Tumor viruses
Download
1 / 9

Tumor viruses - PowerPoint PPT Presentation


  • 137 Views
  • Uploaded on

Tumor viruses. Tumor viruses. Viruses can cause beningn or malignant tumors in many species of animals A few viruses are associated with human tumors. Malignant transformation of cells. Altered morphology Altered growth control Altered cellular properties Altered biochemical properties

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Tumor viruses' - emilie


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Tumor viruses1
Tumor viruses

  • Viruses can cause beningn or malignant tumors in many species of animals

  • A few viruses are associated with human tumors


Malignant transformation of cells
Malignant transformation of cells

  • Altered morphology

  • Altered growth control

  • Altered cellular properties

  • Altered biochemical properties

    can be induced by tumor viruses


Tumorigenesis
Tumorigenesis

  • Provirus:thegenesenterthecellbyinfectionbytumorvirus

  • Oncogene: alreadypresent in thecell

    cellularoncogenes(c-onc) areactivatedbyvirusestooverproducethegrowthfactors

  • Tumorsupressor gene (p53):inactivation of this gene

  • Micro-RNA genes


Tumor viruses2
Tumor viruses

  • Human T-cell lymphotropic virus(HTLV-I):

    • Adult acute T-cell lymphocytic leukemia (ATLL)

    • No viral oncogene (different from animal tumor retroviruses)

    • Tax and rex regulatory genes


Tumor viruses3
Tumor viruses

  • Humanpapillomavirus:

    • E6 and E7 genes

    • Encodeproteinsthatinterferewith p53 andRb(retinoblastom) tumorsupressorgenes

    • Mostlythe HPV(especiallyhighlyoncogenictypes 16 and 18) is integratedintocellular DNA


Tumor viruses4
Tumor viruses

  • EBV:

    • İnduces B cell proliferation

    • Activation of a cellular oncogene

    • Burkitt lymphoma: c-myc oncogene in chromosome 8 is translocated to14 chromosome where large amounts of c-myc RNA are synthesized.


Tumor viruses5
Tumor viruses

  • HBV:

    • Primer hepatocellular carcinoma:integration may activate an oncogen

  • HCV:

    • Chronic infection

  • HHV-8:

    • ?


Animal tumor viuses
Animal tumor viuses

  • DNA Viruses:

    • SV40

    • Adenovirus

    • Poxviruse

  • RNA viruses

    • Retroviruses

      No evidence that they cause tumors in humans