Why do cancer cell lines live forever while normal cells die in culture?
Cancer cell lines often have many mutations that affect their growth. Telomerase activity is switched on in more than 85% of cancer cell lines. This allows the cancer cell lines to maintain the length of their telomeres which helps immortalize them. The remaining cancer cell lines, those that don’t show telomerase activation, employ alternative means of maintaining the length of their telomeres. Telomerase activity is highly repressed in the vast majority of normal somatic cells which causes the cells to eventually enter a state of replicative senescence and stop dividing.
