Filter and export

Publications

What is a Publication?
77 Publications visible to you, out of a total of 77
High-Resolution Cartography of the Transcriptome and Methylome Landscapes of Diffuse Gliomas

Abstract (Expand)

Molecular mechanisms of lower-grade (II–III) diffuse gliomas (LGG) are still poorly understood, mainly because of their heterogeneity. They split into astrocytoma- (IDH-A) and oligodendroglioma-like … (IDH-O) tumors both carrying mutations(s) at the isocitrate dehydrogenase (IDH) gene and into IDH wild type (IDH-wt) gliomas of glioblastoma resemblance. We generated detailed maps of the transcriptomes and DNA methylomes, revealing that cell functions divided into three major archetypic hallmarks: (i) increased proliferation in IDH-wt and, to a lesser degree, IDH-O; (ii) increased inflammation in IDH-A and IDH-wt; and (iii) the loss of synaptic transmission in all subtypes. Immunogenic properties of IDH-A are diverse, partly resembling signatures observed in grade IV mesenchymal glioblastomas or in grade I pilocytic astrocytomas. We analyzed details of coregulation between gene expression and DNA methylation and of the immunogenic micro-environment presumably driving tumor development and treatment resistance. Our transcriptome and methylome maps support personalized, case-by-case views to decipher the heterogeneity of glioma states in terms of data portraits. Thereby, molecular cartography provides a graphical coordinate system that links gene-level information with glioma subtypes, their phenotypes, and clinical context.

Authors: Edith Willscher, Lydia Hopp, Markus Kreuz, Maria Schmidt, Siras Hakobyan, Arsen Arakelyan, Bettina Hentschel, David T. W. Jones, Stefan M. Pfister, Markus Loeffler, Henry Loeffler-Wirth, Hans Binder

Date Published: 26th Jun 2021

Publication Type: Journal

The radioenhancement potential of Schiff base derived copper (II) compounds against lung carcinoma in vitro.

Abstract (Expand)

For the last years, copper complexes have been intensively implicated in biomedical research as components of cancer treatment. Herewith, we provide highlights of the synthesis, physical measurements, … structural characterization of the newly developed Cu(II) chelates of Schiff Bases, Cu(Picolinyl-L-Tryptopahanate)2, Cu(Picolinyl-L-Tyrosinate)2, Cu(Isonicotinyl-L-Tyrosinate)2, Cu(Picolinyl-L-Phenylalaninate)2, Cu(Nicotinyl-L-Phenylalaninate)2, Cu(Isonicotinyl-L-Phenylalaninate)2, and their radioenhancement capacity at kV and MV ranges of irradiation of human lung carcinoma epithelial cells in vitro. The methods of cell growth, viability and proliferation were used. All compounds exerted very potent radioenhancer capacities in the irradiated lung carcinoma cells at both kV and MV ranges in a 100 μM concentration. At a concentration of 10 μM, only Cu(Picolinyl-L-Tyrosinate)2, Cu(Isonicotinyl-L-Tyrosinate)2, Cu(Picolinyl-L-Phenylalaninate)2 possessed radioenhancer properties at kV and MV ranges. Cu(Picolinyl-L-Tryptophanate)2 showed radioenhancer properties only at kV range. Cu(Nicotinyl-L-Phenylalaninate)2 and Cu(Isonicotinyl-L-Phenylalaninate)2 showed remarkable radioenhancer activity only at MV range. All compounds acted in dose-dependent manner at both tested energy ranges. These copper (II) compounds, in combination with 1 Gy irradiation at either 120 kV or 6 MV, are more efficient at delaying cell growth of lung cancer cells and at reducing cell viability in vitro than the irradiation administered alone. Thus, we have demonstrated that the studied copper compounds have a good potential for radioenhancement.

Authors: Gohar Tsakanova, Ani Stepanyan, Elina Arakelova, Violetta Ayvazyan, Vahan Tonoyan, Arsen Arakelyan, Guido Hildebrandt, Elisabeth Schültke

Date Published: 18th Jun 2021

Publication Type: Journal

SARS-CoV-2 detection by extraction-free qRT-PCR for massive and rapid COVID-19 diagnosis during a pandemic in Armenia

Abstract (Expand)

COVID-19 pandemic severely impacted the healthcare and economy on a global scale. It is widely recognized that mass testing is an efficient way to contain the spread of SARS-CoV-2 infection as well as … aid in the development of informed policies for disease management. However, the current COVID-19 worldwide infection rates increased the demand for rapid and reliable screening of infection. We compared the performance of qRT-PCR in direct heat-inactivated (H), heat-inactivated and pelleted (HC) samples against RNA in a group of 74 subjects (44 positive and 30 negative). Then we compared the sensitivity of HC in a larger group of 196 COVID-19 positive samples. Our study suggests that HC samples show higher accuracy for SARS-CoV-2 detection PCR assay compared to direct H (89 % vs 83 % of the detection in RNA). The sensitivity of detection using direct samples varied depending on the sample transport and storage media as well as the viral loads (as measured by qRT-PCR Ct levels). Altogether, all the data suggest that purified RNA provides more accurate results, however, direct sample testing with qRT-PCR may help to significantly increase testing capacity. Switching to the direct sample testing is justified if the number of tests is doubled at least.

Authors: Diana Avetyan, Andranik Chavushyan, Hovsep Ghazaryan, Ani Melkonyan, Ani Stepanyan, Roksana Zakharyan, Varduhi Hayrapetyan, Sofi Atshemyan, Gisane Khachatryan, Tamara Sirunyan, Suren Davitavyan, Gevorg Martirosyan, Gayane Melik-Andreasyan, Shushan Sargsyan, Armine Ghazazyan, Naira Aleksanyan, Xiushan Yin, Arsen Arakelyan

Date Published: 4th Jun 2021

Publication Type: Journal

Telomere Maintenance Pathway Activity Analysis Enables Tissue- and Gene-Level Inferences.

Abstract (Expand)

Telomere maintenance is one of the mechanisms ensuring indefinite divisions of cancer and stem cells. Good understanding of telomere maintenance mechanisms (TMM) is important for studying cancers and … designing therapies. However, molecular factors triggering selective activation of either the telomerase dependent (TEL) or the alternative lengthening of telomeres (ALT) pathway are poorly understood. In addition, more accurate and easy-to-use methodologies are required for TMM phenotyping. In this study, we have performed literature based reconstruction of signaling pathways for the ALT and TEL TMMs. Gene expression data were used for computational assessment of TMM pathway activities and compared with experimental assays for TEL and ALT. Explicit consideration of pathway topology makes bioinformatics analysis more informative compared to computational methods based on simple summary measures of gene expression. Application to healthy human tissues showed high ALT and TEL pathway activities in testis, and identified genes and pathways that may trigger TMM activation. Our approach offers a novel option for systematic investigation of TMM activation patterns across cancers and healthy tissues for dissecting pathway-based molecular markers with diagnostic impact.

Authors: L. Nersisyan, A. Simonyan, H. Binder, A. Arakelyan

Date Published: 26th Apr 2021

Publication Type: Journal

Long-Term Effects of Very Low Dose Particle Radiation on Gene Expression in the Heart: Degenerative Disease Risks

Abstract (Expand)

Compared to low doses of gamma irradiation (γ-IR), high-charge-and-energy (HZE) particle IR may have different biological response thresholds in cardiac tissue at lower doses, and these effects may be … IR type and dose dependent. Three- to four-month-old female CB6F1/Hsd mice were exposed once to one of four different doses of the following types of radiation: γ-IR 137Cs (40-160 cGy, 0.662 MeV), 14Si-IR (4-32 cGy, 260 MeV/n), or 22Ti-IR (3-26 cGy, 1 GeV/n). At 16 months post-exposure, animals were sacrificed and hearts were harvested and archived as part of the NASA Space Radiation Tissue Sharing Forum. These heart tissue samples were used in our study for RNA isolation and microarray hybridization. Functional annotation of twofold up/down differentially expressed genes (DEGs) and bioinformatics analyses revealed the following: (i) there were no clear lower IR thresholds for HZE- or γ-IR; (ii) there were 12 common DEGs across all 3 IR types; (iii) these 12 overlapping genes predicted various degrees of cardiovascular, pulmonary, and metabolic diseases, cancer, and aging; and (iv) these 12 genes revealed an exclusive non-linear DEG pattern in 14Si- and 22Ti-IR-exposed hearts, whereas two-thirds of γ-IR-exposed hearts revealed a linear pattern of DEGs. Thus, our study may provide experimental evidence of excess relative risk (ERR) quantification of low/very low doses of full-body space-type IR-associated degenerative disease development.

Authors: Venkata Naga Srikanth Garikipati, Arsen Arakelyan, Eleanor A. Blakely, Polly Y. Chang, May M. Truongcao, Maria Cimini, Vandana Malaredy, Anamika Bajpai, Sankar Addya, Malik Bisserier, Agnieszka Brojakowska, Abrisham Eskandari, Mary K. Khlgatian, Lahouaria Hadri, Kenneth M. Fish, Raj Kishore, David. A. Goukassian

Date Published: 13th Feb 2021

Publication Type: Journal

Transcriptome Patterns of BRCA1- and BRCA2- Mutated Breast and Ovarian Cancers

Abstract (Expand)

Mutations in the BRCA1 and BRCA2 genes are known risk factors and drivers of breast and ovarian cancers. So far, few studies have been focused on understanding the differences in transcriptome and …d functional landscapes associated with the disease (breast vs. ovarian cancers), gene (BRCA1 vs. BRCA2), and mutation type (germline vs. somatic). In this study, we were aimed at systemic evaluation of the association of BRCA1 and BRCA2 germline and somatic mutations with gene expression, disease clinical features, outcome, and treatment. We performed BRCA1/2 mutation centered RNA-seq data analysis of breast and ovarian cancers from the TCGA repository using transcriptome and phenotype “portrayal” with multi-layer self-organizing maps and functional annotation. The results revealed considerable differences in BRCA1- and BRCA2-dependent transcriptome landscapes in the studied cancers. Furthermore, our data indicated that somatic and germline mutations for both genes are characterized by deregulation of different biological functions and differential associations with phenotype characteristics and poly(ADP-ribose) polymerase (PARP)-inhibitor gene signatures. Overall, this study demonstrates considerable variation in transcriptomic landscapes of breast and ovarian cancers associated with the affected gene (BRCA1 vs. BRCA2), as well as the mutation type (somatic vs. germline). These results warrant further investigations with larger groups of mutation carriers aimed at refining the understanding of molecular mechanisms of breast and ovarian cancers.

Authors: Arsen Arakelyan, Ani Melkonyan, Siras Hakobyan, Uljana Boyarskih, Arman Simonyan, Lilit Nersisyan, Maria Nikoghosyan, Maxim Filipenko, Hans Binder

Date Published: 28th Jan 2021

Publication Type: Journal

Extended-Spectrum β-Lactamases in Human Isolates of Multidrug-Resistant Non-typhoidal Salmonella enterica

Abstract (Expand)

A total of 291 non-duplicate isolates of non-typhoidal Salmonella (NTS) were collected from the fecal samples of patients with salmonellosis in Armenia and Georgia during 1996-2016. The isolates were … tested for resistance to antimicrobials, including extended-spectrum β-lactamases (ESBL). The high prevalence of multidrug-resistance (MDR) and ESBL-producer phenotypes was detected among Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) isolates collected from patients in Armenia between 1996 and 2016. A total of 36 MDR NTS isolates were subjected to whole genome sequencing (WGS) to determine the genetic background of antimicrobial resistance (AMR) and mobile genetic elements. All ESBL-producing S. Typhimurium isolates belonged to the same sequence type (ST328). The ESBL-producer phenotype was associated with plasmid-encoded CTX-M-5 production. A range of other plasmids was associated with resistance to other antimicrobials, including the MDR phenotype.

Authors: Anahit M. Sedrakyan, Zhanna A. Ktsoyan, Karine A. Arakelova, Magdalina K. Zakharyan, Alvard I. Hovhannisyan, Zaruhi U. Gevorgyan, Armine A. Mnatsakanyan, Elene G. Kakabadze, Khatuna B. Makalatia, Nina A. Chanishvili, Jean-Paul Pirnay, Arsen A. Arakelyan, Rustam I. Aminov

Date Published: 22nd Dec 2020

Publication Type: Journal

Powered by
 (v.1.15.0-main)
About ArmLifeBank | Funding and Programmes | Credits
Copyright © 2008 - 2024 The University of Manchester and HITS gGmbH