scholarly journals The dark side of histones: genomic organization and role of oncohistones in cancer

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Stefano Amatori ◽  
Simona Tavolaro ◽  
Stefano Gambardella ◽  
Mirco Fanelli
Keyword(s):  
Pediatric Brain Tumors ◽  
Dominant Negative ◽  
Dark Side ◽  
Main Body ◽  
Cancer Epigenetics ◽  
Histone Fold ◽  
Histone Ptms ◽  
Recurrent Mutations ◽  
Tumor Types

Abstract Background The oncogenic role of histone mutations is one of the most relevant discovery in cancer epigenetics. Recurrent mutations targeting histone genes have been described in pediatric brain tumors, chondroblastoma, giant cell tumor of bone and other tumor types. The demonstration that mutant histones can be oncogenic and drive the tumorigenesis in pediatric tumors, led to the coining of the term “oncohistones.” The first identified histone mutations were localized at or near residues normally targeted by post-translational modifications (PTMs) in the histone N-terminal tails and suggested a possible interference with histone PTMs regulation and reading. Main body In this review, we describe the peculiar organization of the multiple genes that encode histone proteins, and the latter advances in both the identification and the biological role of histone mutations in cancer. Recent works show that recurrent somatic mutations target both N-terminal tails and globular histone fold domain in diverse tumor types. Oncohistones are often dominant-negative and occur at higher frequencies in tumors affecting children and adolescents. Notably, in many cases the mutations target selectively only some of the genes coding the same histone protein and are frequently associated with specific tumor types or, as documented for histone variant H3.3 in pediatric glioma, with peculiar tumors arising from specific anatomic locations. Conclusion The overview of the most recent advances suggests that the oncogenic potential of histone mutations can be exerted, together with the alteration of histone PTMs, through the destabilization of nucleosome and DNA–nucleosome interactions, as well as through the disruption of higher-order chromatin structure. However, further studies are necessary to fully elucidate the mechanism of action of oncohistones, as well as to evaluate their possible application to cancer classification, prognosis and to the identification of new therapies.

scholarly journals Central Role of C2H2-Type Zinc Finger-Containing Genes in Pediatric Brain Tumors

DNA ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 1-21
Author(s):  
Dimitrios S. Kanakoglou ◽  
Andromachi Pampalou ◽  
Lina S. Malakou ◽  
Eleftheria Lakiotaki ◽  
Theodoros Loupis ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Brain Tumors ◽  
Zinc Finger ◽  
Molecular Mechanisms ◽  
Pediatric Brain Tumors ◽  
Cell Polarization ◽  
Gene Clustering ◽  
Tumor Types ◽  
Pediatric Brain

Zinc fingers consist of one of the most abundant motifs in transcription factors and DNA-binding proteins. Recent studies provide evidence on the pathological implication of zinc finger proteins in various neurodevelopmental disorders and malignancies but their role in pediatric brain tumors is largely unexplored. To this end, we investigated the differential expression of zinc finger-containing genes along with relevant biological processes and pathways among four main brain tumor categories (pilocytic astrocytomas, ependymomas, medulloblastomas and glioblastomas). By employing an extended bioinformatic toolset, we performed a preliminary in silico study in order to identify the expression of zinc finger-containing genes and associated functions in pediatric brain tumors. Our data analysis reveals the prominent role of C2H2-type zinc finger-containing genes in the molecular mechanisms underlying pediatric brain tumors followed by the Ring and PHD finger types. Significant dysregulation of ABLIM2 and UHFR1 genes was detected in all tumor types drawing attention to the dysregulation of cell polarization process and Ubiquitin-Proteasome System (UPS) in the pathogenesis of pediatric brain tumors. Moreover, significant gene clustering was observed in multiple locations with two highly visible clusters revealing a contrast in gene regulation between medulloblastomas and the other three brain tumor types, indicating a promising area of future research.

scholarly journals An outline of SARS-CoV-2 pathogenesis and the complement cascade of immune system

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Padmalochan Hembram
Keyword(s):  
Immune System ◽  
Dark Side ◽  
Main Body ◽  
The Novel ◽  
Transmission Chain ◽  
The World ◽  
Therapeutic Molecules ◽  
Rapid Transmission ◽  
Novel Coronavirus ◽  
Near Future

Abstract Background Coronavirus disease 19 is a viral infection caused by a novel coronavirus, SARS-CoV-2. It was first notified in Wuhan, China, is now spread into numerous part of the world. Thus, the world needs urgent support and encouragement to develop a vaccine or antiviral treatments to combat the atrocious outbreak. Main body of the abstract The origin of this virus is yet unknown; however, rapid transmission from human-to-human “Anthroponosis” has widely confirmed. The world is witnessing a continuous hike in SARS-CoV-2 infection. In light of the outbreak of coronavirus disease 19, we have aimed to highlight the basic and vital information about the novel coronavirus. We provide an overview of SARS-CoV-2 transmission, timeline and its pathophysiological properties which would be an aid for the development of therapeutic molecules and antiviral drugs. Immune system plays a crucial role in virus infection in order to control but may have dark side when becomes uncontrollable. The host and SARS-CoV-2 interaction describe how the virus exploits host machinery and how overactive host immune response can cause disease severity also addressed in this review. Short conclusion Safe and effective vaccines may be the game-changing tools, but in the near future wearing mask, washing hands at regular intervals, avoiding crowed, maintaining physical distancing and hygienic surrounding, must be good practices to reduce and break the transmission chain. Still, research is ongoing not only on how vaccines protect against disease, but also against infection and transmission.

scholarly journals Characterization of symbiotic and associated bacteria from entomopathogenic nematode Heterorhabditis sp. (nematode: Heterorhabditidae) isolated from India

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Rashid Pervez ◽  
Showkat Ahmad Lone ◽  
Sasmita Pattnaik
Keyword(s):  
Insect Pests ◽  
Entomopathogenic Nematode ◽  
Alcaligenes Faecalis ◽  
Symbiotic Bacteria ◽  
Rrna Gene ◽  
Main Body ◽  
Associated Bacteria ◽  
Molecular Approaches

Abstract Background Entomopathogenic nematodes (EPNs) harboring symbiotic bacteria are one of the safest alternatives to the chemical insecticides for the control of various insect pests. Infective juveniles of EPNs locate a target insect, enter through the openings, and reach the hemocoel, where they release the symbiotic bacteria and the target gets killed by the virulence factors of the bacteria. Photorhabdus with Heterorhabditis spp. are well documented; little is known about the associated bacteria. Main body In this study, we explored the presence of symbiotic and associated bacteria from Heterorhabditis sp. (IISR-EPN 09) and characterized by phenotypic, biochemical, and molecular approaches. Six bacterial isolates, belonging to four different genera, were recovered and identified as follows: Photorhabdus luminescens, one each strain of Providencia vermicola, Pseudomonas entomophila, Alcaligenes aquatilis, and two strains of Alcaligenes faecalis based on the phenotypic, biochemical criteria and the sequencing of 16S rRNA gene. Conclusion P. luminescens is symbiotically associated with Heterorhabditis sp. (IISR-EPN 09), whereas P. vermicola, P. entomophila, A. aquatilis, and A. faecalis are the associated bacteria. Further studies are needed to determine the exact role of the bacterial associates with the Heterorhabditis sp.

scholarly journals The role of neurohormonal blockers in the primary prevention of acute-, early-, and late-onset anthracycline-induced cardiotoxicity

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Ahmed Ayuna ◽  
Nik Abidin
Keyword(s):  
Primary Prevention ◽  
Myocardial Injury ◽  
Troponin I ◽  
Late Onset ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Main Body ◽  
Converting Enzyme Inhibitors ◽  
Ventricular Ejection Fraction

Abstract Background Anthracycline-induced cardiotoxicity has been classified based on its onset into acute, early, and late. It may have a significant burden on the quality and quantity of life of those exposed to this class of medication. Currently, there are several ongoing debates on the role of different measures in the primary prevention of cardiotoxicity in cancer survivors. Our article aims to focus on the role of neurohormonal blockers in the primary prevention of anthracycline-induced cardiotoxicity, whether it is acute, early, or late onset. Main body of the abstract PubMed and Google Scholar database were searched for the relevant articles; we reviewed and appraised 15 RCTs, and we found that angiotensin-converting enzyme inhibitors (ACEI) and B-blockers were the most commonly used agents. Angiotensin II receptor blockers (ARBs) and mineralocorticoid receptor antagonists (MRAs) were used in a few other trials. The follow-up period was on the range of 1–156 weeks (mode 26 weeks). Left ventricular ejection fraction (LVEF), left ventricular diameters, and diastolic function were assessed by either echocardiogram or occasionally by cardiac magnetic resonance imaging (MRI). The occurrence of myocardial injury was assessed by troponin I. It was obvious that neurohormonal blockers reduced the occurrence of LVEF and myocardial injury in 14/15 RCTs. Short conclusion Beta-blockers, especially carvedilol and ACEI, especially enalapril, should be considered for the primary prevention of acute- and early-onset cardiotoxicity. ARB and MRA are suitable alternatives when patients are intolerant to ACE-I and B-blockers. We recommend further studies to explore and establish the role of neurohormonal blockers in the primary prevention of the acute-, early-, and late-onset cardiotoxicity.

scholarly journals Impact of sex in the prevalence and progression of glioblastomas: the role of gonadal steroid hormones

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Claudia Bello-Alvarez ◽  
Ignacio Camacho-Arroyo
Keyword(s):  
Cell Proliferation ◽  
Steroid Hormones ◽  
Physiological State ◽  
Migration And Invasion ◽  
Low Grade ◽  
Main Body ◽  
Protective Effects ◽  
Gonadal Steroid Hormones ◽  
Gonadal Steroid

Abstract Background As in other types of cancers, sex is an essential factor in the origin and progression of glioblastomas. Research in the field of endocrinology and cancer suggests that gonadal steroid hormones play an important role in the progression and prevalence of glioblastomas. In the present review, we aim to discuss the actions and mechanism triggered by gonadal steroid hormones in glioblastomas. Main body Glioblastoma is the most common malignant primary brain tumor. According to the epidemiological data, glioblastomas are more frequent in men than in women in a 1.6/1 proportion both in children and adults. This evidence, and the knowledge about sex influence over the prevalence of countless diseases, suggest that male gonadal steroid hormones, such as testosterone, promote glioblastomas growth. In contrast, a protective role of female gonadal steroid hormones (estradiol and progesterone) against glioblastomas has been questioned. Several pieces of evidence demonstrate a variety of effects induced by female and male gonadal steroid hormones in glioblastomas. Several studies indicate that pregnancy, a physiological state with the highest progesterone and estradiol levels, accelerates the progression of low-grade astrocytomas to glioblastomas and increases the symptoms associated with these tumors. In vitro studies have demonstrated that progesterone has a dual role in glioblastoma cells: physiological concentrations promote cell proliferation, migration, and invasion while very high doses (out physiological range) reduce cell proliferation and increases cell death. Conclusion Gonadal steroid hormones can stimulate the progression of glioblastomas through the increase in proliferation, migration, and invasion. However, the effects mentioned above depend on the concentrations of these hormones and the receptor involved in hormone actions. Estradiol and progesterone can exert promoter or protective effects while the role of testosterone has been always associated to glioblastomas progression.

scholarly journals mTORC1 and mTORC2 regulate insulin secretion through Akt in INS-1 cells

2012 ◽  
Vol 216 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Olivier Le Bacquer ◽  
Gurvan Queniat ◽  
Valery Gmyr ◽  
Julie Kerr-Conte ◽  
Bruno Lefebvre ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Cell Function ◽  
Antagonistic Effect ◽  
Dominant Negative ◽  
Insulin Content ◽  
Insulin Biosynthesis ◽  
Direct Role ◽  
Β Cell Function ◽  
Glucose Stimulated Insulin Secretion

Regulated associated protein of mTOR (Raptor) and rapamycin-insensitive companion of mTOR (rictor) are two proteins that delineate two different mTOR complexes, mTORC1 and mTORC2 respectively. Recent studies demonstrated the role of rictor in the development and function of β-cells. mTORC1 has long been known to impact β-cell function and development. However, most of the studies evaluating its role used either drug treatment (i.e. rapamycin) or modification of expression of proteins known to modulate its activity, and the direct role of raptor in insulin secretion is unclear. In this study, using siRNA, we investigated the role of raptor and rictor in insulin secretion and production in INS-1 cells and the possible cross talk between their respective complexes, mTORC1 and mTORC2. Reduced expression of raptor is associated with increased glucose-stimulated insulin secretion and intracellular insulin content. Downregulation of rictor expression leads to impaired insulin secretion without affecting insulin content and is able to correct the increased insulin secretion mediated by raptor siRNA. Using dominant-negative or constitutively active forms of Akt, we demonstrate that the effect of both raptor and rictor is mediated through alteration of Akt signaling. Our finding shed new light on the mechanism of control of insulin secretion and production by the mTOR, and they provide evidence for antagonistic effect of raptor and rictor on insulin secretion in response to glucose by modulating the activity of Akt, whereas only raptor is able to control insulin biosynthesis.

scholarly journals Regulation of Insulin Secretion and β-Cell Mass by Activating Signal Cointegrator 2

2006 ◽  
Vol 26 (12) ◽  
pp. 4553-4563 ◽  
Author(s):  
Seon-Yong Yeom ◽  
Geun Hyang Kim ◽  
Chan Hee Kim ◽  
Heun Don Jung ◽  
So-Yeon Kim ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Endocrine Cells ◽  
Potential Role ◽  
Cell Mass ◽  
Dominant Negative ◽  
Transcriptional Coactivator ◽  
Β Cells ◽  
Β Cell ◽  
Islet Mass

ABSTRACT Activating signal cointegrator 2 (ASC-2) is a transcriptional coactivator of many nuclear receptors (NRs) and other transcription factors and contains two NR-interacting LXXLL motifs (NR boxes). In the pancreas, ASC-2 is expressed only in the endocrine cells of the islets of Langerhans, but not in the exocrine cells. Thus, we examined the potential role of ASC-2 in insulin secretion from pancreatic β-cells. Overexpressed ASC-2 increased glucose-elicited insulin secretion, whereas insulin secretion was decreased in islets from ASC-2+/− mice. DN1 and DN2 are two dominant-negative fragments of ASC-2 that contain NR boxes 1 and 2, respectively, and block the interactions of cognate NRs with the endogenous ASC-2. Primary rat islets ectopically expressing DN1 or DN2 exhibited decreased insulin secretion. Furthermore, relative to the wild type, ASC-2+/− mice showed reduced islet mass and number, which correlated with increased apoptosis and decreased proliferation of ASC-2+/− islets. These results suggest that ASC-2 regulates insulin secretion and β-cell survival and that the regulatory role of ASC-2 in insulin secretion appears to involve, at least in part, its interaction with NRs via its two NR boxes.

scholarly journals Depletion of Centromeric MCAK Leads to Chromosome Congression and Segregation Defects Due to Improper Kinetochore Attachments

2004 ◽  
Vol 15 (3) ◽  
pp. 1146-1159 ◽  
Author(s):  
Susan L. Kline-Smith ◽  
Alexey Khodjakov ◽  
Polla Hergert ◽  
Claire E. Walczak
Keyword(s):  
Essential Role ◽  
Dominant Negative ◽  
Primary Role ◽  
Complex Behavior ◽  
Chromosome Movement ◽  
Immunofluorescence Localization ◽  
Microtubule Attachment ◽  
Chromosome Congression

The complex behavior of chromosomes during mitosis is accomplished by precise binding and highly regulated polymerization dynamics of kinetochore microtubules. Previous studies have implicated Kin Is, unique kinesins that depolymerize microtubules, in regulating chromosome positioning. We have characterized the immunofluorescence localization of centromere-bound MCAK and found that MCAK localized to inner kinetochores during prophase but was predominantly centromeric by metaphase. Interestingly, MCAK accumulated at leading kinetochores during congression but not during segregation. We tested the consequences of MCAK disruption by injecting a centromere dominant-negative protein into prophase cells. Depletion of centromeric MCAK led to reduced centromere stretch, delayed chromosome congression, alignment defects, and severe missegregation of chromosomes. Rates of chromosome movement were unchanged, suggesting that the primary role of MCAK is not to move chromosomes. Furthermore, we found that disruption of MCAK leads to multiple kinetochore–microtubule attachment defects, including merotelic, syntelic, and combined merotelic-syntelic attachments. These findings reveal an essential role for Kin Is in prevention and/or correction of improper kinetochore–microtubule attachments.

scholarly journals Exploring the multiple roles of guardian of the genome: P53

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Wasim Feroz ◽  
Arwah Mohammad Ali Sheikh
Keyword(s):  
Cell Cycle ◽  
Dna Repair ◽  
Crucial Role ◽  
Cellular Response ◽  
Genotoxic Stress ◽  
Specific Response ◽  
Main Body ◽  
Repair System ◽  
Tumour Suppression

Abstract Background Cells have evolved balanced mechanisms to protect themselves by initiating a specific response to a variety of stress. The TP53 gene, encoding P53 protein, is one of the many widely studied genes in human cells owing to its multifaceted functions and complex dynamics. The tumour-suppressing activity of P53 plays a principal role in the cellular response to stress. The majority of the human cancer cells exhibit the inactivation of the P53 pathway. In this review, we discuss the recent advancements in P53 research with particular focus on the role of P53 in DNA damage responses, apoptosis, autophagy, and cellular metabolism. We also discussed important P53-reactivation strategies that can play a crucial role in cancer therapy and the role of P53 in various diseases. Main body We used electronic databases like PubMed and Google Scholar for literature search. In response to a variety of cellular stress such as genotoxic stress, ischemic stress, oncogenic expression, P53 acts as a sensor, and suppresses tumour development by promoting cell death or permanent inhibition of cell proliferation. It controls several genes that play a role in the arrest of the cell cycle, cellular senescence, DNA repair system, and apoptosis. P53 plays a crucial role in supporting DNA repair by arresting the cell cycle to purchase time for the repair system to restore genome stability. Apoptosis is essential for maintaining tissue homeostasis and tumour suppression. P53 can induce apoptosis in a genetically unstable cell by interacting with many pro-apoptotic and anti-apoptotic factors. Furthermore, P53 can activate autophagy, which also plays a role in tumour suppression. P53 also regulates many metabolic pathways of glucose, lipid, and amino acid metabolism. Thus under mild metabolic stress, P53 contributes to the cell’s ability to adapt to and survive the stress. Conclusion These multiple levels of regulation enable P53 to perform diversified roles in many cell responses. Understanding the complete function of P53 is still a work in progress because of the inherent complexity involved in between P53 and its target proteins. Further research is required to unravel the mystery of this Guardian of the genome “TP53”.

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