Study reveals how melanoma "decoys" immune cells to escape attack

JERUSALEM, Dec. 29 (Xinhua) -- Scientists have uncovered a stealth tactic used by melanoma, the most serious type of skin cancer, to disable the body's immune defenses, according to a new international study published recently in the journal Cell.

Researchers found that melanoma cells release special particles called melanosomes, which are tiny bubble-like structures, that act as "decoys" to distract and exhaust the immune cells tasked with killing cancer, the study showed.

These melanosomes carry surface markers that mimic those found on cancer cells. When released, they bind directly to killer T cells, a type of immune cell, and trick them into attacking the wrong target, the study showed.

This not only drains the T cells' energy but also triggers their dysfunction and even death, allowing the real melanoma cells to grow unchecked, the study showed.

Experiments showed that blocking the release of melanosomes restored the ability of T cells to infiltrate tumors and slow cancer growth in mice, according to the study.

The study also revealed that patients who did not respond to immunotherapy had more melanosome-covered T cells in their tumors, highlighting the clinical relevance of the discovery. Enditem