Question

You study two cell lines. In one, the MDM2 protein is overexpressed; in the other the p53 protein is absent. What difference would you expect in the behavior of these two cell lines?

Answer 1

The cell line with overexpressed MDM2 protein would inhibit the p53 protein, leading to uncontrolled cell division and an increased risk of tumor development. The cell line where p53 protein is absent lacks its normal functions, such as DNA repair and inducing cell death, resulting in the same consequences. Both conditions can result in abnormal cell behavior and an increased risk of tumor formation.

Step-by-step explanation:

In the cell line where the MDM2 protein is overexpressed, the MDM2 protein will bind to and inhibit the p53 protein. Since p53 is a tumor suppressor protein that plays a crucial role in regulating cell division and preventing the formation of tumors, its inhibition can lead to uncontrolled cell division and an increased risk of tumor development.

On the other hand, in the cell line where the p53 protein is absent, there is no functional p53 to perform its normal functions, such as activating genes involved in repairing DNA damage or inducing cell death when necessary. This absence of p53 can also lead to uncontrolled cell division and an increased risk of tumor development.

Therefore, in both cell lines, the absence of proper p53 function or its inhibition due to MDM2 overexpression can result in abnormal cell behavior and an increased propensity for tumor formation.