Frequent aneuploidy among normal human hepatocytes.

Murine hepatocytes become polyploid and then undergo ploidy reversal and become aneuploid in a dynamic process called the ploidy conveyor. Although polyploidization occurs in some types of human cells, the degree of aneuploidy in human hepatocytes is not known. We isolated hepatocytes derived from healthy human liver samples and determined chromosome number and identity using traditional karyotyping and fluorescence in situ hybridization. Similar to murine hepatocytes, human hepatocytes are highly aneuploid. Moreover, imaging studies revealed multipolar spindles and chromosome segregation defects in dividing human hepatocytes. Aneuploidy therefore does not necessarily predispose liver cells to transformation but might promote genetic diversity among hepatocytes.