At the end of November 2011, I attended the CCRC in Toronto, Canada. It was a good experience. One hot topic in the meeting was about how cancer cells are so plastic and heterogeneous that they can escape treatments and immune systems.
I presented a poster explaining one mechanism of how cancer cells escape the innate immune system. I got many feedback responses. The whole idea of my poster, with the research presented has been already published in Cancer Research Journal, was that cancer cells usually present on their surface a molecule named MICA. This Molecule is detectable by our immune cells, especially natural killer (NK) cells. Once NK cells recognize MICA on cancer cells, they attack and kill them. What we presented is that cancer cells are capable under certain conditions (like low oxygen concentrations i.e. hypoxia) to get rid of MICA, thus escaping being detected and killed by NK cells. We also, found that we can correct this problem by applying very low doses of glyceryl trinitrate (nitroglycerine), the famous drug known as a treatment of heart attacks (ischemic heart disease). Nitroglycerine restored MICA to the surface of cancer cells, even when they are exposed to hypoxia, making them more vulnerable to being killed by NK cells. Applying nitroglycerine patches on mice injected with human prostate cancer cells, reduced tumor growth.