DLC-1 is deleted in primary hepatocellular carcinoma and exerts inhibitory effects on the proliferation of hepatoma cell lines with deleted DLC-1.
We investigated the expression and deletion of DLC-1 (frequently deleted in liver cancer gene), first reported in 1998 and having a high homology with rat p122RhoGAP in hepatocellular carcinoma (HCC). Six (20%) of 30 human HCC samples and 2 (40%) of 5 HCC cell lines were found to have no detectable DLC-1 expression by reverse transcription-PCR. Homozygous DLC-1 deletion was detected by Southern blotting in two of six HCC samples and in both HCC cell lines with no DLC-1 expression. Transfection of DLC-1 into 5 HCC cell lines (two with DLC-1 deletion and three with intact DLC-1) showed significant growth inhibition in these two HCC cell lines with deleted DLC-1 with both 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assays but not in three other HCC cell lines with intact DLC-1. Our findings suggest that DLC-1 may play an important role in hepatocarcinogenesis.
Ng
I O
IO
Department of Pathology, University of Hong Kong, Queen Mary Hospital, China. iolng@hkusua.hku.hk
Liang
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ZD
Cao
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Lee
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TK
D015139:Blotting, Southern; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology; D002455:Cell Division / Q000235:genetics; D020690:GTPase-Activating Proteins; D017353:Gene Deletion; D015870:Gene Expression; D006720:Homozygote; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
C112352:DLC1 protein, human; D020690:GTPase-Activating Proteins; D011506:Proteins; D025521:Tumor Suppressor Proteins