Getting to the bottom of drug-resistance in breast cancer

Problem Title

Getting to the bottom of drug-resistance in breast cancer

Scientific Title

Characterization of Tamoxifen-resistant cell lines

Lily Fitzgerald
Environmental Science
iCons Concentration: 
iCons Class Year: 
Class of 2014
Executive Summary 

Breast cancer is the second leading cause of death among American women. In order to create more effective treatments against this widespread disease, it is important to better understand the diversity among individuals' cancers. Hormone therapies are frequently used to treat patients whose cancer displays certain recognizable traits.

The female hormone estrogen increases cell proliferation, and many breast cancers depend on estrogen to continue limitless replication. Cancers are therefore usually characterized by the presence or absence of expressed Estrogen Receptor α (ERα). Tamoxifen is an antiestrogen drug commonly used to treat ERα positive breast cancers. However, 33% of women treated with Tamoxifen see a recurrence in their breast cancer within five years .

In order to better understand this acquired resistance to Tamoxifen in ERα positive cancer cells, we simulated a treatment by adding Tamoxifen to the media of cells of the MCF-7 line for sixth months. Following this, we performed a cloning by limiting dilution to assess the traits of the individual cells within the Tamoxifen-resistant group. We isolated DNA, RNA, and protein to examine gene expression, methylation, and protein expression in each of the 21 cell lines that resulted. Results of this study will further our understanding of the heterogeneity of Tamoxifen-resistant breast cancer and aid in the development of targeted therapies.

Problem Keywords: 
breast cancer
hormone therapy
Scientific Keywords: 
Estrogen Receptor α