Deleted in liver cancer 1 expression and localization in hepatocellular carcinoma tissue sections

The deleted in liver cancer (DLC) protein family is composed of proteins that are hypothesized to function predominantly by regulating the activity of the small GTPases. The aim of the present study was to determine the expression and exact localization of DLC1 in hepatocellular carcinoma (HCC) tissue sections. In two types of HCC tissues, typical and fibrolamellar, immunohistochemical and immunofluorescent analysis were performed to assess DLC1 immunoreactivity. Additionally, the DLC1 gene status was determined by the fluorescence in situ hybridization. According to the observations, DLC1 is often lost in cancer cells; however, it can remain within the stromal component of tumor sections. The DLC1 immunoreactivity was particularly noticeable within the capsules surrounding the tumor masses. It was found that the DLC1 gene was deleted in 52% of HCC cases. In addition, the hemizygous deletion was observed to be independent of the HCC subtype. The results indicate that although the loss of DLC1 is a common step during hepatocarcinogenesis, this protein may be present in the tumor microenvironment.