Expression of the bcl-2 gene family in normal and malignant breast tissue: Low bax-α expression in tumor cells correlates with resistance towards apoptosis
✍ Scribed by Railf C. Bargou; Peter T. Daniel; Markus Y. Mapara; Kurt Bommert; Christian Wagener; Bianca Kallinich; Hans D. Royer; Bcrnd Dörken
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- French
- Weight
- 799 KB
- Volume
- 60
- Category
- Article
- ISSN
- 0020-7136
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✦ Synopsis
We have studied the expression of the apoptosis-regulating genes bcl-2, bcl-x, box and APO-I /fas (CD95) in human breast cancer. The expression pattern of these genes in human breast-cancer tissues and breast-cancer-derived cell lines was compared to that seen in normal breast epithelium and breast epithelial cell lines. No difference with regard to bcI-2 and bcl-xL expression was observed between normal breast epithelium and tumor tissue or breast cancer and non-malignant epithelial cell lines. In contrast, box-% a splice variant of bar, which promotes apoptosis, is expressed in high amounts in normal cell lines and breast tissue, whereas only weak or no expression could be detected in cancer-cell lines and malignant tissue. In contrast to malignant cell lines, which express low levels of bax-ar, non-malignant epithelial cell lines displaying high amounts of bax-a were highly sensitive to induction of programmed cell death by both serum starvation and APO-Ilfas (CD95) triggering. We therefore propose that dysregulation of apoptosis contributes to the pathogenesis of breast cancer, at least in part, due to an imbalance between anti-apoptosis genes (such as bcI-2/bcI-x) and apoptosis-promoting genes (bax).