'Super' stem cell keeps liver cancer going

Researchers in Hong Kong have discovered what makes liver cancer, a scourge of China and southeast Asia, so tough to beat even after the cancer is surgically removed. Turns out, liver cancers are dotted with a kind of "super cancer stem cell" that are resistant to chemotherapy and keep coming back, Reuters reports. Target these specific cells, and maybe score more victories against liver cancer.

The research, published in the journal Cell Stem Cell, found that liver cancer patients with a high count of a surface protein called CD24 were less likely to survive. "CD24 is like a button, a switch on some cancer stem cells. Once they are switched on, they activate a protein in the cell called STAT3," Irene Ng, of the State Key Laboratory for Liver Research at the University of Hong Kong, told a news conference.

Apparently, STAT3's reason for existence is to cause harm by entering the nucleus of cells, form tumors and be drug-resistant. They know this because they tested the theory on mice, injecting on part of their livers with cancer cells laced with CD24 and another part without. The part with CD24 grew and spread to the lungs, but the other part did not. Then they checked the records of human liver cancer patients and confirmed that those with high CD24 concentrations at a 67% chance of recurrence compared with 21% with low CD24 counts.

So, the researchers speculate, take out STAT3's ability to wreak havoc and that should block liver cancer stem cells, the researchers said. The need appears to be urgent in China. Reuters points out that out of 500,000 new cases of liver cancer worldwide a year, more than half are in China.

- read the Reuters article
- and the abstract in Cell Stem Cell