British researchers have discovered a potentially new method of delivering a cancer-killing protein to tumors, by using genetically engineered stem cells from bone marrow. Experiments conducted on mice and cell cultures showed that adult stem cells – a type known as mesenchymal stem cells- could target cancer cells and deliver the lethal protein to destroy them. This allows the stem cells to attack only the cancer and spare normal healthy tissue, unlike many present cancer treatments which destroys healthy cells.

Essentially, the researchers have combined two pieces of research. The first is that mesenchymal stem cells have an innate ability to seek out tumors throughout the body and induce apoptosis (cell death). The cells have also been altered to express or make the cancer-killing protein called TNF-related apoptosis-inducing ligand or TRAIL.

Studies in cell cultures showed the cells were able to find and kill cells from lung, squamous, breast and cervical cancer. Many types of cancer are highly sensitive to this trail protein. Mice which have been injected with breast tumors demonstrated that the TRAIL protein was able to safely kill the tumors but leave the healthy tissue intact. When they delivered the therapy, 38 percent of the tumors were completely eliminated.

The goal of the research would be to develop a cell-based cancer treatment for humans that specifically targets cancer cells.
An advantage of these cells is that they are “immunoprivileged”, meaning the body will not reject them as foreign invaders. Thus, they can be made in large quantities/batches instead of having to make custom treatments for each patient. Several more safety studies would be needed, but the team hopes human trials could begin in two or three years.

Stem cells are also used in stem cell therapy. Their ability to differentiate into any of the different tissues making up the human body, offers enormous potential to treat and even cure serious diseases such as multiple sclerosis or spinal-cord injury by replacing diseased cells with healthy cells.Once placed into a patient's body, stem cells intended to treat or cure a disease could end up wreaking havoc simply because they are no longer under the control of the clinician.

One of the biggest potential problems with stem cell therapy is the development of tumors. Another problem is that stem cells directed to become beating heart cells might mistakenly end up in the brain when control over the growth of stem cells is lost.Instead of gene therapy being done in the patient, as is the case in cancer, it's being done in the cells in a laboratory before doctors use them for therapy so that they still have control of these cells.

Therapists would rig certain genes to respond to a "remote control" signal. For instance, giving a certain drug could prompt a "suicide" gene to kill a budding tumor.Gene therapy needs to be carefully done and, ideally, two independent gene-manipulation systems would be used to ensure that stem cells remain firmly in control of clinicians.

Original links: http://www.newsdaily.com/stories/tre54i76u-us-cancer-treatment/
http://www.sciencedaily.com/releases/2009/05/090521131317.htm

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