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Huang KW, Hsu KC, Chu LY, Yang JM, Yuan HS, Hsiao YY. Identification of Inhibitors for the DEDDh Family of Exonucleases and a Unique Inhibition Mechanism by Crystal Structure Analysis of CRN-4 Bound with 2-Morpholin-4-ylethanesulfonate (MES). J Med Chem 2016; 59:8019-29. [PMID: 27529560 DOI: 10.1021/acs.jmedchem.6b00794] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The DEDDh family of exonucleases plays essential roles in DNA and RNA metabolism in all kingdoms of life. Several viral and human DEDDh exonucleases can serve as antiviral drug targets due to their critical roles in virus replication. Here using RNase T and CRN-4 as the model systems, we identify potential inhibitors for DEDDh exonucleases. We further show that two of the inhibitors, ATA and PV6R, indeed inhibit the exonuclease activity of the viral protein NP exonuclease of Lassa fever virus in vitro. Moreover, we determine the crystal structure of CRN-4 in complex with MES that reveals a unique inhibition mechanism by inducing the general base His179 to shift out of the active site. Our results not only provide the structural basis for the inhibition mechanism but also suggest potential lead inhibitors for the DEDDh exonucleases that may pave the way for designing nuclease inhibitors for biochemical and biomedical applications.
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Hsiao YY, Huang KW, Hsu KC, Chu LY, Yang JM, Yuan HS. Identification of inhibitors for the DEDDh family of exonucleases and a unique inhibition mechanism revealed by crystal structure analysis of CRN-4 bound with MES. Acta Crystallogr A Found Adv 2016. [DOI: 10.1107/s2053273316096911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Lou L, Zhu J, Lv D, Chen QR, Yang JM, Qin XL. [Modified radical mastoidectomy on"drum sinus" type chronic suppurative otitis media:our experience]. LIN CHUANG ER BI YAN HOU TOU JING WAI KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY, HEAD, AND NECK SURGERY 2016; 30:1068-1071. [PMID: 29798041 DOI: 10.13201/j.issn.1001-1781.2016.13.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Indexed: 02/05/2023]
Abstract
Objective:To our experience of modified radical mastoidectomy on "drum sinus" type chronic suppurative otitis media.Method:We measured the size of tympanic sinus,the extent of meningeal plate lowering and the extent of sigmoid ante-displacement in 54 patients of chronic suppurative otitis media,and determined the criterion of "drum sinus".The patients who comply with the criterion received modified radical mastoidectomy and tympanoplasty via epitympanum approach.The patients were followed up for at least 3 months,The time of dry ear,growth of repaired tympanic membrane,and any complications such as dizziness,facial paralysis,cerebrospinal fluid leakage were recorded.Result:Twenty-nine out of the 54 CSOM patients complied with the criterion of drum sinus.Two cases were lost to follow-up.Therefore,27 cases were included in the study.Three months after the operation,the rate of dry ear was 81.5% Tympanic membrane was successfully repaired in 77.8% of the patients.Three cases had dizziness after operation.No facial paralysis or cerebrospinal fluid leakage was observed.Conclusion:For"drum sinus" type chronic suppurative otitis media,the modified radical mastoidectomy and tympanoplasty via epitympanum approach can be taken.
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Lee JC, Lai WS, Ju DT, Chu YH, Yang JM. Diode laser assisted minimal invasive sphenoidotomy for endoscopic transphenoidal pituitary surgery: our technique and results. Lasers Surg Med 2016; 47:239-42. [PMID: 25810080 DOI: 10.1002/lsm.22340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/30/2014] [Indexed: 11/10/2022]
Abstract
BACKGROUND AND OBJECTIVE During endoscopic sinus surgery (ESS), intra-operative bleeding can significantly compromise visualization of the surgical field. The diode laser that provides good hemostatic and vaporization effects and excellent photocoagulation has been successfully applied in endoscopic surgery with several advantages. The current retrospective study demonstrates the feasibility of diode laser-combined endoscopic sinus surgery on sphenoidotomy. STUDY DESIGN/MATERIALS AND METHODS The patients who went through endoscopic transphenoidal pituitary surgery were enrolled. During the operation, the quality of the surgical field was assessed and graded by the operating surgeon using the scale proposed by Boezaart. RESULTS The mean operation time was 37.80 ± 10.90 minutes. The mean score on the quality of surgical field was 1.95. A positive correlation between the lower surgical field quality score and the shorter surgical time was found with statistical significance (P < 0.0001). No infections, hemorrhages, or other complications occurred intra- or post-operatively. CONCLUSION The diode laser-assisted sphenoidotomy is a reliable and safe approach of pituitary gland surgery with minimal invasiveness. It is found that application of diode laser significantly improved quality of surgical field and shortened operation time.
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Yang JM, Sun GH, Zheng XD, Ren LH, Wang WJ, Li GR, Sun BC. Genetic differentiation of Octopus minor (Mollusca, Cephalopoda) off the northern coast of China as revealed by amplified fragment length polymorphisms. GENETICS AND MOLECULAR RESEARCH 2015; 14:15616-23. [PMID: 26634529 DOI: 10.4238/2015.december.1.13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Octopus minor (Sasaki, 1920) is an economically important cephalopod that is found in the northern coastal waters of China. In this study, we investigated genetic differentiation in fishery populations using amplified fragment length polymorphisms (AFLPs). A total of 150 individuals were collected from five locations: Dalian (DL), Yan-tai (YT), Qingdao (QD), Lianyungang (LY), and Zhoushan (ZS), and 243 reproducible bands were amplified using five AFLP primer combinations. The percentage of polymorphic bands ranged from 53.33 to 76.08%. Nei's genetic identity ranged from 0.9139 to 0.9713, and the genetic distance ranged from 0.0291 to 0.0900. A phylogenetic tree was constructed using the unweighted pair group method with arithmetic mean, based on the genetic distance. The DL and YT populations originated from one clade, while the QD, LY, and ZS populations originated from another. The results indicate that the O. minor stock consisted of two genetic populations with an overall significantly analogous FST value (0.1088, P < 0.05). Most of the variance was within populations. These findings will be important for more sustainable octopus fisheries, so that this marine resource can be conserved for its long-term utilization.
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Lin ZX, Che CT, Lee SS, Chan RCY, Ip PSP, Yang JM. Sophora flavescens (Ku-Shen) as a booster for antiretroviral therapy through cytochrome P450 3A4 inhibition. Hong Kong Med J 2015; 21 Suppl 7:S18-S21. [PMID: 26908268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023] Open
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Lee WH, Yoo JH, Yang JM, Park JK. Effect of the Film-Growth Defects on the Magnetic Microstructure of Epitaxial FePt Thin Film. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2015; 15:8688-8692. [PMID: 26726576 DOI: 10.1166/jnn.2015.11498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Effect of the columnar grain boundaries on the perpendicular magnetic domain structure of epitaxial L10 FePt (001) thin film has been studied using electron holography. The analysis of stray fields shows that both the continuous and columnar epitaxial films of L10 FePt (001) consist of perpendicular magnetic domain walls. In the columnar epitaxial film, however, the perpendicular domain walls tend to be confined to columnar grain boundaries, because columnar boundaries act as pinning sites for the domain walls. The domain wall pinning by columnar grain boundaries leads to a significant hysteresis effect in the perpendicular magnetization of L10 FePt epitaxial films.
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Hsu KC, Sung TY, Lin CT, Chiu YY, Hsu JTA, Hung HC, Sun CM, Barve I, Chen WL, Huang WC, Huang CT, Chen CH, Yang JM. Anchor-based classification and type-C inhibitors for tyrosine kinases. Sci Rep 2015; 5:10938. [PMID: 26077136 PMCID: PMC4468516 DOI: 10.1038/srep10938] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/08/2015] [Indexed: 12/13/2022] Open
Abstract
Tyrosine kinases regulate various biological processes and are drug targets for cancers. At present, the design of selective and anti-resistant inhibitors of kinases is an emergent task. Here, we inferred specific site-moiety maps containing two specific anchors to uncover a new binding pocket in the C-terminal hinge region by docking 4,680 kinase inhibitors into 51 protein kinases, and this finding provides an opportunity for the development of kinase inhibitors with high selectivity and anti-drug resistance. We present an anchor-based classification for tyrosine kinases and discover two type-C inhibitors, namely rosmarinic acid (RA) and EGCG, which occupy two and one specific anchors, respectively, by screening 118,759 natural compounds. Our profiling reveals that RA and EGCG selectively inhibit 3% (EGFR and SYK) and 14% of 64 kinases, respectively. According to the guide of our anchor model, we synthesized three RA derivatives with better potency. These type-C inhibitors are able to maintain activities for drug-resistant EGFR and decrease the invasion ability of breast cancer cells. Our results show that the type-C inhibitors occupying a new pocket are promising for cancer treatments due to their kinase selectivity and anti-drug resistance.
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Lee GC, Lin CH, Tao YC, Yang JM, Hsu KC, Huang YJ, Huang SH, Kung PJ, Chen WL, Wang CM, Wu YR, Chen CM, Lin JY, Hsieh-Li HM, Lee-Chen GJ. The potential of lactulose and melibiose, two novel trehalase-indigestible and autophagy-inducing disaccharides, for polyQ-mediated neurodegenerative disease treatment. Neurotoxicology 2015; 48:120-30. [PMID: 25800379 DOI: 10.1016/j.neuro.2015.03.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 03/07/2015] [Accepted: 03/12/2015] [Indexed: 12/20/2022]
Abstract
The unique property of trehalose encourages its pharmaceutical application in aggregation-mediated neurodegenerative disorders, including Alzheimer's, Parkinson's, and many polyglutamine (polyQ)-mediated diseases. However, trehalose is digested into glucose by trehalase and which reduced its efficacy in the disease target tissues. Therefore, searching trehalase-indigestible analogs of trehalose is a potential strategy to enhance therapeutic effect. In this study, two trehalase-indigestible trehalose analogs, lactulose and melibiose, were selected through compound topology and functional group analyses. Hydrogen-bonding network analyses suggest that the elimination of the hydrogen bond between the linker ether and aspartate 321 (D321) of human trehalase is the key for lactulose and melibiose to avoid the hydrolyzation. Using polyQ-mediated spinocerebellar ataxia type 17 (SCA17) cell and slice cultures, we found the aggregation was significantly prohibited by trehalose, lactulose, and melibiose, which may through up-regulating of autophagy. These findings suggest the therapeutic applications of trehalase-indigestible trehalose analogs in aggregation-associated neurodegenerative diseases.
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Tsai WC, Yang JM, Liu SC, Chu YH, Lai WS, Lin YS, Lee JC. Management of different kinds of head and neck defects with the submental flap for reconstruction. Eur Arch Otorhinolaryngol 2014; 272:3815-9. [PMID: 25542248 DOI: 10.1007/s00405-014-3461-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 12/16/2014] [Indexed: 12/01/2022]
Abstract
Head and neck surgeries often accompany with moderate-sized defects that require time-consuming reconstructions by free flaps. The submental flap is a versatile and time-effective option for reconstruction of orofacial defects providing acceptable cosmetic and functional results without requiring microsurgical techniques. A retrospective case series study of patients who underwent reconstruction with the submental flap between 2009 and 2013 was conducted. There were 36 patients (33 men and 3 women), with a mean age of 56.4 years, enrolled in this study. The primary lesion sites included oral cavity (24 patients), pharynx (8 patients), larynx (2 patients), neck (1 patient) as well as maxillary sinus (1 patient). All flaps were harvested as the myocutaneous flaps. All donor sites were closed primarily without the need of additional surgery. No complete loss of the flap was encountered and two cases developed marginal necrosis of the flap. The submental flap had a reliable pedicle and had minimal donor-site morbidity. It is an excellent flap option for patients with small- to medium-sized defects in head and neck region.
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Chiu YY, Tseng JH, Liu KH, Lin CT, Hsu KC, Yang JM. Homopharma: a new concept for exploring the molecular binding mechanisms and drug repurposing. BMC Genomics 2014; 15 Suppl 9:S8. [PMID: 25521038 PMCID: PMC4290623 DOI: 10.1186/1471-2164-15-s9-s8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Background Drugs that simultaneously target multiple proteins often improve efficacy, particularly in the treatment of complex diseases such as cancers and central nervous system disorders. Many approaches have been proposed to identify the potential targets of a drug. Recently, we have introduced Space-Related Pharmamotif (SRPmotif) method to recognize the proteins that share similar binding environments. In addition, compounds with similar topology may bind to similar proteins and have similar protein-compound interactions. However, few studies have focused on exploring the relationships between binding environments and protein-compound interactions, which is important for understanding molecular binding mechanisms and helpful to be used in discovering drug repurposing. Results In this study, we propose a new concept of "Homopharma", combining similar binding environments and protein-compound interaction profiles, to explore the molecular binding mechanisms and drug repurposing. A Homopharma consists of a set of proteins which have the conserved binding environment and a set of compounds that share similar structures and functional groups. These proteins and compounds present conserved interactions and similar physicochemical properties. Therefore, these compounds are often able to inhibit the proteins in a Homopharma. Our experimental results show that the proteins and compounds in a Homopharma often have similar protein-compound interactions, comprising conserved specific residues and functional sites. Based on the Homopharma concept, we selected four flavonoid derivatives and 32 human protein kinases for enzymatic profiling. Among these 128 bioassays, the IC50 of 56 and 25 flavonoid-kinase inhibitions are less than 10 μM and 1 μM, respectively. Furthermore, these experimental results suggest that these flavonoids can be used as anticancer compounds, such as oral and colorectal cancer drugs. Conclusions The experimental results show that the Homopharma is useful for identifying key binding environments of proteins and compounds and discovering new inhibitory effects. We believe that the Homopharma concept can have the potential for understanding molecular binding mechanisms and providing new clues for drug development.
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Ma N, Lai CS, Chung CH, Yang JM, Hsu KC, Chen CY, Chung TS, Li S, Ho CT, Pan MH. 5-Demethyltangeretin is more potent than tangeretin in inhibiting dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin tumorigenesis. J Funct Foods 2014. [DOI: 10.1016/j.jff.2014.08.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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Lee CC, Maestre-Reyna M, Hsu KC, Wang HC, Liu CI, Jeng WY, Lin LL, Wood R, Chou CC, Yang JM, Wang AHJ. Crowning proteins: modulating the protein surface properties using crown ethers. Angew Chem Int Ed Engl 2014; 53:13054-8. [PMID: 25287606 PMCID: PMC4288931 DOI: 10.1002/anie.201405664] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 07/16/2014] [Indexed: 11/18/2022]
Abstract
Crown ethers are small, cyclic polyethers that have found wide-spread use in phase-transfer catalysis and, to a certain degree, in protein chemistry. Crown ethers readily bind metallic and organic cations, including positively charged amino acid side chains. We elucidated the crystal structures of several protein-crown ether co-crystals grown in the presence of 18-crown-6. We then employed biophysical methods and molecular dynamics simulations to compare these complexes with the corresponding apoproteins and with similar complexes with ring-shaped low-molecular-weight polyethylene glycols. Our studies show that crown ethers can modify protein surface behavior dramatically by stabilizing either intra- or intermolecular interactions. Consequently, we propose that crown ethers can be used to modulate a wide variety of protein surface behaviors, such as oligomerization, domain–domain interactions, stabilization in organic solvents, and crystallization.
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Lee CC, Maestre-Reyna M, Hsu KC, Wang HC, Liu CI, Jeng WY, Lin LL, Wood R, Chou CC, Yang JM, Wang AHJ. Crowning Proteins: Modulating the Protein Surface Properties using Crown Ethers. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201405664] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Yang JM, Rui BB, Chen C, Chen H, Xu TJ, Xu WP, Wei W. Acetylsalicylic acid enhances the anti-inflammatory effect of fluoxetine through inhibition of NF-κB, p38-MAPK and ERK1/2 activation in lipopolysaccharide-induced BV-2 microglia cells. Neuroscience 2014; 275:296-304. [PMID: 24952332 DOI: 10.1016/j.neuroscience.2014.06.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 06/09/2014] [Accepted: 06/10/2014] [Indexed: 01/08/2023]
Abstract
The latest advancements in neurobiological research provide increasing evidence that inflammatory and neurodegenerative pathways play an important role in depression. According to the cytokine hypothesis, depression could be due to the increased production of pro-inflammatory cytokines by microglia activation. Thus, using the BV-2 microglial cell line, the aim of the present study was to investigate whether fluoxetine (FLX) or acetylsalicylic acid (ASA) could inhibit this microglia activation and could achieve better results in combination. Our results showed that FLX could attenuate lipopolysaccharide (LPS)-induced production of interleukin-1β (IL-1β), the expression of the indoleamine 2,3 dioxygenase (IDO) enzyme and the depletion of 5-HT. Moreover, FLX could inhibit phosphorylation of nuclear factor-κB (NF-κB) and phosphorylation of p38 mitogen-activated protein kinase (MAPK), and the combined use with ASA could enhance these effects. Notably, the adjunctive agent ASA could also inhibit phosphorylation of extracellular-regulated kinase 1/2 (ERK1/2). Taken together, our results suggest that FLX may have some anti-inflammatory effects by modulating microglia activation and that ASA served as an effective adjunctive agent by enhancing these therapeutic effects.
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Seo AN, Yang JM, Kim H, Jheon S, Kim K, Lee CT, Jin Y, Yun S, Chung JH, Paik JH. Clinicopathologic and prognostic significance of c-MYC copy number gain in lung adenocarcinomas. Br J Cancer 2014; 110:2688-99. [PMID: 24809777 PMCID: PMC4037828 DOI: 10.1038/bjc.2014.218] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 03/26/2014] [Accepted: 04/01/2014] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND c-MYC copy number gain (c-MYC gain) has been associated with aggressive behaviour in several cancers. However, the role of c-MYC gain has not yet been determined in lung adenocarcinomas classified by genetic alterations in epidermal growth factor receptor (EGFR), KRAS, and anaplastic lymphoma kinase (ALK) genes. We investigated the clinicopathologic and prognostic significance of c-MYC gain for disease-free survival (DFS) and overall survival (OS) according to EGFR, KRAS, and ALK gene status and stages in lung adenocarcinomas. METHODS In 255 adenocarcinomas resected in Seoul National University Bundang Hospital from 2003 to 2009, fluorescence in situ hybridisation (FISH) with c-MYC probe and centromeric enumeration probe 8 (CEP8) was analysed using tissue microarray containing single representative core per each case. EGFR (codon 18 to 21) and KRAS (codon 12, 13, and 61) mutations were analysed by polymerase chain reaction and direct sequencing method from formalin-fixed, paraffin-embedded tissue sections. ALK rearrangement was determined by FISH method. c-MYC gain was defined as >2 copies per nucleus, chromosome 8 gain as ⩾3 copies per nucleus, and gain of c-MYC:CEP8 ratio (hereafter, c-MYC amplification) as ⩾2. RESULTS We observed c-MYC gain in 20% (51 out of 255), chromosome 8 gain in 5.5% (14 out of 255), c-MYC amplification in 2.4% (6 out of 255), EGFR mutation in 49.4% (118 out of 239), KRAS mutation in 5.7% (7 out of 123), and ALK rearrangement in 4.9% (10 out of 205) of lung adenocarcinomas. c-MYC gain was observed in 19% (22 out of 118) of patients with lung adenocarcinomas with an EGFR mutation, but not in any patients with a KRAS mutation, or an ALK rearrangement. c-MYC gain (but not chromosome 8 gain or c-MYC amplification) was an independent poor-prognostic factor in the full cohort of lung adenocarcinoma (P=0.022, hazard ratio (HR)=1.71, 95% confidence interval (CI), 1.08-2.69 for DFS; P=0.032, HR=2.04, 95% CI, 1.06-3.91 for OS), as well as in stage I subgroup (P=0.023, HR=4.70, 95% CI, 1.24-17.78 for DFS; P=0.031, HR=4.65, 95% CI, 1.15-18.81 for OS), and in EGFR-mutant subgroup (P=0.022; HR=2.14; 95% CI, 1.11-4.10 for DFS). CONCLUSIONS c-MYC gain (but not chromosome 8 gain or c-MYC amplification) was an independent poor-prognostic factor for DFS and OS in lung adenocarcinomas, both in full cohort and stage I cancer, and possibly for DFS in EGFR-mutant adenocarcinomas. Additional studies are required to determine if patients with lung adenocarcinoma with c-MYC gain are candidates for additional first-line treatment to mitigate their increased risk for disease progression and death.
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Wang HC, Ho CH, Hsu KC, Yang JM, Wang AHJ. DNA mimic proteins: functions, structures, and bioinformatic analysis. Biochemistry 2014; 53:2865-74. [PMID: 24766129 DOI: 10.1021/bi5002689] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
DNA mimic proteins have DNA-like negative surface charge distributions, and they function by occupying the DNA binding sites of DNA binding proteins to prevent these sites from being accessed by DNA. DNA mimic proteins control the activities of a variety of DNA binding proteins and are involved in a wide range of cellular mechanisms such as chromatin assembly, DNA repair, transcription regulation, and gene recombination. However, the sequences and structures of DNA mimic proteins are diverse, making them difficult to predict by bioinformatic search. To date, only a few DNA mimic proteins have been reported. These DNA mimics were not found by searching for functional motifs in their sequences but were revealed only by structural analysis of their charge distribution. This review highlights the biological roles and structures of 16 reported DNA mimic proteins. We also discuss approaches that might be used to discover new DNA mimic proteins.
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Lou GC, Yang JM, Ke JJ, Wu WQ, Zhou B. Acute pancreatitis induced by placement of a duodenal stent. Endoscopy 2014; 45 Suppl 2 UCTN:E256-7. [PMID: 24008453 DOI: 10.1055/s-0033-1344423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
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94
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Lin CH, Chang TC, Das A, Fang MY, Hung HC, Hsu KC, Yang JM, von Itzstein M, Mong KKT, Hsu TA, Lin CC. Synthesis of acylguanidine zanamivir derivatives as neuraminidase inhibitors and the evaluation of their bio-activities. Org Biomol Chem 2014; 11:3943-8. [PMID: 23695381 DOI: 10.1039/c3ob40624e] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of acylguanidine-modified zanamivir analogs were synthesized and their inhibitory activities against the NAs of avian influenza viruses (H1N1 and H3N2) were evaluated. In particular, zanamivir derivative , with a hydrophobic naphthalene substituent, exhibits the best inhibitory activity against group-1 NA with an IC50 of 20 nM.
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Kim NY, Kang CI, Hur GH, Yang JM, Shin S. Bacillus anthracis lethal toxin induces cell-type-specific cytotoxicity in human lung cell lines. J Appl Microbiol 2014; 116:1334-43. [PMID: 24471528 DOI: 10.1111/jam.12457] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 01/13/2014] [Accepted: 01/23/2014] [Indexed: 12/20/2022]
Abstract
AIMS Inhalational anthrax is caused by the entry of Bacillus anthracis spores into the lung. Inhaled spores are phagocytosed by alveolar macrophages. Bacilli then escape from the macrophage and spread to other cells, initiating a systemic anthrax infection. Based on the pathological studies of primate and human inhalational anthrax cases, it appears that lung tissue injury is a lethal consequence of the disease. Although the cytotoxicity of anthrax lethal toxin to macrophages is well known, it is not clear how anthrax toxin affects the various lung cell types. METHODS AND RESULTS Using model cell lines representing different physiological compartments of the lung, we have investigated the cytotoxic effects of anthrax lethal toxin. The cell response was evaluated through MTT metabolism, neutral red uptake, initiation of apoptosis, and expression and binding activity of anthrax toxin receptors. We found that a human small airway epithelial cell line, HSAEC, was susceptible to anthrax lethal toxin. The other cell lines, A549, MRC-5, H358 and SKLU-1, displayed resistance to anthrax lethal toxin-mediated toxicity, although the expression of anthrax toxin receptors was detected in all the cell lines tested. CONCLUSIONS Our results indicate that cell-type-specific toxicity may be induced by anthrax lethal toxin in human lung tissues and does not correlate with anthrax toxin receptor expression levels. SIGNIFICANCE AND IMPACT OF THE STUDY This work suggests that cell-type-specific cytotoxicity of anthrax toxin in lung cells may cause subsequent lung disease progression. It may explain the initial pathogenic step of inhalational anthrax.
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Liu IH, Lo YS, Yang JM. Template-based scoring functions for visualising biological insights of H-2Kb-peptide-TCR complexes. INT J DATA MIN BIOIN 2014; 8:326-37. [PMID: 24417025 DOI: 10.1504/ijdmb.2013.056079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Major Histocompatibility Complex (MHC), peptide and T-Cell Receptor (TCR) play an essential role of adaptive immune responses. Many prediction servers are available for identification of peptides that bind to MHC class I molecules but often lack detailed interacting residues for analysing MHC-peptide-TCR interaction mechanisms. This study considers both the interface similarity and the interacting force for identifying binding models. Our model, considering both the MHC-peptide and the peptide-TCR interfaces, is able to provide visualisation and the biological insights of binding models. We believe that our model is useful for the development of peptide-based vaccines.
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Zhang Y, Yang WQ, Zhu H, Qian YY, Zhou L, Ren YJ, Ren XC, Zhang L, Liu XP, Liu CG, Ming ZJ, Li B, Chen B, Wang JR, Liu YB, Yang JM. Regulation of autophagy by miR-30d impacts sensitivity of anaplastic thyroid carcinoma to cisplatin. Biochem Pharmacol 2013; 87:562-70. [PMID: 24345332 DOI: 10.1016/j.bcp.2013.12.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 11/29/2013] [Accepted: 12/02/2013] [Indexed: 12/11/2022]
Abstract
miR-30d has been observed to be significantly down-regulated in human anaplastic thyroid carcinoma (ATC), and is believed to be an important event in thyroid cell transformation. In this study, we found that miR-30d has a critical role in modulating sensitivity of ATC cells to cisplatin, a commonly used chemotherapeutic drug for treatment of this neoplasm. Using a mimic of miR-30d, we demonstrated that miR-30d could negatively regulate the expression of beclin 1, a key autophagy gene, leading to suppression of the cisplatin-activated autophagic response that protects ATC cells from apoptosis. A reporter gene assay demonstrated that the binding sequences of miR-30d in the beclin 1-3' UTR was the region required for the inhibition of beclin 1 expression by this miRNA. We further showed that inhibition of the beclin 1-mediated autophagy by the miR-30d mimic sensitized ATC cells to cisplatin both in vitro (cell culture) and in vivo (animal xenograft model). These results suggest that dysregulation of miR-30d in ATC cells is responsible for the insensitivity to cisplatin by promoting autophagic survival. Thus, miR-30d may be exploited as a potential target for therapeutic intervention in the treatment of ATC.
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Wang HC, Hsu KC, Yang JM, Wu ML, Ko TP, Lin SR, Wang AHJ. Staphylococcus aureus protein SAUGI acts as a uracil-DNA glycosylase inhibitor. Nucleic Acids Res 2013; 42:1354-64. [PMID: 24150946 PMCID: PMC3902945 DOI: 10.1093/nar/gkt964] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
DNA mimic proteins are unique factors that control the DNA binding activity of target proteins by directly occupying their DNA binding sites. The extremely divergent amino acid sequences of the DNA mimics make these proteins hard to predict, and although they are likely to be ubiquitous, to date, only a few have been reported and functionally analyzed. Here we used a bioinformatic approach to look for potential DNA mimic proteins among previously reported protein structures. From ∼14 candidates, we selected the Staphylococcus conserved hypothetical protein SSP0047, and used proteomic and structural approaches to show that it is a novel DNA mimic protein. In Staphylococcus aureus, we found that this protein acts as a uracil-DNA glycosylase inhibitor, and therefore named it S. aureus uracil-DNA glycosylase inhibitor (SAUGI). We also determined and analyzed the complex structure of SAUGI and S. aureus uracil-DNA glycosylase (SAUDG). Subsequent BIAcore studies further showed that SAUGI has a high binding affinity to both S. aureus and human UDG. The two uracil-DNA glycosylase inhibitors (UGI and p56) previously known to science were both found in Bacillus phages, and this is the first report of a bacterial DNA mimic that may regulate SAUDG’s functional roles in DNA repair and host defense.
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Abstract
Background The adaptive immune response is antigen-specific and triggered by pathogen recognition through T cells. Although the interactions and mechanisms of TCR-peptide-MHC (TCR-pMHC) have been studied over three decades, the biological basis for these processes remains controversial. As an increasing number of high-throughput binding epitopes and available TCR-pMHC complex structures, a fast genome-wide structural modelling of TCR-pMHC interactions is an emergent task for understanding immune interactions and developing peptide vaccines. Results We first constructed the PPI matrices and iMatrix, using 621 non-redundant PPI interfaces and 398 non-redundant antigen-antibody interfaces, respectively, for modelling the MHC-peptide and TCR-peptide interfaces, respectively. The iMatrix consists of four knowledge-based scoring matrices to evaluate the hydrogen bonds and van der Waals forces between sidechains or backbones, respectively. The predicted energies of iMatrix are high correlated (Pearson's correlation coefficient is 0.6) to 70 experimental free energies on antigen-antibody interfaces. To further investigate iMatrix and PPI matrices, we inferred the 701,897 potential peptide antigens with significant statistic from 389 pathogen genomes and modelled the TCR-pMHC interactions using available TCR-pMHC complex structures. These identified peptide antigens keep hydrogen-bond energies and consensus interactions and our TCR-pMHC models can provide detailed interacting models and crucial binding regions. Conclusions Experimental results demonstrate that our method can achieve high precision for predicting binding affinity and potential peptide antigens. We believe that iMatrix and our template-based method can be useful for the binding mechanisms of TCR-pMHC complexes and peptide vaccine designs.
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Chen SH, Lin SW, Lin SR, Liang PH, Yang JM. Moiety-linkage map reveals selective nonbisphosphonate inhibitors of human geranylgeranyl diphosphate synthase. J Chem Inf Model 2013; 53:2299-311. [PMID: 23919676 DOI: 10.1021/ci400227r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Bisphosphonates are potent inhibitors of farnesyl pyrophosphate synthase (FPPS) and geranylgeranyl diphosphate synthase (GGPPS). Current bisphosphonate drugs (e.g., Fosamax and Zometa) are highly efficacious in the treatment of bone diseases such as osteoporosis, Paget's disease, and tumor-induced osteolysis, but they are often less potent in blood and soft-tissue due to their phosphate moieties. The discovery of nonbisphosphonate inhibitors of FPPS and/or GGPPS for the treatment of bone diseases and cancers is, therefore, a current goal. Here, we propose a moiety-linkage-based method, combining a site-moiety map with chemical structure rules (CSRs), to discover nonbisphosphonate inhibitors from thousands of commercially available compounds and known crystal structures. Our moiety-linkage map reveals the binding mechanisms and inhibitory efficacies of 51 human GGPPS (hGGPPS) inhibitors. To the best of our knowledge, we are the first team to discover two novel selective nonbisphosphonate inhibitors, which bind to the inhibitory site of hGGPPS, using CSRs and site-moiety maps. These two compounds can be considered as a novel lead for the potent inhibitors of hGGPPS for the treatment of cancers and mevalonate-pathway diseases. Moreover, based on our moiety-linkage map, we identified two key residues of hGGPPS, K202, and K212, which play an important role for the inhibitory effect of zoledronate (IC50 = 3.4 μM and 2.4 μM, respectively). This result suggests that our method can discover specific hGGPPS inhibitors across multiple prenyltransferases. These results show that the compounds that highly fit our moiety-linkage map often inhibit hGGPPS activity and induce tumor cell apoptosis. We believe that our method is useful for discovering potential inhibitors and binding mechanisms for pharmaceutical targets.
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