Answer Happy

How do cells infected with HPV that become cancerous are able to be basically immortal? Take a look at the attached diagram and make sure to refer to molecules that are normally involved in the G1/S checkpoint and how the virus evades this checkpoint, which allows infected cells to divide indefinitely. Prevention of p53 and BAK-mediated apoptosis Blockade of IRF3 function E7 rescues E6 from INK4A inhibition INK4A counteracts E6 functions E6 activities Cooperative functions Essential functions for immortalization Activation of telomerase Activation of SRC kinases Proliferation Progression E6 prevents apoptosis caused by a high expression of E7 Induction of chromosomal instabillity by inhibition of p53-mediated DNA repair E2F release, bypass of cyclin-D- CDK4 regulation Synergistic effect in cell immortalization Cell death INK4A becomes functionally inactive E7 activities) Cooperative functions Essential functions for immortalization Stimulation of S-phase genes cyclins A and E Functional inactivation of WAF1+ KIP1 Proliferation Release of phosphorylated RB results in upregulation of INK4A Progression Centriole amplification, induction of aneuploidy