Friday, January 11, 2008

Breakthrough Discovered in Medical Marijuana Cancer Treatment

Tim King

Researchers learned that cannabinoids have been associated with anti-carcinogenic effects, which are responsible in preventing or delaying the development of cancer.
Medical marijuana

(SALEM, Ore.) - A new study reveals that Medical Marijuana can be an effective treatment for cancer, that is the word announced by doctors in Germany who concluded that this clarification of the mechanism of cannabinoid action may help investigators to further explore their therapeutic benefit.

The medical article was originally published in the Journal of the National Cancer Institute Advance Access and online on December 25th 2007.

Cancer cells that were treated with combinations of cannabinoids, antagonists of cannabinoid receptors, and small interfering ribo nucleic acid or 'siRNA' to tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) were assessed for invasiveness, protein expression, and activation of signal transduction pathways.

The biggest contribution of this breakthrough discovery, is that the expression of TIMP-1 was shown to be stimulated by cannabinoid receptor activation and to mediate the anti-invasive effect of cannabinoids.

In other words, they learned that treatment with cannabinoids, one of the active ingredients of the medicinal side of marijuana, has been shown to reduce the invasiveness of cancer cells. Prior to now the cellular mechanisms underlying this effect were unclear and the relevance of the findings to the behavior of tumor cells in vivo remains to be determined.

It is already known that marijuana can stimulate the appetite of patients, but researchers have learned that cannabinoids, in addition to having palliative benefits in cancer therapy, have been associated with anti-carcinogenic effects, which are responsible in preventing or delaying the development of cancer.

"Although the anti-proliferative activities of cannabinoids have been intensively investigated, little is known about their effects on tumor invasion," the article stated.


In this now completed round of research, Matrigel-coated and uncoated Boyden chambers were used to quantify invasiveness and migration, respectively, of human cervical cancer 'HeLa' cells that had been treated with cannabinoids.

The stable anandamide analog R(+)-methanandamide 'MA' and the phytocannabinoid 9-tetrahydrocannabinol 'THC' in the presence or absence of antagonists of the CB1 or CB2 cannabinoid receptors or of transient receptor potential vanilloid 1 (TRPV1) or inhibitors of p38 or p42/44 mitogen–activated protein kinase (MAPK) pathways.

A method known as 'reverse transcriptase–polymerase chain reaction' and immunoblotting were used to assess the influence of cannabinoids on the expression of matrix metalloproteinases and endogenous tissue inhibitors. The role of TIMP-1 in the anti-invasive action of cannabinoids was analyzed by transfecting HeLa, human cervical carcinoma, or human lung carcinoma cells cells with siRNA targeting TIMP-1.

They say all statistical tests were two-sided.


Without modifying migration, MA and THC caused a time and concentration-dependent suppression of HeLa cell invasion through Matrigel that was accompanied by increased expression of TIMP-1.

At the lowest concentrations tested, MA and THC led to a decrease in cell invasion.

"The stimulation of TIMP-1 expression and suppression of cell invasion were reversed by pretreatment of cells with antagonists to CB1 or CB2 receptors, with inhibitors of MAPKs, or, in the case of MA, with an antagonist to TRPV1. Knockdown of cannabinoid-induced TIMP-1 expression by siRNA led to a reversal of the cannabinoid-elicited decrease in tumor cell invasiveness in HeLa, A549, and C33A cells."

The researchers concluded that increased expression of TIMP-1 mediates an anti-invasive effect of cannabinoids. That means that in our future, cannabinoids may offer a therapeutic option in the treatment of highly invasive cancers.

Special thanks to the JNCI Journal of the National Cancer Institute, and to Burkhard Hinz, PhD, Institute of Toxicology and Pharmacology, University of Rostock and the affiliation of authors: Institute of Toxicology and Pharmacology, University of Rostock in Rostock, Germany.

The original report published by Oxford University Press was titled, "Inhibition of Cancer Cell Invasion by Cannabinoids via Increased Expression of Tissue Inhibitor of Matrix Metalloproteinases-1Robert Ramer, Burkhard Hinz."

Breakthrough Discovered in Medical Marijuana Cancer Treatment

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