Ceramide Synthase 6 Mediates Triple-Negative Breast Cancer Response to Chemotherapy Through RhoA- and EGFR-Mediated Signaling Pathways

Hui Chen,Bin He,Feng Ke 한국유방암학회 2022 Journal of breast cancer Vol.25 No.6

Purpose: Limited treatment options and lack of treatment sensitivity biomarkers make the clinical management of triple-negative breast cancer (TNBC) challenging. Ceramide synthase 6 (CERS6) generates ceramides, which are key intermediates in sphingolipid biosynthesis and play important roles in cancer progression and resistance. Methods: CERS6 was analyzed to determine its potential as a treatment sensitivity biomarker. CERS6 levels were determined in patients with breast cancer, and the roles and downstream signaling of CERS6 were analyzed using cellular and biochemical assays. Results: Analysis of CERS6 expression in 195 patients with TNBC and their clinical response to chemotherapy revealed that individuals with CERS6 overexpression experienced significantly inferior responses to chemotherapy than those without CERS6 overexpression. Functional analysis demonstrated that although CERS6 overexpression did not affect TNBC cell growth and migration, it conferred chemoresistance. CERS6 inhibition significantly reduced growth, migration, and survival by suppressing the RhoA- and EGFR-mediated signaling pathways. Compared to control cells, CERS6-depleted cells were consistently less viable at different concentrations of chemotherapeutic agents. Conclusion: Our study is the first to demonstrate that CERS6 may serve as a treatment sensitivity biomarker in patients with TNBC in response to chemotherapy. In addition, our findings suggested that CERS6 may be a therapeutic target for TNBC treatment.

Exploring the Chronic Kidney Disease Patient Uses the Network Problem

Hui-Chen Chiu 한국간호과학회 2009 한국간호과학회 학술대회 Vol.2009 No.10

A Secondary Partial Energy Phase Shift Regulation LLC Resonant Converter with Current Sharing Ability

Hui Chen,Shuai Shao,Hao Jiang,Guohai Ren,Pengying Du 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

This paper proposes a current sharing method for interleaved LLC resonant converter with secondary partial energy phase shift regulation. An AC voltage source with phase shift regulation is constructed and in series with main transformer at secondary side to balance the output currents. With secondary regulation ability, the current imbalance caused by the resonant tank tolerance can be compensated. The major part of power is delivered to load by main transformer, and small portion power is converted by the auxiliary parts, therefore, the energy loss of the conversion is almost as high as conventional LLC resonant converter. The steady state operating principle of the proposed converter is analyzed, and a prototype with two phases current sharing ability is built-up based on the theoretical analysis.

Damage evaluation of seismic response of structure through time-frequency analysis technique

Chen, Wen-Hui,Hseuh, Wen,Loh, Kenneth J.,Loh, Chin-Hsiung Techno-Press 2022 Structural monitoring and maintenance Vol.9 No.2

Structural health monitoring (SHM) has been related to damage identification with either operational loads or other environmental loading playing a significant complimentary role in terms of structural safety. In this study, a non-parametric method of time frequency analysis on the measurement is used to address the time-frequency representation for modal parameter estimation and system damage identification of structure. The method employs the wavelet decomposition of dynamic data by using the modified complex Morlet wavelet with variable central frequency (MCMW+VCF). Through detail discussion on the selection of model parameter in wavelet analysis, the method is applied to study the dynamic response of both steel structure and reinforced concrete frame under white noise excitation as well as earthquake excitation from shaking table test. Application of the method to building earthquake response measurement is also examined. It is shown that by using the spectrogram generated from MCMW+VCF method, with suitable selected model parameter, one can clearly identify the time-varying modal frequency of the reinforced concrete structure under earthquake excitation. Discussions on the advantages and disadvantages of the method through field experiments are also presented.

Selective hydrogenation of phenol for cyclohexanone: A review

Hui Chen,Jinsheng Sun 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.94 No.-

Cyclohexanone from phenol attractively meets the requirements of green chemistry, through catalyticselective hydrogenation, the prevalent methodology in rapid progress recently. In this background,pathways under this methodology are reviewed herein, including possible cyclohexanone formationmechanisms proposed in those years, as well as the corresponding catalysts, such as noble metal, nonnoblemetal and emerging amorphous alloy and heteropoly acids. Among the common catalysts, Pdbasedcatalysts exhibit excellent performance in both conversion and selectivity. Usually, the conversionand selectivity reached almost 100% after the opportune treatment of the metal and support. Othercatalysts such as Pt, Rh, Ni, etc., only perform well in conversion rather than selectivity and the product ismainly cyclohexanol. Amorphous alloys and heteropoly acids, although still relatively rare comparedwith traditional metal catalysts, are bright in prospects indicated by achievements in thisfield. Thereaction mechanism on some catalysts, indistinct to the community, is still in the way of development toovercome the letdown of catalyst design for higher conversion and selectivity industrially. Afterhorizontal comparison of different catalysts, this article manages to give some advice on possiblemethods contributing to the design of efficient and inexpensive catalytic systems.

Dose-Dependent Associations between Wine Drinking and Breast Cancer Risk - Meta-Analysis Findings

Chen, Jia-Yan,Zhu, Hong-Cheng,Guo, Qing,Shu, Zheng,Bao, Xu-Hui,Sun, Feng,Qin, Qin,Yang, Xi,Zhang, Chi,Cheng, Hong-Yan,Sun, Xin-Chen Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.3

Purpose: To investigate any potential association between wine and breast cancer risk. Materials and Methods: We quantitatively assessed associations by conducting a meta-analysis based on evidence from observational studies. In May 2014, we performed electronic searches in PubMed, EmBase and the Cochrane Library to identify studies examining the effect of wine drinking on breast cancer incidence. The relative risk (RR) or odds ratio (OR) were used to measure any such association. Results: The analysis was further stratified by confounding factors that could influence the results. A total of twenty-six studies (eight case-control and eighteen cohort studies) involving 21,149 cases were included in our meta-analysis. Our study demonstrated that wine drinking was associated with breast cancer risk. A 36% increase in breast cancer risk was observed across overall studies based on the highest versus lowest model, with a combined RR of 1.0059 (95%CI 0.97-1.05) in dose-response analysis. However, 5 g/d ethanol from wine seemed to have protective value from our non-linear model. Conclusions: Our findings indicate that wine drinking is associated with breast cancer risk in a dose-dependent manner. High consumption of wine contributes to breast cancer risk with protection exerted by low doses. Further investigations are needed for clarification.

Association between ABCB1 Polymorphisms and Antidepressant Treatment Response in Taiwanese Major Depressive Patients

Hui Hua Chang,Chen-Hsi Chou,Yen Kuang Yang,I Hui Lee,Po See Chen 대한정신약물학회 2015 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.13 No.3

Objective: The multidrug resistance 1 (ABCB1, MDR1) gene, encoding P-glycoprotein, is extensively distributed and expressed in various tissues, such as a blood-brain barrier transporter. P-glycoprotein plays an important role in controlling the passage of substances between the blood and brain. The current study aimed to investigate possible associations of functional ABCB1 polymorphisms (C3435T, G2677T and C1236T) with response to antidepressant treatment and serum cortisol levels in Taiwanese patients with major depressive disorder (MDD). Methods: We recruited 112 MDD patients who were randomized to fluoxetine (n=58, mean dose: 21.4±4.5 mg/day) or venlafaxine (n=54, 80.2±34.7 mg/day) treatment for 6 weeks. The 21-item Hamilton Depression Rating Scale (HDRS) was administered initially and biweekly after treatment, and cortisol levels were assessed initially and after 6-week antidepressant treatment. Results: The initial HDRS scores and the HDRS scores after six weeks of antidepressant treatment were not significantly different among the different genotypes in each polymorphism of ABCB1. The percentage changes of HDRS scores over time were significantly different in the polymorphisms of ABCB1 G2677T (p=0.002). MDD patients with the G/G genotype of ABCB1 G2677T had a worse antidepressant treatment response. However, the polymorphisms of ABCB1 genotypes were not significantly associated with cortisol levels before and after antidepressant treatment in MDD patients. Conclusion: The results suggested that the variants of ABCB1 may influence the short-term antidepressant response in MDD patients. Further details of the underlying mechanisms of ABCB1 in antidepressant treatment remain to be clarified.

Graphite-based selectorless RRAM: improvable intrinsic nonlinearity for array applications

Chen, Ying-Chen,Hu, Szu-Tung,Lin, Chih-Yang,Fowler, Burt,Huang, Hui-Chun,Lin, Chao-Cheng,Kim, Sungjun,Chang, Yao-Feng,Lee, Jack C. The Royal Society of Chemistry 2018 Nanoscale Vol.10 No.33

<P>Selectorless graphite-based resistive random-access memory (RRAM) has been demonstrated by utilizing the intrinsic nonlinear resistive switching (RS) characteristics, without an additional selector or transistor for low-power RRAM array application. The low effective dielectric constant value (<I>k</I>) layer of graphite or graphite oxide is utilized, which is beneficial in suppressing sneak-path currents in the crossbar RRAM array. The tail-bits with low nonlinearity can be manipulated by the positive voltage pulse, which in turn can alleviate variability and reliability issues. Our results provide additional insights for built-in nonlinearity in 1<I>R</I>-only selectorless RRAMs, which are applicable to the low-power memory array, ultrahigh density storage, and in-memory neuromorphic computational configurations.</P>

Dioxygen Activation bya Non-Heme Iron(II) Complex: Theoretical Study toward UnderstandingFerric–Superoxo Complexes

Chen, Hui,Cho, Kyung-Bin,Lai, Wenzhen,Nam, Wonwoo,Shaik, Sason American Chemical Society 2012 Journal of chemical theory and computation Vol.8 No.3

<P>We present a systematic study using density functional theory (DFT) and coupled cluster (CCSD(T)) computations with an aim of characterizing a non-heme ferric-superoxo complex [(TMC)Fe(O-2)(2+) (TMC = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) that was proposed to perform allylic C-H activation of cyclohexene (Lee, Y.-M. et al. J. Am. Chem, Soc. 2010, 132, 10668). As such, we investigated a series of iron-O-2 species without and with a sixth ligand bound to the iron ion in different O-2 coordination modes (end-on and side-on) and different spin states. Most of the iron-O-2 complexes were found to be iron(III)-superoxo species, Fe(III)(O-2(-)), with high-spin (S = 5/2) or intermediate-spin (S = 3/2) ferric centers coupled ferromagnetically or antiferromagnetically to the superoxide anion radical. One iron(IV)-peroxo state, Fe(IV)(O-2(2-)), was also examined. The preference for ferromagnetic or antiferromagnetic coupling modes between the superoxo and ferric radicals was found to depend on the FeOO angle, where a side-on tilt favors ferromagnetic coupling whereas the end-on tilt favors antiferromagnetic states. Experimental findings, e.g., the effects of solvent, spin state, and redox potential of non-heme Fe(II) complexes on O-2 activation, were corroborated in this work. Solvent effects were found to disfavor O-2 binding, relative to the unbound ferrous ion and O-2. The potential H-abstraction reactivity of the iron(III)-superoxo species was considered in light of the recently proposed exchange-enhanced reactivity principle (Shaik, S.; Chen, H.; Janardanan, D. Nat. Chem. 2011, 3, 19). It is concluded that localization and/or decoupling of an unpaired electron in the d-block of high-spin Fe(III) center in the S = 2 and 3 ferric-superoxo complexes during H abstractions enhances exchange stabilization and may be the root cause of the observed reactivity of [(TMC)Fe(O-2)](2+).</P>

Melatonin attenuates scopolamine-induced cognitive impairment via protecting against demyelination through BDNF-TrkB signaling in the mouse dentate gyrus

Chen, Bai Hui,Park, Joon Ha,Lee, Tae-Kyeong,Song, Minah,Kim, Hyunjung,Lee, Jae Chul,Kim, Young-Myeong,Lee, Choong-Hyun,Hwang, In Koo,Kang, Il Jun,Yan, Bing Chun,Won, Moo-Ho,Ahn, Ji Hyeon Elsevier 2018 Chemico-biological interactions Vol.285 No.-

<P><B>Abstract</B></P> <P>Animal models of scopolamine-induced amnesia are widely used to study underlying mechanisms and treatment of cognitive impairment in neurodegenerative diseases such as Alzheimer's disease (AD). Previous studies have identified that melatonin improves cognitive dysfunction in animal models. In this study, using a mouse model of scopolamine-induced amnesia, we assessed spatial and short-term memory functions for 4 weeks, investigated the expression of myelin-basic protein (MBP) in the dentate gyrus, and examined whether melatonin and scopolamine cotreatment could keep cognitive function and MBP expression. In addition, to study functions of melatonin for keeping cognitive function and MBP expression, we examined expressions of brain-derived neurotrophic factor (BDNF) and tropomycin receptor kinase B (TrkB) in the mouse dentate gyrus. Scopolamine (1 mg/kg) and melatonin (10 mg/kg) were intraperitoneally treated for 2 and 4 weeks. Two and 4 weeks after scopolamine treatment, mice showed significant cognitive impairment; however, melatonin and scopolamine cotreatment recovered cognitive impairment. Two and 4 weeks of scopolamine treatment, the density of MBP immunoreactive myelinated nerve fibers was significantly decreased in the dentate gyrus; however, scopolamine and melatonin cotreatment significantly increased the scopolamine-induced reduction of MBP expression in the dentate gyrus. Furthermore, the cotreatment of scopolamine and melatonin significantly increased the scopolamine-induced decrease of BDNF and TrKB immunoreactivity in the dentate gyrus. Taken together, our results indicate that melatonin treatment exerts anti-amnesic effect and restores the scopolamine-induced reduction of MBP expression through increasing BDNF and TrkB expressions in the mouse dentate gyrus.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Long-term treatment of scopolamine (Sco) induces cognitive deficits. </LI> <LI> Long-term treatment of melatonin improves Sco-induced cognitive deficits. </LI> <LI> Sco significantly decreases MBP, BDNF, and TrkB in the dentate gyrus. </LI> <LI> Melatonin restores scopolamine-induced decreases in MBP, BDNF, and TrkB. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>