CBD reshaped the tumor immune environment and boosted immunotherapy response in colon cancer mice | Research

The takeaway

Single-cell sequencing revealed that CBD shifted tumor-associated macrophages from immunosuppressive to anti-tumor states in mice, and combining CBD with anti-PD-1 immunotherapy enhanced tumor control.

Cancer immunology researchers, oncologists following cannabinoid research, and scientists studying tumor microenvironment modulation.

CBD + anti-PD-1 combination outperformed either treatment alone in tumor-bearing mice

What the researchers found

CBD suppressed M2-like (immunosuppressive) macrophages and promoted M1-like (anti-tumor) macrophages within tumors. This shift enhanced macrophage-tumor cell interactions and improved response to anti-PD-1 immunotherapy in xenografted mice.

Why it matters

Many colorectal tumors resist immunotherapy because their immune environment is suppressive. If CBD can reprogram that environment, it could potentially make existing immunotherapies work better.

The numbers in context

CBD shifted macrophage balance from M2 (immunosuppressive) to M1 (anti-tumor). CBD inhibited PI3K-AKT signaling and shifted macrophage metabolism from oxidative phosphorylation to glycolysis. CBD plus anti-PD-1 showed enhanced anti-tumor response vs. either treatment alone.

How the study worked

Single-cell RNA sequencing and single-cell ATAC sequencing of colorectal tumors in mice treated with CBD. Mechanistic studies examined macrophage metabolic reprogramming. Combination experiments tested CBD plus anti-PD-1 antibody in tumor-bearing mice.

What this study cannot tell us

Mouse study with limited translational relevance. Xenograft models do not fully recapitulate human tumor microenvironments. CBD doses in mice may not reflect achievable human exposures. No clinical validation.

How to read the evidence

Sophisticated preclinical study with cutting-edge single-cell methods. However, mouse tumor models frequently do not predict human clinical outcomes.

When this study was published

Published 2023.

The bigger picture

Immunotherapy has transformed cancer treatment but only works in a fraction of patients. Finding ways to overcome immunosuppressive tumor environments is one of the biggest challenges in oncology. This preclinical data puts CBD on the map as a potential immunotherapy adjuvant.

Questions still open

Would CBD produce similar macrophage reprogramming in human colorectal tumors? What CBD doses would be needed to achieve these immunomodulatory effects in cancer patients?

Common questions

Can CBD fight cancer?

This mouse study found CBD changed the immune environment around colon tumors in ways that could help the immune system attack cancer cells. It also improved the effectiveness of an immunotherapy drug. However, these are animal findings and do not mean CBD is a cancer treatment for people.

What did CBD do to immune cells in tumors?

CBD shifted macrophages (a type of immune cell) from an immunosuppressive state (M2) that helps tumors hide from the immune system to an anti-tumor state (M1) that attacks cancer cells. It did this by changing macrophage metabolism through the PI3K-AKT signaling pathway.

Read the original research

Single-cell analyses reveal cannabidiol rewires tumor microenvironment via inhibiting alternative activation of macrophage and synergizes with anti-PD-1 in colon cancer.

Journal of pharmaceutical analysis, 13(7), 726-744

View on PubMed ↗Publisher’s paper ↗

Citation

Sun, Xiaofan; Zhou, Lisha; Wang, Yi; Deng, Guoliang; Cao, Xinran; Ke, Bowen; Wu, Xiaoqi; Gu, Yanhong; Cheng, Haibo; Xu, Qiang; Du, Qianming; Chen, Hongqi; Sun, Yang. (2023). Single-cell analyses reveal cannabidiol rewires tumor microenvironment via inhibiting alternative activation of macrophage and synergizes with anti-PD-1 in colon cancer.. Journal of pharmaceutical analysis, 13(7), 726-744. https://doi.org/10.1016/j.jpha.2023.04.013