title: The altered activity of membrane-bound protein kinase C in human liver cancer.
abstract: The activity of protein kinase C (PKC) in human liver cancer and adjacent normal liver tissue was determined. It was found that the activity of the membrane-bound PKC was significantly decreased in cancer tissue compared with that of the adjacent normal tissues (245.3 +/- 49.3 versus 396.9 +/- 82.4 pmol 32P/min per mg, P < 0.05); while the PKC activity in the cytosolic fraction was not significantly different (50.6 +/- 11.3 versus 40.0 +/- 6.6 pmol 32P/min per mg) concerning protein concentration. The reduced expression of membrane-bound PKC activity was observed at least in 8 of 9 patients. Moreover, the cancer tissue showed a significant decrease in total membranous PKC activity compared with the adjacent normal tissue of each patient (163.1 +/- 38.8 versus 433.8 +/- 92.4 pmol 32P/min per g tissue; P < 0.005) and no difference in total cytosolic PKC activity (285.9 +/- 58.8 versus 311.6 +/- 44.0 pmol 32P/min per g tissue). These results indicate that the progression of the human liver cancer might be associated with the decrease of membrane-bound PKC activity.
authors.affiliation: Department of Surgery, College of Medicine, National Taiwan University, Taipei, ROC.
authors.forename: K J
authors.initials: KJ
authors.lastname: Chang
authors.forename: J K
authors.initials: JK
authors.lastname: Lin
authors.forename: P H
authors.initials: PH
authors.lastname: Lee
authors.forename: Y S
authors.initials: YS
authors.lastname: Hsieh
authors.forename: C K
authors.initials: CK
authors.lastname: Cheng
authors.forename: J Y
authors.initials: JY
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000201:enzymology* / Q000473:pathology; D002462:Cell Membrane / Q000201:enzymology*; D003600:Cytosol / Q000201:enzymology; D005260:Female; D006801:Humans; D008099:Liver / Q000201:enzymology; D008113:Liver Neoplasms / Q000201:enzymology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011493:Protein Kinase C / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D011493:Protein Kinase C