Oncogenesis and the Lucké Virus

Author(s):  
A. E. Vatter ◽  
J. Zambernard

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.

1973 ◽  
Vol 137 (1) ◽  
pp. 85-111 ◽  
Author(s):  
J. C. Unkeless ◽  
A. Tobia ◽  
L. Ossowski ◽  
J. P. Quigley ◽  
D. B. Rifkin ◽  
...  

Chick embryo fibroblast cultures develop fibrinolytic activity after transformation by Rous sarcoma virus (RSV). This fibrinolytic activity is not present in normal cultures, and it does not appear after infection with either nontransforming strains of avian leukosis viruses or cytocidal RNA and DNA viruses. In cultures infected with a temperature sensitive mutant of RSV the onset of fibrinolysis appears after exposure to permissive temperatures and precedes by a short interval the appearance of morphological evidence of transformation. See PDF for Structure The rate of fibrinolysis in transformed cultures depends on the nature of the serum that is present in the growth medium: some sera (e.g., monkey or chicken serum) promote high enzymatic activity, while others (calf, fetal bovine) do not. Some sera contain inhibitors of the fibrinolysin. Based on the effect of a small number of known inhibitors, at least one step of the fibrinolytic process shows specificity resembling that of trypsin. The sera of sarcoma-bearing chickens contain an inhibitor of the fibrinolysin, whereas normal chicken sera do not. For general discussion, conclusions, and summary see the accompanying paper, part II, (J. Exp. Med. 137:112).


2005 ◽  
Vol 133 (7-8) ◽  
pp. 384-387 ◽  
Author(s):  
Maja Cupic ◽  
Ivana Lazarevic ◽  
Nada Kuljic-Kapulica

Oncogenic viruses trigger persistent infections, which can stimulate uncontrolled cell growth by inducing cell transformation. Different oncogenic viruses use different mechanisms for infecting cells. Most oncogenic DNA viruses integrate transforming sets of genes into the host chromosome and encode proteins that bind and inactivate cell growth regulatory proteins, such as p53 and retinoblastoma gene product. Tumorous RNA viruses use different oncogenic mechanisms. Some of them encode oncogenic proteins that are almost identical to the cellular proteins involved in the control of cellular growth. The overproduction or altered function of these oncogenic materials stimulates cell growth. These RNA viruses can cause tumors rapidly. The second group of oncoviruses integrates their promoter sequences and viral enhancers near to the cellular growth-stimulating gene, initiating the transformation of the cell. The third group of RNA tumor viruses encodes a protein tax that transactivates the expression of cellular genes. Virus-induced malignant transformation of the cell represents the first step in the complex process of oncogenesis.


Author(s):  
S.I. Kutukova ◽  
A.B. Chukhlovin ◽  
A.I. Yaremenko ◽  
Yu.V. Ivaskova ◽  
A.Ya. Razumova ◽  
...  

The aim of the study was to assess the prevalence of DNA viruses (HSV I and II, CMV, EBV, HPV6.11, HPV16 and HPV18) in the native oral mucosa of healthy volunteers (n=50; 30 men (60.0%), 20 women (40.0%); 25—74 years, median age — 55.0 years (95% CI 47.60-56.76)). All samples of the normal oral mucosa were detected by real-time PCR to detect viral DNA. The majority of the examined — 76% (33/50) — revealed the DNA: one type of viral DNA in 17 (38.00%) of the examined, a combination of the two types in 14 (28.00%). In the normal oral mucosa, DNA of Epstein-Barr virus was significantly more often detected: 15 (30.00%) (p = 0.0276) and human papilloma viruses 27 (54.00%) (p <0.0001), especially HPV-18 (24 (48.00%)): mono-association in 9 (18.00%) examined and in 7 (14.00%) in combination with EBV DNA (p = 0.0253).


Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1086
Author(s):  
Francois Helle ◽  
Lynda Handala ◽  
Marine Bentz ◽  
Gilles Duverlie ◽  
Etienne Brochot

Extracellular vesicles have recently emerged as a novel mode of viral transmission exploited by naked viruses to exit host cells through a nonlytic pathway. Extracellular vesicles can allow multiple viral particles to collectively traffic in and out of cells, thus enhancing the viral fitness and diversifying the transmission routes while evading the immune system. This has been shown for several RNA viruses that belong to the Picornaviridae, Hepeviridae, Reoviridae, and Caliciviridae families; however, recent studies also demonstrated that the BK and JC viruses, two DNA viruses that belong to the Polyomaviridae family, use a similar strategy. In this review, we provide an update on recent advances in understanding the mechanisms used by naked viruses to hijack extracellular vesicles, and we discuss the implications for the biology of polyomaviruses.


2021 ◽  
Author(s):  
Rajan Saha Raju ◽  
Abdullah Al Nahid ◽  
Preonath Shuvo ◽  
Rashedul Islam

AbstractTaxonomic classification of viruses is a multi-class hierarchical classification problem, as taxonomic ranks (e.g., order, family and genus) of viruses are hierarchically structured and have multiple classes in each rank. Classification of biological sequences which are hierarchically structured with multiple classes is challenging. Here we developed a machine learning architecture, VirusTaxo, using a multi-class hierarchical classification by k-mer enrichment. VirusTaxo classifies DNA and RNA viruses to their taxonomic ranks using genome sequence. To assign taxonomic ranks, VirusTaxo extracts k-mers from genome sequence and creates bag-of-k-mers for each class in a rank. VirusTaxo uses a top-down hierarchical classification approach and accurately assigns the order, family and genus of a virus from the genome sequence. The average accuracies of VirusTaxo for DNA viruses are 99% (order), 98% (family) and 95% (genus) and for RNA viruses 97% (order), 96% (family) and 82% (genus). VirusTaxo can be used to detect taxonomy of novel viruses using full length genome or contig sequences.AvailabilityOnline version of VirusTaxo is available at https://omics-lab.com/virustaxo/.


2015 ◽  
Vol 11 (1) ◽  
Author(s):  
Laetitia Tatiersky ◽  
Louise A. Rollins-Smith ◽  
Ray Lu ◽  
Claire Jardine ◽  
Ian K. Barker ◽  
...  

2004 ◽  
Vol 39 (3) ◽  
pp. 160-174 ◽  
Author(s):  
Tana V. McDaniel ◽  
Megan L. Harris ◽  
Christine A. Bishop ◽  
John Struger

Abstract High levels of contamination in the aquatic environment and wildlife within the Ontario portion of the St. Lawrence River at the Cornwall Area of Concern (AOC) have raised questions about potential impacts on wildlife health. Northern leopard frog embryos were raised in two wetland sites within the AOC and at two reference sites to assess differences in water and sediment quality on survivorship and deformity rates. Chlorinated hydrocarbons (total polychlorinated biphenyls, organochlorine pesticides), polycyclic aromatic hydrocarbons, nutrients and heavy metals were measured in sediment and/or water from the study sites. Levels of some metals such as aluminium, cadmium, chromium and copper, exceeded federal and provincial guidelines for the protection of aquatic life, especially in the two AOC wetlands. Early stage tadpole survivorship was significantly lower and deformity frequency significantly higher at wetlands within the AOC; however, differences were likely not biologically significant. Survivorship and deformity rates of leopard frogs (Rana pipiens) at metamorphosis did not differ significantly among sites. Onset of metamorphosis was accelerated in tadpoles raised in wetlands within the AOC. Tadpoles raised in wetlands within the St. Lawrence River AOC took significantly less time to complete metamorphosis (53–55 days) than did tadpoles raised at reference sites (61–64 days). The phenology of metamorphosis was also more synchronous in tadpoles raised in the AOC, with all tadpoles reaching metamorphosis within a space of 3 to 7 days, as compared to 9 to 12 days at reference wetlands; these differences could not be accounted for by water temperature. Differences in development and survivorship rates between AOC and reference sites may be related to contaminant concentrations in water and sediment. However, no strong evidence for beneficial use impairment in terms of reproductive impairments or elevated deformity rates were seen from caged leopard frogs in the two AOC wetlands.


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