Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

Night Shift Nightmare

Disrupting circadian rhythm increases cancer risk.

A handful of large studies of cancer risk factors have found that working the night shift, as nearly 15 percent of Americans do, boosts the chances of developing cancer.

MIT biologists have now found a link that may explain this heightened risk: in a study of mice, they found that two of the genes that control cells’ circadian rhythms also function as tumor suppressors. Disrupting these genes allows tumors to become more aggressive.

This story is part of the November/December 2016 Issue of the MIT News magazine
See the rest of the issue
Subscribe

The researchers exposed mice to two different schedules. One group lived with a normal routine of 12 hours of light followed by 12 hours of darkness, while the other mice went onto a “jet lag” schedule: every two to three days, they were exposed to an additional eight hours of light. This mimics the biological-clock disruption that occurs when humans work night shifts or travel through multiple time zones. When this happens, the two genes that control the circadian clock, Bmal1 and Per2, don’t get the light cues that cause levels of the proteins they encode to oscillate throughout the day.

“Cells need the light cue, which is like a reset button for the clock,” says Thales Papagiannakopoulos, a former postdoc at MIT’s Koch Institute for Integrative Cancer Research, who worked with Koch Institute director Tyler Jacks on this study.

Under the jet lag scenario, tumors grew faster and were more aggressive than those in the mice living with a normal light/dark schedule. When the researchers kept the mice on a normal schedule but knocked out Bmal1 or Per2, tumors also grew faster. “If you disrupt these genes in every cell of the body, the light cues that you normally receive do not apply,” says Papagiannakopoulos. “It’s a way of taking a molecular hammer and just breaking this clock.”

Cut off? Read unlimited articles today.

Become an Insider
Already an Insider? Log in.
Next in MIT News
Want more award-winning journalism? Subscribe and become an Insider.
  • Insider Plus {! insider.prices.plus !}* Best Value

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus the digital magazine, extensive archive, ad-free web experience, and discounts to partner offerings and MIT Technology Review events.

    See details+

    Print + Digital Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

    Technology Review PDF magazine archive, including articles, images, and covers dating back to 1899

    10% Discount to MIT Technology Review events and MIT Press

    Ad-free website experience

  • Insider Basic {! insider.prices.basic !}*

    {! insider.display.menuOptionsLabel !}

    Six issues of our award winning print magazine, unlimited online access plus The Download with the top tech stories delivered daily to your inbox.

    See details+

    Print Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

  • Insider Online Only {! insider.prices.online !}*

    {! insider.display.menuOptionsLabel !}

    Unlimited online access including articles and video, plus The Download with the top tech stories delivered daily to your inbox.

    See details+

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

/3
You've read of three free articles this month. for unlimited online access. You've read of three free articles this month. for unlimited online access. This is your last free article this month. for unlimited online access. You've read all your free articles this month. for unlimited online access. You've read of three free articles this month. for more, or for unlimited online access. for two more free articles, or for unlimited online access.