Circadian rhythm disorders promote tumor growth

  Recently, Yool Lee, Amita Sehgal and colleagues of the University of Pennsylvania (University of Pennsylvania) published a new study in the open source journal PLOS Biology, which disrupted normal circadian rhythms and promoted tumor growth and anti-cancer drugs. effect. The results show that it can be suppressed. The results of this study provide evidence for a "temporal therapy" mechanism, which refers to the use of cancer drugs to treat cancer based on the inherent circadian rhythm.

  Circadian rhythm regulates many aspects of the physiological activity from the biological level to the intracellular level. Whether it is due to circadian rhythm disorders caused by airplane travel, shift work or sleep disorders, it is a known risk factor for certain cancers. In animal models, hormone-induced circadian rhythm disorders can promote tumor growth, but its underlying mechanism remains unclear. In order to clarify its underlying mechanism, the author used dexamethasone hormone to slowly accelerate the biological rhythm of cultured cells. They found that drug treatment changed the expression of many genes, especially those involved in cell cycle regulation. Circadian rhythm disorders can increase cell proliferation, and this effect can be traced back to increased expression of the cell cycle control protein cyclinD1. Next, cyclin D1 activates cyclone d-dependent kinase 4/6 (CDK4/6). It is a protein that can transform cells from growing to synthesize new DNA, which ultimately leads to cell formation. Because tumor growth is closely related to cell division, many anti-cancer drugs try to stop the growth of cancer cells throughout the cell cycle. Researchers say that an anti-tumor drug called PD-0332991 can block the activity of CDK4/6, and its anti-tumor ability will change over time, so treatment in the morning is more effective than treatment at night. I find. If the circadian rhythm of cells or mice is disturbed, the effect of PD-0332991 will be weakened.

  Saigar said: "The chronic disruption of normal circadian rhythms shows that the balance between tumor suppressor gene expression and tumor progression gene expression is beneficial to tumor growth. Jet lag, shift work, and other chronic diseases. A better understanding of the molecular effects of interference may be Lead to strategies to reduce the cancer risk associated with these behaviors, and better treatment strategies, including arranging cancer treatments to maximize benefits."