According to a new study, published in Science Signaling, fat cells play a role in transforming local melanoma cells in the epidermis to metastatic melanoma cells that migrate to attack different organs.
"We have answered a major question that has preoccupied scientists for years," stated lead study author, Carmit Levy, MD, PhD, and Professor at Tel Aviv University. "What makes melanoma change form, turning aggressive and violent? Locked in the skin's outer layer, the epidermis, melanoma is very treatable; it is still stage I, it has not penetrated the dermis to spread through blood vessels to other parts of the body and it can simply be removed without further damage."
Dr. Levy added, "Melanoma turns fatal when it 'wakes up,' sending cancer cells to the dermis layer of skin, below the epidermis, and metastasizing in vital organs. Blocking the transformation of melanoma is one of the primary targets of cancer research today, and we now know fat cells are involved in this change."
For this study, the investigators analyzed biopsy samples from melanoma patients. They noticed fat cells were consistently found near the location of the tumors. Then, the researchers took fat cells and melanoma cells and placed them next to each other on a petri dish in order to track their movements. Proteins that affect gene expression called cytokines were seen by the scientists to be passed from the fat cells to the melanoma cells.
"Our experiments have shown that the main effect of cytokines is to reduce the expression of a gene called miRNA211, which inhibits the expression of a melanoma receptor of TGF beta, a protein that is always present in the skin," Dr. Levy explained. "The tumor absorbs a high concentration of TGF beta, which stimulates melanoma cells and renders them aggressive."
However, the investigators figured out a way to block this from happening by separating melanoma cells from the fat cells, thereby causing the cancerous melanoma cells to stop migrating.
Further studies are needed to develop a drug that will inhibit cytokines and TGF beta.
For More Information
Golan T, Parikh R, Jacob E, et al (2019). Adipocytes sensitize melanoma cells to environmental TGF-B cues by repressing the expression of miR-211. Sci Signal, 12(591):eaav6847. DOI:10.1126/scisignal.aav6847
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