NCI brings you NIR-PIT

Bliss

I have commented before about the total dependency of the medical profession on acronyms.  This is understandable; if someone writing a paper wanted to discuss naphthalocyaninetrimethylphosphate, for instance  and had to spell it out every time it came up, the paper would be too long to publish, and if published would be impossible to read without coffee and naps.  So:

NCI = National Cancer Institute

NIR = Near Infrared

PIT = Photo Immunotherapy

Treg =Regulatory T cells

This* article from the NCI Newsletter describes another neat trick employing light to activate cancer suppressing agents.  To jog your memory, using light as a weapon against cancer came up earlier:

http://ljb-quiltcutie.blogspot.com/2015/08/more-light-on-cancer.html.  I was encouraged then, and am more so now.

If I understand the NCI article, the new wrinkle goes something like this:  There are two parts.

First, some guys at NCI have succeeded in attaching a “photo-absorber”  to  an antibody specific to receptors  that are “over expressed” on a certain kind of cancer cell.  Then, when the antibody is firmly attached, the appropriate near-infrared light is turned on, the photo receptor swells and the cancer cell is blown all to hell.  Better yet, fragments of the cancer cell in the bloodstream are recognized as “invaders”, triggering an immune response, causing killer T cells to course through the body, looking for similar cancer cells to kill.  Or something like that.  The catch here is that it is necessary to gin up a separate antibody for each cancer type.

However, there seems to be a more general approach.  If I am not too far afield here, the article seems to be saying that in the cancer’s “microenvironment” there exist immune cells (Tregs) that prevent the killer T cells from doing their job.  The game, then, is to attach the light-sensitive photo-bombs to molecules that bind to Tregs – and blow them all to hell.  All cancers have the same kind of Treg, so it seems as though there are the glimmerings of a powerful weapon here.  I am puzzled ,though, about whether it would be necessary to target T cells to each distinct cancer type.  I am over my head here, and had better stop,

By the way, don't hold your breath - phase 2 trials are just beginning..

·    *   http://www.cancer.gov/news-events/cancer-currents-blog/2016/photoimmunotherapy-cancer?cid=eb_govdel