St. Jude research team identifies a gene crucial for normal liver development

St. Jude Children's Research Hospital (ALSAC)
Tuesday, 27 June 2000

Loss of the Prox 1 gene leads to the arrest in hepatocyte migration and to the formation of a smaller liver.

(Memphis, TN, June 27, 2000) Scientists from the Department of Genetics at St. Jude Children's Research Hospital found that the Prox1 gene is required for an important process of liver development called hepatocyte migration. This finding, which is published in the July issue of the journal Nature Genetics, will help shed light on how Prox 1 specifically regulates organ formation during embryonic development.

During the early stages of liver formation, hepatocytes (one of the main cellular components of the liver) develop from the innermost germ layer of the embryonic gut. Then they will begin to move in a cord-like fashion into the surrounding connective tissue where the liver begins to form.

According to Guillermo Oliver, Ph.D., lead investigator of the study, the absence of the Prox1 gene during early embryonic development leads to the formation of a smaller liver, with a reduced number of clustered hepatocytes.

"Although some of the genes required during early stages of liver development have already been identified, little has been known about the molecular mechanisms controlling hepatocyte migration into this organ until now," Oliver said. "While we still are not sure as to why the Prox 1 alteration occurs, the results of the study show that the migration of the hepatocytes is arrested in the mutant liver, thus they cannot colonize this organ and you end up with a liver mostly devoid of hepatocytes."

Results of the study provide novel advances in understanding the genetic control of liver development. The results prove that cellular emergence from the liver's embryonic gut is a genetically distinguishable process from other aspects of early organ development.

"Our next goal is to understand how Prox 1 specifically regulates different processes during early embryonic development as a way to better understand some of the mechanisms behind normal organ formation," Oliver said.

St. Jude, founded by the late entertainer Danny Thomas, is an internationally recognized biomedical research center dedicated to finding cures for catastrophic diseases of childhood. The hospital's work is supported through funds raised by ALSACâ (American Lebanese Syrian Associated Charitiesâ .) All St. Jude patients are treated regardless of their ability to pay. ALSAC covers all costs of treatment beyond those reimbursed by third party insurers, and total costs for families who have no insurance.

For more information, or to contact St. Jude Children's Research Hospital (ALSAC), see their website at: www.stjude.org