Antioxidants accelerate lung cancer progression in mice.
Level 5 - mechanism / opinion, no new human data
Bench and animal research (mouse models and in vitro human cell lines)
PubMed 24477002 · doi:10.1126/scitranslmed.3007653
What was done
Researchers administered dietary supplementation with the antioxidants N-acetylcysteine (NAC) and vitamin E to mouse models of B-RAF- and K-RAS-induced lung cancer. They evaluated tumor progression, overall survival, transcriptomic profiles via RNA sequencing, and cellular markers (reactive oxygen species, DNA damage, and p53 expression) in mouse models and cultured human lung tumor cells, with and without p53 inactivation.
What was found
The abstract reports no numerical data (exact sample sizes, hazard ratios, or survival rates are not provided). Supplementation with NAC or vitamin E accelerated tumor progression and decreased survival in mice. Both antioxidants produced coordinated transcriptomic changes, decreased endogenous antioxidant gene expression, and reduced ROS, DNA damage, and p53 expression in mouse and human lung cancer cells. Inactivation of p53 increased tumor growth to a degree comparable to antioxidant treatment and eliminated the antioxidant-induced acceleration.
Why it matters
These findings identify a mechanistic pathway whereby antioxidants blunt the ROS-p53 tumor suppressor axis, suggesting that antioxidant supplementation may accelerate early tumor progression in high-risk populations such as smokers and COPD patients.
Limits
The study was conducted entirely in animal models and in vitro human cancer cells, meaning direct clinical effects and effective dosages in humans were not evaluated. The abstract reports no numerical values, confidence intervals, or sample sizes.
Cited by
- supports Studies in mice show that administering antioxidants like vitamin E or N-acetylcysteine promotes accelerated tumor growth and metastasis in lung cancer and melanoma.