FER as a novel target for cancer therapy

FER is an intracellular tyrosine kinase which resides in both the cytoplasm and the nucleus of mammalian cells. Although FER is present in a variety of tissues and cells, mice devoid of active FER develop normally and the proliferation of fibroblasts derived from these mice is not impaired in vitro. Thus, FER does not appear to exert an essential function in the proliferation of normal cells. However, several lines of evidence suggest a regulatory role of FER in the progression and growth of malignant tumors. FER is highly expressed in numerous malignant cell lines and the levels of FER in malignant prostate tumors are significantly higher than those detected in benign prostate tumors. Furthermore, downregulation of FER impairs the proliferation of prostate carcinoma cells and attenuates the development of prostate cancer. Recent findings also suggest the involvement of FER in the progression of breast cancer and it has been shown to play a unique regulatory role during cell cycle progression in breast cancer cells. In the current review, we discuss the molecular mechanisms which underlie the pivotal role of FER in the proliferation of malignant cells. The validity of FER as a novel intervening target for cancer therapy is discussed as well.