Growth Dynamics of Breast Cancer Cells: A Study of Growth Regulatory Factors
Abstract
Primary human breast cancer tissues obtained from biopsies or mastectomies were characterized in terms of DNA content by flow cytometric and digital image analyses and expression of growth factor receptors, e.g. estrogen and progesterone receptors. One breast tumor biopsy was accompanied by an axillary lymph node which contained metastatic tumor. The primary (breast) tumor contained two aneuploid stem lines with DNA indices of 1.4 and 1.9 and S-phase fractions of 19.8% and 7.4%, respectively. Metastatic tumor in the axillary lymph node contained only one aneuploid stem line with an S-phase fraction of 9. 6% and a DNA index of 1.7 suggesting the possibility of the emergence of a sub- line in the metastatic tumor. Flow cytometric analysis of mutant p53 expression of BT-474, DU-4475 and SK-BR3 cells indicated that significant differences existed between these three cell lines in terms of time during culture when p53 is expressed and variations in cell-cycle specific expression. These findings have particular relevance to previous reports which showed that the p53 tumor suppressor gene product is involved in the induction of apoptosis as the result of growth factor deprivation possibly by down-requlating bcl-2 expression. A DNA 3'-OH digoxigenin-nucleotide end extension-FITC-anti-digoxigenin labeling technique was used for detecting the presence of fragmented DNA in intact cell nuclei as a marker for apoptosis in etoposide-treated BT-474 and MCF-7 cells. Cell cycle analysis indicated that the number of apoptotic cells increased markedly after 16-23 hours of culture and that these cells were detected primarily in the S-phase fraction.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1996
- Accession Number
- ADA286882
Entities
People
- Bruce C. Velt
Organizations
- William Beaumont Army Medical Center