BCL-2 associated athanogene-1 overexpression in diffuse large B-cell lymphoma

ABSTRACT

Apoptosis and cell cycle regulation play an important role in pathogenesis and tumor progression in patients with Diffuse Large B-Cell Lymphoma [DLBCL]. Bcl-2 associated athanogene-l [BAG-1] is an antiapoptotic protein as well as a regulator of cell growth. There is no conclusive evidence about BAG-i protein expression in this disease. To investigate the expression level of BAG-i protein in DLBCL. Methods: Thirty patients diagnosed from 1997-2004, as having DLBCL, were selected. Also 30 normal lymph nodes were included as normal counterparts in this study. BAG- 1 expression was determined by inmiunohistochemical staining in both DLBCL and normal lymph node samples. Of the 30 DLBCLs examined, 100% were positive for nuclear and 83% were positive for cytoplasmic BAG-1 staining. Of the 30 normal lymph nodes investigated, 20% were positive for nuclear and 0% were positive for cytopiasmic BAG-1 staining. Nuclear staining in DLBCL samples was significantly higher than those of normal lymph nodes [100% versus 20%, p < 0.001]. Besides, cytoplasmic staining in DLBCL samples was significantly higher than those of normal lymph nodes [83% versus 0%, p < 0.001]. There was no association between BAG-i staining and patients' overall survival. Our data indicated that BAG-i protein was deregulated in this disease similar to some other malignancies such as breast and colon cancer. Overexpression of BAG-I in DLBCL suggests that this protein probably plays an important role in the pathogenesis of DLBCL. Besides, higher nuclear BAG-1 staining might be correlated with poor prognosis