Qualy #61 - Rapamycin in cancer treatment
This Qualys episode features a discussion with Matt Kaeberlein, Ph.D., exploring rapamycin's complex effects on cancer and aging, highlighting its limited efficacy for diagnosed cancers and dose-dependent, sex-specific outcomes in mouse studies. It also emphasizes immune function as a key driver in age-related cancer prevention.
Deep Dive Analysis
5 Topic Outline
Rapamycin's Efficacy in Diagnosed Cancers
High-Dose Rapamycin Study in Mice: Sex-Specific Effects
Female Mouse Sensitivity to Rapamycin Dosing
Potential of Rapamycin in Cancer Immune Therapies
Debate: Primary Drivers of Age-Related Cancer Increase
3 Key Concepts
mTOR Inhibition
Turning down the mTOR pathway, often with drugs like rapamycin, is expected to stop cell proliferation. However, cancer cells can evolve to ignore this signal, making mTOR inhibition less effective in advanced cancers.
Immune Surveillance
This is the body's mechanism where the immune system identifies and destroys abnormal cells, including nascent cancer cells, before they can develop into tumors. Its decline with age is considered a significant factor in age-related cancer.
Hematopoietic Cancers
These are cancers that affect the blood, bone marrow, and lymph nodes, such as leukemia and lymphoma. In a high-dose rapamycin mouse study, female mice developed aggressive forms of these cancers.
4 Questions Answered
For most cancers once diagnosed, rapamycin has been disappointing in its effectiveness, suggesting that tumors may have evolved to ignore mTOR inhibition.
Rapamycin can potentially boost age-related immune function and enhance immune surveillance, which could be anti-cancer. However, very high doses might inhibit immune function, potentially promoting or amplifying cancers.
Yes, in mice, females appear to be more sensitive to rapamycin, potentially clearing the drug slower or experiencing a greater mTOR inhibitory effect at the same dose, leading to different outcomes at high doses.
It's likely a combination of factors, including the reduction in immune surveillance, the length of time to accumulate mutations, and the frequency of mutations. The decline in immune function is considered a very important factor.
2 Actionable Insights
1. Seek Professional Medical Advice
Do not use this podcast’s information as a substitute for professional medical advice, diagnoses, or treatment; always seek assistance from your healthcare professionals for any medical conditions you have.
2. Boost Immune Function
Prioritize maintaining a strong immune system, as it is considered a primary anti-cancer mechanism and may be more controllable than other factors like mutation accumulation.
4 Key Quotes
for most cancers once it's reached the point of diagnosis that rapamycin is disappointing in its effectiveness it's not particularly effective
Matt Kaeberlein, Ph.D.
my guess is that because we pushed the dose so high we might have actually taken it too far in the female
Matt Kaeberlein, Ph.D.
immune surveillance is probably the most important anti-cancer mechanism or certainly one of the most important anti-cancer mechanisms
Matt Kaeberlein, Ph.D.
i secretly want that to be the biggest driver because i think we have a better chance to control that
Peter Attia, MD