Qualy #46 - Rapamycin's effects on cancer, cardiovascular disease, and neurodegeneration
This Qualys episode features David Sabatini, M.D., Ph.D., discussing rapamycin's effects on longevity, cancer, and cardiovascular disease. The conversation also explores mTOR's role in neurodegeneration and the theoretical location of the body's appetite center.
Deep Dive Analysis
3 Topic Outline
Rapamycin's Impact on Cancer Onset and Progression
Rapamycin, mTOR, and Neurodegeneration in the Brain
Modulation of mTOR Activity and Nutrient Sensing in the Brain
3 Key Concepts
Immune Surveillance
This is the process by which the immune system detects and eliminates abnormal cells, including cancer cells, before they can develop into tumors. Rapamycin's effects on cancer are interesting because, despite being an immunosuppressant, it does not lead to increased cancer rates in transplant patients, suggesting it has direct anti-cancer properties that balance its immunosuppressive effects.
Autophagy
Autophagy is a fundamental cellular process where cells break down and recycle their own damaged or unnecessary components. It plays a critical role in maintaining cellular health, particularly in the brain, and its impairment or deletion can lead to neurodegeneration.
mTORC1 Activity
The mechanistic Target of Rapamycin Complex 1 (mTORC1) is a protein complex that regulates cell growth, proliferation, and survival. While essential for maintaining healthy synapses and brain growth, its activity must be appropriately modulated to allow for processes like autophagy and ensure overall system health.
4 Questions Answered
Rapamycin is not a cytotoxic agent and is unlikely to cure existing cancer or modulate the initial mutational frequencies that lead to cancer. However, it may affect the growth and immune evasion of cancer cells once they have formed.
While general immunosuppression is linked to higher cancer rates due to reduced immune surveillance, rapamycin's use in transplant patients is not associated with this increased risk. This suggests rapamycin has direct, cancer cell-autonomous effects that counteract the risks of its immunosuppressive properties.
Autophagy, regulated by mTOR, is crucial for brain health, and its impairment can lead to neurodegeneration. mTORC1 activity is necessary for healthy synapses and brain development, but it must be modulated to allow for autophagy and maintain overall brain system health.
Neuronal activity is known to modulate mTORC1 in the brain, but the specific factors that regulate it, especially considering the brain's prioritization of nutrients, are not fully understood and remain an active area of research.
1 Actionable Insights
1. Consult Healthcare Professionals
Do not disregard or delay obtaining medical advice for any medical condition; instead, users should seek the assistance of their health care professionals for any such conditions.
3 Key Quotes
my bet would be that in the case of cancer you're not gonna you're not gonna cure cancer once you've got it but you but i also don't think you're going to modulate the incidence like the mutational frequencies that are giving you cancer.
David Sabatini
the body protects the brain from a nutrient point of view yet mtrog one activity is high there clearly we know that we have to modulate autophagy so something must be inhibiting mtrog one.
David Sabatini
rapamycin is there's some situations where it has some decent activity but in general it's not a cytotoxic agent.
David Sabatini