Publications by authors named "Zhaoli Zhou"

20 Publications

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Quantitative proteomic analysis of the effects of dietary deprivation of methionine and cystine on A549 xenograft and A549 xenograft-bearing mouse.

Proteomics 2021 Sep 5:e2100007. Epub 2021 Sep 5.

Shanghai Key Laboratory of Molecular Imaging. Shanghai University of Medicine & Health Sciences, Shanghai, 201318, China.

Methionine (Met) and cystine (CySS) are key sulfur donors in cell metabolism and are important nutrients for sustaining tumor growth; however, the molecular effects associated with their deprivation remain to be characterized. Here, we devised a xenograft mouse model to assess the impact of their deprivation on A549 xenografts and the xenograft-bearing animal. Results show that Met and CySS deprivation inhibits A549 growth in vitro, not in vivo. Deprivation was detrimental to the xenograft-bearing mouse, as demonstrated by weight loss and renal dysfunction. Differentially expressed proteins in A549 xenograft and mouse kidneys were characterized using quantitative proteomics. Functional annotation and protein-protein interaction network analysis revealed the enriched signaling pathways, including focal adhesion (Fn1) in the A549 xenograft, and xenobiotic metabolism (Cyp2e1) and glutathione metabolism (Ggt1) in the mouse kidney. Met and CySS deprivation inhibits the migratory and invasive properties of cancer cells, as evidenced by reduced expression of the epithelial to mesenchymal transition marker N-cadherin in A549 cells in vitro. Moreover, IGFBP1 protein expression was inhibited in both A549 xenograft and mouse kidneys. This study provides the first insights into changes within the proteome profile and biological processes upon Met and CySS deprivation in a A549 xenograft mouse model. This article is protected by copyright. All rights reserved.
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http://dx.doi.org/10.1002/pmic.202100007DOI Listing
September 2021

Wobble tRNA modification and hydrophilic amino acid patterns dictate protein fate.

Nat Commun 2021 04 15;12(1):2170. Epub 2021 Apr 15.

Laboratory of Cancer Signaling, University of Liège, Liège, Belgium.

Regulation of mRNA translation elongation impacts nascent protein synthesis and integrity and plays a critical role in disease establishment. Here, we investigate features linking regulation of codon-dependent translation elongation to protein expression and homeostasis. Using knockdown models of enzymes that catalyze the mcms wobble uridine tRNA modification (U-enzymes), we show that gene codon content is necessary but not sufficient to predict protein fate. While translation defects upon perturbation of U-enzymes are strictly dependent on codon content, the consequences on protein output are determined by other features. Specific hydrophilic motifs cause protein aggregation and degradation upon codon-dependent translation elongation defects. Accordingly, the combination of codon content and the presence of hydrophilic motifs define the proteome whose maintenance relies on U-tRNA modification. Together, these results uncover the mechanism linking wobble tRNA modification to mRNA translation and aggregation to maintain proteome homeostasis.
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http://dx.doi.org/10.1038/s41467-021-22254-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8050329PMC
April 2021

Characteristics of human papillomavirus infection among women with cervical cytological abnormalities in the Zhoupu District, Shanghai City, China, 2014-2019.

Virol J 2021 03 8;18(1):51. Epub 2021 Mar 8.

Shanghai University of Medicine and Health Sciences Affiliated Zhoupu Hospital, Shanghai, China.

Background: Human papillomavirus (HPV) infection is currently the main cause of cervical cancer and precancerous lesions in female patients. By analyzing 6-year patient data from Shanghai Zhoupu Hospital in China, we retrospectively analyzed the epidemiological characteristics of women to determine the relationship between HPV genotype and cytological test results.

Methods: From 2014 to 2019, 23,724 cases of cervical shedding were collected from Zhoupu Hospital in Shanghai, China. By comparing the results of HPV and ThinPrep cytology test (TCT), the HPV infection rate of patients was retrospectively analyzed. HPV genotyping using commercial kits can detect 21 HPV subtypes (15 high-risk and 6 low-risk). According to the definition of the Bethesda system, seven types of cervical cytology results were involved.

Results: 3816 among 23,724 women, nearly 16.08%, were infected with HPV. The top three highest HPV prevalence rates were high-risk type infection, including HPV52 (3.19%), 58 (2.47%) and 16 (2.34%). The number of single-type HPV infections (3480 (91.20%)) was much larger than the number of multi-type ones (336 (8.8%)). Single-type infections were mainly in women aged 50-60 (16.63%) and women under 30 (15.37%), while multi-type infections were more common in women over 60 (2.67%). By analyzing the long-term trends, between 2014 and 2019, HPV52, 58, and 16 subtypes changed significantly, and the HPV positive rate also changed significantly during this period. Among 4502 TCT positive women, 15 (4.04%), 125 (2.64%),159 (1.54%), 4202 (17.71%) and 1 (0.004%) had atypical glandular cells (AGC), high-grade squamous intraepithelial lesions (HSIL), low-grade squamous intraepithelial lesions (LSIL), atypical squamous cells (ASC)and cervical adenocarcinoma, respectively. The HPV infection rates were 66.08%, 63.99%, 115.20%, 119.50%, and 31.72% for NILM, AGCs, HSILs LSILs and ASCs, respectively.

Conclusions: HPV and TCT screening were very important steps in the secondary prevention of cervical cancer. Through the tracking and analysis of HPV and TCT results in this study, it can provide valuable information for Shanghai's HPV screening and prevention strategies, and provide references for clinical decision-making in the treatment of cervical cancer and precancerous lesions.
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http://dx.doi.org/10.1186/s12985-021-01518-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7938559PMC
March 2021

Preparation and validation of cyclodextrin-based excipients for radioiodinated hypericin applied in a targeted cancer radiotherapy.

Int J Pharm 2021 Apr 25;599:120393. Epub 2021 Feb 25.

Shanghai Key Laboratory of Molecular Imaging, Shanghai University of Medicine and Health Sciences, Shanghai 201318, China. Electronic address:

Background: Iodine-131 labeled hypericin (I-Hyp) has been utilized as a necrosis-avid theragnostic tracer in a dual targeting pan-anticancer strategy called OncoCiDia. Widespread use of previously-tested solvent dimethyl sulfoxide (DMSO) is limited by safety concerns. To tackle this, the present study was designed to explore a clinically feasible excipient for the formulation of the hydrophobic I-Hyp for intravenous administration.

Method: Solubility of Hyp in serial solutions of already-approved hydroxypropyl-β-cyclodextrin (HP-β-CD) was evaluated by UVspectrophotometry and 50% HP-β-CD was chosen for further experiments. Two novel HP-β-CD-based formulations of I-Hyp were compared with previous DMSO-based formulation, with regards to necrosis-targetability and biodistribution, by magnetic resonance imaging, single-photon emission computed tomography (SPECT), gamma counting, autoradiography, fluorescence microscopy and histopathology.

Results: Hyp solubility was enhanced with increasing HP-β-CD concentrations. The radiochemical purity of I-Hyp was higher than 90% in all formulations. The necrosis-targetability of I-Hyp in the novel formulations was confirmed in vivo by SPECT and in vitro by autoradiography, fluorescence microscopy and histopathology. The plasma clearance of radioactivity was faster in the novel formulations.

Conclusion: The novel I-Hyp formulations with HP-β-CD could be a suitable pharmaceutical excipient for I-Hyp for intravenous administration.
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http://dx.doi.org/10.1016/j.ijpharm.2021.120393DOI Listing
April 2021

A novel humanized Frizzled-7-targeting antibody enhances antitumor effects of Bevacizumab against triple-negative breast cancer via blocking Wnt/β-catenin signaling pathway.

J Exp Clin Cancer Res 2021 Jan 12;40(1):30. Epub 2021 Jan 12.

Shanghai Key Laboratory of Molecular Imaging, Shanghai University of Medicine and Health Sciences, 279 Zhouzhu Highway, Pudong New Area, Shanghai, China.

Background: Anti-angiogenic therapy has been widely applied to the clinical treatment of malignant tumors. However, the efficacy of such treatments has been called into question, especially in triple-negative breast cancer (TNBC). Bevacizumab, the first anti-angiogenic agent approved by FDA, actually increases invasive and metastatic properties of TNBC cells, resulting from the activation of Wnt/β-catenin signaling in response to hypoxia. As a critical receptor of Wnt/β-catenin signaling, Frizzled-7 (Fzd7) is aberrantly expressed in TNBC, indicating Fzd7 a potential target for developing drugs to be combined with anti-angiogenic agents.

Methods: Hybridoma technique and antibody humanization technique were utilized to generate a Fzd7-targeting antibody (SHH002-hu1). Biolayer interferometry (BLI) assay and near infrared (NIR) imaging were conducted to detect the affinity and targeting ability of SHH002-hu1. Next, whether SHH002-hu1 could suppress the invasion and migration of TNBC cells induced by Bevacizumab were validated, and the underlying molecular mechanisms were elucidated by luciferase reporter and western blot assays. The nude-mice transplanted TNBC models were established to assess the anti-TNBC activities of SHH002-hu1 when combined with Bevacizumab. Then, the effects on putative TNBC stem-like cells and Wnt/β-catenin signaling were evaluated by immunofluorescence (IF). Further, the tumor-initiating and self-renew capacity of TNBC cells were studied by secondary nude mouse xenograft model and sphere formation assay. In addition, the effects of SHH002-hu1 on the adaptation of TNBC cells to hypoxia were evaluated by the detection of vasculogenic mimicry (VM) and hypoxia-inducible factor-1α (HIF-1α) transcriptional activity.

Results: The novel humanized antibody targeting Fzd7 (SHH002-hu1) exhibited extremely high affinity with Fzd7, and specifically targeted to Fzd7 cells and tumor tissues. SHH002-hu1 repressed invasion, migration and epithelial-mesenchymal cell transformation (EMT) of TNBC cells induced by Bevacizumab through abating Wnt/β-catenin signaling. SHH002-hu1 significantly enhanced the capacity of Bevacizumab to inhibit the growth of TNBC via reducing the subpopulation of putative TNBC stem-like cells, further attenuating Bevacizumab-enhanced tumor-initiating and self-renew capacity of TNBC cells. Moreover, SHH002-hu1 effectively restrained the adaptation of TNBC cells to hypoxia via disrupting Wnt/β-catenin signaling.

Conclusion: SHH002-hu1 significantly enhances the anti-TNBC capacity of Bevacizumab, and shows the potential of preventing TNBC recurrence, suggesting SHH002-hu1 a good candidate for the synergistic therapy together with Bevacizumab.
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http://dx.doi.org/10.1186/s13046-020-01800-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7802198PMC
January 2021

High-quality genome assembly of .

PeerJ 2020 12;8:e10313. Epub 2020 Nov 12.

Shanghai Key Laboratory of Molecular Imaging, Shanghai University of Medicine and Health Sciences, Shanghai, China.

Earthworms enrich the soil and protect the health of their ecological environment. Previous studies on these invertebrates determined their protein content, hormone secretions, medicinal value, and ecological habits, but their whole genomic sequence remains incomplete. We performed whole genome sequencing of (Chen, 1930), which belongs to the genus of the family Megascolecidae. The genome assembly was 729 Mb, with a N50 contig size of 4.2 Mb. In total, 559 contigs were anchored to 41 chromosomes according to the results of Hi-C (High-throughput Chromosome Conformation Capture) technology, which was confirmed by karyological analysis. A comparison of the genomic sequences and genes indicated that there was a whole-genome duplication in followed by several chromosome fusion events. Hox genes and lumbrokinase genes were identified as partial clusters surrounding the genome. Our high-quality genome assembly of will provide valuable information for gene function and evolutionary studies in earthworms.
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http://dx.doi.org/10.7717/peerj.10313DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7666815PMC
November 2020

TP53 mutation influences the efficacy of treatment of colorectal cancer cell lines with a combination of sirtuin inhibitors and chemotherapeutic agents.

Exp Ther Med 2020 Aug 29;20(2):1415-1422. Epub 2020 May 29.

Shanghai Key Laboratory of Molecular Imaging, Shanghai University of Medicine and Health Sciences, Shanghai 201318, P.R. China.

Chemoresistance of colorectal cancer (CRC) leads to tumor recurrence and metastasis and new strategies are urgently needed to improve the outcomes of conventional chemotherapy. Sirtuin (SIRT) inhibitors prevent tumor cell growth by increasing the levels of acetylated histones and non-histones, as well as disrupting survival-related pathways. The aim of the present study was to determine the effect of SIRT inhibitors on CRC chemotherapy. The CompuSyn software program was used to evaluate the synergistic or antagonistic effects of various drugs, and the status of the protein deacetylation regulatory genes in microarray datasets were analyzed using bioinformatics. In HCT116 cells expressing wild-type (wt) , SIRT inhibitors were found to act antagonistically with multiple chemotherapeutic agents (cisplatin, 5-fluorouracil, oxaliplatin, gefitinib, LY294002 and metformin), and decreased the anti-tumor effects of these agents. By contrast, SIRT inhibitors sensitized -mutant (mut) SW620 cells to various chemotherapeutic drugs. Bioinformatics analysis indicated that SIRT1 and protein deacetylation related genes were highly expressed in CRC cells when compared to cells. Therefore, it was hypothesized that the likely mechanism underlying the antagonistic effect of SIRT inhibitors on CRC cells was a reduction in the level of stable p53 protein. The present results indicated that divergent status may translate to a different chemosensitivity profile, and suggested that a combination therapy of SIRT inhibitors and first-line chemotherapeutic drugs may be beneficial for the treatment of patients with CRC.
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http://dx.doi.org/10.3892/etm.2020.8818DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7388297PMC
August 2020

Oxymatrine enhanced anti-tumor effects of Bevacizumab against triple-negative breast cancer via abating Wnt/β-Catenin signaling pathway.

Am J Cancer Res 2019 1;9(8):1796-1814. Epub 2019 Aug 1.

School of Pharmacy, Shanghai University of Medicine and Health Sciences Shanghai 201318, P. R. China.

Bevacizumab, a monoclonal antibody targeting vascular endothelial growth factor A (VEGF-A), was used in combination with traditional chemotherapy as the first line treatment for metastatic colorectal cancer (mCRC), non-small cell lung cancer (NSCLC) and advanced ovarian cancer. However, it shows limited efficacy for human triple-negative breast cancer (TNBC). Bevacizumab shows potent anti-angiogenesis activity, meanwhile, it also increases invasive and metastatic properties of TNBC cells by activiting Wnt/β-Catenin pathway. To overcome this problem, and fully utilize its potency against cancer, further synergistic strategy is recommended to be developed, especially the concurrent use with those Wnt-targeting agents. Here, by screening a small library of traditional Chinese medicine, we identified a Chinese herb derived Oxymatrine, which could target Wnt/β-Catenin signaling and compromise the oncogenic effects of Bevacizumab. Bevacizumab was validated to induce epithelial-mesenchymal cell transformation (EMT) and cancer stem-like properties of TNBC cells in hypoxia/nutritional stress environment. On the contrary, Oxymatrine reversed the EMT phenotype and depleted the subpopulation of TNBC stem cells induced by Bevacizumab. Oxymatrine enhanced the anti-tumor effects of Bevacizumab , and holded the potential of reducing the risk of relapse and metastasis by impairing the self-renewal ability of TNBC stem cells. The underlying mechanism was elucidated: Bevacizumab stimulated Wnt/β-Catenin signaling pathway, and Oxymatrine could compromise this effect. On this foundation, factoring into the satisfactory anti-angiogenic activity and low toxicity, Oxymatrine is a good candidate for the synergistic therapy together with Bevacizumab for the treatment of TNBC.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6726986PMC
August 2019

Sirtuin-mediated deacetylation of hnRNP A1 suppresses glycolysis and growth in hepatocellular carcinoma.

Oncogene 2019 06 11;38(25):4915-4931. Epub 2019 Mar 11.

Shanghai Key Laboratory of Molecular Imaging, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China.

Tumor cells undergo a metabolic shift in order to adapt to the altered microenvironment, although the underlying mechanisms have not been fully explored. HnRNP A1 is involved in the alternative splicing of the pyruvate kinase (PK) mRNA, allowing tumor cells to specifically produce the PKM2 isoform. We found that the acetylation status of hnRNP A1 in hepatocellular carcinoma (HCC) cells was dependent on glucose availability, which affected the PKM2-dependent glycolytic pathway. In the glucose-starved HCC cells, SIRT1 and SIRT6, members of deacetylase sirtuin family, were highly expressed and deacetylated hnRNP A1 after direct binding. We identified four lysine residues in hnRNP A1 that were deacetylated by SIRT1 and SIRT6, resulting in significant inhibition of glycolysis in HCC cells. Deacetylated hnRNP A1 reduced PKM2 and increased PKM1 alternative splicing in HCC cells under normal glucose conditions, thereby reducing the metabolic activity of PK and the non-metabolic PKM2-β-catenin signaling pathway. However, under glucose starvation, the low levels of acetylated hnRNP A1 reduced HCC cell metabolism to adapt to the nutrient deficiency. Taken together, sirtuin-mediated hnRNP A1 deacetylation inhibits HCC cell proliferation and tumorigenesis in a PKM2-dependent manner. These findings point to the metabolic reprogramming induced by hnRNP A1 acetylation in order to adapt to the nutritional status of the tumor microenvironment.
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http://dx.doi.org/10.1038/s41388-019-0764-zDOI Listing
June 2019

A novel antioxidant Mito-Tempol inhibits ox-LDL-induced foam cell formation through restoration of autophagy flux.

Free Radic Biol Med 2018 12 12;129:463-472. Epub 2018 Oct 12.

Department of Geriatrics, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China. Electronic address:

A bulk of cholesteryl esters accumulation in macrophage foam cells drives the occurrence and development of atherosclerosis. Evidence now shows that autophagy plays key roles in the degradation of intracellular lipid droplets via autolysosome, and also in the release of intracellular lipids via cholesterol efflux. In this study, we identified that a mitochondria-targeted antioxidant, Mito-Tempol, has protective effects against cholesteryl esters accumulation by activating autophagy. Mito-Tempol was shown to ameliorate the lipid burden for atherosclerosis, both in vitro and in vivo. In the established in vitro foam cell formation system using oxidized low-density lipoprotein (ox-LDL)-loaded THP-1 macrophages, Mito-Tempol prevented intracellular oxidative stress and attenuated lipid accumulation. Mito-Tempol rescued ox-LDL-impaired autophagic flux, thereby facilitating autophagy-mediated lipid degradation in THP-1 macrophages. Meanwhile, Mito-Tempol also increased the efflux of cholesterol via autophagy-dependent ABCA1 and ABCG1 up-regulation. The classical autophagy pathway of mTOR may be one of the effector for the autophagy restoration of Mito-Tempol. Our findings give the first insight that cardiovascular system disease may benefits more from the treatment of Mito-Tempol for its impact of reversing atherosclerosis via autophagy.
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http://dx.doi.org/10.1016/j.freeradbiomed.2018.10.412DOI Listing
December 2018

Fifteen-gene expression based model predicts the survival of clear cell renal cell carcinoma.

Medicine (Baltimore) 2018 Aug;97(33):e11839

Shanghai University of Medicine & Health Sciences School of Optical-electrical and Computer Engineer of University of Shanghai for Science and Technology Shanghai Key Laboratory for Molecular Imaging, Collaborative Research Center, Shanghai University of Medicine & Health Science Department of Pharmacology, School of Pharmacy, Shanghai University of Medicine & Health Science, Shanghai, China.

Clear-cell renal cell carcinoma (ccRCC) is the major renal cell carcinoma subtype, but its postsurgical prognosis varies among individual patients.We used gene expression, machine learning (random forest variable hunting), and Cox regression analysis to develop a risk score model based on 15 genes to predict survival of patients with ccRCC in the The Cancer Genome Atlas dataset (N = 533). We validated this model in another cohort, and analyzed correlations between risk score and other clinical indicators.Patients in the high-risk group had significantly worse overall survival (OS) than did those in the low-risk group (P = 5.6e-16); recurrence-free survival showed a similar pattern. This result was reproducible in another dataset, E-MTAB-1980 (N = 101, P = .00029). We evaluated correlations between risk score and other clinical indicators. Risk was independent of age and sex, but was significantly associated with hemoglobin level, primary tumor size, and grade. Radiation therapy also had no effect on the prognostic value of the risk score. Cox multivariate regression showed risk score to be an important indicator for ccRCC prognosis. We plotted a nomogram for 3-year OS to facilitate use of risk score and other indicators.The risk score model based on expression of the 15 selected genes can predict survival of patients with ccRCC.
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http://dx.doi.org/10.1097/MD.0000000000011839DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6113007PMC
August 2018

A novel recombinant human Frizzled-7 protein exhibits anti-tumor activity against triple negative breast cancer via abating Wnt/β-catenin pathway.

Int J Biochem Cell Biol 2018 10 7;103:45-55. Epub 2018 Aug 7.

School of Pharmacy, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, PR China; Health School Attached to Shanghai University of Medicine and Health Sciences, Shanghai, 200237, PR China. Electronic address:

Triple negative breast cancer (TNBC) is one of the most difficult malignancy to treat due to a lack of targeted therapy. Studies have demonstrated that the activation of Wnt/β-catenin signaling was preferentially found in TNBC. Frizzled-7 (Fzd7), one of the Wnt receptors, was significantly up-regulated in TNBC and modulated TNBC tumorigenesis through the Wnt signaling pathway, indicating Fzd7 is a biomarker and a potential therapeutic target for TNBC. Here, we designed a recombinant soluble peptide fragment (rhFzd7) to antagonize Fzd7 by competitively binding with Wnt ligands. We demonstrated the ability of rhFzd7 to bind to its ligand, Wnt3a, and monitored the kinetic process using a Biacore X100 system. In addition, the anti-tumor and anti-angiogenic activity of rhFzd7 were studied in vitro and in vivo. Results showed that the purified rhFzd7 pulled down Wnt3a from MDA-MB-231 cells and exhibited high affinity with Wnt3a (KD: 3.41 × 10 M). The data in vitro revealed that rhFzd7 inhibited proliferation and invasion of TNBC cells, and induced apoptosis of TNBC cells effectively. The anti-angiogenic assay indicated that rhFzd7 repressed TNBC angiogenesis in vitro and in vivo. Furthermore, the study in vivo showed that rhFzd7 could sensitize TNBC cells to the anti-tumor effect of Docetaxel. In conclusion, the generation of rhFzd7 lays foundation for the screening of anti-Fzd7 antibody, and this novel design provides an effective candidate for the clinical treatment of TNBC.
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http://dx.doi.org/10.1016/j.biocel.2018.08.004DOI Listing
October 2018

Codon-specific translation reprogramming promotes resistance to targeted therapy.

Nature 2018 06 20;558(7711):605-609. Epub 2018 Jun 20.

Laboratory of Cancer Signaling, University of Liège, Liège, Belgium.

Reprogramming of mRNA translation has a key role in cancer development and drug resistance . However, the molecular mechanisms that are involved in this process remain poorly understood. Wobble tRNA modifications are required for specific codon decoding during translation. Here we show, in humans, that the enzymes that catalyse modifications of wobble uridine 34 (U) tRNA (U enzymes) are key players of the protein synthesis rewiring that is induced by the transformation driven by the BRAF oncogene and by resistance to targeted therapy in melanoma. We show that BRAF -expressing melanoma cells are dependent on U enzymes for survival, and that concurrent inhibition of MAPK signalling and ELP3 or CTU1 and/or CTU2 synergizes to kill melanoma cells. Activation of the PI3K signalling pathway, one of the most common mechanisms of acquired resistance to MAPK therapeutic agents, markedly increases the expression of U enzymes. Mechanistically, U enzymes promote glycolysis in melanoma cells through the direct, codon-dependent, regulation of the translation of HIF1A mRNA and the maintenance of high levels of HIF1α protein. Therefore, the acquired resistance to anti-BRAF therapy is associated with high levels of U enzymes and HIF1α. Together, these results demonstrate that U enzymes promote the survival and resistance to therapy of melanoma cells by regulating specific mRNA translation.
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http://dx.doi.org/10.1038/s41586-018-0243-7DOI Listing
June 2018

tRNA Modification: Is Cancer Having a Wobble?

Trends Cancer 2017 04 27;3(4):249-252. Epub 2017 Mar 27.

Laboratory of Cancer Signaling, University of Liège, 4000 Liège, Belgium; GIGA-Molecular Biology of Diseases, GIGA-Research, University of Liège, 4000 Liège, Belgium. Electronic address:

Translational control of protein synthesis supports tumor development and progression to metastasis. Wobble tRNA modifications are required during translation elongation and sustain proteome homeostasis. Recent work has highlighted the surprising upregulation of the wobble uridine 34 (U34) tRNA cascade in cancer, which underlies the specific requirement for this pathway in tumor development.
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http://dx.doi.org/10.1016/j.trecan.2017.02.004DOI Listing
April 2017

Elp3 links tRNA modification to IRES-dependent translation of LEF1 to sustain metastasis in breast cancer.

J Exp Med 2016 10 10;213(11):2503-2523. Epub 2016 Oct 10.

Laboratory of Cancer Signaling, University of Liège, 4000 Liège, Belgium

Quantitative and qualitative changes in mRNA translation occur in tumor cells and support cancer progression and metastasis. Posttranscriptional modifications of transfer RNAs (tRNAs) at the wobble uridine 34 (U34) base are highly conserved and contribute to translation fidelity. Here, we show that ELP3 and CTU1/2, partner enzymes in U34 mcms-tRNA modification, are up-regulated in human breast cancers and sustain metastasis. Elp3 genetic ablation strongly impaired invasion and metastasis formation in the PyMT model of invasive breast cancer. Mechanistically, ELP3 and CTU1/2 support cellular invasion through the translation of the oncoprotein DEK. As a result, DEK promotes the IRES-dependent translation of the proinvasive transcription factor LEF1. Consistently, a DEK mutant, whose codon composition is independent of U34 mcms-tRNA modification, escapes the ELP3- and CTU1-dependent regulation and restores the IRES-dependent LEF1 expression. Our results demonstrate that the key role of U34 tRNA modification is to support specific translation during breast cancer progression and highlight a functional link between tRNA modification- and IRES-dependent translation during tumor cell invasion and metastasis.
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http://dx.doi.org/10.1084/jem.20160397DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5068235PMC
October 2016

Amphiphilic triblock copolymers with PEGylated hydrocarbon structures as environmentally friendly marine antifouling and fouling-release coatings.

Biofouling 2014 14;30(5):589-604. Epub 2014 Apr 14.

a Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , USA.

The ideal marine antifouling (AF)/fouling-release (FR) coating should be non-toxic, while effectively either resisting the attachment of marine organisms (AF) or significantly reducing their strength of attachment (FR). Many recent studies have shown that amphiphilic polymeric materials provide a promising solution to producing such coatings due to their surface dual functionality. In this work, poly(ethylene glycol) (PEG) of different molecular weights (Mw = 350, 550) was coupled to a saturated difunctional alkyl alcohol to generate amphiphilic surfactants (PEG-hydrocarbon-OH). The resulting macromolecules were then used as side chains to covalently modify a pre-synthesized PS8 K-b-P(E/B)25 K-b-PI10 K (SEBI or K3) triblock copolymer, and the final polymers were applied to glass substrata through an established multilayer surface coating technique to prepare fouling resistant coatings. The coated surfaces were characterized with AFM, XPS and NEXAFS, and evaluated in laboratory assays with two important fouling algae, Ulva linza (a green macroalga) and Navicula incerta, a biofilm-forming diatom. The results suggest that these polymer-coated surfaces undergo surface reconstruction upon changing the contact medium (polymer/air vs polymer/water), due to the preferential interfacial aggregation of the PEG segment on the surface in water. The amphiphilic polymer-coated surfaces showed promising results as both AF and FR coatings. The sample with longer PEG chain lengths (Mw = 550 g mol(-1)) exhibited excellent properties against both algae, highlighting the importance of the chemical structures on ultimate biological performance. Besides reporting synthesis and characterization of this new type of amphiphilic surface material, this work also provides insight into the nature of PEG/hydrocarbon amphiphilic coatings, and this understanding may help in the design of future generations of fluorine-free, environmentally friendly AF/FR polymeric coatings.
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http://dx.doi.org/10.1080/08927014.2014.897335DOI Listing
January 2015

Biomimetic polymer brushes containing tethered acetylcholine analogs for protein and hippocampal neuronal cell patterning.

Biomacromolecules 2013 Feb 29;14(2):529-37. Epub 2013 Jan 29.

Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, United States.

This paper describes a method to control neuronal cell adhesion and differentiation with both chemical and topographic cues by using a spatially defined polymer brush pattern. First, biomimetic methacrylate polymer brushes containing tethered neurotransmitter acetylcholine functionalities in the form of dimethylaminoethyl methacrylate or free hydroxyl-terminated poly(ethylene glycol) units were prepared using the "grown from" method through surface-initiated atom transfer radical polymerization reactions. The surface properties of the resulting brushes were thoroughly characterized with various techniques and hippocampal neuronal cell culture on the brush surfaces exhibit cell viability and differentiation comparable to, or even better than, those on commonly used poly-l-lysine coated glass coverslips. The polymer brushes were then patterned via UV photolithography techniques to provide specially designed surface features with different sizes (varying from 2 to 200 μm) and orientations (horizontal and vertical). Protein absorption experiments and hippocampal neuronal cell culture tests on the brush patterns showed that both protein and neurons can adhere to the patterns and therefore be guided by such patterns. These results also demonstrate that, because of their unique chemical composition and well-defined nature, the developed polymer brushes may find many potential applications in cell-material interactions studies and neural tissue engineering.
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http://dx.doi.org/10.1021/bm301785bDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3619936PMC
February 2013

Structure of Aeropyrum pernix fibrillarin in complex with natively bound S-adenosyl-L-methionine at 1.7 Å resolution.

Acta Crystallogr Sect F Struct Biol Cryst Commun 2012 Aug 26;68(Pt 8):854-9. Epub 2012 Jul 26.

Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.

Fibrillarin is the key methyltransferase associated with the C/D class of small nuclear ribonucleoproteins (snRNPs) and participates in the preliminary step of pre-ribosomal rRNA processing. This molecule is found in the fibrillar regions of the eukaryotic nucleolus and is involved in methylation of the 2'-O atom of ribose in rRNA. Human fibrillarin contains an N-terminal GAR domain, a central RNA-binding domain comprising an RNP-2-like superfamily consensus sequence and a catalytic C-terminal helical domain. Here, Aeropyrum pernix fibrillarin is described, which is homologous to the C-terminal domain of human fibrillarin. The protein was crystallized with an S-adenosyl-L-methionine (SAM) ligand bound in the active site. The molecular structure of this complex was solved using X-ray crystallography at a resolution of 1.7 Å using molecular replacement with fibrillarin structural homologs. The structure shows the atomic details of SAM and its active-site interactions; there are a number of conserved residues that interact directly with the cofactor. Notably, the adenine ring of SAM is stabilized by π-π interactions with the conserved residue Phe110 and by electrostatic interactions with the Asp134, Ala135 and Gln157 residues. The π-π interaction appears to play a critical role in stabilizing the association of SAM with fibrillarin. Furthermore, comparison of A. pernix fibrillarin with homologous structures revealed different orientations of Phe110 and changes in α-helix 6 of fibrillarin and suggests key differences in its interactions with the adenine ring of SAM in the active site and with the C/D RNA. These differences may play a key role in orienting the SAM ligand for catalysis as well as in the assembly of other ribonucleoproteins and in the interactions with C/D RNA.
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http://dx.doi.org/10.1107/S1744309112026528DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3412760PMC
August 2012

The role of hydrogels with tethered acetylcholine functionality on the adhesion and viability of hippocampal neurons and glial cells.

Biomaterials 2012 Mar 22;33(8):2473-81. Epub 2011 Dec 22.

Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA.

In neural tissue engineering, designing materials with the right chemical cues is crucial in providing a permissive microenvironment to encourage and guide neuronal cell attachment and differentiation. Modifying synthetic hydrogels with biologically active molecules has become an increasingly important route in this field to provide a successful biomaterial and cell interaction. This study presents a strategy of using the monomer 2-methacryloxyethyl trimethylammonium chloride (MAETAC) to provide tethered neurotransmitter acetylcholine-like functionality with a complete 2-acetoxy-N,N,N-trimethylethanaminium segment, thereby modifying the properties of commonly used, non-adhesive PEG-based hydrogels. The effect of the functional monomer concentration on the physical properties of the hydrogels was systematically studied, and the resulting hydrogels were also evaluated for mice hippocampal neural cell attachment and growth. Results from this study showed that MAETAC in the hydrogels promotes neuronal cell attachment and differentiation in a concentration-dependent manner, different proportions of MAETAC monomer in the reaction mixture produce hydrogels with different porous structures, swollen states, and mechanical strengths. Growth of mice hippocampal cells cultured on the hydrogels showed differences in number, length of processes and exhibited different survival rates. Our results indicate that chemical composition of the biomaterials is a key factor in neural cell attachment and growth, and integration of the appropriate amount of tethered neurotransmitter functionalities can be a simple and effective way to optimize existing biomaterials for neuronal tissue engineering applications.
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http://dx.doi.org/10.1016/j.biomaterials.2011.12.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3262018PMC
March 2012

A general approach to controlling the surface composition of poly(ethylene oxide)-based block copolymers for antifouling coatings.

Langmuir 2011 Nov 14;27(22):13762-72. Epub 2011 Oct 14.

Materials Department, University of California, Santa Barbara, California 93106, United States.

To control the surface properties of a polystyrene-block-poly(ethylene oxide) diblock copolymer, perfluorinated chemical moieties were specifically incorporated into the block copolymer backbone. A polystyrene-block-poly[(ethylene oxide)-stat-(allyl glycidyl ether)] [PS-b-P(EO-stat-AGE)] statistical diblock terpolymer was synthesized with varying incorporations of allyl glycidyl ether (AGE) in the poly(ethylene oxide) block from 0 to 17 mol %. The pendant alkenes of the AGE repeat units were subsequently functionalized by thiol-ene chemistry with 1H,1H,2H,2H-perfluorooctanethiol, yielding fluorocarbon-functionalized AGE (fAGE) repeat units. (1)H NMR spectroscopy and size-exclusion chromatography indicated well-defined structures with complete functionalization of the pendant alkenes. The surfaces of the polymer films were characterized after spray coating by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure spectroscopy (NEXAFS), showing that the P(EO-stat-fAGE) block starts to compete with polystyrene to populate the surface after only 1 mol % incorporation of fAGE. Increasing the incorporation of fAGE led to an increased amount of perfluorocarbons on the surface and a decrease in the concentration of PS. At a fAGE incorporation of 8 mol %, PS was not detected at the surface, as measured by NEXAFS spectroscopy. Water contact angles measured by the captive-air-bubble technique showed the underwater surfaces to be dynamic, with advancing and receding contact angles varying by >20°. Protein adsorption studies demonstrated that the fluorinated surfaces effectively prevent nonspecific binding of proteins relative to an unmodified PS-b-PEO diblock copolymer. In biological systems, settlement of spores of the green macroalga Ulva was significantly lower for the fAGE-incorporated polymers compared to the unmodified diblock and a polydimethylsiloxane elastomer standard. Furthermore, the attachment strength of sporelings (young plants) of Ulva was also reduced for the fAGE-containing polymers, affirming their potential as fouling-release coatings.
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http://dx.doi.org/10.1021/la202509mDOI Listing
November 2011
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