Apoptosis Modulators: Bcl-2 And P53 Proteins in Childhood Acute Lymphoblastic Leukemia

Apoptosis is a physiologic phenomenon that ensures the balance between cell proliferation and cell death. The physiologic function of apoptosis is to remove the cells that are not necessary for the organism.Abnormalities of apoptosis play an important part in proliferative neoplastic diseases.Regulation of apoptosis depends on the expression of other genes,especially Bcl-2 and P53. Bcl-2 blocks a final common pathway to apoptosis. It confers resistance to a variety of DNA damaging agents. Thus,it appears to prevent the signals that normally activate the apoptosis machinery after DNA damage, from reaching its target. P53 gene is a tumor suppressor gene located on chromosome 17p13. Alterations of the P53 are involved in various types of human cancer. Loss of the normal growth inhibitory activity of P53 protein in most of these tumors occurs as a result of point mutations of the other P53 allele.Acute leukemia is a heterogonous group of malignant disorders arising from hemopoietic progenitor cells at different stages of maturation.It results from uncontrolled proliferation of immature hematopoietic precursors derived from damaged progenitors that lack the capacity to transfer differentiation programs to he precursors to which they give rise.