scholarly journals Spheroid-Derived Cells From Renal Adenocarcinoma Have Low Telomerase Activity and High Stem-Like and Invasive Characteristics

2019 ◽  
Vol 9 ◽  
Author(s):  
Leili Saeednejad Zanjani ◽  
Zahra Madjd ◽  
Arezoo Rasti ◽  
Mojgan Asgari ◽  
Maryam Abolhasani ◽  
...  
Keyword(s):  
Telomerase Activity ◽  
Renal Adenocarcinoma

Oncogenesis and the Lucké Virus

1968 ◽  
Vol 26 ◽  
pp. 200-201
Author(s):  
A. E. Vatter ◽  
J. Zambernard
Keyword(s):  
Rna Viruses ◽  
Vegetative State ◽  
Temperature Sensitive ◽  
Structural Level ◽  
Oncogenic Viruses ◽  
Dna Viruses ◽  
Leopard Frogs ◽  
Renal Adenocarcinoma ◽  
Induced Tumors ◽  
Northern Leopard Frogs

Oncogenic viruses, like viruses in general, can be divided into two classes, those that contain deoxyribonucleic acid (DNA) and those that contain ribonucleic acid (RNA). The RNA viruses have been recovered readily from the tumors which they cause whereas, the DNA-virus induced tumors have not yielded the virus. Since DNA viruses cannot be recovered, the bulk of present day investigations have been concerned with RNA viruses.The Lucké renal adenocarcinoma is a spontaneous tumor which occurs in northern leopard frogs (Rana pipiens) and has received increased attention in recent years because of its probable viral etiology. This hypothesis was first advanced by Lucké after he observed intranuclear inclusions in some of the tumor cells. Tumors with inclusions were examined at the fine structural level by Fawcett who showed that they contained immature and mature virus˗like particles.The use of this system in the study of oncogenic tumors offers several unique features, the virus has been shown to contain DNA and it can be recovered from the tumor, also, it is temperature sensitive. This latter feature is of importance because the virus can be transformed from a latent to a vegetative state by lowering or elevating the environmental temperature.

Efficacy of decitabine in malignant meningioma cells: relation to promoter demethylation of distinct tumor suppressor and oncogenes and independence from TERT

2020 ◽  
pp. 1-10
Author(s):  
Louise Stögbauer ◽  
Christian Thomas ◽  
Andrea Wagner ◽  
Nils Warneke ◽  
Eva Christine Bunk ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Tumor Suppressor ◽  
Promoter Methylation ◽  
Tumor Suppressor Genes ◽  
Telomerase Activity ◽  
High Grade ◽  
Htert Promoter ◽  
Men 1 ◽  
Meningioma Cell ◽  
Tert Expression

OBJECTIVEChemotherapeutic options for meningiomas refractory to surgery or irradiation are largely unknown. Human telomerase reverse transcriptase (hTERT) promoter methylation with subsequent TERT expression and telomerase activity, key features in oncogenesis, are found in most high-grade meningiomas. Therefore, the authors investigated the impact of the demethylating agent decitabine (5-aza-2ʹ-deoxycytidine) on survival and DNA methylation in meningioma cells.METHODShTERT promoter methylation, telomerase activity, TERT expression, and cell viability and proliferation were investigated prior to and after incubation with decitabine in two benign (HBL-52 and Ben-Men 1) and one malignant (IOMM-Lee) meningioma cell line. The global effects of decitabine on DNA methylation were additionally explored with DNA methylation profiling.RESULTSHigh levels of TERT expression, telomerase activity, and hTERT promoter methylation were found in IOMM-Lee and Ben-Men 1 but not in HBL-52 cells. Decitabine induced a dose-dependent significant decrease of proliferation and viability after incubation with doses from 1 to 10 μM in IOMM-Lee but not in HBL-52 or Ben-Men 1 cells. However, effects in IOMM-Lee cells were not related to TERT expression, telomerase activity, or hTERT promoter methylation. Genome-wide methylation analyses revealed distinct demethylation of 14 DNA regions after drug administration in the decitabine-sensitive IOMM-Lee but not in the decitabine-resistant HBL-52 cells. Differentially methylated regions covered promoter regions of 11 genes, including several oncogenes and tumor suppressor genes that to the authors’ knowledge have not yet been described in meningiomas.CONCLUSIONSDecitabine decreases proliferation and viability in high-grade but not in benign meningioma cell lines. The effects of decitabine are TERT independent but related to DNA methylation changes of promoters of distinct tumor suppressor genes and oncogenes.

scholarly journals Bi-allelic MCM10 variants associated with immune dysfunction and cardiomyopathy cause telomere shortening

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ryan M. Baxley ◽  
Wendy Leung ◽  
Megan M. Schmit ◽  
Jacob Peter Matson ◽  
Lulu Yin ◽  
...  
Keyword(s):  
Immune Cell ◽  
Nk Cell ◽  
Restrictive Cardiomyopathy ◽  
Telomerase Activity ◽  
Compound Heterozygous ◽  
Minichromosome Maintenance ◽  
Telomere Shortening ◽  
Clinical Phenotypes ◽  
Eukaryotic Dna ◽  
Minichromosome Maintenance Protein

AbstractMinichromosome maintenance protein 10 (MCM10) is essential for eukaryotic DNA replication. Here, we describe compound heterozygous MCM10 variants in patients with distinctive, but overlapping, clinical phenotypes: natural killer (NK) cell deficiency (NKD) and restrictive cardiomyopathy (RCM) with hypoplasia of the spleen and thymus. To understand the mechanism of MCM10-associated disease, we modeled these variants in human cell lines. MCM10 deficiency causes chronic replication stress that reduces cell viability due to increased genomic instability and telomere erosion. Our data suggest that loss of MCM10 function constrains telomerase activity by accumulating abnormal replication fork structures enriched with single-stranded DNA. Terminally-arrested replication forks in MCM10-deficient cells require endonucleolytic processing by MUS81, as MCM10:MUS81 double mutants display decreased viability and accelerated telomere shortening. We propose that these bi-allelic variants in MCM10 predispose specific cardiac and immune cell lineages to prematurely arrest during differentiation, causing the clinical phenotypes observed in both NKD and RCM patients.

Telomerase activity correlates with tumor aggressiveness and reflects therapy effect in breast cancer

1998 ◽  
Vol 79 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Axel Hoos ◽  
Hedwig H. Hepp ◽  
Sepp Kaul ◽  
Thorsten Ahlert ◽  
Gunther Bastert ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Telomerase Activity ◽  
Tumor Aggressiveness ◽  
Therapy Effect
Sign in / Sign up

Export Citation Format

Share Document