Researchers have discovered how mitochondria plays a role in preventing cells from dying when nutrient deprived. This work was published in Molecular Cell by researchers at McGill University.
A few years ago, Nahum Sonenberg, Ph.D., a McGill professor and one of the senior authors of this study, found that mTOR has control over protein expression in all human cells. In particular, mTOR targets the selective synthesis of proteins destined for the mitochondria, the bacteria-like structures in all our cells that generate the energy needed for cells to grow and divide.
In collaboration with other McGill laboratories, they have now shown that mTOR also controls the expression of proteins that alter the structure and function of mitochondria, therefore protecting the cells from dying.
Currently, many drugs in clinical trials for cancer act on mTOR. These drugs are effective in arresting the expansion and growth of cancer cells. However, even with a lack of nutrients, they are not effective at killing cancer cells off. This new study shows that it is the mitochondria that keeps cancer cells alive and prevents apoptosis.
This advancement offers clues to develop combination therapies that could promote cancer-cell death by reversing the protection offered by mitochondria, the researchers say.
Image: Mitochondrial elongation, induced by mTOR-inhibiting drugs, contributes to cell survival. Image courtesy of the Facility for Electron Microscopy Research/McGill University Department of Anatomy and Cell Biology.