Essentials of Glycobiology—Part 9 (Altered Glycosylation)

Larry A. Law

Altered glycosylation is a universal feature of cancer and contributes to pathogenesis (creation) and progression including metastasis. Metastasis is the process by which cancer cells spread from their original location to other parts of the body. The spread of cancer cells from the place where they first formed to another part of the body makes treatment virtually impossible. In metastasis, cancer cells break away from the original (primary) tumor, travel through the blood or lymph system, and form a new tumor in other organs or tissues of the body. Cancer cells always exhibit altered (not normal) sugar patterns on their glycocalyx. 

Altered Glycosylation

Glycosylation is the term that describes the process of how cells attach particular sugars to proteins and lipids. These sugar strands can involve tens, hundreds, or thousands of sugars. When cancer is diagnosed, it means glycosylation did not take place properly on those cells—it is a universal feature of cancer cells. In our ABO blood typing system, one sugar out of place can be the difference between life and death in a blood transfusion. The body is vigilant and pays particular attention to every sugar on those cell-surface, sugar structures. When glycosylation goes awry and sugars are not where they should be, cancer can result and progress resulting in a very serious situation. The picture below depicts how the immune system fights cancer. APC stands for Antigen Presenting Cell, the cell that gathers specific tumor cell markers to pass onto T-cells and other natural killer cells. 

Cancer

This disease is second only to heart disease for the number of American lives taken in death (610,000 U.S. deaths in 2023). Cancer cells can proliferate throughout the body via metastasis. Metastasis involves the lack of particular sugars called cell adhesion molecules. When a cancer cell loses its grip on surrounding normal cells, it is free to float through the lymph system or the circulatory system. The cancer cell travels to another part of the body and can cause a secondary cancer. Over 98% of all cancers metastasize. This is why surgery and radiation are not more successful. By the time enough cancer cells show up to cause symptoms and a subsequent diagnosis, they have already metastasized. This leaves only chemotherapy as a treatment option and the statistics are extremely poor for success in fighting cancer via that approach. Preventing the growth of cancer in the first place by eating real, healthy food to strengthen cells and your immune system turns out to be the best option for eliminating this disease.