Before birth, a group of more than 200 growth-promoting genes is highly active, fueling the fetus’ explosive growth. After birth, these genes are gradually switched off, apparently to slow body growth as people age and approach adult size.
In cancer cells, some of these genes can be switched back on. One of the major growth-promoting genes is called IGF2. This gene is critical for normal prenatal body growth and is reactivated in many types of cancer, showing remarkably high activity in bladder and prostate cancer and some childhood cancers. However, scientists have not been able to determine what turns IGF2 on and off.
NICHD researchers in the Section on Growth and Development, within the Program on Developmental Endocrinology and Genetics in the Division of Intramural Research, found evidence that a protein known as E2F3 activates the IGF2 gene in both normal development and in cancer—in particular, in bladder and metastatic prostate cancers. More broadly, E2F3 appears to regulate not just IGF2, but also many other genes in the body-growth group. When E2F3 levels are high, these genes are active. When E2F3 levels decrease, so do these genes.
This finding may provide a new avenue to help patients with several different types of cancer (PMID: 23530192).