Y chromosome loss and other genomic alterations in hepatocellular carcinoma cell lines analyzed by CGH and CGH array.

Hepatocellular carcinoma (HCC) is one of the most frequently occurring malignant tumors worldwide. The incidence of HCC is much higher in males than in females. In order to clarify the molecular basis of the male predominance in HCC, we have characterized the detailed genomic alterations in 5 hepatitis B virus integrated Korean HCC cell lines using G-banding, comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), PCR, and CGH array. The commonest alterations were observed in chromosome 7 and Y, as well as chromosomal regions 1q, 8q, 4q, and 16q. The most frequent aberration of genomic material was gain of 1q and loss of chromosome Y. Significant loss of DNA copy number of the cancer related genes that are located on chromosome Y was detected by CGH array. By investigating the karyotypes of the previously reported 21 male HCC cell lines, we found 18 HCC cell lines with Y chromosome loss, indicating that this loss is a significant feature of HCC cell lines. We propose that Y chromosome loss in HCC cell lines may be responsible for the preponderance of males in HCC and its significance may lead to further studies for better understanding of carcinogenesis in HCC.