Biomedical subjects

Alexandra Papoudou-Bai

Publications and source records attributed to Alexandra Papoudou-Bai.

5 recordsLinked to original sources

PubMed2006

Expression of bcl2 family proteins and active caspase 3 in classical Hodgkin's lymphomas.

The expression of various bcl2 family proteins has been reported in Hodgkin and Reed-Sternberg cells, but the proteins bad, bid, and bim have not been analyzed in classical Hodgkin's lymphomas (HLs). This study aimed to investigate the expression of the proteins bcl2, bcl-xl, mcl1, bax, bak, bad, bid, bim, and active caspase 3, and the TUNEL (terminal deoxynucleotidyl transferase-mediated in situ labeling) index to gain further insight into the apoptosis profile of classical HLs. A high expression of the proteins bcl2, bcl-xl, mcl1, bax, bak, bad, bid, and bim in HRS cells was found in 27 of 101 (27%), 95 of 101 (94%), 27 of 97 (29%), 73 of 95 (77%), 37 of 102 (36%), 85 of 94 (90%), 19 of 109 (17%), and 43 of 91 (47%) cases, respectively. The high expression of bcl-xl, bax, and bad in HRS cells in most classical HLs indicates that these proteins may play predominant roles in the regulation of apoptosis in classical HLs. Active caspase 3-positive and TUNEL-positive Reed-Sternberg cells were detected in 47 of 70 (67%; range, 0%-12%) and 60 of 71 (85%; range, 0%-19%) cases, respectively. Significant positive correlations were found between bax/bcl2 (P = .002), bad/bcl2 (P = .020), bad/bcl-xl (P = .003), and bim/mcl1 (P = .036). Based on these findings, it could be hypothesized that the antiapoptotic proteins bcl2, bcl-xl, and mcl1 may counteract the expression of the proapoptotic proteins bax, bad, and bim, thereby contributing to the survival of Reed-Sternberg cells.

Apoptosis↗

PubMed2006

B-cell differentiation immunophenotypes in classical Hodgkin lymphomas.

The bcl6/CD10/MUM1/CD138 B-cell differentiation immunophenotypes were analysed in 101 cases of classical Hodgkin lymphomas (cHL) aiming to elucidate their histogenesis. Three major bcl6/CD10/MUM1/CD138 immunophenotypes were distinguished on the basis of the immunohistochemical positivity of Hodgkin and Reed-Sternberg (H/RS) cells: (a) the late germinal center (GC)/early post-GC B-cell-like immunophenotype (bcl6-/CD10-/MUM1+/CD138-); 59/101 cases (59%), (b) the post-GC B-cell-like immunophenotype (bcl6-/CD10-/MUM1+/CD138+); 24/101 cases (24%) and (c) the indeterminate immunophenotype (bcl6+/CD10-/MUM1+/CD138-: 14 cases and bcl6+/CD10-/MUM1+/CD138+: four cases); 18/101 cases (18%). The above findings indicate that H/RS cells in most cHL display bcl6/CD10/MUM1/CD138 immunophenotypes consistent with late GC/early post-GC or post-GC B-cell differentiation. In addition, H/RS cells in a small fraction of cHL display indeterminate bcl6/CD10/MUM1/CD138 immunophenotypic profiles which are characterized by simultaneous expression of GC, late GC/early post-GC and post-GC B-cell differentiation proteins. These immunophenotypic profiles do not correspond to the differentiation immunophenotypes of normal B-cells and their identification in a part of cHL suggests that the differentiation process of H/RS cells is not complete in a fraction of these cells and/or is still ongoing at the time of observation.

Antigens, Differentiation↗

PubMedDate not supplied

Cell cycle and apoptosis deregulation in classical Hodgkin lymphomas.

Classical Hodgkin lymphomas (cHL) have now been recognized as B-cell lymphomas with some exceptional cases of T-cell origin. In recent years, there has been accumulating evidence that Hodgkin and Reed-Sternberg (H/RS) cells, the presumed neoplastic-cell population in cHL, are characterized by a profound disturbance of the cell cycle and apoptosis regulation. The constitutive activation of the nuclear factor (NF)-kappaB pathway, which is considered to be involved in the proliferation and survival of H/RS cells. Moreover, substantial evidence that H/RS cells have defective cell cycle and apoptosis regulation has been provided by studies showing that these cells are characterized, in a large proportion of cases, by alterations of the p53, Rb and p27 tumor suppressor pathways, overexpression of cyclins involved in the G1/S and G2/M transition such as cyclins E, D2, D3, A and B1, overexpression of cyclin-dependent kinases such as CDK1, 2 and 6 and overexpression of anti-apoptotic proteins such as c-FLIP, bcl-xl, c-IAP2, X-linked I4P and survivin. Recent studies suggest that interleukin 13 (IL-13) is an important growth and survival factor in H/RS cells. Furthermore, the Epstein-Barr Virus (EBV), which is present in H/RS cells in about 30-50% of cHL, has been shown to affect the cell cycle and apoptosis regulation in cHL. The present review summarizes data with respect to the cell cycle and apoptosis deregulation in cHL.

Apoptosis↗

PubMedDate not supplied

B-cell differentiation, apoptosis and proliferation in diffuse large B-cell lymphomas.

Diffuse large B-cell lymphomas (DLBCL) represent the most common type of adult non-Hodgkin's lymphomas in Western countries and are characterized by heterogeneous clinical, histological, immunophenotypic and genetic features. Recent investigations using cDNA and oligonucleotide microarrays have identified molecularly distinct groups of DLBCL with respect to the B-cell differentiation gene expression profile: the germinal center (GC) B-cell-like DLBCL, the activated B-cell-like DLBCL and the type 3 DLBCL. The GC B-cell-like DLBCL were characterized by the expression of genes of the normal GC B-cells, the activated B-cell-like DLBCL were characterized by the expression of genes that are normally induced luring in vitro activation of peripheral blood B-cells, while the type 3 DLBCL did not express either set of genes at a high level. Patients with GC B-cell-like DLBCL had more favorable clinical outcome than those with activated B-cell-like or type 3 DLBCL. Immunohistochemical studies have shown that the bc16/CD10/MUM1/CD138 B-cell differentiation immunophenotypes are prognostically relevant and may predict the cDNA classification in a sizable fraction of DLBCL. In the last few years, there has been accumulating molecular and immunohistochemical evidence indicating links between B-cell differentiation gene expression profiles and expression of apoptosis and cell cycle-associated genes in DLBCL. The present review summarizes data with respect to the relationships between B-cell differentiation, apoptosis and proliferation in DLBCL.

Animals↗

PubMedDate not supplied

Primary lymphomas of bone.

Primary lymphomas of bone are uncommon malignancies. The vast majority of them are non-Hodgkin lymphoma (NHL), whereas primary Hodgkin lymphoma (HL) of bone is extremely rare. Patients with primary NHL of bone commonly present with local bone pain, soft tissue swelling, and a mass or a pathological fracture. There is a slight male preponderance, and most patients are over 45-50 years of age. Primary NHL of bone can arise in any part of the skeleton, but long bones (femurs, tibia) are the most common sites of presentation. Comprehensive immunohistochemical studies are required to establish an accurate histological diagnosis of primary NHL of bone. Most cases of primary NHL of bone are classified as diffuse large B-cell lymphomas (DLBCL) in the World Health Organisation (WHO) classification of hematological malignancies. On full staging evaluation, most patients have disease of stage IE or IIE according to the Ann Arbor system. Several studies indicate that patients with primary NHL of bone have a favorable outcome, especially when treated by combined modality therapy. A number of studies reported that clinical stage is the most important prognostic variable in predicting overall survival. Interestingly, the rare occurrence of primary lymphoma of bone is in contrast with the frequency of plasma cell tumors in bone. This could be due to the fact that, during normal B-cell differentiation, the bone marrow is the normal site of homing of plasma cells which are terminally-differentiated, immunoglobulin-secreting post-germinal center B-cells. In this respect, there is circumstancial evidence that primary NHL of bone may represent tumors of post-germinal center B-cells. The present review summarizes data on the histogenesis of primary NHL of bone in view of the recent histogenetic classification of DLBCL on the basis of the B-cell differentiation gene expression profiles (germinal center vs. post-germinal center B-cell differentiation).

Bone Neoplasms↗