bcl-2 automated and quantitative immunocytochemical assays in breast carcinomas: correlation with 10-year follow-up.
ABSTRACT bcl-2 protein is detectable in human cancers and may be involved in the response to antineoplastic drugs or endocrine therapy in breast carcinomas. In a previous study, we had developed optimal technical conditions for bcl-2 immunodetection. The aim of the present report was to determine the prognostic significance of bcl-2 expression in breast carinomas by the use of a similar immunocytochemical procedure.
bcl-2 immunocytochemical assays were performed on frozen sections by automated immunoperoxidase technique (Ventana) and computer-assisted analysis of digitized colored microscopic images (SAMBA) in a series of 170 breast carcinomas. The results of automated quantitative immunocytochemical assays were correlated with patient follow-up (120 months).
Intense bcl-2 immunocytochemical expression in tumors (cutpoint, 15%) significantly correlated with longer disease-free survival and longer recurrence-free survival in the entire cohort of patients (P = .028 and P = .035, respectively) and also in node-negative subgroups of patients (P = .028 and P = .01; Kaplan-Meier long-rank test; NCSS 6.0.1 software). But bcl-2 immunostained surfaces (cutpoint, 15%) did not correlate with overall survival. In multivariate analysis (proportional hazards regression, Cox model), bcl-2 prognostic significance in terms of disease-free survival was only independent of the tumor size and grade and histoprognostic index (Nottingham prognostic index [NPI]).
bcl-2 immunohistochemical expression is a significant indicator of favorable outcome only in terms of disease-free and local recurrence-free survival. However, bcl-2 expression in tumors is an independent weakly prognostic indicator in breast carcinomas. bcl-2 immunodetection assessed in optimal technical conditions (frozen samples, automation, quantitative analysis, scatter diagram cutoffs) may have some limited practical clinical relevance for the management of patients with breast carcinomas.
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ABSTRACT: Evasion of apoptosis is a hallmark of human cancers, for example in haematological malignancies. Apoptosis is an intrinsic cell death program that is crucial in maintaining tissue homeostasis, for example in the haematopoietic system where there is a high turnover rate of cells. As a result, a decrease in the rate of apoptosis as well as an increase in proliferation favours tumorigenesis as well as tumour progression. Further, the anti-leukaemic action of current treatment approaches, including chemo-, radio- or immunotherapy, critically relies on intact cell death programs in cancer cells. Therefore, defects in apoptosis pathways are frequently associated with the resistance to anticancer therapies. In recent years, the identification and characterization of the molecules and pathways that are involved in the regulation and execution of cell death in leukaemia and lymphoma cells, for example tumour necrosis factor-related apoptosis inducing ligand (TRAIL), 'inhibitor of apoptosis' (IAP) proteins and Bcl-2, have set the ground for the development of novel diagnostic tools and molecular therapeutics targeting apoptosis pathways in haematological malignancies.British Journal of Haematology 03/2009; 145(4):441-54. · 4.94 Impact Factor
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ABSTRACT: c Kit (CD117) expression in tissues has been reported as a relevant target for specific therapy in some human malignancies, but has been poorly documented in breast carcinomas. The prognostic significance of c Kit in a series of 924 breast carcinomas (mean follow-up, 79 months) was investigated using standardised high-throughput quantitative densitometry of immunohistochemical precipitates in tissue microarrays. c Kit was expressed in 14.7% breast carcinomas (and in 42 out of 586 node-negative tumours). In univariate analysis, (log-rank test) the score of c Kit expression correlated with poor patient outcome P=0.02 and particularly in node-negative cases (P=0.002). In multivariate Cox analysis, c Kit was an indicator of metastasis independent of 25 other concomitantly evaluated markers of prognosis. Logistic regression showed that c Kit ranked 10 out of 25 (P=0.041), and was included in a 10-marker signature that allowed 79.2% of the patients to be correctly classified in the metastatic or metastasis-free categories independently of hormone receptors and HER-2 status. Interestingly, c Kit was also a significant predictor of metastasis in node-negative tumours (2 out of 25 ranking, P<0.0001) and included in a six-marker signature of prognosis, correctly classifying 88.6% of the patients (P<0.0001). We concluded that, as assessed by quantitative immunohistochemistry, c Kit is an independent prognostic indicator that could also potentially serve as a target for specific therapy in breast carcinomas.British Journal of Cancer 06/2009; 101(1):48-54. · 5.08 Impact Factor
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ABSTRACT: Forkhead box protein A1 (Foxa1) is an evolutionarily conserved winged helix transcription factor that was traditionally considered to be involved in embryonic development and cell differentiation. However, little is known about the role of Foxa1 in oxidative-stress-induced apoptosis. In this study, hydrogen peroxide (H(2)O(2))-induced apoptosis, upregulation of Foxa1, and the role of Foxa1 in the regulation of bcl2 gene expression were studied in A549 type II pneumocytes. H(2)O(2) upregulated Foxa1 mRNA and protein in a time- and dose-dependent manner. Overexpression of Foxa1 promoted apoptosis, whereas Foxa1 deficiency, induced by antisense oligonucleotides, decreased A549 cell apoptosis induced by H(2)O(2), as shown by flow cytometry. Moreover, Foxa1 overexpression decreased the expression of bcl2, while Foxa1 depletion increased the expression of bcl2. Electrophoretic mobility shift assay and chromatin immunoprecipitation revealed that Foxa1 bound to bcl2 promoter, and H(2)O(2) promoted its DNA binding activity. Luciferase reporter showed that Foxa1 also decreased the transcription activity of bcl2 promoter under normal conditions and oxidative stress. These results indicate that Foxa1 plays a pro-apoptotic role by inhibiting the expression of anti-apoptotic gene bcl2.Cell Stress and Chaperones 02/2009; 14(4):417-25. · 2.48 Impact Factor