August 27, 2009

Cell filaments linked to brain tumors

U.S. scientists say they've determined the most common childhood brain tumor is linked to tiny cell filaments once dismissed as vestiges of evolution.

The University of California-San Francisco scientists discovered the crucial role of the filaments, called primary cilia, by examining malignant human and mouse brain tumors classified as medulloblastomas.

These findings are very exciting, said Professor Arturo Alvarez-Buylla, senior author of the study. He noted cilia have recently been shown to be essential for the cell-signaling that drives both human development, including the differentiation of stem cells into neurons, and some diseases, including polycystic kidney disease.

Analyses of the human medulloblastomas revealed primary cilia were present in some human tumors, but absent in others. That, the researchers said, suggests some tumors in humans can only grow without the cilia, while others can only grow in their presence.

The scientists said their findings are the first direct evidence cilia are linked with the development of cancer and that information could aid the diagnosis of cancer subtypes, as well as identifying potential targets for therapy.

The study appears in the online journal Nature Medicine.