The Inhibitory Effects of
Cannabidiol on Systemic Malignant
To the Editor:
The recent article by Johnson et al.
for highly stimulating reading. Cannabidiol
may attenuate tumor growth in a number of
other systemic malignancies. Decreased tumor
growth in pulmonary malignancies is seen after
administration of cannabidiol. Cannabidiol in-
creases the expression of cyclooxygenase-2 within
the cancerous cells.
Cannabidiol also induces
tissue inhibitor of metalloproteinase-1 synthesis
and activity. Peroxisome proliferator-activated
receptor-gamma expression is augmented at the
same time. Intercellular adhesion molecule-1
induction also is seen typically.
As a result, in-
tratumoral apoptosis is markedly accentuated.
Cannabidiol also downregulates the expression
of plasminogen activator inhibitor-1.
nuclear translocation of peroxisome proliferator-
activated receptor-gamma accompanies the
above changes. Tumor metastasis also is mark-
Similar attenuation of tumor growth is seen
in breast malignancies. It mediates this anti-
neoplastic effect by attenuating mammalian
target of rapamycin signaling.
reticulum stress is typically accentuated and
the cytoplasmic release of cytochrome C is
markedly enhanced. ID1 expression also is in-
hibited at the same time.
On the other hand,
ID2 expression is markedly upregulated. AKT
inhibition accompanies the above changes.
As a consequence, there is both increased apo-
ptosis and intratumoral autophagy. Interest-
ingly, beclin-1 plays a major role in these
The above examples clearly illustrate the sig-
niﬁcant antineoplastic effects of cannabidiol.
Hopefully, the next few years will see increased
studies to fully and further evaluate these anti-
Shailendra Kapoor, MD
Chicago, Illinois, USA
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Ó 2013 U.S. Cancer Pain Relief Committee.
Published by Elsevier Inc. All rights reserved.
0885-3924/$ - see front matter
Vol. 45 No. 4 April 2013 Journal of Pain and Symptom Management e1