Subtle Changes to Tumor Suppressor Gene Affect Cancer Susceptibility
Posted May 05 2010 9:03am
Tumor suppressor genes are genes that produce substances that in turn help control normal biological function and prevent cancer development. The PTEN gene is one of the better known tumor suppressor genes. This gene is highly involved in cell growth regulation and therefore helps cells to grow at a normal rate. Mutations to the PTEN gene can cause a loss of this control, thereby allowing cells to grow out of control. While it is known that major genetic mutations in this gene can result in breast cancer, the effect of minor changes to PTEN gene expression are less clear.
A new cancer research study explored the idea that subtle changes in PTEN expression might induce breast cancer formation. For this study, breast cancer researchers analyzed mice that had intact PTEN genes, but produced the PTEN protein at only 80% of normal levels. The results of this study showed that mice whose PTEN protein production was reduced by only 20% developed a variety of tumors with breast cancer tumors being the most common. The formation of these tumors occurred in the absence of genetic mutations.
This is fascinating cancer research that suggests that any factor that effects PTEN expression levels might impact breast cancer risk, even without causing mutations in the PTEN gene. Interestingly, previous research has shown that dietary changes can effect PTEN expression. For example, one breast cancer study has reported that dietary fish oil might reduce breast cancer risk by enhancing PTEN expression. These results further emphasize the importance of diet and lifestyle choices in regards to breast cancer risk.