A study has found that a protein called PASD1 associated with cancer cells is a powerful suppressor of the biological clock that drives the daily rhythms of cells throughout the body.
A master clock in the brain, tuned to the daily cycle of light and dark, sends out signals that synchronize the molecular clocks ticking away in almost every cell and tissue of the body.
“The clock is not always disrupted in cancer cells, but studies have shown that disrupting circadian rhythms in mice causes tumors to grow faster, and one of the things the clock does is set restrictions on when cells can divide,” said Carrie Partch, a professor of chemistry and biochemistry at University of California Santa Cruz.
The discovery added to a host of evidence suggesting a link between cancer and disruption of daily or circadian rhythms. It also offers new insights into the molecular mechanisms of the biological clock.
“Understanding how PASD1 is regulating the circadian clock could open the door to developing new therapies. We could potentially find ways to disrupt it in those cancers in which it is expressed,” Partch noted.
The researchers also studied cancer cell lines that express PASD1 and showed that blocking the protein (using RNA interference techniques) turned the clock cycle back on in those cells.
“By understanding what makes the clock tick and how it is regulated, we may be able to identify points where we can intervene pharmacologically to treat disorders in which the clock is disrupted,” Partch concluded.
The study appeared in Molecular Cell.