Arab Israeli pediatric pulmonologist Dr. Fahed Hakim wants us all to get more sleep.  According to research he conducted at University of Chicago Comer Children’s Hospital during a two-year fellowship there, sleep may help the body fight cancer.

Dr. Hakim practices at Haifa’s Rambam Hospital and in a private clinic in Nazareth.  A Christian Arab, he was offered a joint American Physicians Fellowship/Israel Medical Association Fellowship in 2010, and took his young family to Chicago.  There, he conducted research on the connection between poor sleep habits and conditions such as obesity and high blood pressure.

“People with sleep disorders tend to eat much more,” says Hakim. “This creates a vicious cycle, because they keep gaining weight, and if they become obese, they are prone to sleep apnea.”

The first year of Hakim’s Chicago fellowship in pediatrics, the head of the pediatrics hospital, David Gozal, ran a lab devoted to this topic. As that research wrapped up, new studies were coming out which piqued Hakim’s interest.

“We knew from epidemiological studies that people whose Circadian rhythm is disrupted – like night-shift workers – have a higher incidence of cancer,” says Hakim.

“We also knew that sleep apnea sufferers, who snore and wake up dozens of times a night, have a higher tendency to cancer. In other words, the more hypoxic a person is – the lower the levels of his oxygen – the more he is disposed to cancer. Studies on this emerged just when we began to think about our next research project. So we decided to ask how it happens and why.”

Hakim began studying mice.  The control group was permitted to sleep normally, while the remaining mice were woken repeatedly.  Then all the mice were injected with cancer cells.

Within four weeks, the number of cancer cells and the volume of tumors in the sleepless mice was double that of the control group.  The tumors in the first group were more invasive, too, spreading to adjacent tissue.

“To understand why, we looked at the tumor micro-environment,” says Hakim.

“When you have an invader in your body, your immune system tries to attack it. The cells that eat invaders, like bacteria, are called macrophages. Tumor cells have two kinds of macrophages — M-1 and M-2. M-1 helps the immune system; M-2 helps the invader. In the sleep-fragmented mice, instead of having more M-1 cells to help the immune system fight the tumors, the M-2 cells came out to help the tumors.”

Hakim’s team examined why the M-2 levels were so high.  They found that M-2s collected around the edges of the cancer cells and signalled more macrophages to the area using the TLR4 receptor – a protein that activates the immune system.

“What we found was that the TLR4 in the sleep-deprived mice was highly activated,” Hakim says. “So we decided to knock out the TLR4. And we discovered that the tumors in the mice in which we knocked out the TLR4 did not grow as quickly.”

This is big news for the scientific community, because it points researchers in a new pharmaceutical direction.

Hakim’s research appeared in the January issue of the Journal of Cancer Research.