Inhibition of expression of PKC-alpha by antisense mRNA is associated with diminished cell growth and inhibition of amylase secretion by AR4-2J cells.
AR4-2J pancreatoma cells were stably transfected with an expression vector containing the cDNA for PKC-alpha in the antisense orientation. Transfectants designated antisense-alpha AA1, AA2, and AA3 exhibited marked reductions in PKC-alpha expression and decrements in cell growth. The magnitude of the decrement in cell growth paralleled the reduction in PKC-alpha expression, i.e., AA3 > AA1 > AA2. The ability of dexamethasone to induce cell differentiation as assessed by a rise in cellular amylase levels was not markedly affected by the reduction in PKC-alpha expression. Unstimulated amylase release was attenuated in AA1 cells and almost completely blocked in AA2 transfectants. The AA2 transfectant cell line failed to elicit a secretory response to caerulein, and the AA1 transfectant exhibited a lack of the secondary phase of stimulated amylase secretion. These findings demonstrate that PKC-alpha is involved in the mechanisms regulating growth and secretion in AR4-2J cells, but is not necessary for the induction of amylase stores following differentiation.
Zhang
X
X
Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 14214, USA.
Wen
J
J
Aletta
J M
JM
Rubin
R P
RP
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D002108:Ceruletide / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D010179:Pancreas / Q000187:drug effects / Q000254:growth & development*; D010190:Pancreatic Neoplasms; D011493:Protein Kinase C / Q000096:biosynthesis* / Q000235:genetics; D051571:Protein Kinase C-alpha; D016372:RNA, Antisense; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D014162:Transfection; D014407:Tumor Cells, Cultured
D007527:Isoenzymes; D016372:RNA, Antisense; D012333:RNA, Messenger; D003907:Dexamethasone; D002108:Ceruletide; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D000681:Amylases