Liver cancer usually develops as a result of liver disease that progresses, such as cirrhosis or hepatitis B. In 2023, in France, the number of new cases of liver cancer is estimated to be 11,658. Risk factors associated with liver cancer are: alcohol consumption (responsible for 48% of cases) and tobacco, overweight and obesity, hepatic steatosis (excess fat in the liver), hemochromatosis or even hepatitis B and C viruses. But researchers think so. A risk factor associated with liver cancer that was unknown until now has been discovered: a disruption of the internal clock.
To reach their conclusions, published in the Journal of Hepatology, the researchers worked on a humanized mouse model. ” We co-author Dr. Worked with a humanized mouse model developed by Carl Dimit Bissig. Lead author Dr Loning Fu said. ” In this animal model, the animal liver contains both human and murine liver cells, allowing us toStudy the effect of circadian rhythm disruption on cancer development in human cells. » As a reminder, the circadian rhythm is the human body’s internal clock that imposes a 24-hour cycle on us. This clock synchronization is essentially done using light. It can be disrupted by certain ailments.
The rats studied were divided into two groups. One of them was kept in sync with the natural day and night cycle. Another group was given an unrestricted cycle, with alternating daylight and dark exposure, to simulate the changes a person experiences each week on a round-trip flight from San Francisco to London for several weeks.
Disruption of the internal clock may explain the occurrence of liver cancer
In their conclusions, the researchers explained that a group of rats exposed to an irregular day/night cycle may have suffered harmful effects. ” We found that, compared to mice maintained under normal light and dark cycles, Mice in the jet lag group had shorter lifespans and increased cirrhosisJaundice (when the skin or whites of the eyes turn yellow) and cancer also develop in mouse and human liver cells. Dr Loning Fu said. ” Importantly, chronic jet lag also induced metastasis from humanized livers. »
But this is not the only discovery the researchers have made. Altered day/night exposure had the effect of altering the circadian rhythm of mice that developed liver cancer. Slow the progression of tumors. ” One of the paper’s important findings is that once tumors grow spontaneously in response to chronic circadian disruption, returning mice to a normal circadian clock slows tumor growth and prevents metastasis. Co-corresponding author Dr. David Moore said.
“Chronic circadian dysfunction is carcinogenic to humans”.
This work allows us to learn more about the mechanisms of carcinogenesis, as Dr. As explained by Lonning Fu: “ This work provides new knowledge that may promote the development of improved therapies for these cancers and better understand the mechanisms of carcinogenesis. “Furthermore, Disruption of circadian rhythms may explain the occurrence of cancer on a more global scale. ” Our work shows that circadian influences on cancer cannot be underestimated: chronic circadian dysfunction is carcinogenic to humans. Dr. David Moore said.
