The Relationship Between the Regulatory Retinoblastoma Protein and the Pro-apoptotic Protein BAK in Cancer Cells

About 15% percent of women in the U.S. will develop breast cancer. With such an alarming number, understanding the disease has become a critical matter. Cancer happens when mutated cells starts to show uncontrolled growth and will no longer undergo the process known as apoptosis, or cell suicide. The Retinoblastoma (Rb) protein is tumor suppressor protein, meaning it works to regulate the cell division and prevent the uncontrolled growth of cells. The cell division cycle is a highly regulated process that controls the growth and division of mammalian cells.  The role of Rb in cell cycle control is to prevent proliferation in the absence of mitogenic signals. RB is one of the most critical proteins related to cancer, therefore understanding its mechanism in the cell is crucial in order to understand the disease.

Bak is a pro-apoptotic protein also present in cells. Bak is involved in determining the time in which cells should be terminated. It plays an essential role in the induction of apoptosis as it is responsible for mitochondrial fragmentation.  We know that the retinoblastoma protein works with many other proteins inside the cell. It was recently discovered that both proteins, Rb and Bak, are associated with each other. However the physiological relevance of this interaction is still a mystery to us.

Our main goal in our research is to determine the functional significance of Rb association with Bak, find out if the activation of Rb regulates the interaction with Bak and to understand if Bak binds to the full length Rb or only a section of the protein.

Our first step toward the answers to our questions involve the use of C33A cancer cells and a technique known as transfection. Transfection is a technique that allows us to introduce a plasmid caring a gene into a cell. C33As are known to have a dysfunctional Rb. Then use a technique known as gel electrophoresis that will allows us to observe and compare the relationship between bak and rb. In another set of experiments we will use bacteria cells to determine the parts of Rb that bind to Bak.

Finally, with these experiment we hope to understand these two proteins more fully so an understanding of cancer apoptosis is possible.