• Journal of Genetic Medicine
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• v.12 no.2
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• pp.72-78
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• 2015

Recently, noninvasive prenatal test (NIPT) has been adopted as a primary screening tool for fetal chromosomal aneuploidy. The principle of NIPT lies in isolating the fetal fraction of cell-free DNA in maternal plasma and analyzing it with bioinformatic tools to measure the amount of gene from the target chromosome, such as chromosomes 21, 18, and 13. NIPT will contribute to decreasing the need for unnecessary invasive procedures, including amniocentesis and chorionic villi sampling, for confirming fetal aneuploidy because of its higher positive predictive value than that of the conventional prenatal screening method. However, its greater cost than that of the current antenatal screening protocol may be an obstacle to the adoption of this innovative technique in clinical practice. Digital polymerase chain reaction (dPCR) is a novel approach for detecting and quantifying nucleic acid. dPCR provides real-time diagnostic advantages with higher sensitivity, accuracy, and absolute quantification than conventional quantitative PCR. Since the groundbreaking discovery that fetal cell-free nucleic acid exists in maternal plasma was reported, dPCR has been used for the quantification of fetal DNA and for screening for fetal aneuploidy. It has been suggested that dPCR will decrease the cost by targeting specific sequences in the target chromosome, and dPCR-based noninvasive testing will facilitate progress toward the implementation of a noninvasive approach for screening for trisomy 21, 18, and 13. In this review, we highlight the principle of dPCR and discuss its future implications in clinical practice.

• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.355-362
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• 2014

We have developed a fully automated high throughput drug screening (HTDS) system based on the microfluidic cell culture array to perform combinational chemotherapy. This system has 64 individually addressable cell culture chambers where the sequential combinatorial concentrations of two different drugs can be generated by two microfluidic diffusive mixers. Each diffusive mixer has two integrated micropumps connected to the media and the drug reservoirs respectively for generating the desired combination without the need for any extra equipment to perfuse the solution such as syringe pumps. The cell array is periodically exposed to the drug combination with the programmed LabVIEW system during a couple of days without extra handling after seeding the cells into the microfluidic device and also, this device does not require the continuous generation of solutions compared to the previous systems. Therefore, the total amount of drug being consumed per experiment is less than a few hundred micro liters in each reservoir. The utility of this system is demonstrated through investigating the viability of the prostate cancer PC3 cell line with the combinational treatments of curcumin and tumor necrosis factor-alpha related apoptosis inducing ligand (TRAIL). Our results suggest that the system can be used for screening and optimizing drug combination with a small amount of reagent for combinatorial chemotherapy against cancer cells.

• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.148-153
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• 1996

Activation of the T lymphocytes results in a variety of early biochemical events ultimately leading to cell proliferation and lymphokine production. Stimulation of the signal transduction cascade in T cells through the T cell receptor coincides with activation of the phosphatidylinositol-phospholipase C (PI-PLC) pathway. Therefore, we have established a model system to screen immune-simulator that can increase the hydrolysis of phosphoinositides in human T cell leukemia Jurkat cells. As a result of screening from herbal medicine extract, 4 extracts (O1ibanum, Ephedrae Herba, Real Gar, Saussureae Radix) were found 14 increase the production of inositol phosphates. All the active fraction from the four kinds of extract were fluted in a different retention time on C-18 HPLC and these active fraction also showed difference in cell specificity. And all the active fractions increased DNA synthesis in T cell. Therefore, it is suggested that the active fraction among 4 extracts might contain a compound having different properties one another.

• International Journal of Stem Cells
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• v.17 no.2
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• pp.204-211
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• 2024

With recent advances in adeno-associated virus (AAV)-based gene therapy, efficacy and toxicity screening have become essential for developing gene therapeutic drugs for retinal diseases. Retinal organoids from human pluripotent stem cells (hPSCs) offer a more accessible and reproducible human test platform for evaluating AAV-based gene therapy. In this study, hPSCs were differentiated into retinal organoids composed of various types of retinal cells. The transduction efficiencies of AAV2 and AAV8, which are widely used in clinical trials of inherited retinal diseases, were analyzed using retinal organoids. These results suggest that retinal organoids derived from hPSCs serve as suitable screening platforms owing to their diverse retinal cell types and similarity to the human retina. In summary, we propose an optimal stepwise protocol that includes the generation of retinal organoids and analysis of AAV transduction efficacy, providing a comprehensive approach for evaluating AAV-based gene therapy for retinal diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4533-4537
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• 2013

Objective: To use microarray chip technology for screening of stem cell radiation related miRNAs in laryngeal squamous cell carcinoma; study and explore the relationship of miRNAs with radiosensitivity of laryngeal squamous cells. Method: After conventional culture and amplification of the laryngeal squamous carcinoma cell line Hep-2, CD 133+ cells were screened out with combination of isolated culture of stem cell microspheres and FACS for preparation of laryngeal cancer stem cells. After radiation treatment, miRNAs of laryngeal squamous carcinoma stem cells before and after radiation were enriched and purified. After microarray hybridization with mammalian miRNA and scanning of fluorescence signal, the miRNAs of laryngeal squamous carcinoma stem cells before and after radiation was subject to differential screening and clustering analysis. Real-time quantitative RT-PCR was used to verify part of the differentially expressed miRNAs. Results: 70 miRNAs related to laryngeal cancer stem cell radiation with 2-fold difference in expression were screened out, in which 62 were down-regulated and 8 were up-regulated. Fluorescent quantitative RT-PCR results were consistent with miRNAs chip results. Conclusion: Some miRNAs may be involved in self-regulation with laryngeal squamous carcinoma stem cell radiation.

• Journal of Microbiology and Biotechnology
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• v.5 no.5
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• pp.264-268
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• 1995

Sulforhodamine B(SRB) assay was performed on the human lung carcinoma, A549 cell line to screen soil microorganisms for production of anti-cancer agent. Among 4, 265 microorganisms, 45 isolates were selected for their cytotoxicity and tested for their effects on the expression of c-myc by RNA slot blot and Northern blot analysis resulting in selection of No.2303 isolate. This No.2303 was identified as Streptomyces sp. by ISP classification and the chemotaxonomic analysis method. NO.2303 inhibited the expression of cmyc in Col0320 DM and A549 cell lines. The culture extract of No. 2303 also inhibited the progression of the cell cycle of Go in NIH 313 cells, implying that the extract also inhibited the expression of c-myc in NIH 313 cell.

• Animal cells and systems
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• v.6 no.2
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• pp.181-181
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• 2002

Nek2 is a mammalian protein kinase that is structurally homologous to NIMA, a mitotic regulator in Aspergillus nidulans. We recently observed that the Nek2 protein was localized in multiple sites within a cell in a cell cycle state-specific manner. This suggests that Ndk2 is involved in diverse cellular functions during the cell cycle progression. To have a better understanding on cellular functions in which Nek2 participates, we carried out yeast two-hybrid screening and isolated six candidate clones whose products interact with Nek2. Most of Nek2-interacting proteins (NIPs) appear cytoplasmic, suggesting that Nek2 is involved in cellular functions in cytoplasm. Further experiments are under progress to confirm their interactions with Nek2 and to understand their biological significance.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1162-1168
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• 2007

Although widely used as a host for recombinant protein production, Escherichia coli is unsuitable for massive screening of recombinant clones, owing to its poor secretion of proteins. A vector system containing T4 holin and T7 lysozyme genes under the control of the ptsG promoter derivative that is inducible in the absence of glucose was developed for programmed cell lysis of E. coli. Because E. coli harboring the vector grows well in the presence of glucose, but is lysed upon glucose exhaustion, the activity of the foreign gene expressed in E. coli can be monitored easily without an additional step for cell disruption after the foreign gene is expressed sufficiently with an appropriate concentration of glucose. The effectiveness of the vector was demonstrated by efficient screening of the amylase gene from a Bacillus subtilis genomic library. This vector system is expected to provide a more efficient and economic screening of bioactive products from DNA libraries in large quantities.

• Korean Journal of Plant Resources
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• v.6 no.1
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• pp.25-32
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• 1993

Many plants, which collected from Korea, were applied to antitumor and cytotoxic screeing tests against sarcom 180 a ascitec in mice, V-79 KB and P388 cultured cells. The results are summarixed as follows:1) The total packed cell volum method has been used for the antineoplastic screening for from natural higher plants in Korea. By this method, we have found out that the root, leaf and stem of Tripterygiu, regelii Spragne & Taketa having strong antineoplastic activity and also Rumex Japonicus Houtt. Eragrositis ferru-ginea Beauv. and Patrinia scabio-saefolia Fischer showed significant activity to anticancer tumor while cynanchum wilfordii Hemsley, and Rosa polyantha Sieb. et Zacc. showed slight activity to antitumor. 2) Among the 13 tested plants, the root and stem of Tripterygium regelii Spragne & Taketa and Amethystanthus excisus Nakai showed strong antitumor activity by the V79 cytotoxic cell screening test. 3) Twelve plants, which are glowing in mountainous area of Korea tested to anticancer activity. From the results, Eragrositis ferru-ginea Beauv., Angelica gigas Nakai, Geranium sibiricum L., Patrinia scabio-saefolia Fisher, Cynanchum wilfordii Hemsley, and Rubia akane Nakai have been proved to be anti-cancer plants by using P388 cell cultured method. 4) Tripterygiu, resgelii Spragne & Taketa, Eragrositis ferru-ginea Beauv., Patrinia scabio-saefoli Fisher, Cynanchum wilfordii Hemsley and Rasa polyantha Sieb. et Zacc., var. genuina Thunb. showed strong anti-tumor activity both total packed cell volume method and Cytotoxicity method.

• Journal of Genetic Medicine
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• v.12 no.2
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• pp.66-71
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• 2015

Down syndrome screening with cell-free DNA (cfDNA) in the maternal plasma has recently received much attention in the prenatal diagnostic field. Indeed, a large amount of evidence has already accumulated to show that screening tests with cfDNA are more sensitive and specific than conventional maternal serum and/or ultrasound screening. Globally, more than 1,000,000 of these noninvasive prenatal tests (NIPTs) have been performed to date. There are several different methods for NIPTs that are currently commercially available, including shotgun massively parallel sequencing, targeted massively parallel sequencing, and single nucleotide polymorphism (SNP)-based methods. All of these methods have their own advantages and disadvantages. In this review, I will focus specifically on the SNP-based NIPT.