MicroRNA (miRNA) is a type of genetic material in cells that regulates how DNA and genes make proteins. Mutations in genes that code for miRNA have been implicated in the formation of cancers, including malignant mesothelioma. Researchers hope to use these small biomolecules to develop new cancer treatments.
What Is MicroRNA?
MicroRNAs are very short strands of ribonucleic acid (RNA) present in the cells of all living things. They are essential to the expression of genes and the creation of proteins in cells.
RNA and DNA
DNA (deoxyribonucleic acid) is a large biomolecule that contains the code for making all the proteins an organism needs. To express genes in DNA and make those proteins requires RNA.
There are several types of RNA with different roles in the production of proteins. The role of microRNA is to control how genes are expressed. They can slow or increase the production of a protein by binding to specific genes on the DNA molecule.
These microRNAs generally serve an inhibitory or silencing effect on gene coding and thus serve various purposes in tissue differentiation and cellular regulation.
What Is the Role of miRNA in Cancer?
When the genes that code for miRNA are damaged or mutated, it affects how other genes are expressed. If the mutation reduces the amount of miRNA produced, it can result in the protein that particular miRNA regulates being over- or under-expressed.
In other words, changes in miRNA genes can have a wide range of effects on protein levels in cells. If the affected miRNA is responsible for keeping cell growth in check, a mutation can lead to out-of-control growth and the development of cancer.
Some microRNA strands might have an inhibitory effect on cancer cell proliferation and spread, leading researchers to study them as potential treatment agents for various cancer types.[1][2]
Does microRNA Cause Mesothelioma?
MicroRNA is not directly a cause of mesothelioma. The role of miRNA in cancer development is complicated and poorly understood. These small molecules could contribute to mesothelioma through many pathways.
For instance, microRNA is thought to play a role in DNA repair:
- Expression of specific microRNAs enables DNA repair.
- Expression of other forms of microRNA can inhibit DNA repair.
Researchers are still untangling the knot of miRNA and how it causes cancer. They have identified some specific miRNA molecules over- or under-expressed in mesothelioma and other cancers.[3]
Can MicroRNA Be Used to Treat Mesothelioma?
Once the microRNAs that aid in DNA repair at the cellular or molecular levels have been identified, they might be used as a means of treating mesothelioma and other cancers.
The Potential for Treating Cancer with miRNA
They can contribute to tumor-suppressing genes, “putting on the brakes,” and subsequently slowing the formation of cancer cells. This means that some microRNAs may be involved in halting the spread of mesothelioma before it has a chance to grow and spread.
If microRNAs could be used to send a molecular message to initiate DNA repair at an increased rate, cancer cells could potentially give way to healthy cells, leading to tumor shrinkage or even eradication of cancerous growth.
The expression of some microRNAs in mesothelioma appears to be damaged. Researchers found that restoring the function of these particular microRNA strands aids in cancer suppression, which might lead to a possible treatment option for cancers such as mesothelioma.[3]
A Breakthrough in the Delivery of miRNA Treatment for Mesothelioma
One of the challenges of treating mesothelioma with miRNA is delivering the compound to cancer cells. Mesothelioma grows as multiple small nodules on the tissue around the lungs or abdomen. It is much easier to deliver targeted treatments to one or two large masses, which is how many other cancers grow.
A team of researchers recently made a breakthrough in solving this problem. They developed a miRNA that could slow mesothelioma growth but needed a way to deliver it.[4]
They developed a strategy that uses a hydrogel injected or sprayed into the pleural space. The hydrogel encapsulates the miRNA for treatment and covers the surface of the pleural tissue and its multiple cancer nodules. It gets into all the spaces where cancer cells might be hiding.[4]
This delivery method has only been used in animal models. The researchers hope to develop it into a useful system for human patients.
Can Mesothelioma Patients Benefit from miRNA Treatments Now?
There are currently no real treatments that use microRNA manipulation to treat malignant mesothelioma at the time of this writing.
Researchers remain interested in evaluating how microRNA can treat various diseases, including malignant mesothelioma. Many current studies and clinical trials focus on understanding miRNA’s role in cancer and its use as a diagnostic marker.
With the current focus on targeted therapy with cancer types, researchers may develop treatments based on specific microRNA damage identified in tumor cells. Additional research and clinical trials are needed to determine the role for cancer therapy.
MicroRNA to Diagnose Mesothelioma and Monitor Treatment
While treatment with miRNA lags, these small molecules are already proving valuable as biomarkers for disease. Biomarkers help diagnose cancer type and stage. They can also be used to determine the effectiveness of treatment.
miRNA as a diagnostic marker is a promising strategy for mesothelioma patients. Researchers hope they can be used to screen patients and make diagnoses earlier.
Mesothelioma is difficult to diagnose, but if markers in the blood unique to this cancer could be identified, doctors may be able to diagnose mesothelioma in its early stages. This gives patients more treatment options and better outcomes. Some studies have found specific microRNAs could serve as these markers for mesothelioma.[4]
miRNA Is a Molecular Therapy
Molecular therapies are treatment methods that target specific molecules that might play a role in cancer cell proliferation and spread. In other words, these therapies slow or even halt the growth of cancer cells at the most basic level.
miRNA is one line of research in developing molecular therapies for mesothelioma and other cancers.
Some molecular therapies involve using small molecules that can penetrate a cancer cell and interrupt its ability to “thrive and survive,” thus causing the cancer cell to die. In contrast, others use antibodies to carry cancer-killing agents to the site of the tumor.
Although not all cancers are currently treatable with molecular therapy methods, these methods have been successfully used to treat several forms of cancer, including malignant mesothelioma.
Implications for the Future
Since microRNA manipulation can have an inhibitory effect on cancer growth, gene manipulation therapy might be an option in the future.
Gene therapy is a broad field in cancer treatment with ongoing research. Manipulating miRNA might become another tool for gene therapies and cancer treatment.
Hopefully, those diagnosed with malignant mesothelioma will have the opportunity to participate in clinical trial research, which will provide new drug therapy options. Patients with mesothelioma must consider participating in clinical trials to develop available treatment options further.
