Scientists at the Johns Hopkins Kimmel Cancer Center have identified 16 genes that breast cancer cells use in order to survive in the bloodstream after they've escaped the low-oxygen regions of a tumor. The research was published in the journal Nature Communications, reports News Medical.

During the respective experiments on mice and human cell lines, scientists have discovered mechanisms that help cancer cells survive in conditions of low oxygen level (hypoxia) and spread in the body. According to the researchers, the cells inside the tumors—especially when there is a lack of oxygen—adapt to the stress they feel when they enter the bloodstream.

The 16 genes found help cancer cells protect themselves from active forms of oxygen that cause acid stress. This enables the latter to move to more favorable zones where they can enter the bloodstream and spread to other parts of the body.

The research team—led by Daniele Gilkes, Ph.D., an assistant professor of oncology at Johns Hopkins—color-coded hypoxic cells green, then applied a technique called spatial transcriptomics to identify which genes were turned on in the perinecrotic region, and that stayed on when the cells migrated to more oxygenated tumor regions. This made it possible to find out which genes are active under hypoxia conditions. In studies on mice, scientists have confirmed that a subset of genes persist long after the cells have left the original tumor.

Results were particularly predictive for triple-negative breast cancer (TNBC), which has a high rate of recurrence. The researchers found that patient biopsies from TNBC that had recurred within three years had higher levels of a protein called MUC1.

These findings bring scientists closer to understanding the mechanisms of tumor stability in the face of hypoxia, and this may help to develop new means of combating aggressive types of cancer.