A team of researchers from The University of North Carolina at Chapel Hill have recently reported the discovery of a new drug target for melanoma treatment. The study was published in the journal Clinical Cancer Research and is entitled “IL2 Inducible T-cell Kinase, a Novel Therapeutic Target in Melanoma.”
Melanoma is the deadliest form of skin cancer. It is an aggressive cancer in which cells within skin moles become malignant (usually due to ultraviolet radiation from sunshine or tanning beds), gaining the potential to quickly spread to other parts of the body if not treated. The American Cancer Society estimates that melanoma is diagnosed in less than 5% of all skin cancers, although it is the cause of approximately 75% of all deaths related to this malignancy.
Melanoma is curable when detected and treated early before spreading to the lymph nodes, with patients having an estimated five-year survival rate of approximately 98%. If the cancer goes undetected, spreads (metastasize) or if it recurs, it can become extremely difficult to treat and the five-year survival rate falls significantly to 62% if melanoma has spread to the lymph nodes and to only 16% in individuals whose melanoma has spread to other organs.
In the study, researchers reveal the discovery of what they believe to be a driver of cancer’s growth in melanoma, the enzyme interleukin-2 inducible T-cell kinase (ITK). ITK was found to be highly expressed in primary and metastatic melanomas in comparison to non-cancerous moles. This enzyme is, however, usually only found in a subset of the body’s immune cells, and is involved in the activation, development and production of certain immune cells.
“The cancerous cells were packed with that protein, and it was bizarre — that’s not supposed to be there,” noted the study’s senior author Dr. Nancy E. Thomas in a news release.
The team found that cells engineered to have lower ITK expression reproduced more slowly. An experimental inhibitor of ITK induced a similar effect on cells and when tested in melanoma mice models, it caused a reduction in the tumor’s growth. “We have discovered that ITK is highly expressed in melanoma even though it was thought to be restricted to immune cells, and when you inhibit it, you decrease melanoma growth,” explained Dr. Thomas. “Therefore, we think it’s a good potential drug target.”
“New therapies are needed because of the high mortality rate for metastatic melanoma, and the ability of melanomas to become resistant to many of the current therapies,” added the study’s lead author Dr. Craig Carson. This new finding may lead to a novel treatment strategy for melanoma. In fact, one drug inhibitor of ITK’s activity has already been approved for blood cancers.
“ITK has been conceived of as a therapeutic target for inflammatory diseases such as chronic obstructive pulmonary disorder, but because ITK had not been noted in melanoma before, it has not been a target for its treatment,” concluded Dr. Carson. “I expect ITK to become an important therapeutic target for melanoma because of the expected minimal side effects, and the fact that ITK is found in so many of the melanomas we have investigated.”
