Related Experiment Videos
Changing patterns of gene expression identify multiple steps during regression of rat prostate in vivo
J Gubbay1, J P Doyle, M Skinner
1Howard Hughes Medical Institute, The Rockefeller University, New York, New York 10021, USA.
Abstract:
The rat ventral prostate is an androgen-dependent organ that undergoes dramatic cell death upon removal of testosterone by surgical castration. Several well characterized criteria, such as nuclear condensation, organelle blebbing, and DNA fragmentation, have been used to demonstrate that most of this cell loss is due to programmed cell death, or apoptosis, of the secretory epithelial cells. In addition to changes in morphology, it is well known that cells undergoing apoptosis show alterations in gene expression, and it is widely assumed that many of these genes are directly involved in the mechanism of programmed cell death. Using poly A+ RNA derived from normal rat prostate as well as from the regressing prostates of castrated rats, we have used a PCR-based subtractive hybridization approach to generate complementary DNA (cDNA) libraries greatly enriched in cDNAs strongly regulated during rat prostate regression. Several hundred of the genes represented in these libraries appear to be strongly regulated during prostate regression and most of these are prostate specific. Sequence analysis indicates that up to 30% of these clones are similar or identical to genes of known function, approximately 20% are similar to expressed sequence tags (ESTs), and as many as 50% of these clones have not been characterized previously. Analysis of selected clones using in situ hybridization indicates that they are expressed specifically in prostate epithelial cells, and that certain of these clones are regulated temporally in a pattern consistent with apoptosis. The patterns of gene expression include: 1) genes whose expression decreases uniformly after removal of androgen, indicative of androgen sensitive genes; 2) genes whose expression increases in apoptotic prostate cells and in other tissues, suggesting a class of genes generally involved in apoptosis; 3) and genes whose expression increases in individual regressing prostate epithelial cells, suggesting a class of prostate specific genes associated with apoptosis.
Insights
Researchers identified genes involved in programmed cell death (apoptosis) in rat prostate tissue after testosterone removal. This study reveals new prostate-specific genes linked to apoptosis during regression.
Area of Science:
- Molecular Biology
- Cell Biology
- Andrology
Background:
- The rat ventral prostate is an androgen-dependent organ.
- Castration leads to significant cell death, primarily through apoptosis of secretory epithelial cells.
- Apoptotic cells exhibit altered gene expression, suggesting involvement in programmed cell death mechanisms.
Purpose of the Study:
- To identify genes regulated during rat prostate regression following androgen withdrawal.
- To characterize prostate-specific genes involved in apoptosis.
Main Methods:
- Utilized PCR-based subtractive hybridization to create cDNA libraries from normal and regressing rat prostates.
- Analyzed gene expression patterns using in situ hybridization.
- Sequenced and characterized identified cDNA clones.
Main Results:
- Generated cDNA libraries enriched for genes regulated during prostate regression.
- Identified several hundred regulated genes, many of which are prostate-specific.
- Found that up to 50% of identified clones represent previously uncharacterized genes.
- Observed distinct temporal and spatial expression patterns consistent with apoptosis in epithelial cells.
Conclusions:
- Androgen withdrawal triggers significant changes in gene expression within the rat ventral prostate.
- Identified novel prostate-specific genes associated with apoptosis.
- The study provides insights into the molecular mechanisms of programmed cell death in an androgen-dependent organ.