Telomerase inactivation,”cells become immortalized, but are not cancer cells (mouse cells) –>used to identify human oncogenes*took DNA of human tumors, added them to mouse cell lines that have already been immortalized. They aren’t tumor cells, but still require growth factorsBehavior of cells: telomeres are structures on end of chromosomes that have to be maintained every time cells replicatetelomerase expressed at high level (gets shut off very early (exception is stem cells))normal cells: telomere gets bit shorter each replication (50)In cancer cells: telomerase gets reactivated, but not properly regulated. telomeres get too large. Don’t become senescent; but undergo chromosomal rearrangement (lose p53)*took normal cells, try to very carefully reactivate telomerase to become cancer cells
but cannot control telomerase precisely”