12 11 2012 B ionizing radiation charged energetic particles certain electromagnetic radiation some viruses o Mutations vs carcinogens NOT THE SAME Mutations explicitly cause dna damage Carcinogens can promote cancer without causing mutations How to know AMES TEST Epigenetics o Viruses o Cause cancer by 2 ways Expression of oncoproteins RNA tumor viruses capture host oncoproteins DNA tumor viruses inactivate tumor suppressors oncoproteins in these typically don t have cellular counterparts Insertional Mutagenesis Insertion of viral genome into host genome Can inactivate tumor suppressors and activate Aneuploidy oncogenes o Changes in the amount of DNA o Majority of human tumors of aneuploid 1 State of Altered chromosomal structure 2 State of Altered chromosomal complement 3 process of Changing chromosome structure 4 process of Changing chromosome complement Cell become aneuploidy through errors in o DNA replication o DNA repair o Chromosome segregation o Checkpoint function History it aneuploidy chromosomes necessary for development Cells with extra centrosomes can arise through cytokinesis failures MUTATION VS CARCINOGEN