Directed antisense therapy confirms the role of protein kinase C-alpha in the tumorigenicity of pancreatic cancer.
BACKGROUND
The level of expression of the alpha isoform of protein kinase C (PKC-alpha) has been shown to correlate inversely with the pathologic differentiation of human pancreatic cancers.


METHODS
We stably transfected a moderately differentiated pancreatic cell line (HPAC) to overexpress PKC-alpha and examined the survival rates compared with parent HPAC according to an orthotopic model. Next we used a PKC-alpha antisense oligonucleotide specifically to down-regulate this isoform in vitro and examine the effect of treatment in vivo again according to the orthotopic model.


RESULTS
Animals implanted with the overexpressing cell line had a mortality rate almost twice that of those implanted with the parent cell line (P < .01). Treatment with antisense oligonucleotide in increasing concentrations down-regulated PKC-alpha mRNA by Northern blot analysis and reverse transcriptase-polymerase chain reaction. Animals treated with antisense oligonucleotide after orthotopic implantation of pancreatic cancer cells survived statistically longer than those treated with vehicle alone (P = .005). Treatment with a scrambled oligonucleotide also conferred a survival benefit compared with vehicle alone (P < .01).


CONCLUSIONS
Tumorigenicity of pancreatic cancer is related directly to PKC-alpha expression in vivo as demonstrated by decreased survival when overexpressed. PKC-alpha expression can be down-regulated directly (antisense) and indirectly (scrambled) in vitro, which subsequently confers a dramatic survival benefit in vivo.
Denham
D W
DW
Department of Surgery, University of South Florida, Tampa 33601, USA.
Franz
M G
MG
Denham
W
W
Zervos
E E
EE
Gower
W R
WR
Rosemurgy
A S
AS
Norman
J
J
D000230:Adenocarcinoma / Q000378:metabolism / Q000401:mortality / Q000628:therapy*; D000818:Animals; D015197:Carcinogenicity Tests; D016373:DNA, Antisense / Q000494:pharmacology; D018076:DNA, Complementary / Q000494:pharmacology; D004195:Disease Models, Animal; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy; D006801:Humans; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000401:mortality / Q000628:therapy*; D011493:Protein Kinase C / Q000235:genetics* / Q000378:metabolism; D051571:Protein Kinase C-alpha; D012333:RNA, Messenger / Q000235:genetics; D016019:Survival Analysis; D014407:Tumor Cells, Cultured / Q000201:enzymology
D016373:DNA, Antisense; D018076:DNA, Complementary; D007527:Isoenzymes; D012333:RNA, Messenger; C496628:PRKCA protein, human; C496630:Prkca protein, mouse; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha