Scientific Program

Conference Series Ltd invites all the participants across the globe to attend 5th International Conference on Integrative Biology London, UK.

Day 2 :

  • Molecular Biology
Speaker
Biography:

Bernard Lopez has completed his PhD at the age of 27 years from University of Lyon I and postdoctoral studies from Curie Institute (Paris), followed by a sabbatical from and Brandeis university (Waltham, Ms, USA). He is first class research director at CNRS (French state organisation for basic research). He has published more than 70 papers in reputed journals and has been serving as a scientific advisor of many organizations.

Abstract:

Replication stress is an endogenous stress that can be at the origin of senescence or tumour initiation. Replication stress can generates mitosis defects including anaphases bridges, expression of common fragile sites, extra-centrosomes and multipolar segregations. All these troubles generate uneven chromosome segregation and aneuploidy. This suggests that DNA damages arising from replication should reach mitosis. To test this hypothesis wen checked the accumulation of foci of RPA, which recognize single-stranded DNA, in cells in late G2, following a low or endogenous replication stress. Cells treated with low doses of hydroxyurea (HU, 10 µM) or untreated cells defective for homologous recombination (HR); which plays a pivotal role in the resumption of arrested replication forks, both experience an increase in the number of RPA foci, in late G2 phase. These foci do not colocalise with progressing replication forks completing replication, and thus should correspond to spontaneous replication fork arrest. ChIP-seq analysis with RPA antibodies in G2 phase, reveals two types of enrichment efficiency. Highly enriched sequences (more than 400) do not contained fragile sites and correspond to early replicating sequences. Interestingly many of these sequences correspond to transcription starting sites (TSS), revealing thus the conflict between replication and transcription. Among the genes involved a set of 10 genes involved in DNA damage response and cell cycle checkpoint have been selected and specific chromatin-IP experiment confirmed the binding of RPA after HU. Therefore promoters of genes controlling genome stability are hot spots of endogenous/low replication stress favouring damaged cells to escape to cell surveillance. Therefore should amplify genome instability.

Speaker
Biography:

After studying physics and optics at the University of Montpellier, David Pastré developed at the time of his thesis (1996-1999)a set up to collect cathodoluminescence in near field. During a postdoctoral fellowship at the University of Virginia (2000-2001), he designed a method to observe living mammalian cells at high-resolution with a scanning ion conductance microscope. As a teacher-researcher at the University of Evry, he deciphered the mechanisms leading to DNA absorption on mica and studied the formation of DNA and RNA/protein complexes on mica by atomic force microscopy.

David Pastré is now at the head of the SABNP laboratory (INSERM unit U1204) and professor at the University of Evry. He is currently investigating, at the cellular and molecular levels, the dynamics and structure of RNA/protein complexes involved in the control of protein expression and the mechanisms which regulate microtubule dynamics. He also continues to develop novel methods to explore cellular and molecular processes.

Abstract:

The functions of many proteins and their interplay remain elusive, which limits the developmentsof diagnostic and treatment of many human diseases. To address this issue, methods are currently developed to decipher protein interactions in cells.We recently developed a new technology to probe protein interactions (PPI) along microtubules inspecifically engineered mammalian cells by fluorescence microscopy (Boca et al., Scientific Reports, 2015). A bait protein is brought to microtubules and the presence of putative molecular partners, attracted by the bait protein, is then detected on microtubules by fluorescence microscopy. Here we present the advantages of this technology compared to other approaches and itslatest developments. The domain of applications are broad spanning from discovery of new drugs that target protein or mRNA interactions, identifying molecular targets, exploring the consequences of mutations and the possible corrections of pathogenic consequences.

Eleonora Braga

Institute of General Pathology and Pathophysiology, Russia

Title: Tumor suppressor miRNAs: Hypermethylation and novel potential targets in breast cancer
Speaker
Biography:

Braga E.A. has completed her PhD at the age of 28 at Lomonosov Moscow State University, Bioorganic Chemistry Department. She has taken a part in Russian Human Genome Project and HUGO. She was an Invited Principle Investigator at Karolinska Institute (Stockholm, Sweden, 1999-2000). She completed her full Dr. of Biology Sc. at Engelhardt Institute of Molecular Biology in 2007. She is a head of Laboratory of Pathogenomics and Transcriptomics at Institute of General Pathology and Pathophysiology, Moscow, Russia. She has published more than 70 papers in reputed Journals.

Abstract:

Epigenetic mechanisms including DNA methylation and interaction between miRNAs and mRNAs are the most dynamic mechanisms of genes deregulation in cancer. The aim of this study was to identify novel miRNAs, involved in down-regulation of some cancer-associated genes, and could be down-regulated itself by DNA methylation, in breast cancer (BC). We analyzed expression and methylation profiles of 20 tumor-suppressor miRNAs and 15 cancer-associated genes, which interactions were predicted by algorithms of miRWalk 2.0 database. Representative set of 58 paired (tumor/normal) BC samples; methylation-specific PCR, qPCR and the IBM SPSS Statistics Base 20 software package were used. We first observed hypermethylation of MIR-127, -132, -1258, -193a, and hypomethylation of MIR-191. Using qPCR, we established a strong correlation between promoter methylation and expression levels of 12 miRNA genes, confirming the functional importance of altered methylation patterns. The significant negative correlations were revealed between expression level alterations for the following pairs: CCND1 – miR-212-3p, -34a-5p, -34c-3p; BCL2 – miR-24-2-5p, -212-3p, -124-3p; BCL6 – miR-34a-5p, -24-2-5p. The results of transfection of MCF7 cell line with miR-124-3p duplex strengthened hypothesis on direct or indirect interaction of this miRNA with BCL2 mRNA. Thus, systemic role of hypermethylation in deregulation of miRNAs and its targets was shown, and novel potential interactions of 5 miRNAs with CCND1, BCL2, and BCL6, being involved in cell cycle regulation, apoptosis, EMT and metastasis, were suggested, that could be useful as missing chains in signaling pathways and potential targets in complex BC therapy. This work was financially supported by the Russian Science Foundation grant 14-15-00654.

Biography:

Abstract:

Double-strand breaks (DSBs) trigger rapid and transient transcription pause to prevent collisions between repair and transcription machineries at damage sites. Little is known about the mechanisms that ensure transcription block after DNA damage. Here we reveal a novel role of the negative elongation factor, NELF, in blocking transcription activity nearby DSBs. We show that NELF-E and NELF-A are rapidly recruited to DSB sites. Furthermore, NELF-E recruitment and its repressive activity are both required for switching off transcription at DSBs. Remarkably, using I-Sce-I endonuclease and CRISPR-Cas9 systems, we observed that NELF-E is preferentially recruited, in a PARP1-dependent manner, to DSBs induced upstream transcriptionally active rather than inactive genes. Moreover, the presence of RNA polymerase II is a prerequisite for the preferential recruitment of NELF-E to DNA breakage sites. Additionally, we demonstrate that NELF-E is required for intact repair of DSBs. Altogether, our data identified NELF complex as a new component in the DNA damage response.

Biography:

Peleg Hasson has completed his PhD at the age of 33 years from the Hebrew University, Jerusalem, Israel University and continued his postdoctoral studies at the MRC-National Institute of Medical Research, London. He has started his own lab at the Technion's Rappaport Faculty of Medicine in 2010.

Abstract:

For muscles to function, myofibers have to stretch and anchor at the myotendinous junction (MTJ), a region rich in extracellular matrix (ECM). Integrin signaling is required for MTJ formation, and mutations affecting the cascade lead to muscular dystrophies in mice and humans. Underlying mechanisms for integrin activation at the MTJ and ECM modifications regulating its signaling are unclear. We show that lysyl oxidase-like 3 (LoxL3) is a key regulator of integrin signaling that ensures localized control of the cascade. In LoxL3 mutants, myofibers anchor prematurely or overshoot to adjacent somites, and are loose and lack tension. We find that LoxL3 complexes with and directly oxidizes Fibronectin (FN), an ECM scaffold protein and integrin ligand enriched at the MTJ. We identify a mechanism whereby localized LoxL3 secretion from myofiber termini oxidizes FN, promoting FN polymerization thus priming it for integrin activation at the tips of myofibers and ensuring correct positioning and anchoring of myofibers along the MTJ.

Biography:

Yangyang Yu is professor at center for diabetes, obesity and metabolism in department of physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong province, China.

Abstract:

Toll-like receptors (TLRs) expressed on mast cells are essential for effective host defense against a wide variety of pathogens. Previous studies have demonstrated that TLR2 agonists Pam3CSK4 and PGN both stimulated IL-8 release in human mast cells. To determine the molecular basis for this phenomenon, we utilized a human mast cell line LAD2 cells. We found that only release of IL-8 stimulated by Pam3CSK4 was TLR2-mediated, which was confirmed by specific TLR2 shRNA. Heterotrimeric G proteins have been previously implicated in TLRs signaling in macrophages and monocytes. In the current study, we showed that PamCSK4 induced the activation of MAPKs, NF-κB, PI3K-Akt and Ca2+-calcineurin-NFAT signaling cascades in LAD2 cells. Go proteins were required for the activation of MAPKs and NF-κB in TLR2 stimulated LAD2 cells. Therefore, genetic depletion of Gαo proteins also leaded to reduction of IL-8 release in LAD2 cells. Taken together, the data presented here suggest that TLR2 activation in human mast cells promotes the release of inflammatory mediators via distinct signaling pathways that partially depends on Go protein action.

Biography:

Rinat Arbel-Goren completed her PhD in 2002 in Life Sciences at the Department of Molecular Biology of the Cell, Weizmann Institute of Science Rehovot, Israel, under Prof. Y. Zick. From 2002-2005, she carried out a Postdoc in the Department of Immunology, under Prof Y. Reisner. Since 2006 she is a Staff Scientist in the Department of Physics of Complex Systems, Weizmann Institute of Science, in the lab of Prof. J. Stavans. In addition to the above, her current research topics include:Effects of post-transcriptional regulation by small-RNAs on phenotypic variability; Effects of phenotypic variability during development in cyanobacteria.

Abstract:

During horizontal gene transfer processes, imported exogenous DNA sequences integrate at unique sites in the host bacterial genome, driving genetic diversity. One example is viral infection, which is known to allow the acquisition of pathogenic traits.After entering an Escherichia coli cell, the ∼5x104-long bacteriophage λ DNA must locate a unique site among ∼5x106 possible sites on the bacterial genome, with high efficiency and within physiological times, to integrate and establish lysogeny. What are the mechanisms that allow it to do it?We followed the targeting process in individual live E. coli cells in real-time, by marking fluorescently both the phage DNA after entry into the host, and a chromosomal sequence near the integration site. Surprisingly, we found that λ DNA does not carry out an active search. Instead, it remains confined near its entry point into the cell following infection, preferentially at the poles, where it undergoes limited diffusion. The encounter between the 15 bp-long target sequence on the chromosome and the recombination site on the viral genome is facilitated by thedirected motion of bacterial DNA generated during chromosome replication and segregation.A different mechanism of target location is observed during conjugation betweenB. subtilis cells:  integrating conjugating elements imported from donor cells carry out anomalous diffusion within host cellsin their search for their target insertion sites, which move concomitantly, driven by replication of the host genome. These finding demonstrate that there are different solutions to the target location problemduring horizontal gene transfer processes.

Biography:

Kuo-Ping Chiu got his PhD in Microbiology from UC Davis and did his postdoc at Harvard Medical School on Neurosciences. His research interest is tightly associated with biotechnologies, cancer biology, next-generation sequencing, genomics, bioinformatics and microbiology. He has strong experiences in both academia and industry. Currently, he is working as an Associate Research Fellow in Academia Sinica, Taiwan. Besides doing research, he also teaches in a number of universities. He holds four patents issued by US and Taiwan and has published 35 research articles in reputed journals, two book chapters and a book entitled “Next-Generation Sequencing and Sequence Data Analysis”. He recently published a biotechnology called T Oligo-Primed Polymerase Chain Reaction (TOP-PCR), which is a powerful method for the amplification of minute DNA fragments in body fluids.

Abstract:

Early-onset breast cancer (EOBC) in women at age 40 or younger is associated with poorer prognosis and higher mortality rate compared to late-onset breast cancer (LOBC) occurring at age 50 or older. In order to gain a deeper insight of EOBC pathology, we analyzed NGS data, produced by whole-genome sequencing (WGS) and by whole-exome sequencing (WES), of 88 EOBC patients originally categorized into 5 subtypes. Results indicate that EOBC cases are in fact constituted by a high-mutation (HM) subgroup and a low-mutation subgroup. The former is featured by high number (avg. 1662/patient) of nonsynonymously mutated (NSM) genes, universal aberration in olfactory transduction pathway resulted mainly from olfactory receptor (OR) defects and certain common NSM genes found in all patients, while the latter by low number (avg. 100/patient) of NSM genes and aberration in RNA transport pathway. The HM-LM bipartite nature seems to be subtype-independent, making EOBC readily distinguishable from LOBC. Our data directly link EOBC to OR-mediated olfactory system. Presumably, by interacting with enormous odorants and environmental hormones in the surroundings and having crosstalk with ER signaling, ORs may play a key role in EOBC etiology. Results also suggest that aberration in olfactory transduction pathway and the common NSM genes can be useful biomarkers for HM type of earlyonset breast cancer.