Study: CBD Reduces Tumor Growth and Lowers Immune Evasion Marker HLA-G

The findings come from experiments using JEG-3 choriocarcinoma cells, a model commonly used to study cancer behavior and immune-related pathways. Researchers from San Sebastian University, the University of Concepción, and the University of La Plata first determined safe concentrations of CBD and a high-CBD extract through standard viability testing. They then examined how the compounds influenced tumor cell activity, including proliferation, apoptosis, and migration. Across multiple assays, CBD reduced cell growth, increased programmed cell death, and limited the ability of tumor cells to move and spread. Markers such as Ki-67, Caspase-3, and MMP-9 showed clear shifts consistent with decreased aggressiveness.

The study’s most notable result was a significant decline in HLA-G expression. HLA-G is a non-classical immune molecule that allows tumors to avoid immune detection, and both CBD treatments lowered it at the mRNA and protein level. The effect was dose-dependent, time-dependent, and fully reversible once treatment stopped, suggesting CBD actively regulates this pathway rather than causing lasting suppression.

By weakening tumor viability while reducing an immune-escape mechanism, the researchers say CBD could theoretically enhance antitumor immunity or complement immunotherapy approaches. They note that further work in additional cancer types and in vivo models will be needed to confirm how widely this mechanism applies.