Stem cells and mesothelioma is a prominent new area of research for this rare and aggressive cancer. Recent research has shown a connection between cancer growth stem cells in tumors. Researchers hope to use these cancer stem cells to develop new treatments.
What Are Stem Cells?
Stem cells are a cell type in the human body that can become any other cell type. These unique cells are almost a blank template or the building blocks upon which all other cell types can be written.[1]
Stem cells can divide and produce more stem cells, or they can turn into specialized cells. These are cells with specific functions, for example, blood cells, immune cells, muscle cells, or brain cells.
The Importance of Stem Cells in Medicine
The unique ability of stem cells to turn into specialized cells has made them of great interest to medical researchers. They use these cells to test the safety of new medications, for instance.
Researchers are also using stem cells as potential treatments. There is huge potential for using stem cells to generate healthy cells and tissue to replace diseased or damaged tissue. In cancer, stem cells can become problematic, generating cancer in new types of cells. This is an important area of cancer research.
Can Stem Cells Reverse Cancer?
Stem cells can be a problem in cancer, but they also represent a potential solution. Stem cells have the potential to replace cancerous tissue or to be used against cancer cells and to attack them.
What Are Cancer Stem Cells?
Cancer stem cells (sometimes referred to as “CSCs”) are a special type of stem cell found in some forms of cancer, including malignant mesothelioma.
Like all stem cells, CSCs have the potential to become various other cell types. CSCs can become any tumor-specific cell in the human body.
Just as healthy stem cells from bone marrow can develop into healthy skin or muscle tissue, CSCs can become any cell type in a tumor.[2]
How Cancer Stem Cells Contribute to Cancer Development
Cancer stem cells are thought to drive the ongoing growth, development, and spread of tumors in various types of cancer. Cancer stem cells generally resist chemotherapy and can multiply indefinitely.
CSCs might make up only a very small percentage of a tumor mass. However, if they continue to replicate, the tumor can never be fully eradicated, as researchers are beginning to find.
Recent results from Swiss researchers in the Division of General Thoracic Surgery at University Hospital Berne were published in the International Journal of Oncology. These findings suggest that CSCs may play a role in the recurrence of cancer after treatment.
Some tumors thought to be completely eradicated with chemotherapy or surgery often return after the completion of treatment. Researchers believe this may be due to CSCs remaining in the body even after the tumor itself has been eliminated.[3]
Stem Cells and Mesothelioma Treatment
Researchers are looking at stem cells in several different ways to harness them as innovative mesothelioma treatments.
Systemic Stem Cells as a Mesothelioma Treatment
Although CSCs can turn remission upside down, research shows innovative stem cell treatment could be promising for cancer patients.
For example, a recent study by British researchers at University College London indicates that systemic treatment with stem cells programmed to cause apoptosis or cell death could effectively eradicate mesothelioma tumors.
By targeting and destroying the tumor cells, the stem cells can “clear up” the cancerous cells without causing damage to surrounding healthy cells.[4]
Targeting Mesothelioma Stem Cells
Researchers have confirmed that mesothelioma tumors contain stem cells, MSCs, that contribute to ongoing tumor growth. In one study, researchers found that MSCs in a mouse model did resist treatment from chemotherapy and radiation.
They found that MSCs help repopulate the tumors with cells, which reduces the effectiveness of treatment. They are now investigating genes in MSCs that would make more effective targeted therapies for mesothelioma.[5]
Drugs to Target Mesothelioma Stem Cells
Novel drugs are being developed to specifically target the stem cells responsible for tumor growth. One drug designed to attack mesothelioma stem cells made it into clinical trials. Unfortunately, the trial was halted because the drug did not seem to be working.
The drug, called defactinib, showed promising results in phase I clinical trials; however, phase II, which involved more participants, was not as successful. Patients tolerated the drug well, but efficacy was low in the 372 patients involved.
Results for patients receiving the drug were no better than those receiving a placebo.[6] The trial was stopped due to these disappointing results.
This one drug’s failure to kill mesothelioma stem cells does not mean the end of this line of research. More drugs are being developed and tested. Defactinib may be tested again in combination with different chemotherapy drugs.
Mesenchymal Stem Cell Treatment at Pacific Mesothelioma Center
Another type of stem cell treatment under study for mesothelioma is mesenchymal stem cell treatment. Mesenchymal stem cells were discovered in the stroma, which is a connective tissue found throughout the body.
These cells can differentiate into bone, cartilage, fat, and muscle cells. They also may have the ability to moderate the immune system. Exactly how they work is still not completely understood. Researchers are investigating how these stem cells could be used to treat various diseases.
At the Pacific Mesothelioma Center, researchers are using mesenchymal stem cells to develop new treatments for mesothelioma.
These stem cells are being tested as vectors for delivering drugs to tumors and for use as supplements to immunotherapy treatments. Mesenchymal stem cells may enhance the body’s immune system to help it target and kill cancer cells.
Stem Cell Vaccines
Led by Stanford University researchers, a group has developed a type of vaccine against cancer that shows promise in lab animals. They injected mice with induced pluripotent stem cells (iPS cells) that matched each individual’s genetics.
The iPS cells are similar to cancer cells and act like a vaccine, stimulating the immune system to recognize and attack any cancer cells that develop. They next injected the mice with cancer cells, including mesothelioma cells. The vaccine prevented cancer formation in the mice.
The researchers are trying other cancer types and using the iPS cells as a treatment for existing cancer. They hope to move into human clinical trials soon.[7]
Will Mesothelioma Ever Be Curable with Stem Cells?
Although recent research findings on the therapeutic use of systemically delivered stem cells show promise, they are only preliminary. More research is necessary to determine the validity and efficacy of the initial findings.
However, if further trials prove successful, stem cell therapy could provide novel treatment options. These innovative treatment methods could prove more effective, increasing the overall quality and length of life for patients.
Can I Opt for Stem Cell Treatment for My Mesothelioma?
Stem cell therapy is not currently offered as part of standard therapy but might be an option in a clinical trial. If you or someone you know has been diagnosed with malignant mesothelioma and is interested in exploring the possibilities of stem cell treatment, talk to your doctor about clinical trials.
While treatments offered by clinical trials are limited to those who qualify, you may be able to participate. Several trials are studying the effects of stem cell treatment for mesothelioma in human subjects. Speak with your physician to determine which studies may be right for you.
