Fat provokes metastases
Researchers from Tel Aviv University, led by Professor Karmit Levy and Dr. Tamar Golan, have answered the main question that has occupied scientists for years: what causes melanoma cells to become more aggressive?
Melanoma responds well to treatment when it is located in the upper layers of the epidermis. But after germination into the dermis, cancer is able to spread through the blood vessels to other organs, and it is much more difficult to overcome metastases.
"Waking up" in this way, melanoma becomes fatal. Blocking the metastasis of melanoma is one of the main tasks of cancer researchers. The authors of this work found out that fat cells are involved in the process of melanoma malignancy.
During the study, scientists conducted dozens of biopsies in patients with melanoma and found a suspicious phenomenon: fat cells were always near cancer cells. They placed fat cells in a Petri dish next to melanoma cells and monitored the interaction between them.
Fat cells transferred cytokine proteins that affect gene expression to cancer cells. The main effect of cytokines was to reduce the expression of the gene encoding miRNA211, which suppresses the expression of Transforming growth factor beta (TGF-beta) in cancer cells. The resulting high concentrations of TGF-beta were absorbed by cancer cells, making them more aggressive.
The researchers also found a way to block the malignancy pathway. In the laboratory, they were able to reverse this process by removing fat cells from cancer cells: the melanoma "calmed down", the cells stopped migrating.
Experiments on mouse models of melanoma yielded similar results: the restoration of miRNA211 expression blocked the formation of distant melanoma metastases.
The researchers tested treatments based on suppressing the production of cytokines and TGF-beta, which had never before been used to treat melanoma. These drugs are currently being studied as possible treatments for pancreatic cancer, and are also undergoing clinical trials for prostate, breast, ovarian and bladder cancers. They restrained the development of metastases and that they returned the melanoma to a relatively "calm" state.
The results of the study can become the basis for the development of new drugs against melanoma metastasis, including the search for drugs that already exist, but have never been used for this purpose before.
Article by T. Golan et al. Adipocytes sensitize melanoma cells to environmental TGF-β cues by repressing the expression of miR-211 published in the journal Science Signaling.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of Tel Aviv University: Study: Fat Cells Play Key Role in Dangerous Transformation of Melanoma.