In a new study, researchers from Queen Mary College, University of London, UK, discovered that molecules released from invasive skin cancer reprogram the healthy immune cells to help spread cancer. Targeting these molecules with inhibitory drugs may help prevent this invasive skin cancer from recurring after treatment. The results of the study were published in the Cell, entitled “Regional Activation of Myosin II in Cancer Cells Drives Tumor Progression via a Secretory Cross-Talk with the Immune Microenvironment.”
The researchers obtained cells from the margins of invasive melanoma in mouse and human tumor samples in order to study the effects of a protein called myosin II produced by them. They found that high levels of myosin II in these cells not only made them more migratory, but also triggered the release of chemicals that reprogram the immune system. These chemicals affect the surrounding healthy immune cells called macrophages and hijack their natural cancer-killing power. This means that these immune cells do not attack cancer cells, but ultimately help these cancer cells survive. Some of these chemicals also form small holes in the blood vessels, allowing cancer cells to escape into the blood and invade new parts of the body.
The author of the paper, Professor Victoria Sanz-Moreno of the Bartz Cancer Institute at Queen Mary’s College, University of London, said, “This study highlights how cancer cells interact with and influence their environment for growth and spread. Treatments for these chemicals that alter the immune system may help prevent the spread of the disease.
The researchers also found that IL-1A released by myosin II-rich cells is the key to making cancer cells more aggressive. By blocking myosin II activity with different drugs, they reduced the amount of IL-1A produced by melanoma cells in mouse and human tumor samples.
Professor Sanz-Moreno explained, “By using a therapeutic drug that blocks myosin II activity or IL-1A release, we can reduce the aggressiveness of this tumor and slow its growth, making it easier to treat.”
Drugs that block myosin II activity have been used to treat diseases such as glaucoma, a progressive ophthalmic disease. These researchers are planning further laboratory studies to explore whether drugs that block myosin II activity can be used in conjunction with existing melanoma treatments.
Sanz-Moreno added, “We look forward to verifying whether inhibitory drugs can be combined with other targeted therapies. By identifying effective therapeutic combinations, we hope to improve the treatment effect with myosin II/IL-1A inhibitors in the future and reduces the risk of melanoma recurrence.”
Mirella Georgouli et al. Regional Activation of Myosin II in Cancer Cells Drives Tumor Progression via a Secretory Cross-Talk with the Immune Microenvironment. Cell, 2019, doi:10.1016/j.cell.2018.12.038.