Patente Que Prova Poder Anti-Tumoral Da Maconha

[HST]

Patente US20130059018 Requerente: Otsuka Pharmaceutical Co., Limited, Gw Pharma Limited

ABSTRACT

This invention relates to the use of phytocannabinoids, either in an isolated form or in the form of a botanical drug substance (BDS) in the treatment of cancer. Preferably the cancer to be treated is cancer of the prostate, cancer of the breast or cancer of the colon.

DESCRIPTION

This invention relates to the use of phytocannabinoids, either in an isolated form or in the form of a botanical drug substance (BDS), as a prophylactic or in the treatment of cancer. Typically the cancer to be treated is a cancer of the: prostate, breast, skin, glioma, colon, lung or a bone or lymph metastasis. The phytocannabinoids may be used in combination with other cancer treatments.

BACKGROUND

Cancer is a class of diseases which occurs because cells become immortalised; they fail to heed customary signals to turn off growth which is a normal function of remodelling in the body that requires cells to die on cue. Apoptosis, or programmed cell death, can become defective and when this happens malignant transformation can take place. The immortalised cells grow beyond their normal limits and invade adjacent tissues. The malignant cells may also metastasise and spread to other locations in the body via the bloodstream or lymphatic system. Cancer cells often form a mass known as a tumour.

There are about 200 different types of cancer; the cancers can start in any type of body tissue although many cancers will metastasise into other body tissues. There are many different causes of cancer and these include; carcinogens, age, genetic mutations, immune system problems, diet, weight, lifestyle, environmental factors such as pollutants, some viruses for example the human papilloma virus (HPV) is implicated in cervical cancer and some bacterial infections are also known to cause cancers.

There are many different treatment options for cancer and the treatment sought is often determined by the type and stage of the cancer. Treatment options include; chemotherapeutic drug treatment, hormonal drug treatment, radiotherapy, surgery, complementary therapies and combinations thereof.

Prostate cancer is the most common type of cancer in men and accounts for 24% of all UK male cancers. In 2006 there were over 35,000 new cases of prostate cancer diagnosed in the UK alone.

The prostate is a gland in the male reproductive system and symptoms of cancer in the prostate can include pain, difficulty urinating, problems with sexual intercourse and erectile dysfunction. Prostate cancer may metastasise to the bones and or lymph nodes. Treatment options for prostate cancer include surgery, radiation therapy, chemotherapy and hormone treatment.

Hormone treatment usually involves treatment with an anti-androgen such as cyproterone acetate, flutamide or bicalutamide, either alone or in combination with a chemotherapeutic agent. These treatments work to stop the production of testosterone (androgen) which can slow down tumour growth or even shrink the tumour. While the prostate cancer cells are responding to anti-androgens, they are referred to as ‘hormone-sensitive’ prostate cancer. Unfortunately, after a few years of treatment with anti-androgens the prostate cancer stops responding to hormone treatment and is termed ‘hormone-insensitive’ prostate cancer. At this stage the cancer growth cannot be controlled by the hormone treatment.

In order to test the effectiveness of different compounds in the treatment of either hormone-sensitive or hormone-insensitive prostate cancer two different cell lines can be used. The cell line LNCaP are hormone-sensitive prostate cancer cells which were derived from a supraclavicular lymph node metastasis in a 50 year old male in 1977. The cell line DU-145 are hormone-insensitive prostate cancer cells which were derived from a brain metastasis.

It is known that expression levels of both cannabinoid receptors, CB1 and CB2, were significantly higher in CA-human papillomavirus-10 (virally transformed cells derived from adenocarcinoma of human prostate tissue), and other human prostate cells LNCaP, DU-145, PC3, and CWR22RN1 than in human prostate epithelial and PZ-HPV-7 (virally transformed cells derived from normal human prostate tissue) cells (Sarfaraz, 2005).

Additionally it is known that WIN-55,212-2 (mixed CB1/CB2 agonist) treatment with hormone sensitive LNCaP cells resulted in a dose- (1-10 Mmol/L) and time-dependent (24-48 hours) inhibition of cell growth. Blocking of CB1 and CB2 receptors by their antagonists SR141716 (CB1) and SR144528 (CB2) significantly prevented this effect.

These results suggested that WIN-55,212-2 or other cannabinoid receptor agonists could be developed as novel therapeutic agents for the treatment of prostate cancer.

Cannabis has been ascribed to be both a carcinogen and anti-cancer agent. In particular smoking cannabis is known to be carcinogenic as the cannabis smoke contains at least 50 different known carcinogenic compounds, many of which are the same substances found in smoked tobacco. One of these carcinogens, benzopyrene is known to cause cancer as it alters a gene called p53, which is a tumour suppressor gene. Cannabis contains the substance tetrahydrocannabinol (THC) which has been shown to cause benzopyrene to promote the p53 gene to change.

Researchers however have discovered that some cannabinoids, including THC and cannabidiol (CBD) are able to promote the re-emergence of apoptosis so that some tumours will heed the signals, stop dividing, and die. The process of apoptosis is judged by observation of several phenomena including: reduced cellular volume, condensation of nuclear chromatin, changes in distribution of phospholipids in plasma membrane phospholipids, and cleavage of chromatin into DNA fragments called DNA ladders.

Fonte: http://www.google.com/patents/US20130059018