It is increasingly being realized that circulating microvascular cells may be important markers for a wide variety of cancers. An article appeared in the September issue of Journal of Internal Medicine, "Cell culture detection of microvascular cell death in clinical specimens of human neoplasms and peripheral blood," reporting a novel system that was developed for testing anti-microvascular drug effects in fresh biopsy specimens of human tissue, cavitary fluids and blood.
Three-dimensional microclusters of tumor cells were isolated from fresh tumor biopsy specimens and cultured for 96 hours (polypropylene, round-bottomed, 96-well microplates) in the presence and absence of test drugs.
A private laboratory has worked with the use of DMSO and/or alcohol as an anti-angiogenic enhancer and potentiator and has measured it with fresh "live" tumor specimens in cell culture assays.
What alcohol does is to reduce the secretion of VEGF by the tumor cells. The assay shows the abrogating effect of alcohol upon VEGF. It both reduces VEGF and makes a drug like Avastin work better, possibly overcoming tumor resistance to Avastin.
Wound healing requires neovascularization. Alcoholics have notoriously poor wound healing. In rat systems, relatively low doses of alcohol do impair vascularization in wounds.
Alcolol may have a membrane effect, basically puts the cell to sleep so that it doesn't think it requires a blood supply. In the presence of a drug like Avastin, you have a lethel 1-2 combination which knocks out the new vessels which are dependent on VEGF for survival.
For an antiangiogenesis effect, it would be necessary to drink a bottle of wine per day, an amount considered unhealthy. A better option may be polyphenols extracted from plants converted into a tablet. The use of plant polyphenols as therapeutic tools presents important advantages, because they have a good safety profile, a low cost and they can be obtained everywhere on the planet.
Source: J Intern Med 2008; 264: 275-287
A Microvascular Viability Assay for anti-angiogenesis-related Drugs
Angiogenesis is essential for the growth and metastasis (spread) of cancer. A growing tumor requires nutrients and oxygen, which helps it grow, invade nearby tissue, and metastasize. To reach these nutrients, the tumor builds new blood vessels. In fact, growing tumors can become inactive if they can't find a new supply of nutrients.
Angiogenesis starts when cancer cells produce a variety of growth factors and other activators (biologic molecules that begin a process). Growth factors cause endothelial cells (the cells that line blood vessels) to produce chemicals that break down the nearby tissue and the extracellular matrix (the spaces between cells). Then, the endothelial cells divide into more cells and begin building new blood vessels. Other elements, such as stromal cells (cells that form connective tissue), provide structural support for the new blood vessels.
Because angiogenesis is necessary in the growth and spread of cancer, each part of the angiogenesis process is a potential target for new cancer therapies. The assumption is that if a drug can stop the tumor from receiving the supply of nutrients, the tumor will "starve" and die.
Anti-angiogenesis drugs work by blocking the activity of vascular endothelial growth factor (VEGF) to prevent the growth of new capillaries into the tumor and thereby sustain tumor growth. In addition to VEGF, researchers have identified a dozen other activators of angiogenesis, some of which are similar to VEGF.
VEGF causes angiogenesis by attaching to special receptors (proteins on the outside of cancer cells that act like doorways), and this action starts a series of chemical reactons inside the cell. Because VEGF is so important to angiogenesis, it is a target of new cancer treatments.
Since tumor growth is dependent on angiogenesis, and angiogenesis is dependent on VEGF, a drug like Avastin directly binds to VEGF to directly inhibit angiogenesis. Within 24 hours of VEGF inhibition, endothelial cells have been shown to shrivel, retract, fragment and die by apoptosis. Tumors which secrete relatively low levels of VEGF might be more susceptible to an agent like Avastin which works by blocking VEGF (Avastin "sensitive" tumors). It potently inhibits the formation of new blood vessels.
Vatalanib (PTK/ZK) is a small molecule tyrosine kinase inhibitor with broad specificity that targets all VEGF receptors (VEGFR), the platelet-derived growth factor receptor, and c-KIT. It is a multi-VEGFR inhibitor designed to block angiogenesis and lymphangiogenesis by binding the intracellular kinase domain of all three VEGFRs, VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), and VEGFR-3 (Flt-4). Vatalanib is a targeted drug that inhibits the activity of all known receptors that bind VEGF. The drug potently inhibits the formation of new blood vessels (angiogenesis).
In some cases, these and other drugs, kill tumor cells without killing microvascular cells in the same time frame. In other cases they kill microvascular cells without killing tumor cells. In yet other cases they kill both types of cells or neither type of cells. The ability of these agents to kill tumor and/or microvascular cells in the same tumor specimen is highly variable among the different agents.
A major modification of the DISC (cell death) assay allows for the study of anti-microvascular drug effects of standard and targeted agents, such as Avastin, Nexavar and vatalanib. The Microvascularity Viability Assay is based upon the principle that microvascular (endothelial and associated) cells are present in tumor cell microclusters obtained from solid tumor specimens. The assay which has a morphological endpoint, allows for visualization of both tumor and microvascular cells and direct assessment of both anti-tumor and anti-microvascular drug effect. CD31 cytoplasmic staining confirms morphological identification of microcapillary cells in a tumor microcluster.
The principles and methods used in the Microvascularity Viability Assay include: 1. Obtaining a tissue, blood, bone marrow or malignant fluid specimen from an individual cancer patient. 2. Exposing viable tumor cells to anti-neoplastic drugs. 3. Measuring absolute in vitro drug effect. 4. Finding a statistical comparision of in vitro drug effect to an index standard, yielding an individualized pattern of relative drug activity. 5. Information obtained is used to aid in selecting from among otherwise qualified candidate drugs.
It is the only assay which involves direct visualization of the cancer cells at endpoint, allowing for accurate assessment of drug activity, discriminating tumor from non-tumor cells, and providing a permanent archival record, which improves quality, serves as control, and assesses dose response in vitro.
Photomicrographs (below) of the assay can show that some clones of tumor cells don't accumulate the drug. These cells won't get killed by it. The Assay measures the net effect of everything which goes on (Functional Profiling methodology). Are the cells ultimately killed, or aren't they?
This kind of technique exists today and might be very valuable, especially when active chemoagents are limited in a particular disease, giving more credence to testing the tumor first. After all, cutting-edge techniques can often provide superior results over tried-and true methods that have been around for many years.
Source: Eur J Clin Invest, Volume 37(suppl. 1):60, April 2007
Presentation:
http://weisenthalcancer.com/Professi...ofessional.htm
Yes cut off their blood supply and suffocate them..
Suzan W.
Hybrid Mode
