Apoptosis-Regulating Proteins and Prognosis in Diffuse Large B Cell Non-Hodgkin’s Lymphomas

Abstract

We evaluated the expression of apoptosis-regulating proteins (p53, Bcl-2, Bax, Bak and Mcl-1) in paraffin-embedded tissues of 33 patients with diffuse large B cell non-Hodgkin’s lymphoma , and assessed the relationship of these proteins to clinical outcome and response to chemotherapy. Our results showed that p53 expression was an independent immunohistochemical parameter related to a poor prognosis in these lymphomas. Bcl-2, Bax, Bak and Mcl-1 proteins, though highly expressed in almost all cases were not associated with prognosis or response to treatment.

Determination of apoptosis, proliferation status and O6-methylguanine DNA methyltransferase methylation profiles in different immunophenotypic profiles of diffuse large B-cell lymphoma

“…These results suggested that bcl-2 independent apoptosis is an important factor influencing cell death in many NHLs [22]. Overall results of previous studies [10,19,[22][23][24][25][26][27] and our results indicate that the expressions of bcl-2 family proteins are variable and heterogeneous in DLBCL. The dual effect of bcl-2 family proteins may show individual variation in the pathogenesis and prognosis of DLBCLs.…”

“…(Turk J Hematol 2011;28: 15-26) Anahtar kelimeler: Büyük B-hücreli lenfomalarda apoptosis ve proliferasyon tosis and proliferation status in CD10/bcl-6/MUM1 immunophenotypic differentiation profiles is considerably limited. Although the immunohistochemical expression of the apoptosis-associated bcl-2 family proteins, bcl-2, bax, bak, and mcl1, was reported in DLBCLs [19][20][21][22][23][24][25][26][27][28], the expression levels of bcl-xl, bad, bid proteins and their relations with the status of apoptosis and proliferation were not extensively analyzed in these lymphomas [25].…”

Bcl-2 protein expression is the strongest independent prognostic factor of survival in primary cutaneous large B-cell lymphomas

“…Whereas some of these studies, including fewer than 65 patients, led to negative results, [37][38][39][40] more powerful analyses of more than 150 patients found that bcl-2 protein overexpression was independently related to relapse, 29 disease-free survival, 30,31 or overall survival. 32 In view of recent in vitro studies in human leukemia cell lines, 41,42 it has been suspected that a high bcl-2 expression may confer resistance to several antineoplastic agents.…”

“…Variable percentages of bcl-2-positive tumor cells have been used to define bcl-2 overexpression. 37,38,40 However, major studies in noncutaneous diffuse large B-cell lymphomas consistently classified cases as bcl-2-expressing lymphomas if the protein was detected in more than 50% 31,32 or 60% 30 of tumor cells. In our patients with a PCLBCL, the 50% cutoff had a high clinical pertinence and a strong independent prognostic value.…”

Mcl-1 is required for Akata6 B-lymphoma cell survival and is converted to a cell death molecule by efficient caspase-mediated cleavage

“…Mcl-1 is highly expressed in some malignant B-cells (Ghia et al, 1998;Kitada et al, 1998;Soini et al, 1998;Agarwal and Naresh, 2002;Pagnano et al, 2002;Spets et al, 2002;Khoury et al, 2003), and this can correlate with clinical behaviour, such as failure to obtain complete remission in chronic lymphocytic leukemia (CLL) (Kitada et al, 1998). Importantly, enforced expression of Mcl-1 in transgenic mice promotes lymphomagenesis with a higher probability than Bcl-2 (approx.…”