Analysis of MicroRNA Expression in Breast Cancer Stem Cells
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: Breast tumors contain a heterogeneous subpopulation of cancer cells. We have proposed that only a minority population of cancer cells, called breast cancer stem cells, have the extensive ability to self-renew and proliferate. Our laboratory has prospectively identified the solid cancer stem cells from human breast cancer. Cancer stem cells should be the target of cancer therapy because tumor can easily relapse or metastasize, if significant numbers of cancer stem cell remain after treatment. MicroRNAs (miRNAs) are short non-coding regulatory RNAs that are expressed in a tissue-specific and developmentally regulated manner whose expression is frequently aberrant in breast cancer. The ability of miRNA that simultaneously regulate many target genes makes them attractive candidates for regulating stem cell self-renewal and cell fate decisions. If so, then they may provide novel therapeutic targets for the treatment of breast cancer.
 
 
 
 
 
 
 
 We hypothesize that miRNAs are key regulators of breast cancer stem cell self-renewal and differentiation. We further predict that we can identify key miRNAs that regulate the breast cancer stem cells by identifying species that are differentially expressed by the cancer stem cells, their non-tumorigenic progeny, or normal breast epithelial cells. Finally, we predict that anti-miRNA oligonucleotide that targets cancer stem cell specific miRNA will affect self-renewal and differentiation capacities of cancer stem cells and impair breast cancer progression. Our aims are;
 
 
 
 #1. To explore the specifically expressed miRNAs in breast cancer stem cells.
 
 
 
 #2. To identify the target protein controlled by the cancer stem cell specific miRNAs.
 
 
 
 #3. To determine an effect of miRNA knockdown on breast cancer progression.
 
 
 
 
 
 
 
 We will employ flow cytometry to isolate cancer stem cells, other cancer cells, and normal epithelial cells. The source of human breast tumor cells will be large primary tumor or pleural (lung) effusions of breast cancer patients, and xenograft human breast tumors grown in mice. Specific biomarkers will be used to collect cancer stem cells (CD44+CD24-/low Lineage-), other cancer cells that represent non-tumorigenic progeny (CD44+CD24+ Lineage-), or normal breast epithelial cells (ESA+Lineage-). Total RNA will be isolated and smaller RNA that contains miRNA will be enriched. Purified miRNA samples of cancer stem cell population and their progeny will be labeled and miRNA expression profiles will be analyzed by microarray. We will identify the candidate of miRNA target genes by using computational algorithm database, and analyze their expression by Western blotting. The effect of miRNA inhibitors, such as artificial oligonucleotides on the growth of cancer stem cells will be monitored using the mouse xenograft models.
 
 
 
 
 
 
 
 This project will promote our understanding about breast cancer stem cells. It is proposed that tumor will relapse if the cancer stem cells remain after therapies. Our approach will contribute to clarify the difference between breast cancer stem cells and other breast cancer cells. Our project will be the first phase to test the concept of breast cancer stem cell therapy by using anti-miRNA approach.