Protein kinase C activity as a potential marker for colorectal neoplasia.
Protein kinase C (PKC) is a mediator of transmembrane signal transduction, important in cell growth and differentiation. Cell activation by extracellular signals is associated with a translocation of PKC from the cytosol to the membrane. We measured and compared PKC activity in cytosol and membrane fractions of normal and neoplastic colorectal tissue. Total and membrane-associated PKC activity in normal colorectal tissue was greater in patients (N = 16) with colorectal cancer compared to that from patients with a normal colonoscopy (N = 16), P < 0.01. A similar trend was noted in PKC activity of normal colorectal tissue from patients with adenomas compared to patients with a normal colonoscopy. PKC activity (total, membrane-associated, percent membrane) was not different in neoplastic colorectal tissue compared to that of adjacent normal tissue. However, there was a considerable range of PKC activity noted in all groups, which would limit the utility of PKC activity as a marker for colorectal neoplasia.
McGarrity
T J
TJ
Department of Medicine, University Hospital, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
Peiffer
L P
LP
D000236:Adenoma / Q000737:chemistry; D014408:Biomarkers, Tumor / Q000032:analysis*; D002277:Carcinoma / Q000737:chemistry; D002462:Cell Membrane / Q000737:chemistry; D003106:Colon / Q000737:chemistry; D015179:Colorectal Neoplasms / Q000737:chemistry* / Q000175:diagnosis; D003600:Cytosol / Q000737:chemistry; D006801:Humans; D011493:Protein Kinase C / Q000032:analysis*
D014408:Biomarkers, Tumor; D011493:Protein Kinase C