In vivo patterns of Bcl-2 family protein expression in breast carcinomas in relation to apoptosis.
The expression of the pro-apoptotic proteins (Bax, Bak) and anti-apoptotic proteins (Bcl-2, Bcl-X, Mcl-1) was studied by immunohistochemistry in 110 invasive ductal breast carcinomas. The results were correlated with tumour grade, expression of oestrogen receptor (ER) and p53 protein, and the apoptotic index by combined morphology, immunohistochemistry, and a terminal UTP nick end labelling (TUNEL) procedure. Overall, Bcl-2, Bcl-X, Mcl-1, Bax, Bak, ER, and p53 were detected in 62, 75, 68, 75, 60, 68 and 26 per cent of the cases respectively, but at different levels in each case. A high apoptotic index was correlated with high tumour grade (p<0.001), overexpression of p53 (p<0.001), Bak expression (p<0.001), and low expression of Bcl-2 (p<0.001) and ER (p<0.001). No correlation was found between the apoptotic index and Bax, Bcl-X, and Mcl-1 immunostaining results. The expression of Bcl-2 and Bcl-X was correlated to that of ER. Overall, the results of this study strongly suggest that Bcl-2 and Bak expression is critical in regulating apoptosis in breast carcinomas.
Laboratoire d'Anatomie et Cytologie Pathologiques, Institut Claudius Regaud, 20-24 Rue du Pont Saint Pierre, 31052 Toulouse Cedex, France.
P
P
Rochaix
S
S
Krajewski
J C
JC
Reed
F
F
Bonnet
J J
JJ
Voigt
P
P
Brousset
D017209:Apoptosis / Q000502:physiology*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling; D008565:Membrane Proteins / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D050998:bcl-2 Homologous Antagonist-Killer Protein
C494772:BAK1 protein, human; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011960:Receptors, Estrogen; D016159:Tumor Suppressor Protein p53; D050998:bcl-2 Homologous Antagonist-Killer Protein