Expression of human alpha-actinin in human hepatocellular carcinoma.
Little is known regarding gene expression during hepatocyte transformation. We have isolated an alpha-actinin complementary DNA from a human hepatocellular carcinoma library. This partial 2.4-kilobase complementary DNA has high homology with human placental and chicken nonmuscle alpha-actinins; our isolate contains the entire 3' noncoding region and it is within these sequences where the major differences between the vertebrate alpha-actinin complementary DNAs arise. Northern analysis revealed a 3.5-kilobase transcript in nonmuscle and a smaller 3.0-kilobase species in muscle tissue. Levels of alpha-actinin expression were low in normal liver and we investigated its expression during both hepatocyte proliferation and transformation. We found no increase during rat hepatocyte regeneration up to 24 h following two-thirds hepatectomy. However, high levels of alpha-actinin transcripts were observed in human hepatocellular carcinoma compared to noninvolved adjacent liver. We conclude that the alpha-actinin gene is highly expressed when hepatocytes have assumed the malignant phenotype.
Nishiyama
M
M
Molecular Hepatology Laboratory, Massachusetts General Hospital Cancer Center, Charlestown 02129.
Ozturk
M
M
Frohlich
M
M
Mafune
K
K
Steele
G
G
Wands
J R
JR
D000185:Actinin / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000032:analysis*; D002645:Chickens; D004247:DNA / Q000032:analysis*; D015972:Gene Expression Regulation, Neoplastic; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000032:analysis*; D008115:Liver Regeneration; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D014407:Tumor Cells, Cultured
D000185:Actinin; D004247:DNA