Association Between Recreational Physical Activity and mTOR Signaling Pathway Protein Expression in Breast Tumor...

Area of Science:

• Oncology
• Molecular Biology
• Exercise Science

Background:

• Physical activity (PA) is associated with decreased mTOR signaling in animal models of mammary cancer, suggesting potential benefits.
• The mTOR pathway is central to cellular energy sensing and growth regulation, influenced by PA.

Purpose of the Study:

• To examine the association between self-reported recreational PA levels and protein expression within the mTOR signaling pathway in human breast tumor tissue.
• To investigate how different intensities of PA impact mTOR pathway activity in breast cancer.

Main Methods:

• Analysis of tumor tissue from 739 breast cancer patients, with 125 having adjacent-normal tissue.
• Measurement of protein expression for mTOR, phosphorylated (p)-mTOR, p-AKT, and p-P70S6K.
• Classification of PA levels based on CDC guidelines: sufficient, insufficient, or no PA.

Main Results:

• Sufficient PA was associated with a 35.8% increase in p-P70S6K and a 28.5% increase in total phosphoprotein expression in tumors.
• Sufficient vigorous PA was linked to higher expression of mTOR (17.7% increase) and total phosphoprotein (28.6% increase) in tumors.
• Guideline-concordant PA levels correlated with increased mTOR signaling pathway activity in breast tumors.

Conclusions:

• Contrary to animal models, PA consistent with guidelines showed increased mTOR signaling activity in human breast tumors.
• The study highlights the complexity of PA's effects on mTOR signaling in humans, necessitating consideration of behavioral and biological factors.
• Findings provide a basis for further research into exercise-mediated mTOR pathway mechanisms and their clinical relevance in breast cancer.