You need a combination of different factors," explains Marko Horb
, lead author of the study and a postdoctoral research officer at the Centre for Regenerative Medicine at the University of Bath
in England. Horb
colleagues basically engineered a souped-up version of a gene called Pdx1, which is necessary for fashioning the pancreas out of undifferentiated embryonic or stem cells.
The idea was to introduce the super-Pdx1 into liver cells to see if they would produce pancreatic cells.
The theory worked in two different tests, one using human cells and the other using tadpoles of the African clawed frog.
When the Pdx1 gene was added to human liver cells in the laboratory, the cells acquired characteristics of pancreas cells and some even produced insulin.
"All we've done at this stage is to show, that with the gene we put in, a certain proportion of cells that received it became part of the pancreas," Horb
says."They produced insulin and amylase but we haven't shown they work in response.The important thing is to show they respond to glucose."
...SOURCES: Marko Horb, Ph.D., postdoctoral research officer, Centre for Regenerative Medicine, Department of Biology and Biochemistry, University of Bath, England; Robert Fisher, M.D., professor of surgery and director of liver transplantation and transplantation research, Virginia Commonwealth University Medical Center, Richmond; Lijun Yang, M.D., assistant professor of pathology, University of Florida College of Medicine, Gainesville; Jan. 21, 2003 Current Biology