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Mitotic catastrophe is the predominant response to histone acetyltransferase depletion
Ha, G-H,Kim, H-S,Lee, C G,Park, H-Y,Kim, E-J,Shin, H-J,Lee, J-C,Lee, K-W,Lee, C-W Macmillan Publishers Limited 2009 Cell death and differentiation Vol.16 No.3
Histone acetylation induces chromatin opening by perturbing higher-order chromatin compaction and folding, suggesting that histone acetylation and deacetylation dynamics are central to chromosome condensation or decondensation. The condensation of chromosomes during mitosis is an essential prerequisite for successful chromosome segregation. In this study, we depleted three representative histone acetyltransferases (HATs; p300, CBP, and P/CAF) using shRNAs to explore their role in regulating mitotic progression and chromosome segregation. We showed that HAT depletion severely interfered with the normal timing of mitotic progression, and it reduced condensin subunit levels. The predominant response to HAT depletion, in both human primary and cancer cells, was a mitotic catastrophe following aberrant mitotic arrest. Alternatively, adaptation to HAT depletion, particularly in cancer cells, led to multinucleation and aneuploidy. Interestingly, mitotic catastrophe induced by HAT depletion appeared to be coupled to the signaling process of H2AX phosphorylation and foci formation, independently of DNA double-strand breaks and DNA damage. Taken together, our results provide novel molecular evidence that HAT proteins maintain mitotic chromatin assembly and integrity as a cellular determinant of mitotic cell death.Cell Death and Differentiation (2009) 16, 483–497; doi:10.1038/cdd.2008.182; published online 19 December 2008
Ha, G.-H.,Kim, D.-Y.,Breuer, E.-K.,Kim, C. K. INTERNATIONAL INSTITUTE OF ANTICANCER RESEARCH 2018 Anticancer research Vol.38 No.3
<P>Background/Aim: Breast cancer is the most common malignant cancer type in women, and triple-negative breast cancer (TNBC) is an extremely aggressive subtype of breast cancer with poor prognosis rates. The present study investigated the antitumor effect of polo-like kinase 1 (PLK1) inhibitor in combination with the tankyrase-1 (TNKS1) inhibitor on TNBC cells. Materials and Methods: We evaluated the antitumor effects of combination therapy with PLK1 and TNKS1 inhibitor using cell viability analysis, apoptosis assay and transwell assay for cell invasion and migration in TNBC cells. Results: Combination treatment with PLK1 and TNKS1 inhibitors not only inhibited the invasion and migration capacity of TNBC cells, but also increased the apoptosis and cell death of TNBC cells. The viability of TNBC cells with low expression of beta-catenin and high expression of PLK1 was not affected by treatment with PLK1 inhibitor. However, the combination treatment with the TNKS1 inhibitor significantly decreased cell invasion and migration and increased apoptosis. Conclusion: Combination therapy of PLK1 and TNKS1 inhibitors may improve the therapeutic efficacy of the current treatment for TNBC.</P>
Ha, G-H,Kim, H-S,Go, H,Lee, H,Seimiya, H,Chung, D H,Lee, C-W Macmillan Publishers Limited 2012 CELL DEATH AND DIFFERENTIATION Vol.19 No.2
Telomere length is critical for chromosome stability that affects cell proliferation and survival. Telomere elongation by telomerase is inhibited by the telomeric protein, TRF1. Tankyrase-1 (TNKS1) poly(ADP-ribosyl)ates TRF1 and releases TRF1 from telomeres, thereby allowing access of telomerase to the telomeres. TNKS1-mediated poly(ADP-ribosyl)ation also appears to be crucial for regulating the mitotic cell cycle. In searching for proteins that interact with polo-like kinase-1 (Plk1) by using complex proteomics, we identified TNKS1 as a novel Plk1-binding protein. Here, we report that Plk1 forms a complex with TNKS1 in vitro and in vivo, and phosphorylates TNKS1. Phosphorylation of TNKS1 by Plk1 appears to increase TNKS1 stability and telomeric poly(ADP-ribose) polymerase (PARP) activity. By contrast, targeted inhibition of Plk1 or mutation of phosphorylation sites decreased the stability and PARP activity of TNKS1, leading to distort mitotic spindle-pole assembly and telomeric ends. Taken together, our results provide evidence of a novel molecular mechanism in which phosphorylation of TNKS1 by Plk1 may help regulate mitotic spindle assembly and promote telomeric chromatin maintenance.
Design of a High Performance Patch Antenna for GPS Communication Systems
Hamedi-Hagh, Sotoudeh,Chung, Joseph,Oh, Soo-Seok,Jo, Ju-Ung,Park, Noh-Joon,Park, Dae-Hee The Korean Institute of Electrical Engineers 2009 Journal of Electrical Engineering & Technology Vol.4 No.2
This paper presents the design of a patch antenna for GPS portable devices. The antenna is designed to operate at Ll band on an FR4 PCB with a thickness of 1.6mm, a dielectric constant of 3.8 and two metallization layers. The antenna has a dimension of 49mm${\times}$36mm and operates at 1.5754GHz with a return loss of -36dB and a measured bandwidth of 250MHz.
Hamidreza Hagh Ranjbar,Afrouzossadat Hosseini Abari,Seyed Mahdi Ghasemi,Najmeh Ghorbani 한국생물공학회 2022 Biotechnology and Bioprocess Engineering Vol.27 No.4
Epsilon-Poly-L-lysine (ε-PL) is a non-toxic cationic homopolypeptide with unique bioactive properties. In this study, two novel polylysine producers, Paenibacillus polymyxa HS6 and Stenotrophomonas maltophilia YS8 were isolated from different soil samples and identified by 16S rDNA sequence analysis. To obtain pure cationic polypeptide from these bacteria, chemical precipitation with sodium tetraphenylborate was used. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, High-performance liquid chromatography, and Fourier-transform infrared spectroscopy confirmed the purified cationic compound to be polylysine. The antioxidant activity of ε-PL was determined by the 2,2-diphenyl-1-picryl-hydrazyl-hydrate method. Moreover, the anticancer and cytotoxic effects were evaluated against MCF-7, HT-29, and L929 cells by thiazolyl blue tetrazolium bromide and flow cytometry. The maximum yields of 1.8 and 0.39 g/L polylysine were obtained by P. polymyxa HS6 and S. maltophilia YS8, respectively. The results showed that radical scavenging activity of polylysine at a minimum concentration (0.18 mg/mL) was at least 7% which increased to 90% at 8 mg/mL. Furthermore, the highest anticancer activity was observed against the MCF-7 cells (99.5%) at 0.5 mg/mL concentration, while almost no toxicity was observed towards L929 cells. Based on the results obtained in this study, it is suggested that the polylysine produced by P. polymyxa HS6 and S. maltophilia YS8 is a potential bioactive compound with significant anticancer and antioxidant properties.
Design of Next Generation Amplifiers Using Nanowire FETs
Hamedi-Hagh, Sotoudeh,Oh, Soo-Seok,Bindal, Ahmet,Park, Dae-Hee The Korean Institute of Electrical Engineers 2008 Journal of Electrical Engineering & Technology Vol.3 No.4
Vertical nanowire SGFETs(Surrounding Gate Field Effect Transistors) provide full gate control over the channel to eliminate short channel effects. This paper presents design and characterization of a differential pair amplifier using NMOS and PMOS SGFETs with a 10nm channel length and a 2nm channel radius. The amplifier dissipates $5{\mu}W$ power and provides 5THz bandwidth with a voltage gain of 16, a linear output voltage swing of 0.5V, and a distortion better than 3% from a 1.8V power supply and a 20aF capacitive load. The 2nd and 3rd order harmonic distortions of the amplifier are -40dBm and -52dBm, respectively, and the 3rd order intermodulation is -24dBm for a two-tone input signal with 10mV amplitude and 10GHz frequency spacing. All these parameters indicate that vertical nanowire surrounding gate transistors are promising candidates for the next generation high speed analog and VLSI technologies.
Design of UHF CMOS Front-ends for Near-field Communications
Hamedi-Hagh, Sotoudeh,Tabesh, Maryam,Oh, Soo-Seok,Park, Noh-Joon,Park, Dae-Hee The Korean Institute of Electrical Engineers 2011 Journal of Electrical Engineering & Technology Vol.6 No.6
This paper introduces an efficient voltage multiplier circuit for improved voltage gain and power efficiency of radio frequency identification (RFID) tags. The multiplier is fully integratable and takes advantage of both passive and active circuits to reduce the required input power while yielding the desired DC voltage. A six-stage voltage multiplier and an ultralow power voltage regulator are designed in a 0.13 ${\mu}m$ complementary metal-oxide semiconductor process for 2.45 GHz RFID applications. The minimum required input power for a 1.2 V supply voltage in the case of a 50 ${\Omega}$ antenna is -20.45 dBm. The efficiency is 15.95% for a 1 $M{\Omega}$ load. The regulator consumes 129 nW DC power and maintains the reference voltage in a 1.1% range with $V_{dd}$ varying from 0.8 to 2 V. The power supply noise rejection of the regulator is 42 dB near a 2.45 GHz frequency and performs better than -32 dB from 100 Hz to 10 GHz frequencies.
Applications of Nanowire Transistors for Driving Nanowire LEDs
Hamedi-Hagh, Sotoudeh,Park, Dae-Hee The Korean Institute of Electrical and Electronic 2012 Transactions on Electrical and Electronic Material Vol.13 No.2
Operation of liquid crystal displays (LCDs) can be improved by monolithic integration of the pixel transistors with light emitting diodes (LEDs) on a single substrate. Conventional LCDs make use of filters to control the backlighting which reduces the overall efficiency. These LCDs also utilize LEDs in series which impose failure and they require high voltage for operation with a power factor correction. The screen of small hand-held devices can operate from moderate brightness. Therefore, III-V nanowires that are grown along with transistors over Silicon substrates can be utilized. Control of nanowire LEDs with nanowire transistors will significantly lower the cost, increase the efficiency, improve the manufacturing yield and simplify the structure of the small displays that are used in portable devices. The steps to grow nanowires on Silicon substrates are described. The vertical n-type and p-type nanowire transistors with surrounding gate structures are characterized. While biased at 0.5 V, nanowire transistors with minimum radius or channel width have an OFF current which is less than 1pA, an ON current more than 1 ${\mu}A$, a total delay less than 10 ps and a transconductance gain of more than 10 ${\mu}A/V$. The low power and fast switching characteristics of the nanowire transistor make them an ideal choice for the realization of future displays of portable devices with long battery lifetime.