Breast Cancer Research and Treatment

, Volume 129, Issue 1, pp 37–47

Pathways mediating the effects of cannabidiol on the reduction of breast cancer cell proliferation, invasion, and metastasis

Authors

    • California Pacific Medical CenterResearch Institute
  • Ryuichi Murase
    • California Pacific Medical CenterResearch Institute
  • Rigel T. Christian
    • California Pacific Medical CenterResearch Institute
  • Darryl Lau
    • California Pacific Medical CenterResearch Institute
  • Anne J. Zielinski
    • California Pacific Medical CenterResearch Institute
  • Juanita Allison
    • California Pacific Medical CenterResearch Institute
  • Carolina Almanza
    • California Pacific Medical CenterResearch Institute
  • Arash Pakdel
    • California Pacific Medical CenterResearch Institute
  • Jasmine Lee
    • California Pacific Medical CenterResearch Institute
  • Chandani Limbad
    • California Pacific Medical CenterResearch Institute
  • Yong Liu
    • California Pacific Medical CenterResearch Institute
  • Robert J. Debs
    • California Pacific Medical CenterResearch Institute
  • Dan H. Moore
    • California Pacific Medical CenterResearch Institute
  • Pierre-Yves Desprez
    • California Pacific Medical CenterResearch Institute
Preclinical study

DOI: 10.1007/s10549-010-1177-4

Cite this article as:
McAllister, S.D., Murase, R., Christian, R.T. et al. Breast Cancer Res Treat (2011) 129: 37. doi:10.1007/s10549-010-1177-4

Abstract

Invasion and metastasis of aggressive breast cancer cells are the final and fatal steps during cancer progression. Clinically, there are still limited therapeutic interventions for aggressive and metastatic breast cancers available. Therefore, effective, targeted, and non-toxic therapies are urgently required. Id-1, an inhibitor of basic helix-loop-helix transcription factors, has recently been shown to be a key regulator of the metastatic potential of breast and additional cancers. We previously reported that cannabidiol (CBD), a cannabinoid with a low toxicity profile, down-regulated Id-1 gene expression in aggressive human breast cancer cells in culture. Using cell proliferation and invasion assays, cell flow cytometry to examine cell cycle and the formation of reactive oxygen species, and Western analysis, we determined pathways leading to the down-regulation of Id-1 expression by CBD and consequently to the inhibition of the proliferative and invasive phenotype of human breast cancer cells. Then, using the mouse 4T1 mammary tumor cell line and the ranksum test, two different syngeneic models of tumor metastasis to the lungs were chosen to determine whether treatment with CBD would reduce metastasis in vivo. We show that CBD inhibits human breast cancer cell proliferation and invasion through differential modulation of the extracellular signal-regulated kinase (ERK) and reactive oxygen species (ROS) pathways, and that both pathways lead to down-regulation of Id-1 expression. Moreover, we demonstrate that CBD up-regulates the pro-differentiation factor, Id-2. Using immune competent mice, we then show that treatment with CBD significantly reduces primary tumor mass as well as the size and number of lung metastatic foci in two models of metastasis. Our data demonstrate the efficacy of CBD in pre-clinical models of breast cancer. The results have the potential to lead to the development of novel non-toxic compounds for the treatment of breast cancer metastasis, and the information gained from these experiments broaden our knowledge of both Id-1 and cannabinoid biology as it pertains to cancer progression.

Keywords

Id-1 Id-2 Helix-loop-helix Cannabinoid ERK ROS Lung metastasis

Abbreviations

CBD

Cannabidiol

Δ9-THC

Δ9-Tetrahydrocannabinol

ERK

Extracellular signal-regulated kinase

FBS

Fetal bovine serum

Id

Inhibitor of DNA binding

ROS

Reactive oxygen species

TOC

α-Tocopherol

Supplementary material

10549_2010_1177_MOESM1_ESM.tif (32 kb)
Figure 1 supplementary. CBD reduces the number of metastatic foci above 1 mm in the syngeneic BALB/c mouse model. Primary tumors were generated in BALB/c mice by subcutaneous injection of 1 × 105 4T1 cells and subsequently developed lung metastases. As described above, treatment with CBD was initiated upon detection of the first palpable tumor. Visible lung metastases were counted and measured by using a dissecting microscope. Lung metastatic foci measured included those (A) <1 mm, (B) 1–2 mm, and (C) > 2 mm. Significant differences were determined using the unpaired Student’s t-test.(TIFF 32 kb)

Copyright information

© Springer Science+Business Media, LLC. 2010