Plain Language Summary: "Recurrent Rearrangements in PRKACA and PRKACB in Intraductal Oncocytic Papillary Neoplasms of the Pancreas and Bile Duct"
While the focus of this paper is on pancreatic tumors, the work is very important for understanding fibrolamellar hepatocellular carcinoma (FLC) of the liver. FLC in the liver is almost always associated with the first part of the protein DNAJB1 being spliced onto the bulk of a protein called PRKACA (for those who want technical details, it is the active part of something called protein kinase A).
What is it that is special about the fusion of DNAJB1 to PRKACA? Is there something unique about the DNAJB1 or would anything added onto the front end of PRKACA have a similar effect? This group reports that they have found a short segment of another protein, ATP1B1, fused to the front end of PRKACA that is found in tumors of the pancreas and liver. The cells look very similar to those of fibrolamellar. Thus, the results strongly suggest that it is not something specific about DNAJB1, but other things added onto the front end of PRKACA can contribute to forming tumors. It remains to be show if there is anything else in these cells that are contributing to the tumors or expression of this new fusion gene is sufficient to produce the tumor.