The study will entail assessing the molecular characterization of the cells and includes the analysis of (1) gene expression patterns, (2) DNA methylation profiles, (3) chromatin structure, (4) genetic alterations, and (5) protein levels. Each of these will be performed at global, genome-wide scale using array (SNP arrays or oligo/cDNA microarrays) or high-throughput sequencing approaches (SAGE-Serial Analysis of Gene Expression, MSDK-Methylation Specific Digital Karyotyping, and exon re-sequencing), as well as at the individual gene/protein level using lower throughput technologies such immunohistochemistry, mRNA in situ hybridization, in situ MSP (methylation specific PCR), quantitative MSP, quantitative PCR, immunoblot, and mass-spec based fragment analysis. The functional characterization of the cells includes culturing the cells in vitro and injecting them into immunodeficient mice to assay for their ability to generate normal mammary gland or breast tumor outgrowth. In addition to the analysis of the cells directly obtained from the patients, in some cases, the cells may be engineered to express or down-regulate a gene of interest. For example, based on the initial molecular studies we expect to identify genes that may regulate the pluripotency of stem cells or their differentiation. Candidate genes already include HOXA10, FOXC1, and additional ones may be identified. To test the functional relevance of these genes, genes will overexpressed or downregulated in the different cells using lentiviruses and then with the molecular and functional characterization of the resulting cells using approaches as described above.
If this study is successful, other patients with DCIS may someday benefit. DCIS may become invasive or may remain noninvasive. This study could potentially help physicians determine which patients with DCIS are more likely to progress to invasive cancer and/or recur. Patients with DCIS may be able to be stratified with respect to need for more or less amiressive tailored therapies.
There is strong interest to determine the type of DCIS that progresses to cancer. This study may help put some of the pieces in place to help make this determination. If DCIS tissue could be characterized to determine which ones will progress to invasive cancer, they could be treated earlier and more aggressively while others may avoid unnecessary treatment (overtreatment).