• mechanisms
  • These two mechanisms differ in their biology and epidemiology: direct tumor viruses must have at least one virus copy in every tumor cell expressing at least one protein or RNA that is causing the cell to become cancerous. (wikipedia.org)
  • Thus, viruses not only have been shown to represent etiologic agents for many human cancers but have also served as tools to reveal mechanisms that are involved in all human malignancies. (aacrjournals.org)
  • Capecchi and Smithies independently discovered applications to mouse embryonic stem cells, however the highly conserved mechanisms underlying the DSB repair model, including uniform homologous integration of transformed DNA (gene therapy), were first shown in plasmid experiments by Orr-Weaver, Szostack and Rothstein. (wikipedia.org)
  • Fox's primary achievement in the early part of his career was to turn bacterial transformation into an experimental model for genetic analysis that was to provide key insights into the mechanisms of genetic modification. (wikipedia.org)
  • genomic
  • Our results demonstrated that S/MAR DNA vectors are able to produce genetically modified cells without the limitations of random genomic integration, whilst providing extra-chromosomal mitotic stability and sustained transgene expression at high level. (aacrjournals.org)
  • There is a diverse classification scheme for the various genomic changes that may contribute to the generation of cancer cells. (wikipedia.org)
  • thus
  • It thus appears that an excess of c-myc protein is a primary cause of numerous cancers. (aacrjournals.org)
  • The fact that AAV has evolved to integrate into this ubiquitously transcribed region and that the chromosomal motifs required for integration are located a few nucleotides upstream of the translation initiation start codon of MBS85 suggests that the transcriptional activity of MBS85 might influence site-specific integration and thus might be involved in the evolution of this mechanism. (pubmedcentralcanada.ca)
  • Thus, RSV became known as the first oncogenic retrovirus that could be used to study the development of cancer molecularly. (wikipedia.org)
  • thus, each host gene locus is hit by the provirus integration in many cells of the target tissue at different positions. (aacrjournals.org)
  • What is being discussed amid heated arguments against "aids deniers" are the scientific merits of the isolation of the virus that is said to cause AIDS, and thus of the tests that determine whether a person is infected or not. (newmediaexplorer.org)
  • The work of her team thus demonstrated a mechanism involved in the direct tumorigenic effect of this virus. (wikipedia.org)
  • Once inside the host cell cytoplasm, the virus uses its own reverse transcriptase enzyme to produce DNA from its RNA genome, the reverse of the usual pattern, thus retro (backwards). (wikipedia.org)
  • Thus, it is common for people diagnosed with cancer to have been treated for other diseases, which were hypothesized to be causing their symptoms. (wikipedia.org)
  • proteins
  • We have been investigating site-specific DNA recognition by DNA regulatory proteins, the dynamics of a protein regulated genetic switch and the origin of the genetic code. (epress.com)
  • Harris, L., Sullivan, M. and Hickok, D. Genetic sequences of hormone response elements share similarity with predicted alpha helices within DNA binding domains of steroid receptor proteins: A basis for site-specific recognition. (epress.com)
  • Gag proteins are necessary for virion assembly and mature virus infection of the host cell. (wikipedia.org)
  • Such a virus can efficiently infect cells but, once the infection has taken place, requires a helper virus to provide the missing proteins for production of new virions. (wikipedia.org)
  • citation needed] Viruses expressing pathogen proteins are currently being developed as vaccines against these pathogens, based on the same rationale as DNA vaccines. (wikipedia.org)
  • Since their dysfunction has been strongly associated with increased susceptibility to several types of cancer, the proteins that facilitate homologous recombination are topics of active research. (wikipedia.org)
  • Hence, it is an enveloped virus with a condensed, central core, and has barely visible envelope spikes, or proteins. (wikipedia.org)
  • cellular
  • The virus abuses this cellular equipment for its own replication. (bio-medicine.org)
  • These findings should provide a framework to further elucidate the complex interactions between the virus and its cellular host in this unique pathway to latency. (pubmedcentralcanada.ca)
  • The process is characterized by changes at the cellular, genetic, and epigenetic levels and abnormal cell division. (wikipedia.org)
  • As of 2016 (when the Institute's latest 5-year funding plan began), the Institute engages in several areas of research: Provides leadership in data aggregation and informatics innovation, develops high-throughput cellular models of cancer for genome-wide functional screens and drug testing, and explores somatic mutation's role in clonal evolution, ageing and development. (wikipedia.org)
  • Cells
  • Two years later Temin concluded that the transformed morphology of the cells was controlled by a genetic property of RSV. (wikipedia.org)
  • Viruses are very small 'organisms' that can infect the cells of other animals or plants. (cancerquest.org)
  • Current methods for the genetic modification of cells typically use integrating genotoxic viruses that can potentially disrupt the molecular behavior of cancer cell lines due to their random nature of integration. (aacrjournals.org)
  • Human BxPC3 pancreatic cancer cells were stably transfected with a pSMARt-UBC-Luc and cultured for 4 weeks under selection. (aacrjournals.org)
  • Firstly, this is because viruses cannot truly be isolated in pure culture-even stringent isolation techniques cannot exclude undetected contaminating viruses with similar density characteristics, and viruses must be grown on cells. (wikipedia.org)
  • Viruses, which most people try to avoid at all costs, are wonderfully efficient at getting into the cells of their host organisms and inserting themselves into their host's DNA. (hawaii.edu)
  • Consistent with the idea of increased destruction, CD4 + T cells from simian immunodeficiency virus (SIV)-infected macaques have been shown to have a substantially higher turnover rate than CD4 + T cells from uninfected macaques ( 30 , 41 , 52 , 65 ). (pubmedcentralcanada.ca)
  • Furthermore, the frequency of HIV-1-infected CD4 + T cells in humans is, on average, very low ( 14 ) and likely is too low if virus-induced death subsequent to infection is solely responsible for HIV-1-mediated CD4 + T-cell depletion ( 20 ), given known parameters of CD4 + T-cell dynamics in the setting of HIV-1 infection ( 2 ). (pubmedcentralcanada.ca)
  • The virus itself stores its nucleic acid in the form of a +mRNA (including the 5'cap and 3'PolyA inside the virion) genome and serves as a means of delivery of that genome into cells it targets as an obligate parasite , and constitutes the infection . (thefullwiki.org)
  • Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cells are transformed into cancer cells. (wikipedia.org)
  • The 'foam' part of 'foamy virus' comes from syncytium formation and the rapid vacuolization of infected cells which creates a 'foamy' appearance. (wikipedia.org)
  • The binding receptor for foamy viruses is not entirely know, however it is know that the virus is capable of infecting a board spectrum of cells, meaning the binding receptor must be quite prevalent in most forms of cells. (wikipedia.org)
  • Paul Berg used a modified SV40 virus containing DNA from the bacteriophage λ to infect monkey kidney cells maintained in culture. (wikipedia.org)
  • The ISET approach has also been applied to the sensitive isolation and genetic characterization of circulating fetal trophoblastic cells. (wikipedia.org)
  • A number of discrete genetic events have to occur in order to enable individual tumor cells that have the capacity to grow at an ectopic site. (wikipedia.org)
  • All tumor cells show the six hallmarks of cancer. (wikipedia.org)
  • They include: Cell growth and division absent the proper signals Continuous growth and division even given contrary signals Avoidance of programmed cell death Limitless number of cell divisions Promoting blood vessel construction Invasion of tissue and formation of metastases The progression from normal cells to cells that can form a detectable mass to outright cancer involves multiple steps known as malignant progression. (wikipedia.org)
  • infection
  • Infection of the cervix with high-risk human papillomavirus (HPV) is regarded as the main causal factor in cervical cancer. (scielo.org.za)
  • These induce an immune response that blocks initial HPV infection and confers protection against cancer associated with HPV 16 and 18 and some closely related variants. (scielo.org.za)
  • Although HPV infection initiates disease, cervical cancer is a multi-step process, with other contributing factors, including multiple sexual partners, tobacco carcinogens, a weakened immune system and sexually transmitted infection by human immunodeficiency virus (HIV), Chlamydia trachomatis and Neisseria gonorrhoeae, thought to contribute to the aetiology. (scielo.org.za)
  • The World Health Organization 's International Agency for Research on Cancer estimated that in 2002, infection caused 17.8% of human cancers, with 11.9% caused by one of seven viruses. (wikipedia.org)
  • A minority of persons (or animals) will go on to develop cancers after infection. (wikipedia.org)
  • Secondly, asymptomatic virus infection and carriage is the norm for most tumor viruses, which violates Koch's third principle. (wikipedia.org)
  • Human immunodeficiency virus type 1 (HIV-1) is the etiologic agent of AIDS, which is a manifestation of the progressive CD4 + T-cell depletion that occurs in the setting of HIV-1 infection ( 19 , 59 ). (pubmedcentralcanada.ca)
  • In other examples, UV light from solar radiation causes DNA damage that is important in melanoma, helicobacter pylori infection produces high levels of reactive oxygen species that damage DNA and contributes to gastric cancer, and the Aspergillus metabolite, aflatoxin, is a DNA damaging agent that is causative in liver cancer. (wikipedia.org)
  • gene therapy
  • At DKFZ, Associate Professor (PD) Dr. Stephanie Laufs and Dr. Frank Giordano are trying to find out whether AIDS viruses can be used as gene delivery vehicles in gene therapy. (bio-medicine.org)
  • Therefore, the researchers took a very close look by starting an analysis of more than 46,000 known integration sites of HIV-based gene delivery vehicles that were determined in various gene therapy studies or are available in gene databases. (bio-medicine.org)
  • HONOLULU - A jumping gene first identified in a cabbage-eating moth may one day provide a safer, target-specific alternative to viruses for gene therapy, researchers say. (hawaii.edu)
  • In cancer, he suspects gene therapy will focus on this type of modification of normal tissue for protective purposes as well as manipulating the immune response. (hawaii.edu)
  • He was, e.g., concerned about the biological effects of radiation, the dangers of biological warfare, the risks of gene therapy and (later) of genetic recombination, and on all these issues, he was actively involved in efforts to reduce risks and guarantee public safety. (wikipedia.org)
  • humans
  • Humans are susceptible to a large number of different viruses. (cancerquest.org)
  • Through their mutagenic activity or their effects on cell behavior, viruses play a significant role in the development of particular cancers in many different animals, including humans. (cancerquest.org)
  • For example, adenoviruses do not cause cancer in humans but are instead responsible for colds, conjunctivitis and other acute illnesses. (wikipedia.org)
  • Genetic studies of common diseases in humans suffer significant limitations for practical and ethical reasons. (wikipedia.org)
  • replication
  • Human adeno-associated virus type 2 (AAV-2) is a nonpathogenic parvovirus that requires helper functions provided by viruses such as adenovirus or herpes simplex virus for efficient replication of its genome ( 2 , 60 ). (pubmedcentralcanada.ca)
  • During the 1960s, two findings emerged: replication-competent isolated viruses were related to RSV, but were non-transforming, and an isolated replication-defective strain of RSV was transformation-competent. (wikipedia.org)
  • The term's early usage included any bacterial genetic material that exists extrachromosomally for at least part of its replication cycle, but because that description includes bacterial viruses, the notion of plasmid was refined over time to comprise genetic elements that reproduce autonomously. (wikipedia.org)
  • recombination
  • Homologous recombination is a type of genetic recombination in which nucleotide sequences are exchanged between two similar or identical molecules of DNA. (wikipedia.org)
  • Homologous recombination is also used in horizontal gene transfer to exchange genetic material between different strains and species of bacteria and viruses. (wikipedia.org)
  • Homologous recombination is conserved across all three domains of life as well as viruses, suggesting that it is a nearly universal biological mechanism. (wikipedia.org)
  • Homologous recombination is also used in gene targeting, a technique for introducing genetic changes into target organisms. (wikipedia.org)
  • In 1947, the microbiologist Joshua Lederberg showed that bacteria-which had been assumed to reproduce only asexually through binary fission-are capable of genetic recombination, which is more similar to sexual reproduction. (wikipedia.org)
  • diseases
  • Many pathological disorders or diseases, including cervical cancer, are characterised by the exacerbated activation and maintenance of inflammatory pathways. (scielo.org.za)
  • In ancient Egypt, intellectual power was primarily restricted to priests who claimed to be direct recipients of divine knowledge, so it is not surprising that writings of the time attributed the etiology of diseases such as cancer to the "will of Gods" ( 1 , 2 ). (aacrjournals.org)
  • This approach permits the performance of non-invasive prenatal diagnosis of genetic diseases through a simple blood sample avoiding miscarriage related to the current invasive procedures (amniocentesis, chorionic villus sampling) and representing a major scientific advance as a reliable non-invasive alternative to the classical invasive techniques of prenatal diagnosis. (wikipedia.org)
  • Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. (wikipedia.org)
  • Many cancers can be prevented by not smoking, maintaining a healthy weight, not drinking too much alcohol, eating plenty of vegetables, fruits and whole grains, vaccination against certain infectious diseases, not eating too much processed and red meat, and avoiding too much sunlight exposure. (wikipedia.org)
  • Cancers are a large family of diseases that involve abnormal cell growth with the potential to invade or spread to other parts of the body. (wikipedia.org)
  • clinical
  • VAL401 is the reformulation of a clinical drug to enable use in the treatment of cancer. (aacrjournals.org)
  • From a clinical point of view, early detection of CTC is predicted to allow prevention of metastases and early screening of invasive cancers. (wikipedia.org)
  • Christian Bréchot has investigated the clinical impact of the genetic variability of HCV, his clinical trials demonstrated the efficacy of interferon-ribavirin combination therapy in treating HCV infections. (wikipedia.org)
  • adenovirus
  • In fact, in one study, three patients developed leukemia after the virus inserted itself upstream of a cancer-causing gene, and in another study, a patient died because of an immune response to an adenovirus. (hawaii.edu)
  • infect
  • Some viruses are tumorigenic when they infect a cell and persist as circular episomes or plasmids, replicating separately from host cell DNA ( Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus ). (wikipedia.org)
  • vaccines
  • These cancers might be easily prevented through vaccination (e.g., papillomavirus vaccines ), diagnosed with simple blood tests, and treated with less-toxic antiviral compounds. (wikipedia.org)
  • Such knowledge proved instrumental to the development of the first cancer vaccines against cancers having an infectious etiology. (aacrjournals.org)
  • Furthermore
  • Furthermore, we provide evidence for bidirectional MBS85 promoter activity and demonstrate that the minimal motifs required for AAV site-specific integration are present in the 5′ untranslated region of the gene and play a posttranscriptional role in the regulation of MBS85 expression. (pubmedcentralcanada.ca)
  • Furthermore, some viruses integrate into the cell genome facilitating stable expression. (wikipedia.org)
  • cause
  • Metastasis is the major cause of cancer morbidity and mortality. (aacrjournals.org)
  • Viruses are not the same as bacteria although both can cause human disease. (cancerquest.org)
  • An oncovirus is a virus that can cause cancer . (wikipedia.org)
  • The vast majority of human and animal viruses do not cause cancer, probably because of longstanding co-evolution between the virus and its host. (wikipedia.org)
  • The case challenges the validity of the theory that a virus called HIV does indeed cause a large number of disrelated illnesses that, individually, have been known before AIDS became a household word. (newmediaexplorer.org)
  • Next step: Does the virus actually cause all the illnesses that are ascribed to it or is it an innocent passenger that all of us carry while other 'risk factors', such as intravenous drug use, do the major damage. (newmediaexplorer.org)
  • Montagnier has actually stated that "it would be a tribute to their (dissidents like us) courage and honour to abandon the HIV cause of AIDS in the face of overwhelming evidence (Virus, New York, WW Norton & Company Inc, 1999). (newmediaexplorer.org)
  • Different theories on the cause of cancer found favor over time, but none considered an infectious etiology until the 20th century. (aacrjournals.org)
  • DNA damage is considered to be the primary cause of cancer. (wikipedia.org)
  • As one example of an exogenous carcinogeneic agent, tobacco smoke causes increased DNA damage, and these DNA damages likely cause the increase of lung cancer due to smoking. (wikipedia.org)
  • Tobacco use is the cause of about 22% of cancer deaths. (wikipedia.org)
  • occur
  • Such mice are cancer-prone but generally only develop disease after a long latency, indicating that additional somatic "hits" must occur before an overt tumor forms. (aacrjournals.org)
  • genetically
  • Breast cancer is consensually considered genetically and clinically as a heterogeneous disease, in that it reflects the heterogeneity of the normal breast tissue at its origin17873350. (wikipedia.org)
  • host
  • Therefore, it is crucial for them to know where exactly HIV integrates into the genetic material of the host cell. (bio-medicine.org)
  • The virus buds or pushes on the plasma membrane, which allows it to leave the cell with a new outer membrane from the host cell. (wikipedia.org)
  • There are two ways viruses can enter the host cell: cell receptor endocytosis or fusion. (wikipedia.org)
  • This process may be beneficial to the virus if it allows for rapid production of progeny but can be seriously detrimental to the host. (cancerquest.org)
  • Other viruses are only carcinogenic when they integrate into the host cell genome as part of a biological accident, such as polyomaviruses and papillomaviruses. (wikipedia.org)
  • Analysis of such tumor clones allows for the identification of integration sites of individual proviruses in the host genome. (aacrjournals.org)
  • A retrovirus is an RNA virus that is replicated in a host cell via the enzyme reverse transcriptase to produce DNA from its RNA genome. (thefullwiki.org)
  • It is difficult to detect the virus until it has infected the host. (thefullwiki.org)
  • The process by which foamy viruses enter a cell lacks certain levels of characterization, however it is know that the virus particle first attaches to its host using the SU glycoprotein present on its envelope. (wikipedia.org)
  • A retrovirus is a single-stranded positive-sense RNA virus with a DNA intermediate and, as an obligate parasite, targets a host cell. (wikipedia.org)
  • The surface glycoproteins contain the major domains that interact with the host cell receptor while the transmembrane (TM) glycoproteins anchor the surface glycoproteins to the virus membrane. (wikipedia.org)
  • The TM glycoproteins are directly involved in the fusion of the virus and host membranes for entry. (wikipedia.org)
  • transduction
  • Later he was to extend the powerful modes of analysis developed in this early work to the investigation of genetic modification in transduction and conjugation as well. (wikipedia.org)
  • lung cancer
  • Preclinical data indicate potential use of the reformulated drug in lung cancer, where many subsets of patients have currently a high unmet medical need. (aacrjournals.org)
  • enzyme
  • Therefore, virologists are urgently searching for new approaches to blocking this key enzyme of the virus. (bio-medicine.org)
  • Enclosed within the envelope is a capsid surrounding single stranded RNA, integrase, protease, and reverse transcriptase, an enzyme that allows for the reversal of genetic transcription. (wikipedia.org)
  • cell
  • The AIDS virus inserts its genetic material into the genome of the infected cell. (bio-medicine.org)
  • These data imply that dysregulated MYC gene expression is potentially involved in the pathogenesis of breast cancer, especially by favoring local cell proliferation. (aacrjournals.org)
  • Endocytosis is the process where the virus binds a receptor on the target cell membrane, and the virus is taken into or endocytosed into the cell. (wikipedia.org)
  • Fusion occurs when the virus fuses together with the target cell membrane and releases its genome into the cell. (wikipedia.org)
  • Certain integrations (or their proper combinations) provide a cell with a growth advantage, the cell clone expands, giving rise to a tumor ( 3 ). (aacrjournals.org)
  • Human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a neurological disease observed only in 1-2 % of infected individuals. (microbiologyresearch.org)
  • Temin's description of how tumor viruses act on the genetic material of the cell through reverse transcription was revolutionary. (wikipedia.org)
  • The genetic variance between metastatic foci is significant for only particular locus and within specific cell populations or only one-cell population shows differences and some loci are divergent only in one cell subpopulation. (wikipedia.org)
  • Directly or indirectly, it led, e.g., to the search for RNA viruses by Tim Loeb (1961), to the discovery of the SOS response in bacteria by Miroslav Radman (1976), and to the development of techniques of bacterial cell fusion by Pierre Shaeffer (1976). (wikipedia.org)
  • virology
  • Other measures, such as A.B. Hill's criteria , are more relevant to cancer virology but also have some limitations in determining causality. (wikipedia.org)
  • In the century since its inception, the field of tumor virology has provided groundbreaking insights into the causes of human cancer. (aacrjournals.org)
  • This rich history promises that tumor virology will continue to contribute to our understanding of cancer and to the development of new therapeutic and preventive measures for this disease in the 21st century. (aacrjournals.org)
  • a position that had been hard to fill because, at the time, virology was not considered pertinent to cancer research. (wikipedia.org)
  • emergence
  • In 1540, the failure of Andreas Vesalius to confirm the existence of black bile led to the demise of the humoral theory and the eventual emergence of the related lymph theory of cancer ( 2 , 4 ). (aacrjournals.org)