TELOMERE DYNAMICS AND TELOMERASE ACTIVITY IN CELL SENESCENCE AND CANCER

Human somatic cells have a mortal phenotype that is under stringent ge netic control and is dominant over unlimited proliferation. Reversal o f this phenotype (immortality) may be required for tumour growth. Soma tic cell division is accompanied by a decrease in telomeric DNA result ing in progressively shorter telomeres, a process that has been implic ated in the control of the proliferative lifespan of cells. Conversely , telomere stabilization and expression of telomerase, the enzyme that elongates telomeric DNA, have been proposed as crucial to cell immort alization and tumour growth. This review discusses the data supporting this hypothesis, focusing on human cell, and addresses their implicat ions for the management of cancer.