Modification of Epigenetic Changes in Cancer by the Stromal Environment
Abstract
The stromal environment can modulate important epigenetic changes that are seen in carcinogenesis. We hypothesize that growth of primary, normal (non-tumorigenic) epithelial cells in the presence of stromal fibroblasts that have been isolated from a mammary adenocarcinoma will change the frequency of methylation events at promoter sequences such as for l4-3-3sigma and pl6. Promoter hypermethylation of l4-3-3sigma is a frequent event in both early and later stages of breast cancer and silencing occurs in over 90% of breast tumors. We have successfully established a methylation-specific PCR assay to distinguish methylated from unmethylated alleles of the l4-3-3sigma promoter. We found that l4-3-3sigman is unmethylated in normal HMEC. We further determined that vHMEC, postulated to be a very early step in breast carcinogenesis, also lacks appreciable hypermethylation of l4-3-3sigma promoter sequences. Interestingly, 14-3-3sigma is methylated in mammary fibroblasts. To address whether mammary Stroma affects the frequency of methylation in mammary epithelial cells using our established methylation-specific PCR assay, will require partitioning techniques to separate fibroblasts (with methylated 14-3-3sigma sequences) from rare epithelial cells that may have hypermethylated the same sequences.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2004
- Accession Number
- ADA430193
Entities
People
- Thea D. Tlsty
Organizations
- University of California, San Francisco