Melanoma tumor cells can protect themselves using immune response

A team of researchers from Yale and Johns Hopkins have discovered the molecular pathway by which the body’s own immune response may allow for the growth of melanoma, the most dangerous type of skin cancer. The researchers found that patients whose tumors expressed B7-H1, an immune-inhibiting molecule in melanoma tumors, experienced suppression of the inflammatory immune response, which promoted the growth and aggressiveness of their melanoma tumors. This happened because tumor cells utilize an active component of the immune response itself, called interferon gamma, to turn on B7-H1 and protect themselves by suppressing the immune system. “We were surprised to find that aggressive tumors can not only escape or hide from infiltrating immune cells, but can go on the attack -- using interferon gamma as a weapon against the immune system,” Lieping Chen, lead author of the study, said.