Fatty Acid Synthase (FASN) as a Therapeutic Target for Breast Cancer Metastasis.

Abstract

Abstract Numerous solid tumors confirm increased expression of FASN. FASN expression is upregulated in early steps of breast cancer, such as DCIS, and is associated with poor clinical outcome in more advanced disease. The objective of this study is to evaluate FASN inhibition as a prevention of breast cancer progression and as an effective treatment of metastasis. We utilized the model the MCF10CA1 series of cell lines, which complete the spectrum of breast cancer progression ranging from non-transformed breast epithelial cells to metastatic breast cancer cells. These metastatic cell lines are CA1A and CA1D cells (short for MCF10A-CA1A and MCF10A-CA1D), which metastasize to the lung following a tail vein injection. Interestingly, we determine that with the progression of breast cancer in these model series the level of FASN was correlated with the evolution to a more aggressive phenotype. The CA1A and CA1D cells expressed the highest levels of FASN. To determine whether FASN plays a role in the aggressiveness of these cells we introduced a specific FASN silencing RNA into CA1A and CA1D cells and isolated stable cell lines in which FASN expression was significantly reduced. Stable expression of a FASN shRNA completely abrogated the anchorage-independent growth ability of the metastatic cells and furthermore these cells reverted from EMT to MET (Mesenchymal Epithelial Transition) as demonstrated by a Matrigel 3Dimentional (3D) assay and the immunofluorescence staining of E-Cadherin in matrigel. These results emphasize the potential of FASN as a therapeutic target and as a key modulator of breast cancer progression and metastasis. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6160.