Author: Bolysbek Dana
Editor: Merentsova Anastasia
Metastases are cancer cells that break away from the primary tumor and "settle" in other organs.
The chances of recovery are greatly reduced if the tumor metastases. Previous studies have shown that metastases are formed by clumps of cancer cells that separate from the primary tumor and migrate to other tissues through the bloodstream. However, until now, little was known about why these clumps of circulating tumor cells (CTCs) leave the tumor.
The experiments were based on a mouse model of breast cancer: the researchers analyzed the separation conditions of CTCs and their molecular and cellular biological properties, as well as the oxygen supply inside these tumors, which are equivalent to human cancerous tissue.
It turned out that different areas of the tumor are supplied with oxygen at different levels: cancer cells with a lack of oxygen were found where the tumor had relatively fewer blood vessels - in the tumor nucleus, as well as in well-defined peripheral areas.
The research team then examined the CTC clusters that had detached from these tumors and found that they also suffered from a lack of oxygen. This led to the conclusion that cells leave the tumor if they don't get enough oxygen.
This insight prompted researchers to take a closer look at the effect of so-called pro-angiogenic treatments: they stimulated the formation of blood vessels, thereby increasing the oxygen supply of tumor cells. As expected, the number of separating CTC clusters decreased, the mice developed fewer metastases, but at the same time, the primary tumor significantly increased in size.
Source: https://medicalxpress.com/news/2020-09-lack-oxygen-tumors-metastasis.html
