• International journal of advanced smart convergence
• /
• v.7 no.1
• /
• pp.48-63
• /
• 2018

The combination of Simian Virus40 (SV40)'s large T antigen with its replication origin is commonly used in molecular studies to enhance the expression of heterogeneous genes through multiplying the plasmid copy number. There are no reports related to the impact of the SV40 T antigen on plant, multiple fissional, cell-type. This study explores the response of two multiple-fission microalgal cells, Scenedesmus quadricauda and Chlorella vulgaris, to the expression of the T-antigen, with aim of applying SV40 T-antigen to increase the expression efficiency of foreign genes in the two species. Different levels of low-expression have been constructed to control the expression of SV40 T antigen using three heterogenous promoters (NOS, CaMV35S, and CMV). Chlorella cultures showed slowdown in the growth rate for samples harboring the T antigen under the control of CaMV35S and CMV promoters, unlike Scenedesmus cultures which showed no significant difference between samples and could have silenced the expression.

• Biomedical Science Letters
• /
• v.10 no.2
• /
• pp.85-92
• /
• 2004

Immortalization of primary corneal cells has influence on pharmacy, medical and biological fields. Especially, investigation of immortalization mechanism using viral oncoproteins is useful for medical treatments, and these cell lines will be useful materials for toxic test of medical supplies and cell biological experiments. Rabbit corneal fibroblasts in culture undergo a finite number of divisions before they reach a terminally non-proliferating state known as replicative senescence. Therefore, we attempted to induce immortalization of rabbit corneal fibroblasts with SV 40 large T antigen. As a result of experiment, expression of SV 40 large T antigen was confirmed, and expression of proteins related to cell cycle repressor was decreased in the transfection group compared with non-transfection group. According to the results of cell cycle phase distribution test, SV 40 large T antigen-transfected cells had obtained higher proliferation rate than primary cells. It was confirmed that during induction of immortalization, SV 40 large T antigen was not able to increase telomerase activity. In conclusion, we made a rabbit corneal fibroblast cell line with SV40 large T antigen. This cell line will be useful for further studies of mammalian fibroblast biology, particularly with regard to angiogenesis and malignant transformation. In addition, this cell line offers opportunity for testing potential therapeutics and can be used for toxicity tests of materials or cosmetics. In the future, our cell line can potentially be utilized in a wide range of biology related fields.

• The Korean Journal of Zoology
• /
• v.28 no.3
• /
• pp.166-178
• /
• 1985

In order to express hepatitis B surface antigen $(HB_sAg)$ containing pre-surface antigen region in mammalian calls, 2.7 kb DNA fragment containing pre-surface region-$HB_sAg$ gene poly(A) addition site of HBV genome was cloned into simian virus 40(SV 40) based chimeric vector pSVOB. 2.7 kb DNA fragment was derived from pHBVD 107 containing tandem copies of the HBV genome in a head-to-tail arrangement by Bgl II digestion. Construction of the vector pSVOE involved the incorporation of SV40 sequences spanning the viral origin of replication and 72 bp repeats (enhancer) into a pBR 322 derivative lacking sequences which inhibit replication in mammalian cells. Bam HI linker was inserted at the Pvu II site in the proximity of SV40 late promoter of pSVOE and named as pSVOB. To construct the recombinant plasmid pSVBS, pHBVD 107 was digested with Bgl II to isolate 2.7kb DNA fragment and the fragment was ligated into the Bam HI site of pSVOB by ligation. Preliminary result showed that the recombinant plasmid pSVBS produced $HB_sAg$ in the monkey cell producing large T antigen (COS cell).

• Clinical and Experimental Reproductive Medicine
• /
• v.30 no.4
• /
• pp.317-324
• /
• 2003

목 적: 본 실험의 목적은 자궁내막세포를 분리 및 배양법 확립과 함께 불멸화 시키는 것이다. 방 법: 자궁내막에서 상피세포(epithelial cells)와 기질세포(stromal cells)의 분리는 Satyawaroop 등(1979)의 방법에 기초를 두었다. 자궁내막에서 상피세포와 기질세포의 순수 분리도를 확인하고, 불멸화된 기질세포에서 SV40 large T antigen을 확인하기 위하여 면역형광 염색(immunocytochemistry)과 Western blot 기법을 이용하였다. 정상 기질세포의 경우 subconfluence (60%) 상태에서 transfection을 진행하였다. 순수 분리된 plasmid DNA와 Qiagen 사의 superfect를 이용하여 transfection을 실시하였다. 결 과: 본 연구에서 우리는 두 가지 형태의 자궁내막 세포의 분리 및 배양에 성공하였다. 상피세포는 다면체의 형태를 띠며, 선(grandular)조직의 조각으로부터 나선형으로 자란다.기질 세포는 길쭉한 형태를 띠며, 상피세포에 비해 오래 살고, 빠르게 증식하여 나란한 형태로 배열된 세포 다발(cell bundle)을 형성한다. 이렇게 분리된 세포들은 95%의 균질성을 보였으며, 면역형광염색과 western blot을 통해 확인 하였다. 한편 SV40(Simian Virus 40) large T 항원을 암호화 하고 있는 염기 서열을 포함한 플라스미드 벡터로 안정적인 트랜스펙션을 시킴으로써 불멸화 된 자궁내막의 기질 세포주를 확립하였다. 불멸화 된 세포는 그 세포가 유래한 정상의 세포와 동일한 표현형을 가지고 있었다. 결 론: 본 연구에서, 우리는 자궁내막에서 상피세포(epithelial cells)과 기질세포(stromal cells)를 분리하여 배양법을 확립하였다. 동시에 SV40 large T antigen을 이용하여 불멸화된 세포주를 확립하였다. 이렇게 확립된 세포주는 자궁의 생리작용 연구 및 자궁내막증(Endometriosis)과 자궁암(Endometrial cancer) 등과 같은 여러 자궁관련 질병 연구에 많은 도움이 될 것으로 사료된다.

• Journal of Life Science
• /
• v.24 no.12
• /
• pp.1301-1307
• /
• 2014

Adipose-derived stem cells (ADSCs) are considered promising tools for tissue regeneration. However, ADSCs have very poor proliferation capacity. Therefore, fetal bovine serum (FBS) is generally added to the culture media of ADSCs. As FBS contains many uncharacterized components that may affect cellular functions, methods for serum-free cultures of ADSCs have been widely investigated. In this study, to develop an efficient method for a serum-free culture of ADSC-T, we used an ADSC line established by introducing the simian virus 40 (SV40) T gene into primary ADSCs. We then investigated the effect of amino acids, vitamins, and other components on the growth of ADSC-T. When the ADSC-T cells were plated with DMEM/F12 serum-free medium, the cells did not proliferate, and the mixture of amino acids, vitamins, and B27 supplement did not increase the growth of the cells. However, when the ADSC-T cells were provided with serum-free DMEM/F12 after they had been cultured with serum-supplemented DMEM for 24 h, the cells proliferated, and the vitamins and B27 supplement increased the cell growth. Stem-Pro serum-free medium also appeared to be useful as a suspension culture for the ADSC-T cells. The ADSC-T cells secreted large amounts of proteins of around 70 kDa. Insulin-like growth factor (IGF) and fibroblast growth factor basic (FGF basic) were secreted by ADSC-T in larger amounts in the serum-free culture than in the serum-supplemented culture.

• Reproductive and Developmental Biology
• /
• v.31 no.3
• /
• pp.145-152
• /
• 2007

Transgenic mice were generated by microinjecting a plasmid DNA containing the SV40 (simian virus 40) large T antigen (Tag) gene fused with mouse albumin promoter/enhancer sequences into fertilized one-cell mouse embryos. Among eleven founder transgenic animals, four developed hepatocellular carcinoma, two showed kidney cancer and one developed skin and brain tumors. Three stable transgenic lines, #1-2, #1-6 and #1-11 were established. Members of the lines #1-6 and #1-11 reproducibly developed liver tumors by 8 to 10 weeks of age but did not exhibit any phenotypic changes in other tissues. Histological changes loading to liver tumor formation occurred with predictable kinetics and could be classified into three distinct stages; (a) newborn to 3 weeks of age, characterized by hyperplastic hepatocytes with reduced amounts of cytoplasm without any nuclear alterations, (b) between 4 to 8 weeks of age, characterized by diffuse liver cell dysplasia without observable tumor nodules, and (c) 9 weeks of age and thereafter, characterized by hepatocellular carcinomas in the background of extensive liver dysplasia. Metastasis to the lung from a liver carcinoma was observed in #1-11 founder animal. This transgenic mouse system displays similarities with human liver cancers in a number of aspects and provides a useful model for the study of molecular events involved in hepatocarcinogenesis.