Vitamin B2 will help to find cancer stem cells
A new specific marker of cancer stem cells
NanoNewsNet based on CNIO materials: Experts from CNIO discover shining cells responsible for developing tumoursTumors are a mosaic of very different – morphologically and molecular – cells.
It is estimated that cancer stem cells, which have recently been responsible for the occurrence of cancer and for the development of resistance to traditional anticancer drugs, account for only 1-2% of the tumor mass. Such a small percentage of cancer stem cells in solid tumors makes it very difficult to isolate and analyze them, as well as to study the causes of drug resistance.
Scientists from the Spanish National Cancer Research Center (Centro Nacional de Investigaciones Oncologicas, CNIO) have discovered and described a new specific marker of cancer stem cells. It turned out to be riboflavin, or vitamin B2, a pigment that, as a result of its accumulation in intracellular vesicles, emits green light. This property can be used to track, isolate and purify cancer stem cells without antibodies or other more expensive and complex methods.
The results of the study are published in the journal Nature Methods (Irene Miranda-Lorenzo et al., Intracellular autofluorescence: a biomarker for epithelial cancer stem cells).
"The discovery of this new marker is a breakthrough, as it can be used to isolate tumor stem cells – the most invasive and chemically resistant cancer cells. Autofluorescence makes it possible to track these cells in a simple and inexpensive way, as well as to study the origin of tumor resistance to chemotherapy drugs," says Irene Miranda, the first author of the article. "As a rule, we only see the leaves of the tree represented by tumors, but we cannot see the roots [stem cancer cells], which are really responsible for the progression and growth of the tumor."
This discovery, confirmed on several types of tumors, including biopsy samples obtained from patients with pancreatic, liver, colon and lung cancer, raises the question: why do tumor stem cells accumulate vitamin B2?
In their article, the researchers showed that this is due to an increase in levels of ABCG2, a protein responsible for the transport of vitamin B2 into intracellular vesicles that give luminosity to cells. However, the factors behind this phenomenon have yet to be established.
Despite questions about its nature, autofluorescence can help in the development of future therapeutic approaches within personalized medicine and in the development of more effective anticancer drugs.
"Now we will be able to isolate autofluorescent cells from biopsy samples and test their sensitivity to experimental or already marketed drugs," the researchers say.
"Using this method, we want to accelerate the search for new drugs or combinations of them to specifically destroy cancer stem cells," adds study co–author Bruno Sainz.
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