In a new study published in Cell Death Discovery, researchers in Sydney, Australia, have uncovered new details about how pleural mesothelioma tumors release materials that make surrounding cells supportive of their growth and spread. The study, conducted by scientists at the Asbestos and Dust Diseases Research Institute, focuses on microscopic packages that cancer cells send to other cells in their environment.
Mesothelioma Cells Send Out Messages
Pleural mesothelioma is one of the most aggressive cancers. The disease is caused by exposure to asbestos, but the mechanisms behind how it grows and spreads are poorly understood, and survival rates remain low. In an effort to bridge that knowledge gap, Australian researchers analyzed mesothelioma tumor cells in the laboratory to learn more about extracellular vesicles and their role. These tiny bubbles, produced by mesothelioma and many other types of cancer, carry molecular cargo from one cell to another. Part of that cargo is microRNA, which are small genetic molecules that can switch genes on and off inside the cells that receive them.
The team found that mesothelioma vesicles’ mix of microRNAs are very different from that of healthy cells. The number of molecules known to promote cancer was increased, and the number of molecules that normally restrict tumor growth was reduced. The disease’s two main forms, epithelioid and non-epithelioid, each carried their own distinct microRNAs, some of which were only found in one subtype. The researchers believe these could become biomarkers that would help doctors identify a patient’s subtype and guide treatment decisions.
Mesothelioma Cells Release Materials that Encourage Their Own Growth
Mesothelioma tumors are largely surrounded by connective tissue cells called fibroblasts; they make up much of a tumor’s immediate environment. When the researchers exposed fibroblasts to mesothelioma vesicles, the fibroblasts took on an inflammatory profile resembling “cancer-associated fibroblasts.” They produced higher levels of inflammatory and tissue-remodeling proteins along with signals that have been linked to cancer growth.
Mesothelioma vesicles also affected EZH2, a protein that helps control which genes are active. Vesicles from epithelioid tumors increased the protein’s activated form, while those from non-epithelioid tumors decreased it. Importantly, the reprogrammed fibroblasts created surroundings that support tumor growth, allowing mesothelioma cells to move and multiply faster.
Research Provides New Mesothelioma Target
Mesothelioma victims and their families know how limited treatment options can be. This research suggests that the rare form of cancer actively recruits healthy tissue to help it thrive. The communication pathways identified in the study could become targets for future therapies designed to cut those lines of communication.
If you or someone you love has been diagnosed with mesothelioma and you need more information on research or the resources available to you, contact the Patient Advocates at Mesothelioma.net today at 1-800-692-8608.
