Expression of Bax in relation to Bcl-2 and other predictive parameters in breast cancer.
BACKGROUND
It has been suggested that modification of the physiological susceptibility to induction of programmed cell death in transformed cells contributes to the pathogenesis of cancer. One of the major regulators of cell death is the bcl-2 family. In breast cancer, altered expression of Bcl-2 has been described. Distribution of its counterpart Bax and the differential expression pattern have still to be evaluated.


METHODS
Bax expression was investigated by immunohistochemistry in 122 primary breast cancers. Results were correlated with expression of Bcl-2 and other variables of predictive value.


RESULTS
There was a positive association between Bax expression and histological grading, (over)expression of c-erbB-1 and -2 and proliferative activity. The correlation was most significant in cases where no concomitant Bcl-2 expression could be detected. In the same subgroup an inverse correlation with positivity for estrogen (and progesterone) receptors was observed. The presence of Bax was not significantly associated with either tumor type and size, nodal status or expression of c-erbB-3.


CONCLUSIONS
Expression of Bax was coupled with negative histopathological features, especially when expression of Bcl-2 was downregulated concomitantly. It may appear that alterations of the differential Bax/Bcl-2 expression pattern take part in deregulation of proliferation and loss of differentiation, thus playing an important role in malignant progression.
Binder
C
C
Department of Haematology/Oncology, Georg-August-University, Göttingen, Germany.
Marx
D
D
Binder
L
L
Schauer
A
A
Hiddemann
W
W
D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D016009:Chi-Square Distribution; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics; D009367:Neoplasm Staging; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000032:analysis* / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2; D012189:Retrospective Studies; D051028:bcl-2-Associated X Protein
C494826:BAX protein, human; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein