• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.89-96
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• 2017

The CRISPR/Cas9 is a core technology that can result in a paradigm for breeding new varieties. This study describes in detail the sgRNA design, vector construction, and the development of a transgenic plant and its molecular analysis, and demonstrates how gene editing technology through the CRISPR/Cas9 system can be applied easily and accurately. CRISPR/Cas9 facilitates targeted gene editing through RNA-guided DNA cleavage, followed by cellular DNA repair mechanisms that introduce sequence changes at the site of cleavage. It also allows the generation of heritable-targeted gene mutations and corrections. Here, we present detailed procedures involved in the CRISPR/Cas9 system to acquire faster, easier and more cost-efficient gene edited transgenic rice. The protocol described here establishes the strategies and steps for the selection of targets, design of sgRNA, vector construction, and analysis of the transgenic lines. The same principles can be used to customize the versatile CRISPR/Cas9 system, for application to other plant species.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8503-8512
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• 2016

The purpose of this study was to provide a detailed explanation of the mechanism of bisanthracycline, WP 631 in comparison to doxorubicin (DOX), a first generation anthracycline, currently the most widely used pharmaceutical in clinical oncology. Experiments were performed in SKOV-3 ovarian cancer cells which are otherwise resistant to standard drugs such as cis-platinum and adriamycin. As attention was focused on the ability of WP 631 to induce apoptosis, this was examined using a double staining method with Annexin V and propidium iodide probes, with measurement of the level of intracellular calcium ions and cytosolic cytochrome c. The western blotting technique was performed to confirm PARP cleavage. We also investigated the involvement of caspase activation and DNA degradation (comet assay and immunocytochemical detection of phosphorylated H2AX histones) in the development of apoptotic events. WP 631 demonstrated significantly higher effectiveness as a pro-apoptotic drug than DOX. This was evident in the higher levels of markers of apoptosis, such as the externalization of phosphatidylserine and the elevated level of cytochrome c. An extension of incubation time led to an increase in intracellular calcium levels after treatment with DOX. Lower changes in the calcium content were associated with the influence of WP 631. DOX led to the activation of all tested caspases, 8, 9 and 3, whereas WP 631 only induced an increase in caspase 8 activity after 24h of treatment and consequently led to the cleavage of PARP. The lack of active caspase 3 had no outcome on the single and double-stranded DNA breaks. The obtained results show that WP 631 was considerably more genotoxic towards the investigated cell line than DOX. This effect was especially visible after longer times of incubation. The above detailed studies indicate that WP 631 generates early apoptosis and cell death independent of caspase-3, detected at relatively late time points. The observed differences in the mechanisms of the action of WP631 and DOX suggest that this bisanthracycline can be an effective alternative in ovarian cancer treatment.

• The Korea Journal of Herbology
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• v.21 no.4
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• pp.27-36
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• 2006

Objectives : This study was performed for the investigation of anticancer effects of methanol extract of Rheum Rhizoma (MeOH-RR) on a human liver cancer cell line (HepG2). Methods : To study the cytotoxic effect of MeOH-RR on HepG2 cells, the cell viability was determined by XTT reduction method and trypan blue exclusion assay. The cleavage of poly ADP-ribose polymerase (PARP), a substrate for caspase-3 and a typical sign of apoptosis, and the activation of procaspase-3, -8 and -9 were examined by western blot analysis. Furthermore, MeOH-RR-induced apoptosis was confirmed by DNA fragmentation. The release of cytochrome c from mitochondria to cytosol, the level of Bcl-2 and Bax were examined by western blot analysis. Results : MeOH-RR reduced proliferation of HepG2 cells in a dose-dependent manner at 24 h and 48 h treatment. MeOH-RR induced the activation of caspase-3, -8, and -9 and the cleavage of poly ADP-ribose polymerase (PARP), a substrate for caspase-3. Furthermore, treatment with MeOH-RR resulted in internucleosomal DNA fragmentation, evidenced by the formation of a DNA ladder on agarose gel, a hallmark of cells undergoing apoptosis. MeOH-RR downregulated Bcl-2, upregulated Bax, and increased the release of cytochrome c from the mitochondria into cytosol in a dose-dependent manner. Moreover, MeOH-RP increased caspase-3 activity. Conclusion : There results suggest that MeOH-RR induce apoptosis via mitochondrial pathway and caspase-3-dependent pathway in HepG2 cells. There results suggest that MeOH-RR is potentially useful as a chemotherapeutic agent in human liver cancer.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.734-742
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• 2012

To compare RNA interference-mediated gene silencing technique and T-DNA integration for gene function analysis in Chinese cabbage, BrSAMS-knockout (KO) line and BrSAMS-knockdown (KD) line were used. The KO line had lost the function of a Brassica rapa S-adenosylmethionine synthetase (BrSAMS) gene by T-DNA insertion and the KD line had shown down-regulated BrSAMS genes' expression by dsRNA cleavage. From microarray results of the KO and KD lines, genes linked to SAMS such as sterol, sucrose, homogalacturonan biosynthesis and glutaredoxin-related protein, serine/threonine protein kinase, and gibberellin-responsive protein showed distinct differences in their expression levels. Even though one BrSAMS gene in the KO line was broken by T-DNA insertion, gene expression pattern of that line did not show remarkable differences compared to wild type control. However, the KD line obtained by RNAi technique showed prominent difference in its gene expression. Besides, change of polyamine and ethylene synthesis genes directly associated with BrSAMS was displayed much more in the KD line. In the microarray analysis of the KO line, BrSAMS function could not be clearly defined because of BrSAMS redundancy due to the genome triplication events in Brassicaceae. In conclusion, we supposed that gene knock-down method by RNAi silencing is more effective than knock-out method by T-DNA insertion for gene function analysis of polyploidy crops such as Chinese cabbage.

• The Journal of Korean Medicine
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• v.26 no.4
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• pp.12-21
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• 2005

Objectives: In the present study, we investigated whether an aqueous extract of Armeniacae semen induces apoptotic neuronal cell death upon mouse N2a neuroblastoma cells. Methods: 1. Cell viability was determined by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTI) assay. 2. For in situ detection of apoptotic cells, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, 4,6-diamidino-2-phenylindole (DAPI) staining. 3. The fraction of cells was revealed by flow cytometric analysis used that. 4. For detection of apoptotic DNA cleavage, DNA fragmentation assay was performed. 5. For detection of bax and bcl-2, Western blot analysis was performed. 6. Caspase enzyme activity was measured using caspase-3 assay. Results: From the present results, N2a neuroblastoma cells treated with Armeniacae semen extract exhibited several characteristics of apoptosis. A treatment of Armeniacae semen extract was shown to increase the expression of Bax, a proapoptotic protein, and the treatment decreased the expression of Blc2, an anti-apoptotic protein. In addition, Armeniacae semen extract increased the caspase-3 enzyme activity. Conclusions: The present results show that Armeniacae semen extract induces apoptotic cell death in mouse N2a neuroblastoma cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.2
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• pp.202-211
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• 2013

The purpose of this study is to investigate the apoptotic effect of Phellodendri Cortex water extract (PCWE) on pancreatic cancer cells and to find out the regulating mechanisms. Human-derived pancreatic cancer cell line, MIA PaCa-2 cells were treated by PCWE with various concentrations and the cytotoxicity was determined by MTT assay. The activation of Annexin V, DNA fragmentation, cell cycle arrest and caspase activation were observed to investigate the role of PCWE in pancreatic cancer cells. Also, to find out the regulating mechanisms, we examined the ROS production. The treatment of PCWE induced the cell death in both concentration and time dependent manner. The treatment of PCWE also increased the expression of Annexin V, DNA fragmentation, cell cycle arrest, and cleavage of caspase, which means cell-death PCWE induced was apoptosis but not necrosis. The ROS production was increased by PCWE treatment and the blockade of ROS inhibited the PCWE-induced cell death. These results could suggest that PCWE induced apoptosis via ROS release in pancreatic cancer cell.

• Journal of Life Science
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• v.8 no.1
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• pp.102-108
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• 1998

The nascent from of glycosylphosphatidylinositol (GPI)-anchored proteins possesses both amino and carboxy terminal hydrophobic signal sequences to direct processing in the endoplasmic reticulum (ER). Following cleavage of the amino-terminal signal peptide, the carboxy-terminal peptide is processed. Previously, mouse lymphocyte NDA: agrinine ADP-ribosyltransferase (Yac-1) was cloned and the deduced amino acid sequence of the Yac-1 transferase contained hydrophobic amino and carboxy termini, consistent with known signal sequences of GPI-anchored proteins. This tranferase was present on the surface of NMU (rat mammary adenocarcinoma) cells transfected with the wildtype cDNA and was released with phosphatidylinositol-specific phosphilpase C. Expression of the mutant protein, lacking the carboxy terminal hydrophobic sequence, resulted in the peoduction of soluble, secreted from of the transferase. This result shows that carboxy terminal sequence is important for GPI-attachment.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.29-36
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• 2007

The xynA gene encoding the xylanase A of Paenibacillus sp. DG-22 was isolated with a DNA probe obtained by PCR amplification, using degenerated primers deduced from the amino acid residues of the known N-terminal region of the purified enzyme and the conserved region in the family 11 xylanases. The positive clones were screened on the LB agar plates supplemented with xylan, by the Congo-red staining method. The xynA gene consists of a 630-bp open reading frame encoding a protein of 210 amino acids, and the XynA preprotein contains a 28-residues signal peptide whose cleavage yields a l82-residues mature protein of a calculated molecular weight of 20,000Da and pI value of 8.77. The cloned DNA fragment also has another ORF of 873 nucleotides that showed 76% identity to the putative transcriptional activator of Bacillus halodurans C-125. Most of the xylanase activity was found in the periplasmic space of E. coli. The xynA gene was subcloned into pQE60 expression vector to fuse with six histidine-tag. The recombinant xylanase A was purified by heating and immobilized metal affinity chromatography. The optimum pH and temperature of the purified enzyme were 6.0 and $60^{\circ}C$, respectively. This histidine-tagged xylanase A was less thermostable than the native enzyme.

• Korean Journal of Microbiology
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• v.24 no.4
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• pp.357-363
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• 1986

Synthesis of threonine and methionine in yeast, Saccharomyces cerevisiae shares a common pathway from aspartate via homoserine. HOM6 gene encodes homoserine dehydrogenase (HSDH) which catalyzes the inter-conversion of beta-aspartate semialdehyde and homoserine. The level of HSDH is under methionine specific control. A recombinant plasmid (pEK1: 13.3kb), containing HOM6 gene, has been isolated and cloned into E. coli by complenemtary transformation of a homoserine auxotrophic yeast strain M-20-20D (hom6, trp1, ura3) to a prototrophic M20-20D/pEK1, using a library of yeast genomic DNA fragments in a yeast centromeric plasmid, YCp50(8.0kb). Isolation of HOM6has been primarily confirmed by retransformation of the original yeast strain M20-20D, using the recombinant plasmid DNA which was extracted from M20-20D/pEK1 and subsequently amplified in E. coli. Eleven cleavage sites in the insery (5.3kb) have been localized through fragment analysis for 8 restriction endonucleases; Bgl II(2 site), Bgl II(1), Cla I(3), Eco RI(1), Hind III(2), Kpn I (1), Pvu II(1) and Xho I(1).

• Molecules and Cells
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• v.25 no.2
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• pp.224-230
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• 2008

Ceramides are well-known second messengers that induce apoptosis in various kinds of cancer cells, and their effects are closely related to radiation sensitivity. Phytoceramides, the yeast counterparts of the mammalian ceramides, are also reported to induce apoptosis. We investigated the effect of a novel ceramide derivative, N-acetylphytosphingosine (NAPS), on the radiosensitivity of NCI-H460 human lung carcinoma cells and its differential cytotoxicity in tumor and normal cells. The combination of NAPS with radiation significantly increased clonogenic cell death and caspase-dependent apoptosis. The combined treatment greatly increased Bax expression and Bid cleavage, but not Bcl-2 expression. However, there was no effect on radiosensitivity and apoptosis in BEAS2B cells, which derive from normal human bronchial epithelium. Cell proliferation and DNA synthesis were significantly inhibited by NAPS in both NCI-H460 and BEAS2B cells, but only the BEAS2B cells recovered by 48h after removal of the NAPS. Furthermore, the NCI-H460 cells underwent more DNA fragmentation than the BEAS2B cells in response to NAPS. Our results indicate that NAPS may be a potential radiosensitizing agent with differential effects on tumor vs. normal cells.