold for tissue engineered bone regeneration.

A 57 years old female received xenogenic bone graft for the extraction socket augmentation of right maxillary molars and for the sinus floor elevation six months ago. The bone graft sites were healed uneventfully and showed marked radiopacity in the postoperative X-ray view. Before dental implant insertion the bone biopsy was made using trephine bur and examined pathologically. The graft bones showed minimum new bone deposition with dysplastic epithelium. The epithelium was proliferative on the surface of graft bones forming epithelial strands and nests, similar to the odontogenic epithelium. The immunohistochemical study was performed using different antisera of odontogenic markers, growth factors, oncogenes, etc. The epithelial cells were strongly positive for pan-keratins, EGF, pAKT, and HSP-70, consistently positive for PCNA, p53, EGFR, 14-3-3, and survivin, slightly positive for ameloblastin, but rarely positive for amelogenin. Particularly the matrix of graft bone was slightly positive for EGF. Taken together, it is presumed that the abnormal epithelium on the graft bones was derived from odontogenic epithelial elements, Malassez epithelial rests, distributed at the periodontal tissue of maxillary molars, and that they might undergo dysplastic proliferation affected by the release of growth factors and osteogenic proteins from the graft bones. It is also suggested that the graft bone substitutes inserted for the dental implant possibly have a potential to induce the proliferation of odontogenic epithelial rests leading to the pathogenesis of odontogenic cysts and tumors.

The carcinogenesis mechanism of human salivary gland adenocarcinoma NOS is poorly understood. MicroRNA155(miRNA155) has been involved in the carcinogenesis of many malignant tumors. The purpose of this study was to examine the role of miRNA155 in tumor growth and invasion of adenocarcinoma NOS. Using SGT cells as a model for adenocarcinoma NOS, cell proliferation was examined by MTT assay after knocking down miRNA155 expression, and cell cycle analysis was performed. Invasive capacity by a Transwell culture assay, and miRNA155 expression in SGT cell line by RT-PCR were examined. In MTT assay, proliferation of SGT-miRNA155 cells was decreased prominently after 96 hrs. Proliferation of SGT cells was markedly inhibited by knocking down miRNA155, resulting from a blockade of cell cycle in the G1 phase, but apoptosis was increased about 4 folds. In adhesion assay, SGT-miRNA155 cells decreased about 60% compared to SGT cells. In invasion assay, inhibition of miRNA155 significantly suppressed the invasive capacity of about 34% SGT cells. mRNA expression of SGT-miRNA155 cells prominently were decreased compared to SGT cells by RT-PCR. It suggested that miRNA155 could play an role in cell cycle progression and invasion in SGT cells, including antitumor effect. These results have provided insights into the carcinogenic mechanisms and new intervention method of salivary gland adenocarcinoma NOS.

Despite many researches related with in-vitro culture of porcine spematogonial stem cells (SSCs), adherent culture system widely used has shown a limitation in the maintenance of porcine SSC self-renewal. Therefore, in order to overcome this obstacle, suspension culture, which is known to have numerous advantage over adherent culture, was applied to the culture of porcine SSCs. Porcine SSCs retrieved from neonatal testes were suspension-cultured for 5 days or 20 days, and characteristics of suspension-cultured porcine SSCs including proliferation, alkaline phosphatase (AP) activity, and self-renewal-specific gene expression were investigated and compared with those of adherent-cul-tured porcine SSCs. As the results, the suspension-cultured porcine SSCs showed entirely non-proliferative and significantly higher rate of AP-positive cells and expression of self-renewal-specific genes than the adherent-cultured porcine SSCs. In addition, long-term culture of porcine SSCs in suspension condition induced significant decrease in the yield of AP staining-positive cells on post-day 10 of culture. These results showed that suspension culture was inappropriate to culture porcine SSCs, because the culture of porcine SSCs in suspension condition didn’t stimulate proliferation and maintain AP activity of porcine SSCs, regardless of culture periods.