Study reveals potential new target for cancer therapy
Scientists from the University of Virginia School of Medicine and their collaborators at EMBL in Germany, have discovered how yeast cells survive during nutrient scarcity. The finding, which involves the cells entering a dormant state to survive stress, could pave the way for innovative cancer treatments. The research was led by Ahmad Jomaa, PhD, from the Department of Molecular Physiology and Biological Physics at UVA's School of Medicine.
Yeast cells' survival mechanism mirrors cancer cells' behavior
The survival mechanism of yeast cells, particularly S. pombe, is especially fascinating because it's similar to human cells. This makes it an excellent research tool to study cellular processes in healthy and cancerous cells. Jomaa's team discovered that when yeast cells hibernate to survive stress, they wrap themselves in an unexpected blanket - their mitochondria become coated with deactivated ribosomes, which are cellular machinery that usually produce proteins.
Unraveling the mystery of ribosomes and mitochondria
The reason inactive ribosomes attach themselves to the mitochondria remains a mystery. Simone Mattei, PhD, from EMBL, suggested that a starved cell might start digesting itself, so the ribosomes could be coating the mitochondria for protection or triggering a signaling cascade within them. The team was able to visualize this attachment at a molecular level using powerful single-particle cryo-electron microscopy and cryo-electron tomography techniques.
Ribosomes attach 'upside down' on mitochondria
The researchers found the ribosomes had latched on "upside down" on the mitochondria, using a small subunit of their structure. This kind of interaction had never been seen before and could help decode how cells go into dormancy and wake up. Maciej Gluc, a graduate student in Jomaa's lab, said they were surprised to find this as they knew cells save energy and shut down their ribosomes, but didn't expect them to latch on in an upside state on mitochondria.
Implications for cancer treatment and future research
The findings could have significant implications for understanding cancer. Cancer cells often enter dormancy or "quiescence" to survive nutrient shortages due to their unchecked growth, and evade detection by our immune systems. Understanding this process could lead to new ways of targeting these cells, improving patient outcomes and preventing relapses. Jomaa stated that his team's future research will focus on understanding not only how cells regulate entry into dormancy but also how they awaken from it.
