Find and destroy
A group of researchers from the University of Texas at Dallas has developed a new method of localization of aggressive tumor cells. The purpose of this direction is to prevent metastasis and prevent cancer recurrence after successful treatment.
Not all cancer cells are the same. There is a small group of cells that are much more aggressive than others — these are cancer stem cells. They generate secondary tumors, even after the primary tumor has been successfully cured. These cells are hard to destroy, but even harder to find.
Stem cells are found in various tissues of the body. Unlike normal cells, which have a limited lifespan, they can divide and regenerate over a long period of time. They are also non-specialized: some cells can transform into another type of cell. For example, bone marrow stem cells can become osteocytes, adipocytes, or blood cells.
Cancer stem cells are also not specialized and are capable of self-healing until they turn into cancer cells.
The most effective existing methods of treating primary tumors cannot destroy cancer stem cells. Even if the primary tumor is successfully treated, these cells can migrate into the blood and remain unnoticed by the immune system. After the end of the course of therapy, they can give rise to tumor recurrence and metastases. Such secondary tumors may appear years later. They are often more aggressive and more difficult to treat.
The destruction of stem cells in the primary tumor gives hope to finally defeat the malignant process. Currently, there are no clinically tested drugs selectively targeting cancer stem cells. The difficulty lies, first of all, in the search – there are few of them, and they usually "hide" deep in the tumor tissue.
The researchers used a two-step sorting process of about 40,000 chemical compounds to search for a substance that would selectively bind to breast cancer stem cells, while ignoring mature cancer cells.
Initially, the authors wanted to find a way to differentiate cancer cells from healthy ones. But in the course of the work, it turned out that the new method is more specific and allows you to isolate cancer stem cells.
Using the available data on the physical properties that distinguish cancer stem cells, the authors of the study incubated stem and mature breast cancer cells together with 40,000 small plastic balls coated with several copies of one of the ligands.
The process of searching for a compound that is tropic to cancer stem cells: plastic balls carrying various agents are marked in blue, cancer stem cells are marked in red. Source: UT Dallas.
After two tests, a specific ligand was identified that bound only to cancer stem cells. It was used to separate them from the mature ones.
To confirm the properties of ligands to find cancer stem cells, the cell sets isolated by them were injected into mice and the animals were observed, assessing the growth of the tumor.
In the group of cancer stem cells, rapid tumor growth was noted. It is noteworthy that in the group of mice injected with tumor cells, having previously removed the stem cells, there was no tumor growth at all. These data prove that the elimination of cancer stem cells leads to tumor degeneration.
The authors write that ligands capable of finding cancer stem cells can be used both in the treatment and diagnosis of oncological diseases. The simplest application model: attaching a drug to a ligand that would selectively destroy cancer stem cells.
Article by L. Chen et al. A Synthetic Binder of Breast Cancer Stem Cells is published in Chemistry — A European Journal.
Aminat Adzhieva, portal "Eternal Youth" htpp://vechnayamolodost.ru based on the materials of UTD News Center: University Scientists Isolate Cancer Stem Cells Using Novel Method.