January 18, 2012
Plasmacytoid DCs: Tumor-Killing Immune Cells
Some skin cancers, in particular basal cell carcinoma, can be successfully treated with a prescription cream containing the compound imiquimod. The antitumor effect of imiquimod is multifactorial. One of the more complex aspects of imiquimod's antitumor effects is its ability to modify the immune response. A team of researchers led by Maria Sibilia, at the Medical University of Vienna, Austria, has now identified a new way in which imiquimod modifies the immune system to clear tumors in a mouse model of melanoma, the most deadly form of skin cancer. Specifically, the team found that topical application of imiquimod leads to the recruitment of immune cells known as plasmacytoid DCs to the site of the tumor. Moreover, exposure to imiquimod at the site of the tumor then converts these cells into tumor-cell killers. Nina Bhardwaj and colleagues, at New York University, New York, discuss in an accompanying commentary the implications of these data for antitumor therapies designed to combat both skin cancers and other cancers.
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