Publications by authors named "Canquan Mao"

19 Publications

  • Page 1 of 1

Targeting PAR2 Overcomes Gefitinib Resistance in Non-Small-Cell Lung Cancer Cells Through Inhibition of EGFR Transactivation.

Front Pharmacol 2021 22;12:625289. Epub 2021 Apr 22.

School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, China.

Drug resistance can notably restrict clinical applications of gefitinib that is a commonly used EGFR-tyrosine kinase inhibitors (EGFR-TKIs) for non-small cell lung cancer (NSCLC). The attempts in exploring novel drug targets and reversal strategies are still needed, since gefitinib resistance has not been fully addressed. Protease-activated receptor 2 (PAR2), a G protein-coupled receptor, possesses a transactivation with EGFR to initiate a variety of intracellular signal transductions, but there is a lack of investigations on the role of PAR2 in gefitinib resistance. This study established that protease-activated receptor 2 (PAR2), actively participated in NSCLC resistant to gefitinib. PAR2 expression was significantly up-regulated when NSCLC cells or tumor tissues became gefitinib resistance. PAR2 inhibition notably enhanced gefitinib to modulate EGFR transactivation, cell viability, migration and apoptosis in gefitinib-sensitive and-resistant NSCLC cells, suggesting its reversal effects in gefitinib resistance. Meanwhile, the combination of a PAR2 inhibitor (P2pal-18S) and gefitinib largely blocked ERK phosphorylation and epithelial-mesenchymal transition (EMT) compared to gefitinib alone. Importantly, we probed its underlying mechanism and uncovered that PAR2 blockade sensitized gefitinib and reversed its resistance mainly via β-arrestin-EGFR-ERK signaling axis. These effects of PAR2 inhibition were further confirmed by the study which showed that P2pal-18S reactivated gefitinib to inhibit tumor growth via restricting ERK activation. Taken together, this study could not only reveal a new mechanism of receptor-mediated transactivation to modulate drug resistance, but also provide a novel drug target and direction for overcoming gefitinib resistance in NSCLC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2021.625289DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8100583PMC
April 2021

PAMs inhibits monoamine oxidase a activity and reduces glioma tumor growth, a potential adjuvant treatment for glioma.

BMC Complement Med Ther 2020 Aug 15;20(1):252. Epub 2020 Aug 15.

Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Rm. 518, 1985 Zonal Ave, Los Angeles, CA, 90089, USA.

Background: Monoamine oxidase (MAO) A catalyzes oxidative deamination of monoamine neurotransmitters and dietary amines and regulates brain development and functions. Recently, we showed that MAO A mediates the progression and migration of glioma and MAO A inhibitors reduce glioma cell growth. Glioblastoma (GBM) is a common and most malignant brain tumor which is difficult to treat. Temozolomide (TMZ) is the current standard chemotherapy for glioma, but tumors usually become resistant and recur. So far, no effective therapy for TMZ-resistant glioma is available. Natural plant antimicrobial solution (PAMs) is a Chinese herbal medicine which has been used for decades without toxicity and has multiple medical functions including anti- inflammatory effects. Here, we report the effects of PAMs on glioblastoma growth.

Methods: The growth of TMZ -sensitive (U251S),-resistant (U251R) human glioma cells, and mouse glioma cell line GL-26 were assessed by MTS colorimetric assay, colony formation, and cell migration assays. Male C57BL/6 mice were implanted subcutaneously or intracranial with luciferase-positive mouse glioma GL-26 cells and treated with vehicle; MAO A inhibitor clorgyline (10 mg/kg); TMZ (1 mg/kg); PAMs (48 mg/kg) alone or in combination with TMZ (1 mg/kg) for 14 days. At the end of the treatment, mice were sacrificed, MAO A catalytic activity in tumors was measured, and tumor sizes were determined by imaging and weight.

Results: These results show that PAMs inhibits MAO A catalytic activity in all three glioma cell lines studied U251S, U251R, and GL-26. PAMs reduced glioma growth and has greater effects in combination with low dose of TMZ than PAMS or TMZ alone in all three cell lines as shown by MTS, colony formation, and cell migration assays. Using the subcutaneous or intracranial GL-26 glioma mouse model, PAMs reduced the tumor growth and MAO A activity, similar to the MAO A inhibitor clorgyline. Combining PAMs with non-toxic dose TMZ increased survival to a greater extent than those of PAMs or TMZ alone.

Conclusions: This is the first study which suggests that PAMs alone or co-administration with low doses of TMZ may be a potential adjuvant to reduce the toxicity of TMZ and to abrogate drug resistance for the effective treatment of glioma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12906-020-03041-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7429690PMC
August 2020

G Protein-coupled Receptors in Cancer Stem Cells.

Curr Pharm Des 2020 ;26(17):1952-1963

School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, China.

G protein-coupled receptors (GPCRs) are highly expressed on a variety of tumour tissues while several GPCR exogenous ligands become marketed pharmaceuticals. In recent decades, cancer stem cells (CSCs) become widely investigated drug targets for cancer therapy but the underlying mechanism is still not fully elucidated. There are vigorous participations of GPCRs in CSCs-related signalling and functions, such as biomarkers for CSCs, activation of Wnt, Hedgehog (HH) and other signalling to facilitate CSCs progressions. This relationship can not only uncover a novel molecular mechanism for GPCR-mediated cancer cell functions but also assist our understanding of maintaining and modulating CSCs. Moreover, GPCR antagonists and monoclonal antibodies could be applied to impair CSCs functions and consequently attenuate tumour growth, some of which have been undergoing clinical studies and are anticipated to turn into marketed anticancer drugs. Therefore, this review summarizes and provides sufficient evidences on the regulation of GPCR signalling in the maintenance, differentiation and pluripotency of CSCs, suggesting that targeting GPCRs on the surface of CSCs could be potential therapeutic strategies for cancer therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2174/1381612826666200305130009DOI Listing
November 2020

Down-regulation expression of TGFB2-AS1 inhibits the proliferation, migration, invasion and induces apoptosis in HepG2 cells.

Genes Genomics 2019 08 7;41(8):951-959. Epub 2019 May 7.

School of Life Sciences and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, People's Republic of China.

Background: Hepatocellular carcinoma (HCC) is the leading cause of cancer mortality and without effective prognosis. Previous study has been confirmed that the abnormal expression of long non-coding RNAs (lncRNAs) TGFB2-AS1 was involved in tumorigenesis. However, the biological functions of TGFB2-AS1 in hepatocellular carcinoma (HCC) remain largely unclear.

Objective: We comprehensively assess the clinical significance of TGFB2-AS1 and investigate the biological functions of TGFB2-AS1 on HCC HepG2 cells.

Methods: We firstly confirmed the expression of TGFB2-AS1 between tumor and normal tissues using public available transcriptome data. We analyzed the clinical significance of TGFB2-AS1 using the TCGA HCC datasets. The biological functions of TGFB2-AS1 on HCC HepG2 cells were explored by multiple in vitro assays.

Results: We found that TGFB2-AS1 was remarkably increased in HCC tissues (P = 0.00148) and exhibited a potential predictive marker for HCC, with an area under curve (AUC) of 0.708 (P = 0.0034) using the fifty pairs of matched HCC tissues of TCGA. Besides, higher expression of TGFB2-AS1 in HCC tissues was identified as being positively associated with advanced tumor (P = 0.012) and disease stage (P = 0.009) in 355 HCC cases using independent sample nonparametric test. Downregulation of TGFB2-AS1 expression significantly restrained proliferation (P < 0.01) and impaired colony formation (P < 0.05). Furthermore, TGFB2-AS1 depletion remarkably promoted the apoptosis of HepG2 cells (P < 0.05) and inhibited migration and invasion (P < 0.01).

Conclusion: Taken together, these findings suggested that TGFB2-AS1 might serve as a potential therapeutic target for HCC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s13258-019-00826-6DOI Listing
August 2019

An APOE-independent cis-eSNP on chromosome 19q13.32 influences tau levels and late-onset Alzheimer's disease risk.

Neurobiol Aging 2018 06 3;66:178.e1-178.e8. Epub 2018 Jan 3.

Tanz Centre for Research in Neurodegenerative Diseases, and Department of Medicine, University of Toronto, Toronto, Ontario, Canada.

Although multiple susceptibility loci for late-onset Alzheimer's disease (LOAD) have been identified, a large portion of the genetic risk for this disease remains unexplained. LOAD risk may be associated with single-nucleotide polymorphisms responsible for changes in gene expression (eSNPs). To detect eSNPs associated with LOAD, we integrated data from LOAD genome-wide association studies and expression quantitative trait loci using Sherlock (a Bayesian statistical method). We identified a cis-regulatory eSNP (rs2927438) located on chromosome 19q13.32, for which subsequent analyses confirmed the association with both LOAD risk and the expression level of several nearby genes. Importantly, rs2927438 may represent an APOE-independent LOAD eSNP according to the weak linkage disequilibrium of rs2927438 with the 2 polymorphisms (rs7412 and rs429358) defining the APOE-ε2, -ε3, and -ε4 alleles. Furthermore, rs2927438 does not influence chromatin interaction events at the APOE locus or cis-regulation of APOE expression. Further exploratory analysis revealed that rs2927438 is significantly associated with tau levels in the cerebrospinal fluid. Our findings suggest that rs2927438 may confer APOE-independent risk for LOAD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.neurobiolaging.2017.12.027DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7050280PMC
June 2018

Transcriptome profiling analysis of differentially expressed mRNAs and lncRNAs in HepG2 cells treated with peptide 9R-P201.

Biotechnol Lett 2017 Nov 31;39(11):1639-1647. Epub 2017 Jul 31.

School of Life Sciences and Engineering, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China.

Objective: To characterize the transcriptome profile of hepatocellular carcinoma (HCC) HepG2 cells treated with peptide 9R-P201 for further functional verification and HCC drug development.

Results: 1557 mRNAs (1125 upregulated and 432 downregulated) and 881 lncRNAs (640 upregulated and 241 downregulated) with significant differential expression were identified using RNA-seq. The qRT-PCR results showed that the differential expression of several mRNAs and lncRNAs coincided with the RNA-seq results. Differentially expressed mRNAs and lncRNAs presented a significant difference in genomic characteristics but no preference under 9R-P201 treatment compared with control. The GO and KEGG functional enrichment analyses showed that differentially expressed mRNAs and lncRNAs remarkably enriched in cancer-related biological processes and signaling pathways. Finally, we screened out 33 TFs, 273 lncRNAs and 94 target genes with high degree interaction which were remarkably associated with the tumorigenesis and progression of cancers using betweenness centrality analysis.

Conclusion: These findings offer novel insights into the mechanism of 9R-P201 in HepG2 cells and provide new opportunities for the future 9R-P201-based drug development and the treatment of hepatocellular carcinoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10529-017-2407-1DOI Listing
November 2017

PAMs ameliorates the imiquimod-induced psoriasis-like skin disease in mice by inhibition of translocation of NF-κB and production of inflammatory cytokines.

PLoS One 2017 2;12(5):e0176823. Epub 2017 May 2.

School of Life Sciences and Engineering, Southwest Jiaotong University, Chengdu, China.

Psoriasis is a chronic and persistent inflammatory skin disease seriously affecting the quality of human life. In this study, we reported an ancient formula of Chinese folk medicine, the natural plant antimicrobial solution (PAMs) for its anti-inflammatory effects and proposed the primary mechanisms on inhibiting the inflammatory response in TNF-α/IFN-γ-induced HaCaT cells and imiquimod-induced psoriasis-like skin disease mouse model. Two main functional components of hydroxysafflor Yellow A and allantoin in PAMs were quantified by HPLC to be 94.2±2.2 and 262.9±12.5 μg/mL respectively. PAMs could significantly reduce the gene expression and inflammatory cytokines production of Macrophage-Derived Chemokine (MDC), IL-8 and IL-6 in TNF-α/IFN-γ-induced HaCaT cells. PAMs also significantly ameliorates the psoriatic-like symptoms in a mouse model with the evaluation scores for both the single (scales, thickness, erythema) and cumulative features were in the order of blank control < Dexamethasone < PAMs < 50% ethanol < model groups. The results were further confirmed by hematoxylin-eosin staining, RT-qPCR and immunohistochemistry. The down-regulated gene expression of IL-8, TNF-α, ICAM-1 and IL-23 in mouse tissues was consistent with the results from those of the HaCaT cells. The inhibition of psoriasis-like skin inflammation by PAMs was correlated with the inactivation of the translocation of P65 protein into cellular nucleus, indicating the inhibition of the inflammatory NF-κB signaling pathway. Taken together, these findings suggest that PAMs may be a promising drug candidate for the treatment of inflammatory skin disorders, such as psoriasis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0176823PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5413058PMC
September 2017

Genetic association of rs1344706 in ZNF804A with bipolar disorder and schizophrenia susceptibility in Chinese populations.

Sci Rep 2017 01 25;7:41140. Epub 2017 Jan 25.

Wuxi Mental Health Center, Nanjing Medical University, Wuxi, China.

Rs1344706 in the the zinc finger protein 804A (ZNF804A) gene has been identified to be associated with schizophrenia and bipolar disorder (BD) in Europeans. However, whether rs1344706 is associated with schizophrenia in Chinese populations remains inconclusive; furthermore, the association between rs1344706 and BD in Chinese populations has been rarely explored. To explore the association between rs1344706 and schizophrenia/BD in Chinese populations, we genotyped rs1344706 among 1128 Chinese subjects (537 patients with BD and 591 controls) and found that rs1344706 showed marginal allelic association with BD (P = 0.028) with T-allele being more prevalent in cases than that in controls (OR = 1.19, 95% CI 1.03-1.37). Meta-analysis of rs1344706 by pooling all available data showed that rs1344706 was significantly associated with BD (P = 0.001). Besides, positive association of rs1344706 with schizophrenia was observed in Northern Chinese (P = 0.005). Furthermore, ZNF804A is highly expressed in human and mouse brains, especially in prenatal stage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep41140DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5264157PMC
January 2017

The ACEII recombinant Trichoderma reesei QM9414 strains with enhanced xylanase production and its applications in production of xylitol from tree barks.

Microb Cell Fact 2016 Dec 28;15(1):215. Epub 2016 Dec 28.

Department of Biology, Lakehead University, Thunder Bay, ON, P7B 5E1, Canada.

Background: ACEII transcription factor plays a significant role in regulating the expression of cellulase and hemicellulase encoding genes. Apart from ACEII, transcription factors such as XYR1, CRE1, HAP2/3/5 complex and ACEI function in a coordinated pattern for regulating the gene expression of cellulases and hemicellulases. Studies have demonstrated that ACEII gene deletion results in decreased total cellulase and xylanase activities with reduced transcript levels of lignocellulolytic enzymes.

Results: In this study, we have successfully transformed the ACEII transcription factor encoding gene in Trichoderma reesei to significantly improve its degrading abilities. Transformation experiments on parental strain T. reesei QM9414 has resulted in five genetically engineered strains T/Ace2-2, T/Ace2-5, T/Ace2-8, T/Ace5-4 and T/Ace10-1. Among which, T/Ace2-2 has exhibited significant increase in enzyme activity by twofolds, when compared to parental strain. The T/Ace2-2 was cultured on growth substrates containing 2% bark supplemented with (a) sugar free + MA medium (b) glucose + MA medium and (c) xylose + MA medium. The bark degradation efficiency of genetically modified T/Ace2-2 strain was assessed by analyzing the xylitol production yield using HPAEC. By 6th day, about 10.52 g/l of xylitol was produced through enzymatic conversion of bark (2% bark + MA + xylose) by the T/Ace2-2 strain and by 7th day the conversion rate was found to be 0.21 g/g. Obtained results confirmed that bark growth medium supplemented with D-xylose has profoundly increased the conversion rate of bark by T/Ace2-2 strain when compared to sugar free and glucose supplemented growth media. Results obtained from scanning electron microscopy has endorsed our current results. Bark samples inoculated with T/Ace2-2 strain has showed large number of degraded cells with clearly visible cavities and fractures, by exposing the microfibrillar interwoven complex.

Conclusion: We propose a cost effective and ecofriendly method for the degradation of lignocellulosic biomass such as bark to produce xylitol by using genetically modified T. reesei. Efficient conversion rate and production yield obtained in our current study provides a great scope for the xylitol industries, as our method bypasses the pretreatment of bark achieving clean and low-cost xylitol production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12934-016-0614-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5192574PMC
December 2016

A novel peptide, 9R-P201, strongly inhibits the viability, proliferation and migration of liver cancer HepG2 cells and induces apoptosis by down-regulation of FoxM1 expression.

Eur J Pharmacol 2017 Feb 21;796:175-189. Epub 2016 Dec 21.

Laboratory of Molecular Evolution and Applied Biology, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China. Electronic address:

Overexpression of FoxM1 was closely related to the proliferation, metastasis, chemo-resistance and poor prognosis of various cancers. FoxM1 was regarded as the Achilles' heel of cancer and a potential target for anti-cancer drug discovery. We previously obtained several high affinity peptides from the phage random library against the DNA binding domain of FoxM1c (FoxM1c-DBD) protein. Here in this paper, we found that 9R-P201, one of the novel peptides, showed stronger inhibition to HepG2 cancer cells than those of DU145, HUVEC and L-02 cells with an IC of 43.6µg/ml (13.1µM). The peptide was highly effective to liver cancer cells with an IC for L-02 cells of 2855.9µg/ml. We confirmed that 9R-P201 aggregated in the cell nucleus and the expression of FoxM1 was significantly down-regulated at both transcriptional and translational levels in HepG2 cells, leading to the suppression of cell proliferation, migration, angiogenesis, and induction of apoptosis. Whole genomic RNA sequencing analysis revealed that 357 genes were significantly and differentially expressed, most of them were enriched in cancer-associated biological processes. Finally, treatment of HepG2 xenografts with 9R-P201 resulted in growth inhibition and down-regulation of foxM1 expression in tumors. Collectively, our findings suggested that 9R-P201 could strongly inhibit the viability, proliferation and migration of liver cancer HepG2 cells and induce apoptosis by down-regulation of FoxM1 and regulation of related gene expression in signal transduction passways. Thus, 9R-P201 holds great potential as a lead anti-cancer drug targeting FoxM1.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejphar.2016.12.029DOI Listing
February 2017

Common variants in CACNA1C and MDD susceptibility: A comprehensive meta-analysis.

Am J Med Genet B Neuropsychiatr Genet 2016 09 3;171(6):896-903. Epub 2016 Jun 3.

National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.

Major depressive disorder (MDD) is one of the most common psychiatric disorders with a relatively high heritability (35-40%). Though rs1006737 in the CACNA1C gene showed significant association with MDD in a British large-scale candidate association study, most of the replication analyses with relatively small sample size reported negative association. Moreover, this locus has never been identified in previous genome-wide association studies (GWAS) for MDD. Here, we conducted a comprehensive meta-analysis of the association between CACNA1C variants and MDD risk by combining all published data. Genetic data from one European GWAS and five individual follow-up studies, which include up to 12,629 patients of MDD and 28,653 controls, that is, the largest sample size on CACNA1C to date, were collected. Rs1006737 showed significant association with MDD in the fixed-effect model (Z = 2.56, P = 0.011, OR = 1.08, 95%CI = 1.04-1.12) and the association remained after reanalyzing the data according to ethnicity. We additionally analyzed other 25 SNPs, genotyped in only one replication study, across the CACNA1C locus, and found that two SNPs, rs4765905 (P = 0.041, OR = 1.05, 95%CI 1.00-1.09) and rs4765937 (P = 0.025, OR = 1.05, 95%CI 1.01-1.09) showed nominal association with MDD, while rs2239073 (P = 0.002, OR = 1.07, 95%CI 1.02-1.11) exhibited significant association with MDD, which survived from multiple corrections. Our study provides support for positive association between CACNA1C and MDD; however, the current data suggest the necessity of replication analyses in a larger-scale sample. © 2016 Wiley Periodicals, Inc.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ajmg.b.32466DOI Listing
September 2016

Accelerated leukocyte telomere erosion in schizophrenia: Evidence from the present study and a meta-analysis.

J Psychiatr Res 2016 08 30;79:50-56. Epub 2016 Apr 30.

National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China.

Human telomeres consist of tandem nucleotide repeats (TTAGGG) and associated proteins, and telomere length (TL) is reduced progressively with cell division over the lifespan. Telomere erosion might be accelerated or prevented to varying degrees when exposure to serious medical illnesses. In previous studies, an association between TL decrease and schizophrenia has been extensively reported; however, the results remain largely controversial. To further investigate TL in schizophrenia patients and reconcile this controversy, we first measured leucocyte TL (LTL) in our samples (52 paranoid schizophrenia, 89 non-paranoid patients and 120 controls), and then conducted a comprehensive meta-analysis of the existing results of LTL in patients of schizophrenia compared to healthy subjects. Totally, 11 studies encompassing 1243 patients of schizophrenia and 1274 controls were included in the final meta-analysis model. In our samples, significant reduction of LTL in paranoid schizophrenia was observed compared to controls (F = 50.88, P < 0.001); whereas there was no significant difference in LTL between non-paranoid schizophrenia and controls (F = 0.842, P = 0.360). For meta-analysis, random-effects model showed significant LTL decrease in patients of schizophrenia when compared to controls (Z = 2.07, P = 0.039, SMD = -0.48, 95% CI = -0.94 to -0.03). Moreover, a marginal decrease in LTL was observed in medicated patients (Z = 1.92, P = 0.055, SMD = -0.58, 95% CI = -1.18-0.01) and those patients with poor response to antipsychotics (Z = 1.76, P = 0.078, SMD = -0.60, 95% CI = -1.27-0.07). In conclusion, we observed significant reduction of LTL in individuals with schizophrenia compared with controls. However, all the studies included in the meta-analysis were cross-sectional, and better controlled long-term studies are needed to replicate this result.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jpsychires.2016.04.010DOI Listing
August 2016

[Virtual screening and molecular simulations of antisense peptides targeting MT1-MMP].

Sheng Wu Gong Cheng Xue Bao 2015 Feb;31(2):269-80

Membrane type-1 matrix metalloproteinase (MT1-MMP or MMP14) plays the pivotal role in tumor development and metastasis, so it is a promising drug target in malignancy. To acquire MT1-MMP specific binding peptides, we first analyzed MMPs sequences to find the divergent and specific sequence of MT1-MMP by bioinformatics approach, then set the specific sequence as the sense peptide target and designed antisense peptide library. Finally, by means of molecular docking, molecular dynamics simulation and in vitro cell assays, we screened the antisense peptide library against MT1-MMP and further studied the obtained specific peptides. Here, we identified the divergent and specific sequence of AYIREGHE (Named MT1-loop) located in MT1-MMP loop by multiple sequence alignment and established the antisense peptides library with capacity of 1 536 sequences. After two rounds of virtual screening, we obtained five antisense peptides with Rerankscores in the top for further screening. They all interacted with MT1-MMP, and docked well at the active site composed of MT1-loop sequence. Analysis of the affinities of these five antisense peptides to other MMPs (MMP1-3, MMP7-13, MMP14 HPX, MMP16) revealed that the peptide FVTFPYIR was more specific to MT1-MMP. Molecular dynamics simulation showed that the peptide FVTFPYIR might affect the stability of MT1-MMP and thus have effects on its activities. Meanwhile, the peptide FVTFPYIR could specifically inhibit the growth of MG63 and MDA-MB-231 tumor cells both of which expressed MT1-MMP. The work provides a new insight and way for the development of antitumor lead peptides targeting MT1-MMP.
View Article and Find Full Text PDF

Download full-text PDF

Source
February 2015

Systemic Screening of Strains of the Lion's Mane Medicinal Mushroom Hericium erinaceus (Higher Basidiomycetes) and Its Protective Effects on Aβ-Triggered Neurotoxicity in PC12 Cells.

Int J Med Mushrooms 2015 ;17(3):219-29

laboratory of Molecular Evolution and Applied Biology, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, China.

Hericium erinaceus possesses multiple medicinal values. To date, however, there have been few studies of the systemic screening of H. erinaceus strains, and the neuroprotective effects of H. erinaceus prepared from homogenized, fresh fruiting bodies are not fully understood. In this study, 4 random primers were selected and used in random amplified polymorphic DNA (RAPD) polymerase chain reaction (PCR) to screen and evaluate the genetic diversity of 19 commercial strains of H. erinaceus from different localities in China. A total of 66 bands were obtained, and the percentage of polymorphic loci reached 80.30%. Five dendrograms were constructed based on RAPD by Jaccard cluster and within-group linkage analysis. Primer S20 as well as all 4 primers had great potential as specific primers for RAPD-PCR molecular identification and differentiation of H. erinaceus strains. Based on the results of submerged culture and fruiting body cultivation, strains HT-N, HT-J1, HT-C, and HT-M were identified as superior among the 19 H. erinaceus strains. Further study showed that the oral preparation of homogenized, fresh fruiting bodies of H. erinaceus could attenuate the Aβ25-35-triggered damage in PC12 cells by significantly increasing cell viability and by decreasing the release of lactate dehydrogenase. In conclusion, RAPD-PCR combined with liquid and solid cultures can be used well in the screening and identification of H. erinaceus strains, and products prepared from homogenized, fresh fruiting bodies of H. erinaceus had neuroprotective effects on PC12 cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1615/intjmedmushrooms.v17.i3.20DOI Listing
January 2016

Identification and analysis of the regulatory network of Myc and microRNAs from high-throughput experimental data.

Comput Biol Med 2013 Sep 13;43(9):1252-60. Epub 2013 Jun 13.

School of Life Sciences and Bioengineering, Southwest Jiaotong University, Chengdu 610031, PR China.

As a transcription factor, c-Myc exerts significant influence in cancer development by regulating transcription of a large number of target genes including microRNAs. However, details of regulatory networks composed of Myc, microRNAs, and microRNA target genes are still unclear. Here, at system level, we built a comprehensive Myc-regulated miRNAs (Myc-miRNAs) regulatory network through the integration of experimentally validated high-throughput data and computational predictions. Using miRNA genomic information with ChIP-PET, we identified 30 Myc-miRNAs and found most of these Myc-miRNAs target genes were significantly enriched in cell cycle, apoptosis, cell proliferation GO terms and Myc-regulated signaling pathways, using gene sets enrichment analysis. We found most Myc-miRNAs involved in Myc-related cancer pathways expressed abnormally in Myc-associated tumors through the integration of diverse types of experimental data. Based upon Myc target genes identified by ChIP-chip assays, we identified that 1031 Myc-miRNAs feed-forward loops (FFLs) were significantly different from those obtained by chance; also, 11 high-quality FFLs were extracted from experimentally validated interactions. Finally, we built the miRNA-protein interaction network of experimentally validated Myc-miRNAs and discussed the more complex network composed of several FFLs networks. As shown in this study, we performed comprehensive analysis of the Myc-miRNAs regulatory network and provided potential Myc-miRNAs target genes which were involved in Myc pathway and cancer-related biological processes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.compbiomed.2013.06.002DOI Listing
September 2013

Epitope mapping of metuximab on CD147 using phage display and molecular docking.

Comput Math Methods Med 2013 3;2013:983829. Epub 2013 Jun 3.

Center of Bioinformatics (COBI), Key Laboratory for NeuroInformation of Ministry of Education, University of Electronic Science and Technology of China, Chengdu 610054, China.

Metuximab is the generic name of Licartin, a new drug for radioimmunotherapy of hepatocellular carcinoma. Although it is known to be a mouse monoclonal antibody against CD147, the complete epitope mediating the binding of metuximab to CD147 remains unknown. We panned the Ph.D.-12 phage display peptide library against metuximab and got six mimotopes. The following bioinformatics analysis based on mimotopes suggested that metuximab recognizes a conformational epitope composed of more than 20 residues. The residues of its epitope may include T28, V30, K36, L38, K57, F74, D77, S78, D79, D80, Q81, G83, S86, N98, Q100, L101, H102, G103, P104, V131, P132, and K191. The homology modeling of metuximab and the docking of CD147 to metuximab were also performed. Based on the top one docking model, the epitope was predicted to contain 28 residues: AGTVFTTV (23-30), I37, D45, E84, V88, EPMGTANIQLH (92-102), VPP (131-133), Q164, and K191. Almost half of the residues predicted on the basis of mimotope analysis also appear in the docking result, indicating that both results are reliable. As the predicted epitopes of metuximab largely overlap with interfaces of CD147-CD147 interactions, a structural mechanism of metuximab is proposed as blocking the formation of CD147 dimer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2013/983829DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3686076PMC
January 2014

Cellulase activities in biomass conversion: measurement methods and comparison.

Crit Rev Biotechnol 2010 Dec 24;30(4):302-9. Epub 2010 Sep 24.

Biorefining Research Initiative, Lakehead University, Thunder Bay, Ontario, Canada.

Cellulose, the major constituent of all plant materials and the most abundant organic molecule on the Earth, is a linear biopolymer of glucose molecules, connected by β-1,4-glycosidic bonds. Enzymatic hydrolysis of cellulose requires mixtures of hydrolytic enzymes including endoglucanases, exoglucanases (cellobiohydrolases), and β-glucosidases acting in a synergistic manner. In biopolymer hydrolysis studies, enzyme assay is an indispensable part. The most commonly used assays for the individual enzymes as well as total cellulase activity measurements, including their advantages and limitations, are summarized in this review article. In addition, some novel approaches recently used for enzyme assays are summarized.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3109/07388551.2010.490938DOI Listing
December 2010

A conformation-constrained peptide library based on insect defensin A.

Peptides 2004 Apr;25(4):629-35

Beijing Institute of Basic Medical Sciences, P.O. Box 130 (3), Beijing 100850, PR China.

Here, we reported a conformation-constrained peptide library, that was constructed based on the scaffold of a 29 amino acids peptide derived from insect defensin A. The peptide scaffold was designed utilizing the InsightII molecular modeling software and then displayed on M13 filamentous bacteriophage by fusion with coat protein III. The library was constructed by randomization of seven positions located within the two loops of the peptide scaffold generating approximately 8.3 x 10(8) transformants. Sequences from 14 randomly selected phage clones indicated that the distribution of nucleotides and amino acids paralleled with the expected frequency. Screening against the target proteins: tumor necrosis factor alpha, TNF receptor 1, TNF receptor 2 and monoclonal antibody against BMP-2 showed significant enrichment in all cases. The results presented here show that the reconstructed insect defensin A domain will be a promising non-antibody protein scaffold for the presentation of a phage-displayed constrained peptide library.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.peptides.2004.01.022DOI Listing
April 2004