Melanoma is the most aggressive and deadly type of skin cancer and kills one person every 52 minutes (according to data from the international Skin Cancer Foundation), with the number of diagnosed cases on the rise for the past 30 years. There is still no full remedy for this life-threatening disease.
“The threat of melanoma is not in the initial tumor that appears on the skin, but rather in its metastasis – cancer cells sent off to colonize in vital organs like the brain, lungs, liver and bones, said Levy.
The researchers began by examining pathology samples taken from melanoma patients. “We looked at samples of early melanoma, before the invasive stage,” said Levy. “To our surprise, we found changes in the morphology of the dermis – the inner layer of the skin – that had never before been reported. Our next task was to find out what these changes were and how they related to melanoma.”
Scientists have known for years that melanoma forms in the outer layer of the skin, the epidermis. At this early stage the cancer is unable to send off colonizing cancer cells, because it has no access to the blood vessels that carry the cells to other parts of the body. The tumor first needs to contact the abundant blood vessels running through the dermis.
She explains, “We found that even before the cancer itself invades the dermis, it sends out tiny vesicles containing molecules of microRNA. These induce the morphological changes in the dermis, in preparation for receiving and transporting the cancer cells. It now became clear to us that by blocking the vesicles, we may be able to stop the disease altogether.”
The researchers found for two chemicals that could intervene and block the process in its earliest stages. One (SB202190) inhibits the delivery of the vesicles from the melanoma tumor to the dermis, while the other (U0126) prevents the morphological changes in the dermis even after the arrival of the vesicles. Both substances were tested successfully in the lab, and may serve as promising candidates for future drugs.
Another advantage of the finding is that changes in the dermis and the vesicles themselves, can be used as powerful indicators for early diagnosis of melanoma.
“Our study is an important step on the road to a full remedy for the deadliest skin cancer,” concluded Levy. “We hope that our findings will help turn melanoma into a nonthreatening, easily curable disease.”