Protein in stem cells 'linked to cancer'

Scientists have found that a protein abundant in embryonic stem cells plays a major role in cancer, which they claim offers a possible new target for drug development.

A team at the Stem Cell Program at Children's Hospital Boston, led by Indian-origin scientist Srinivas Viswanathan, has discovered that LIN28 protein can transform cells to a cancerous state, and that it is abundant in a variety of advanced human cancers like liver cancer and ovarian cancer.

According to them, LIN28 and a related protein, LIN28B, may be involved in some 15 per cent of human cancers.

By blocking or suppressing LIN28, it might be possible to revive the let-7 family's natural tumour-suppressing action.

"Linking this protein to advanced cancer is a very exciting new result. It gives us a new target to attack, especially in the most resistant and hard-to-treat cases," team member George Daley said.

LIN28, which is abundant in embryonic stem cells and prevents them from differentiating into specific cell types, was originally discovered to influence embryonic development in worms some 25 years ago.

Development, stem cell generation and carcinogenesis are known to be closely related, but until last year's study connected LIN28 to let-7, it hadn't been clear how.

"LIN28 is a fascinating protein that acts in stem cells and cancers, and is teaching us that cancer is often a disease of stem cells," Daley said.

The findings are published in the latest edition of the 'Nature Genetics' journal.