The century-old BCG vaccine may be the nemesis of stubborn liver cancer

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The century-old BCG vaccine may be the nemesis of stubborn liver cancer

The century-old BCG vaccine may be the nemesis of stubborn liver cancer

According to a study by the University of California, Davis Health Center, a single injection of the 102-year-old tuberculosis vaccine BCG has been shown to effectively trigger the immune response in mice and shrink their liver cancer tumors. The findings suggest that BCG may be another approach to treating this notorious and hard-to-treat cancer.

As the most common type of liver cancer, hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths globally. Despite treatment methods including surgery, radiation, chemotherapy, immunotherapy, and liver transplantation, the prognosis remains poor.

In the process of seeking alternative therapies for HCC, researchers at the University of California, Davis Medical Center conducted a study to explore whether the century-old BCG vaccine used to prevent tuberculosis could be an effective anti-cancer drug.

The study found that in addition to its specific effects on tuberculosis, the BCG vaccine also has non-specific protective effects, including effects on the immune system, with systemic implications. The U.S. Food and Drug Administration has approved the use of BCG for the treatment of bladder cancer, and clinical trials have also explored its use in fibromyalgia and diabetes. Therefore, researchers are eager to test its efficacy against this stubborn liver cancer.

Yvonne Wan, the corresponding author of the study, said, “HCC is very difficult to treat. This cancer is considered a cold tumor, with a poor response to immunotherapy. We have good reason to believe that BCG can stimulate the immune response. Therefore, we injected mice with a certain dose of BCG who had liver cancer, and to our surprise, the BCG was enough to activate the body’s immune system, reducing the tumor burden.”

Researchers subcutaneously injected a single dose of BCG in a liver cancer mouse model, similar to how humans are injected with BCG. They found that this therapy could reduce inflammation, promote immune cells, especially anti-cancer T cells and macrophages, to infiltrate the liver tumor, thereby shrinking the tumor. BCG also triggered the IFN-gamma signaling pathway, promoting the recognition and elimination of tumor cells by recruiting T cells.

“We found that BCG treatment resulted in T cells and macrophages moving toward the tumor,” Wan said. “It also activated the body’s immune system, enhanced IFN-gamma signaling, thus playing a role in anti-HCC. Although previous studies have shown gender differences in the effect of BCG on immunity, our data shows that both male and female HCC mice respond to BCG treatment.”

Other studies have shown that the effect of BCG on immunity differs between genders, but no such findings were found in the current study.

Researchers plan to investigate whether BCG can be used to prevent liver cancer and whether it can effectively treat other types of cancer.

Wan said, “If BCG can treat stubborn tumors like liver cancer, I believe it will also be effective against other difficult-to-treat cancers. We still need more research to move forward. For example, we don’t know how long this immune memory will last, so the long-term efficacy of this vaccine remains a mystery. The mechanism of action may be complex and requires further study.”

This study was published in the journal Advanced Science.

The century-old BCG vaccine may be the nemesis of stubborn liver cancer