Cannabis extract shrinks brain tumours

The World's No.1 Science & Technology News Service



Cannabis extract shrinks brain tumours


05:00 15 August 04

NewScientist.com news service

Cannabis extracts may shrink brain tumours and other cancers by blocking the growth of the blood vessels which feed them, suggests a new study.

An active component of the street drug has previously been shown to improve brain tumours in rats. But now Manuel Guzmán at Complutense University, Spain, and colleagues have demonstrated how the cannabis extracts block a key chemical needed for tumours to sprout blood vessels – a process called angiogenesis.

And for the first time, the team has shown the cannabinoids impede this chemical in people with the most aggressive form of brain cancer - glioblastoma multiforme.

Cristina Blázquez at Complutense University, and one of the team, stresses the results are preliminary. “But it’s a good point to start and continue,” she told New Scientist.

“The cannabinoid inhibits the angiogenesis response - if a tumour doesn’t do angiogenesis, it doesn’t grow,” she explains. “So if you can improve angiogenesis on one side and kill the tumour cells on the other side, you can try for a therapy for cancer.”

"This research provides an important new lead compound for anti-cancer drugs targeting cancer's blood supply,” says Richard Sullivan, head of clinical programmes, at Cancer Research UK.


Fat molecule


The team tested the effects of delta-9-tetrahydrocannabinol in 30 mice. They found the marijuana extract inhibited the expression of several genes related to the production of a chemical called vascular endothelial growth factor (VEGF).

VEGF is critical for angiogenesis, which allows tumours to grow a network of blood vessels to supply their growth. The cannabinoid significantly lowered the activity of VEGF in the mice and two human brain cancer patients, the study showed.

The drug did this by increasing the activity of a fat molecule called ceramide, suggests the study, as adding a ceramide inhibitor stifled the ability of the cannabinoid to block VEGF.


Small and pallid


“We saw that the tumours [in mice] were smaller and a bit pallid,” adds Blázquez. The paleness of the cancer reflected its lack of blood supply as a result of the treatment. In the human patients, she says: "It seems that it works, but it's very early."




Subscribe to New Scientist for more news and features

Related Stories


Cannabis can help MS sufferers
07 November 2003

Cannabis drugs pass testing 'milestone'
05 November 2002

Breast cancer spreads by hijacking body’s drainage network
01 February 2001


For more related stories
search the print edition Archive



Weblinks


American Association for Cancer Research

Cancer Research UK

Primary brain tumours, MedlinePlus

Cancer Research




Sullivan points out: “Although this work is at an early stage of development other research has already demonstrated that VEGF is an important drug target for a range of cancers.”

He emphasises the need for further work on cannabinoid combinations. “Cannabinoids would need to generate very strong data in the future as there are already a number of VEGF inhibitors in clinical development,” he says.

The two patients in the ongoing study are among 14 in a clinical trial of the drug. The patients are given one cycle of treatment, lasting a few days, and their survival and general health are being studied.

Journal reference: Cancer Research (vol 64, p


Im diggin it man....

Great post.

-- tAc

very

very

That is a great post we welcome the info on this an we are proud of all our members that an article will enhance the knowledge here thanx again bogart

Thank you for the post!

another reason why MJ is the most wonderful gift we have been given....

And here's more on Dr. Guzeman's work....

Pubdate: Sun, 15 Aug 2004
Source: Scotland On Sunday (UK)
Copyright: 2004 The Scotsman Publications Ltd.
Contact: letters_sos@scotlandonsunday.com
Details: http://www.mapinc.org/media/405
Website: http://www.scotlandonsunday.com/
Author: Murdo MacLeod
Bookmark: http://www.mapinc.org/topics/cannabinoids
Bookmark: http://www.mapinc.org/mmj.htm (Cannabis - Medicinal)
Bookmark: http://www.mapinc.org/people/Biz+Ivol
Bookmark: http://www.mapinc.org/find?207 (Cannabis - United Kingdom)

CANNABIS HOPE FOR BRAIN CANCER

CANNABIS is set to be used in the battle against deadly brain cancers that affect around 4,000 people in the UK each year, it has emerged.

Scientists have shown that cannabinoids - the active ingredients
responsible for the drug's 'high' - hold back the growth of blood vessels which feed tumours.

Tumours of the brain and the central nervous system kill about 340 Scots each year, and many more undergo extensive surgery in a bid to save their lives.

The cannabis findings hold out hope for brain tumour sufferers that they could live longer and be treated using less invasive techniques.

The research will also reignite the debate over the use of cannabis for other medicinal purposes. Many multiple sclerosis sufferers have campaigned for the drug to be legalised, but ministers have been reluctant to allow its widespread use. Although the status of cannabis was reclassified in January, which meant that possession of the drug would be less harshly punished, it has still not been legalised for medicinal purposes and supplying cannabis is still treated as a serious offence.

The new research, which was conducted by scientists at Complutense University in Madrid, saw cannabinoids injected into mice with gliomas, which are fast-growing brain tumours.

The cannabinoids appear to block genes making a protein called VEGF (vascular endothelial growth factor) that stimulates the sprouting of blood vessels. Cutting off the blood supply to a tumour means it is unable to grow and spread.

In studies, cannabinoids significantly reduced the activity of VEGF in laboratory mice. They also lowered VEGF levels in tumour tissue samples taken from two patients with glioblastoma multiforme, the most lethal type of brain tumour.

About 4,400 new cases of brain tumour are diagnosed in the UK each year. A small percentage of these are grade four gliomas, the most aggressive and dangerous brain tumours, also known as glioblastoma multiforme.

Only about 6% of people diagnosed with these high grade cancers live for more than three years.

The disease is normally treated with surgery, followed by radiotherapy alone or in combination with chemotherapy. But the main tumour often evades complete destruction and grows again to kill the patient.

Cannabinoids had previously been shown to inhibit the growth of blood vessels in mice. But the mechanism involved remained a mystery and it was not known if the same effect occurred in humans.

Professor Manuel Guzman, from Complutense University in Madrid, who led the research, said: "In both patients, VEGF levels in tumour extracts were lower after cannabinoid inoculation."

Writing in the journal Cancer Research, Guzman's team said the findings suggested that cannabinoids may offer a potential new way to treat incurable brain tumours.

A leading British cancer expert last night welcomed the findings of the study. Dr Richard Sullivan, the Head of Clinical Programmes for Cancer Research UK, said: "This research provides an important new lead compound for anti-cancer drugs targeting cancer's blood supply. Although this work is at an early stage of development other research has already demonstrated that VEGF is an important drug target for a range of cancers.

"The key now will be to show further activity in pre-clinical cancer
models, find out in which combinations cannabinoids show greatest activity and formulate a product that can be tested in man."

Biz Ivol, a veteran campaigner for the legalisation of cannabis for medical purposes, last night hailed the results but claimed authorities would be unlikely to act on the findings of the study.

In 2001, Ivol - who lives in Orkney - was charged with intent to supply cannabis after it emerged that she baked chocolates with cannabis in them and sent them to fellow sufferers to relieve their pain. Ivol was expected to stand trial in 2003 but the case was dropped when the Crown decided not to proceed because of Ivol's poor health. She then attempted suicide in protest at her treatment.

She said: "It's very good news to hear that there is the possibility of a new development in fighting cancer. But it really is getting more and more ridiculous. There are all these trials and pieces of research which find out all kinds of things but they won't legalise cannabis.

"It could be used to treat hundreds of things and it is legal in other European countries.

"Why are we holding out in this country?"

Doug Keil, the general secretary of the Scottish Police Federation, said that officers were not opposed to the development of medicines based on cannabis but warned that smoking the drug was still an offence.

Cannabis-based sprays are also under development but MS sufferers claim that until the sprays are ready to be marketed they should be allowed access to cannabis to ease their chronic pain.