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| Blood vessel configuration of the head and brain. Source: Gunther von Hagens, Body Worlds |
Angiogenesis, or the formation of new
blood vessels, is a common factor in most diseases, including cancer. Under
normal conditions, the body is able to regulate the amount of blood vessels
being formed to a healthy set point. For example, after injury, angiogenesis is
stimulated and inhibitors can then be activated to trim back any excessive
growth. However, the disruption of the control of angiogenesis can lead to
certain complications, such as stroke—inadequate angiogenesis, or
cancer—excessive angiogenesis. This pathologic angiogenesis has been the target
for emerging therapies and treatments, such as selectively aimed inhibition of
abnormal tumor vessel formation in breast cancer and brain tumors. For example,
Avastin, an antiangiogenic drug, was approved by the FDA in 2004 to aid the
treatment of various cancers. Other drugs work to control the cyclooxygenase
pathway which contributes to the regulation of pro-angiogenesis. The selective
inhibition of COX (thromboxanes, prostaglandins, and prostacylcins) works to
help prevent angiogenesis that would otherwise support cancer growth.
Although the antiangiogenic approach has
proved promising, it’s limits lie in treating already developed and late stage
cancers. Therefore, potential preventative measures of antiangiogenesis are
being explored. For example, 30-35% of environmentally caused cancer can be
attributed to diet. Therefore, researchers seek to identify dietary factors
that might prevent abnormal angiogenesis.
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| Red grapes. Photo credit: Liv Friis-Larsen/iStock/Getty Images Source: www.livestrong.com |
Several foods contain active compounds which
are natural inhibitors of angiogenesis, including red grapes (resveratrol), strawberries
(ellagic acid), tomatoes (lycopene) and soy (genistein). Trials measuring the
effectiveness of these dietary compounds have been observed to be as effective as synthesized drugs. For example, one study followed 79,000 men over 20 years.
These men ate cooked tomatoes (containing lycopene) 2-3 times a week and showed
a 40-50% reduction in their risk of developing prostate cancer. Those who did
develop cancer had a much lower density of blood vessels feeding their cancer
cells. The use of realistic, dietary concentrations of resveratrol (found in red
grapes/wine) also displayed a 60% reduction in abnormal vessel development.
Researchers aim to develop a rating system for foods based on their
antiangiogenic properties and efficacy.
- There are also other conditions (especially common in the United States) that may be mediated by antiangiogenesis therapy…can you think of any?
- What are some potential side effects of antiangiogenesis drugs?
- What do you think about preventative dietary control?
References:
DuBois S, Demetri G. Mar 2007. Markers of angiogenesis and clinical features in patients with sarcoma. Cancer, 109(5): 813-819.
Available from: http://www.ncbi.nlm.nih.gov/pubmed/17265525
Gately S, Li WW. April 2004. Multiple roles of COX-2 in tumor angiogenesis: a target for antiangiogenic therapy. Seminars in Oncology 31(7): 2-11.
Available from: http://www.seminoncol.org/article/S0093-7754(04)00189-7/abstract
Li WW. Feb 2010. Can we eat to starve cancer? TED Talks. [Presentation]
Available from: http://www.ted.com/talks/william_li#t-1170457
This is a very interesting topic, Hannah. You certainly hear about specific foods being "cancer fighting" or "cancer causing", so I think that it's great that researchers are working on a rating system for antiangiogenic properties. In physiology, we discussed angiogenesis in terms of exercising. There are articles that show that cardiovascular disease could be mediated by therapeutic angiogenesis. This could restore blood flow to ischemic tissue, which is important for delivering oxygen and glucose. Although this is different than the antiangiogenesis that you mentioned in regards to cancer prevention and treatment, it is still important in cardiovascular disease.
ReplyDeleteI believe that this is one of the best interventions for cancer treatment thus far. By developing a way to cut off the blood supple for a tumor would drastically increase survival rate for cancer patients. As I mentioned to you earlier about the ability of tumors to develop blood vessels in places that normally don't have blood vessels shows the incredible power of angiogenesis that tumors have. I have included a link to a website that discusses this, its a little was down on the page.
ReplyDeleteI have a couple thoughts and concerns about this being used as a drug. Lets say the dosage needed to properly sequester the tumor is high enough that is seriously cause serious systemic effects. If this was the case then the risks from taking the drug would greatly out weigh the potential benefits. Let say you break or sprain your ankle while taking this drug, you would never be able to heal. If it was a broken bone this could lead to serious infection and many other life threatening complications.
I am also curious if these people eating these antiangiogenic containing foods have milder issues as a mentioned above? Do they difficulty in healing or developing strength? It seems to me as one of those fix all type of things the latest "no carb or trans fat" diet of cancer treatment. Obliviously this is one of the more promising treatments for cancer but as all ways their are many questions that still need to be answered.
http://www.cancer.gov/cancertopics/understandingcancer/angiogenesis/AllPages
Hannah, I love that you mentioned Resveratrol!! As part of my research, I’ve been trying to dissolve it, so I’ve look at a lot of papers discussing its application. It’s interesting that the researchers you are talking about have listed Resveratrol as having anti-angiogenic properties that can be a preventative measure; it seems that Resveratrol has loads of properties and applications in preventative healthcare, but it seems that loads of research is now being done to use it as a ‘cure!’
ReplyDeleteThere’s a PhD at Anschutz whose lab does lots of work with Resveratrol (among other things) and his research has found that the resveratrol in grape seed extract reduced the number of polyps in induced-intestinal cancer in a murine model. They believe that the mechanism by which Resveratrol exhibits an inhibitory effect on polyp multiplicity and growth is by reducing tumor-cell proliferation and increasing apoptosis.
Here's the article describing that experiment: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805888/#__sec7title