• The Journal of the Korean bone and joint tumor society
• /
• v.11 no.2
• /
• pp.118-125
• /
• 2005

Purpose: The expression of apoptosis-related genes, such as survivin, bcl-2, and bax has been examined in the human osteosarcoma and then evaluated the correlation with clinical data of patients. Materials and Methods: Fifty human osteosarcoma specimens were established from incisional biopsy and examination of survivin, bcl-2, and bax by immunohistochemical study was performed. We investigated the correlation of survivin, bcl-2, bax and their two or three combined expressions with clinical data including the response of chemotherapy, local recurrence, distance metastasis, and oncologic outcome. Results: Survivin was showed in 26 cases (52%), bcl-2 in 23 cases (46%), and bax in 21 cases (42%) osteosarcoma. And coexpression of survivin and bcl-2 was showed in 19 cases (38%), survivin and bax in 13 cases (26%), bcl-2 and bax in 8 cases (16%), and all three expression was showed in 8 cases (16%). There was no correlation between their apoptosis related gene and histologic difference, the presence of local recurrence and distant metastasis. Whereas neoadjuvant chemotherapy response correlated with bcl-2 expression (P=0.04), and survivin and bcl-2 coexpression (P=0.044) with poor chemoresponse. The rate of died of disease was correlated with bcl-2 (P=0.001), survivin and bcl-2 coexpression (P=0.027) with bad outcome. Survival curves of bcl-2 (P=0.0075), survivin and bcl-2 (P=0.0012) was showed negative correlation in the Kaplan-Meier method. Conclusion: The apoptosis related gene expression was relatively high in osteosarcoma, bcl-2 expression was correlated with poor chemotherapy response and poor survival rate, but survivin was correlated with this oncologic outcome only in the bcl-2 coexpression. The examination of immunohistochemical stain of apoptosis related gene in osteosarcoma could be helpful in the judgment of osteosarcoma prognosis.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.12
• /
• pp.1909-1921
• /
• 2007

Significant progress has recently been made concerning the engineering of deoxysugar biosynthesis. The biosynthetic gene clusters of several deoxysugars from various polyketides and aminoglycosides-producing microorganisms have been cloned and studied. This review introduces the biosynthetic pathways of several deoxysugars and the generation of novel hybrid macrolide antibiotics via the coexpression of deoxysugar biosynthetic gene cassettes and the substrate-flexible glycosyltransferases in a host organism as well as the production of TDP-deoxysugar derivatives via one-pot enzymatic reactions with the identified enzymes. These recent developments in the engineering of deoxysugars biosynthesis may pave the way to create novel secondary metabolites with potential biological activities.

• KSBB Journal
• /
• v.16 no.1
• /
• pp.1-10
• /
• 2001

Escherichia coli has been used as an expression work horse for foreign genes. This article summarized recent development in genetic engineering techniques for overproduction of medical proteins and industrial enzymes. Special emphasis was placed upon research activities concerning folding and refolding of inclusion bodies at genetic and fermentation levels. Plasmid and mRNA stabilization, development of strong inducible promoters, modification of translational elements and reduction of rpoteolytic degradation were carried out to elevate an expression level of a target protein. Optimization of culture conditions, improvement of denaturation and renaturation steps and coexpression of molecular chaperones or foldase were accomplished to produce active proteins in soluble form. Fusion protein systems with selective separation and surface display technology were also performed in an effort to make the E. coli expression system more effective and versatile.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.8
• /
• pp.1353-1356
• /
• 2008

RNase E (Rne) plays a major role in the decay and processing of numerous RNAs in E. coli, and protein inhibitors of RNase E, RraA and RraB, have recently been discovered. Here, we report that coexpression of RraA or RraB reduces the ribonucleolytic activity in rne-deleted E. coli cells overproducing RNase ES, a Streptomyces coelicolor functional ortholog of RNase E, and consequently rescues these cells from growth arrest. These findings suggest that the regulators of ribonuclease activity have a conserved intrinsic property that effectively acts on an RNase E-like enzyme found in a distantly related bacterial species.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2001.10a
• /
• pp.188-188
• /
• 2001

Human cytochrome B5 (CYB5) was coexpressed with cytochrome P450 1A2 (CYP1A2), NADPH-CYP450 reductase (CYPR) and Ν-acetyltransferase 2 (NAT2) in Chinese hamster ovary (CHO) cells. The expression of four proteins was determined by Western blot analyses. The introduction of cDNAs to CHO cells were transduced via retroviral vectors. The cytotoxicity assay of 2-aminoanthracene (2-AA) and aflatoxin B$_1$were approximately 4-fold more sensitive than CYB5 free cells.(omitted)

• Proceedings of the Korean Information Science Society Conference
• /
• 2002.10c
• /
• pp.739-742
• /
• 2002

This paper addresses a new statistical method, IFSAcycle, which is an unsupervised learning method of analyzing cell cycle-related gene expression data. The IFSAcycle is based on the independent feature subspace analysis (IFAS) [3], which generalizes the independent component analysis (ICA). Experimental results show the usefulness of IFAS: (1) the ability of assigning genes to multiple coexpression pattern groups; (2) the capability of clustering key genes that determine each critical point of cell cycle.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.10
• /
• pp.6081-6084
• /
• 2013

Objective: Both estrogen receptors, ER alpha ($ER{\alpha}$) and ER beta ($ER{\beta}$), are expressed in 50-70% of breast cancer cases. The role of $ER{\alpha}$ as a prognostic marker in breast cancer has been well established as its expression is negative correlated with tumor size and lymph node metastasis. $ER{\beta}$ is also a favorable prognostic predictor although this is less well documented than for $ER{\alpha}$. Materials and Methods: To explore whether ERs independently or together might influence clinical outcome in breast cancer, the correlation between the ERs with the clinicopathological features was analyzed in 84 patients. Results: $ER{\alpha}$ expression negatively correlated with tumor stage (r=-0.246, p=0.028) and tended to be negatively correlated with lymph node status (r=-0.156, p=0.168) and tumor size (r=-0.246, p=0.099). Also, $ER{\beta}$ was negatively correlated with nodal status (r=-0.243, p=0.028), as was coexpression of $ER{\alpha}$ and $ER{\beta}$ (p=0.043, OR=0.194, 95% CI= 0.040-0.953). Conclusion: Coexpression of ERs might serve as an indicator of good prognosis in breast cancer patients.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.4
• /
• pp.685-692
• /
• 2001

A gene, Egl, from Paenibacillus sp. KCTC 8848P encoding endo-${\circ}$-1,4-glucanase was cloned and expressed in Escherichia coli. It consisted of an open reading frame of 1,191 bp for a protein that consisted of 397 amino acids with a molecular weight of 44,539 Da. The deduced amino acid sequence of the endo-${\circ}$-1,4-glucanase gene had a 94% similarity to the endo-$\beta$-1,4-glucanase of Bacillus polymyxa. The Egl gene was also expressed in Saccharomyces cerevisiae secreting Endomyces fibuliger $\beta$-glucosidase (BGL1) under the control of the alcohol dehydrogenase (ADC1) gene promoter, S. cerevisiae transformant producing both endo-${\circ}$-1,4-glucanase and ${\circ}$-glucosidase grew on carboxymethyl cellulose as the sole carbon source.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.12
• /
• pp.2034-2042
• /
• 2015

A one-pot process of enzymatic synthesis of deoxythymidine-5'-triphosphate (5'-dTTP) employing whole cells of recombinant Escherichia coli coexpressing thymidylate kinase (TMKase) and acetate kinase (ACKase) was developed. Genes tmk and ack from E. coli were cloned and inserted into pET28a(+), and then transduced into E. coli BL21 (DE3) to form recombinant strain pTA in which TMKase and ACKase were simultaneously overexpressed. It was found that the relative residual specific activities of TMKase and ACKase, in pTA pretreated with 20 mM ethylene diamine tetraacetic acid (EDTA) at 25℃ for 30 min, were 94% and 96%, respectively. The yield of 5'-dTTP reached above 94% from 5 mM deoxythymidine 5'-monophosphate (5'-dTMP) and 15 mM acetyl phosphate catalyzed with intact cells of pTA pretreated with EDTA. The process was so effective that only 0.125 mM adenosine-5'-triphosphate was sufficient to deliver the phosphate group from acetyl phosphate to dTMP and dTDP.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.2
• /
• pp.228-233
• /
• 2008

Effects of chaperones on mRNA stability and gene expression were studied in order to develop an efficient Escherichia coli expression system that can maximize gene expression. The stability of mRNA was modulated by introducing various secondary structures at the 5'-end of mRNA. Four vector systems providing different 5'-end structures were constructed, and genes encoding GFPuv and endoxylanase were cloned into the four vector systems. Primer extension assay revealed different mRNA half-lives depending on the 5'-end secondary structures of mRNA. In addition to the stem-loop structure at the 5'-end of mRNA, coexpression of dnaK-dnaJ-grpE or groEL-groES, representative heat-shock genes in E. coli, increased the mRNA stability and the level of gene expression further, even though the degree of stabilization was varied. Our work suggests that some of the heat-shock proteins can function as mRNA stabilizers as well s protein chaperones.