Mammary Gland Development and Tumorigenesis

The focus of our laboratory is to understand the role of cyclin D1 in tumorigenesis. Cyclin D1 is the second most frequently amplified oncogene in human cancer. In our effort to functionally dissect the mechanism of action for cyclin D1 in cancer, we discovered that overexpressed cyclin D1 activates a cdk-independent transcriptional program. Here, the transcription factor C/EBPβ was identified as the effector of cyclin D1. Ongoing efforts are directed toward determining how the cyclin D1-C/EBPβ pathway participates in breast cancer and other epithelial malignancies. Further, guided by the belief that understanding the normal function of cyclin D1 and C/EBPβ will provide insights into their oncogenic action, we are studying the role of cyclin D1’s C/EBPβ-dependent transcriptional function in mammary gland development.