Monday, December 28, 2015

Our Immune System and Cancer

Strengthen your immune system to stop cancer by eating specific foods is a message I see in certain social media circles. This message about food usually comes from people promoting natural, alternative approaches to disease prevention and treatment verses man-made conventional treatment options like chemotherapy. It gives the impression that cancer is a simple disease that can be prevented or even cured by healthy living. Of course eating healthy allows our bodies to function at its best and respond to invaders that make us ill, but this message about food, our immune system, and cancer is not exactly accurate. Cancer is our own cells, so our body doesn't always detect those cells as harmful. Plus cancer cells do some tricky things to their microenvironment and to certain types of immune system cells in order to survive. After looking at a video on u-tube--link included at bottom of post--I found our immune system's natural response to cancer is way more complicated than anything I imagined.

Even if you don't finish reading this post, please watch the video below. If nothing else comes of your watching it, you will at least have a glimpse of why breast cancer survival rates are not changing rapidly. 

At this point, you might be thinking, "But what about the immunotherapy approaches to cancer that are making the news these days?"

There are a few drugs (Herceptin is one) used today that target a specific part of a cancer cell. These drugs are suspected of enhancing a body's immune system and its response to cancer. Unfortunately--at least in my understanding--how these drugs actually cause an immune response is not completely understood. 

Targeting an individual's particular cancer using their immune system is no easy task. In the case of cancer vaccines, each person's cancer must be analyzed for targets such as proteins and then the person's immune system is "taught" (for lack of a better way to describe it) or altered in some way to find the cancer cells and stop them. (Immune system cells are first taken from an individual and taught to recognize a cellular malfunction. Then they are infused back into the body to seek and destroy those cancer cells.) From what I can tell, immunotherapy can only be used presently in a small subset of patients because there are so few drugs currently developed that can target specific proteins on cancer cells or enhance other immune cells so they can recognize the abnormal cells. In my opinion, the term immunotherapy may not be the best word to use for this kind of treatment, but I do not have the medical background and understanding to offer another term in this new realm of precision medicine.

(Cancer.org has good information about immunotherapy. Please go to their website for more information since I may have created a indecipherable mess in my explanation of it.)

As I stated in the beginning of this post, I watched a video--found on twitter--about cancer and the immune system of mice. Below is the tweet I saw about this video describing how cancer cells are able to enter the bloodstream and metastasize.

This is what I saw:
Spying On Breast Cancer Metastasis .

The video shows how macrophages created from white blood cells actually help cancer cells move around the body. Did you read that word in bold? "Help" is a dark contrast to the meaning of "stop" in a discussion about cancer metastasizing. The macrophages are helping cancer cells find their way into the bloodstream therefore the immune system has taken an unexpected role in response to a damaged cell. This once again tells me there is so much still to learn.

You may remember learning about macrophages from high school biology class or possibly from Biology 101 in college. If you didn't or don't remember, macrophages develop from a special group of white blood cells. When cells are damaged because of infection, macrophages engulf and digest the cells. Then an antigen forms on the outside of the macrophages signaling other macrophages to seek and destroy other cells infected in the same way. Any future invaders of this type will quickly be eliminated by the immune system because the body has macrophages already created to kill this particular invader. If the immune system is working correctly, they will detect and destroy them before an animal shows any signs of illness. Remember cancer is not an invader therefore the difficulty to get our immune system to recognize there is a problem is not easily solved by simply eating an asparagus smoothie.

The research and video describing how macrophages help instead of hinder cancer cells was done at Albert Einstein College of Medicine in New York City. Edison Leung and Allison Harney are the creators. Since this immune response has only been captured in mice, saying this is how cancer metastasizes in humans is a jump, but the possibility is real. 

The video is short. For science lovers, I hope you find it informative and fascinating--also terrifying of course.  






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