APOPTOSIS, HEMATOPOIESIS AND LEUKEMOGENESIS

Apoptosis, or physiological cell death, is the way in which unwanted c ells are removed. The majority of cells formed during haemopoiesis are destined to die by apoptosis before they are fully differentiated, an d homeostasis of cell number is maintained by a balance between mitosi s and apoptosis. Many haematological malignancies are associated with changes in the number of cells undergoing apoptosis, which may be a di rect or an indirect effect. Genetic mutations that prevent cell death cause cells to accumulate and can eventually lead to malignancy. Alter natively, oncogenic mutations that lead to increased cell production c an indirectly cause a decrease in apoptosis in some populations and an increase in others. Chemotherapeutic drugs may kill cells directly, o r indirectly by inducing apoptosis as a stress response. Therapeutic s trategies are evolving to increase the propensity of malignant cells t o die by either means and to mitigate side effects by reducing apoptos is in non-malignant cells.