Kimberly M. Hicks, Pharm.D., M.H.A., Clinical Pharmacy Specialist at BioPlus Specialty Pharmacy
The body’s immune system possesses all the tools it needs to kill cancer cells, so why does cancer sneak past our defenses so many times? Cancer cells – in an elaborate game of cat and mouse – employ numerous techniques to cloak themselves as invisible to the immune system. This means that the immune system’s call to arms often doesn’t happen until it is too late.
Here’s just one example of the intrigue between cancer cells and the immune system: Natural killer cells are one of the key parts of the immune system’s arsenal for seeking out and destroying damaged cells in the body, including tumor cells. Yet in response, tumors pump out a certain protein (called TGF-beta) that dials down the activity of natural killer cells in the body.
Researchers from Moffitt Cancer Center in Tampa have tracked how lung cancer cells do in fact evade detection by natural killer cells – and thinking ahead to how this can be counteracted in cancer treatment – these scientists are exploring ways that patients with lung cancer might be able to stop the evasion. In other words, it might be possible in the future to take away this malicious tool of cancer cells and get the immune system to destroy those rogue cells.
Similarly, researchers at the Cedars-Sinai Samuel Oschin Comprehensive Cancer Institute are working in an animal model to ramp up the immune response in mice with lung or pancreas tumors. So far, this is resulting in cell death of the tumors.
The immune-stimulating compounds in this research are an mTOR inhibitor and CD4 antibody. When used, they make it so the once-invisible tumor cells are seen by the immune system and thus targeted for destruction.
Take heart, although the finish line is still a ways off, cancer researchers are getting closer all the time. With lung cancer as the current leading cancer killer in both men and women in the United States, any progress against this killer can’t come soon enough.
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American Lung Association.
Donatelli SS, Zhou J-M, Gilvary DL, et al. TGF-beta–inducible microRNA-183 silences tumor-associated natural killer cells. PNAS 2014:1319269111v1-201319269.
Wang Y, Sparwasser T, Figlin R, et al. Foxp3+ T cells inhibit antitumor immune memory modulated by mTOR inhibition. Cancer Res 2014;74(8):2217-28.