BIO 203 Lecture Notes - Lecture 18: Natural Killer Cell, Cytotoxic T Cell, Telomerase
Document Summary
Cancer cells do not self-destruct when their dna is damaged. This makes them difficult to kill with radiation or chemotherapy. Treatments designed to damage dna of cancer cells and trigger self- destruction. In the lab, most normal human cells divide 50 to 60 times and then enter a nondividing state called senescence. Telomeres might be the way that a cell counts the number of times it has divided. Pieces of dna at tips of chromosomes. When dna is copied for cell division, a tiny piece of every telomere in the cell is shaved off. Cancer cells do not stop producing telomerase. Telomeres are reconstructed after each cell division. May allow cell division to continue indefinitely. Cancer cells release special growth factors that cause capillaries to invade the tumor. Deliver additional growth factors that spur tumor growth. Serve as routes by which cancer cells can leave the tumor and spread to other locations.
