Increased expression of follistatin in breast cancer reduces invasiveness and clinically correlates with better survival

Background/Aim: Activin and its antagonist follistatin (FST) have been implicated in several solid tumours. This study investigated the role of FST in breast cancer. Materials and Methods: FST expression was examined using reverse transcription polymerase chain reaction (RT-PCR), real-time quantitative polymerase chain reaction (qPCR) and immunohistochemistry in a cohort of breast cancer samples. Expression was correlated to pathological and prognostic parameters in our patient cohort. FST was overexpressed in MCF-7 cells and assays for growth and invasion were performed. Results: FST is expressed in breast tissue, in the cytoplasm of mammary epithelial cells. Expression was decreased in breast cancer tissue in comparison to normal mammary tissue. Over-expression of FST in vitro led to significantly increased growth rate and reduced invasion. Higher FST associates with lower-grade tumours and better survival. Conclusion: Our results suggest a role for FST as a suppressor of invasion and metastasis in breast cancer.