Cancer cells are locked into an epic game of hide-and-seek with our body. Naturally, our body is tuned to recognize and eliminate foreign matter with the help of our immune system. Cancer is no exception. Routine inspection shows the presence of tumour infiltrating lymphocytes (TILs) deep inside of tumours removed during surgery. These TILs are immune cells that have the natural ability to recognize and attack cancer cells in our body. However, cancer cells can send out signals that shut down the ability of our immune system to recognize them. In other words, they are effectively hiding from the immune system. Recognizing this dangerous game of hide-and seek, scientists have learned how to isolate and expand the small number of TILs trapped in tumours in the lab so they can be reintroduced back into the patient. The process of reintroducing the TILs into patients has become known as adoptive cell therapy (ACT) and shows promising results towards treating many types of cancer, such as metastatic melanoma, methothelioma, ovarian, breast and pancreatic cancers.
During surgery, complete removal of cancer with a rim of normal tissue around it called a clear margin. It is crucial for helping to prevent cancer from returning (1). Current efforts to assess whether the entire tumour has been removed rely on pre-operative imaging, post-operative reports, and the good judgment of physicians during the heat of surgery. However, failure to fully remove the tumour can result in additional surgeries, delays in subsequent therapy, not to mention to the higher emotional distress of the patient and increases in health care costs. It is also possible that microscopic traces of tumour can remain to re-emerge at a later date. A recent breakthrough comes from the lab of Réjean Lapointe at the Université de Montreal (2). He and his research team developed an “immuno-super gel” to help overcome some of the hurdles of current cancer therapies. His 3D matrix gel, containing large numbers of cultivated TILs, may be poised and ready to destroy any cancer left behind during surgeries. Imagine for a moment the potential for this technology. The gel, charged with power of our own immune system, is injected into a surgical site. Once there, the TILs multiply and migrate out of the gel into the surrounding tissue where they seek out and destroy the left over cancer cells not removed. By destroying the left over cancer cells the new technology reduces the chances that any cancer will re-emerge. This research has the potential to solve a pitfall in current cancer treatment by combining surgery with immunotherapy!
Scientists are continuing to push the boundaries of innovation by combining new technologies with ACT. The technology behind the 3D gel matrix is a modified version of naturally occurring substances found in shellfish. The chemical modifications provide additional matrix stability. The leap forward comes from scientists discovering conditions that facilitate the physical support of the TILs, maintain them in a healthy state, and enable their slow release out of the gel. Studies carried out in the lab have shown that these specialized immune cells released from the gel can kill cancer cells in a petri dish. In a second part of the study, they also showed preliminary evidence that the gel is safe when injected into mice. The safety and stability of a therapeutic is critical in the success of early-stage clinical trials.
If reading about exciting new therapies like this fosters a deep sense of hope and excitement; you are not alone. The Canadian Cancer Society has recently released their top ten Canadian cancer discoveries of 2016 (3). It’s no surprise that the immuno-super gel described here ranks among the discoveries which provide new insights into cancer biology and treamtment, turning the lights back on in the efforts to seek out ever last cancer cell in our body.
This article was written by Dr. Martin Smith. Dr. Smith completed his PhD at the University of Waterloo studying how proteins can cause cancer. He currently works for the Ontario Brain Institute where he studies brain disease. To learn more about Dr. Smith and his research check out our members page.
1) Using 3D to fine-tune breast cancer surgery and save lives. Link:
2) Monette A, Ceccaldi C, Assaad E, Lerouge S, Lapointe R. Chitosan thermogels for local expansion and delivery of tumor-specific T lymphocytes towards enhanced cancer immunotherapies. Biomaterials. 2016 Jan (75): pp. 237-49.
3) Our top ten research stories of 2016, Canadian Cancer Society. Link: http://www.cancer.ca/en/about-us/our-research/research-impact/?region=on