The pattern of expression of the apoptotic inducer Fas and the apoptotic inhibitor bcl-2 oncogenes immunohistochemicaly in bone-marrow invaded by the non-Hodgkin lymphomas

Apoptosis is a feature commonly seen in tumors; it is an actively regulated cellular process that leads to cell death, in fact the ability to resist apoptosis may seem to offer an advantage to a growing tumor by slowing down the cell loss rate. The present study is a retrospective study aiming at evaluating the Fas/Apo-1, CD95 and bcl-2 oncoproteins immunohistochemically in 30 bone marrow tissue specimens invaded by non- Hodgkin lymphomas (stage IV), 60% of cases were under chemotherapy regimen, while the remainders were still. The study included the significance of the apoptotic inducer Fas/CD95 and apoptotic inhibitor bcl-2 immunoreactivity in relation to a number of clinicopathological variables including age, sex, pattern of malignant cell infiltration in bone marrow, type of malignant cells disseminated and the effect of chemotherapy in relation to apoptotic changes. Fas/CD95 immunoreactivity was positive in 23 cases; 76.7%, positive immunoreactivity was significantly associated with the chemotherapeutic effect (p= 0.0002). On the other side bcl-2 immunoreactivity was positive in 7 cases; 23.3%. A significant association was found between bcl-2 positive immunoreactivity and sex (p= 0.03), pattern of malignant cell infiltration in bone marrow (p= 0.02) and lack of therapy effects (p= 0.0004). As a conclusion (1) Apoptosis is a common feature in non-Hodgkin 's lymphomas as confirmed by the high incidence of the apoptotic inducer Fas/CD95 positive immunoreactivity; (2) Fas/CD95 and bcl-2 as a tumor markers may work as a useful aid in establishing an apoptosis interpretation in cases of non-Hodgkin 's lymphomas (stage IV); (3) Fas/CD95 expression translate the chemotherapeutic effects on malignant cells in non-Hodgkin 's lymphomas; meanwhile the apoptotic inhibitor bcl-2 expression is an independent negative prognostic marker that has been shown to confer resistance to apoptosis.