Biology of Cancer Chapter 3
Terms in this set (54)
Discovers a chicken Sarcoma virus.
Rous protocol for inducing sarcomas in chickens
responsible for creating tumor. created cancer at will and had never ending supply of agent.
Rabbit tumors called myxoma.
Viruses Have Simple Life Cycles
genome at core of virus, covered in coated protein. They enter cell and become uncoated.
Rous Sarcoma virus is discovered to transform infected cells in culture
The Virion of RSV and related viruses
An RSV-induced Focus
reveals a focus of rouse sarcoma virus transformed chicken embryo fibroblasts surrounded by a monolayer of uninfected cells. The focus stands out because it is multiple cell layers thick and because of the rounded morphology of the transformed cells and their refractility which contrasts with the flattened morphology of the normal cells.
The continued presence of RSV is needed to maintain transformation
Transformed cells Forming Foci
contact inhibition- when cells touch each other and cease to proliferate. When one of these cells is infected with RSV and its decendents acquire a rounded morphology and lose contact inhibition. as a consequence they proliferate
Transformed cells Forming Foci
Temperature-Sensitive mutant and the maintenance of transformation by RSV
when cells were shifted to 41 degrees, the viral transforming function was inactivated and cells reverted to normal morphology, when temperature was shifted back, transformation was regained. Viral genome continued to be present in these cells at heigh temperature inspite of their normal appearance
Viruses containing DNA molecules are also able to induce cancer
Tumor Virus Genomes
Tumor viruses induce multiple changes in cell phenotype including acquisition of tumorigenicity
SV40 circular genome, and can be super coiled.
properties of transformed cells
The immune system and tumors
they lack thymus and highly immunocompromised.
Tumor virus genomes persist in virus transformed cells by becoming part of host cell DNA
Integration of SV40 DNA
Retroviral genomes become integrated into the chromosomes of infected cells
The life cycle of an RNA tumor virus like RSV
configuration of integrated SV40 genomes
use of restriction enzymes cleavage site mapping revealed the configurations of SV40 genomes integrated into into the chromosomal DNA of virus transformed cells. amplification.
DNA integrate rarely
a version of the src gene carried by RSV is also present in uninfected cells
lower case S and italicize referes to gene
Structure of the Rous Sarcoma virus genome
The construction of a src-specific DNA probe ( side bar 3.5)
Evolutionary Tree of the src gene
wide spread, everyone has src genes.
RSV exploits a kidnapped cellular gene to transform cells
capture of src by Avian Leukosis Virus
Hybrid virus like RSV originate via sloppy replication promiscuous acquisitions of cellular genes 3.7
The vertebrate genomes carries a large group of pro to-oncogenes
genes that can cause danger, proto don't start off as cancer or tumor causing. First was c-src.
implies that genomes of normal vertebrate cells carry a gene that has the potential under certain circumstances to induce cell transformation and thus cancer
acutley transforming retroviruses and oncogenes that they have acquired
many are receptors of tyrosine. G proteins most involved in cell signaling.
slowly transforming retroviruses activate pro to-oncogenes by inserting their genomes adjacent to theses cellular genes
Retro viruses transform very quickly, others transform over a longer period of time and insert genes.
non oncogene viruses.
myc- if you increase, it programs apoptosis.
Some retroviruses naturally carry oncogenes
transplant a human tumor and the host will not reject it.
cell killing. These effects of viruses together with their ability to spread rapidly throughout a tissue, enables these agents to leave a path of destruction .
OTHER SETS BY THIS CREATOR
Chapter 4 Biology of cancer
Biology of Cancer chapter 2
Biology of cancer chapter 1
THIS SET IS OFTEN IN FOLDERS WITH...
Biology of Cancer Exam 5