BEIJING (Xinhua) .- One reason why many types of cancer are so dangerous is that they metastasize. A new study led by Chinese scientists revealed that bacteria in tumor cells aid cancer relocation and promote cell survival during tumor progression.
Researchers at the Westlake Biomedical and Life Sciences Laboratory found that the microbes could hijack tumor cells and boost the strength of those host cells against mechanical stress in the bloodstream.
“Our study reveals that cancer cell behavior is also controlled by microbes hiding within tumors, most of which were originally thought to be sterile,” said Cai Shang, lead author of the paper. .
Shang and his colleagues used a mouse model of breast cancer with significant amounts of live bacteria inside the cells, similar to human breast cancer.
The bacteria in cancerous tissue are about 10 times richer than those in normal breast tissue, according to the study published the day before yesterday in the scientific journal “Cell.”
Serves as transportation
The researchers found that microbes can travel through the circulatory system with cancer cells, and these passing bacteria are able to regulate the network of cellular actin, a protein that is involved in many types of cell movement, including muscle contraction.
The study also showed that those microbes specialized in relocating cancer cells, rather than affecting carcinoma “in situ.”
“Just one injection of bacteria into the breast tumor can cause a tumor that originally rarely metastasized to start to progress,” Shang said.
The researchers then injected antibiotics into the mice’s blood to specifically kill the tumor bacteria. They found that the tumor did not shrink but lung metastasis decreased markedly.
Furthermore, by injecting those microbes back into the mice, metastasis increased markedly, according to the study.
The researchers tried to explain that tumor cells in the blood tend to die under mechanical stress but the microbes inside them could make them stronger by rebuilding their skeletons.
The study did not explain how the bacteria manage to invade and thrive in tumor cells to produce such positive mutualism.
The researchers said further study could hint at a new strategy for correctly implementing antibiotics for cancer therapy in the clinic.
Currently, the findings do not prove that the use of antibiotics during cancer treatment benefits patients, Shang pointed out.
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