Antisense targeting protein kinase C alpha and beta1 inhibits gastric carcinogenesis.
Protein kinase C (PKC) family, which functions through serine/threonine kinase activity, is involved in signal transduction pathways necessary for cell proliferation, differentiation, and apoptosis. Its critical role in neoplastic transformation and tumor invasion renders PKC a potential target for anticancer therapy. In this study, we investigated the effect of targeting individual PKCs on gastric carcinogenesis. We established gastric cancer cell lines stably expressing antisense PKCalpha, PKCbeta1, and PKCbeta2 cDNA. These stable transfectants were characterized by cell morphology, cell growth, apoptosis, and tumorigenicity in vitro and in vivo. PKCalpha-AS and PKCbeta1-AS transfectants showed a different morphology with flattened, long processes and decreased nuclear:cytoplasmic ratio compared with the control cells. Cell growth was markedly inhibited in PKCalpha-AS and PKCbeta1-AS transfectants. PKCalpha-AS and PKCbeta1-AS cells were more responsive to mitomycin C- or 5-fluorouracil-induced apoptosis. However, antisense targeting of PKCbeta2 did not have any significant effect on cell morphology, cell growth, or apoptosis. Furthermore, antisense inhibition of PKCalpha and PKCbeta1 markedly suppressed colony-forming efficiency in soft agar and in nude mice xenografts. Inhibition of PKCalpha or PKCbeta1 significantly suppressed transcriptional and DNA binding activity of activator protein in gastric cancer cells, suggesting that PKCalpha or PKCbeta1 exerts their effects on cell growth through regulation of activator protein activity. These data provide evidence that targeting PKCalpha and PKCbeta1 by antisense method is a promising therapy for gastric cancer.
Department of Gastroenterology, Rui-jin Hospital, Shanghai, P.R. China.
Xiao-Hua
XH
Jiang
Shui-Ping
SP
Tu
Jian-Tao
JT
Cui
Marie C M
MC
Lin
Harry H X
HH
Xia
Wai Man
WM
Wong
Annie On-On
AO
Chan
Man Fung
MF
Yuen
Shi-Hu
SH
Jiang
Shiu-Kum
SK
Lam
Hsiang-Fu
HF
Kung
Jae Won
JW
Soh
I Bernard
IB
Weinstein
Benjamin Chun-Yu
BC
Wong
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D002448:Cell Adhesion / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D045744:Cell Line, Tumor; D016373:DNA, Antisense / Q000008:administration & dosage* / Q000235:genetics; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000235:genetics; D064546:Protein Kinase C beta; D051571:Protein Kinase C-alpha; D013274:Stomach Neoplasms / Q000201:enzymology / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D018808:Transcription Factor AP-1 / Q000037:antagonists & inhibitors; D014162:Transfection; D023041:Xenograft Model Antitumor Assays
D016373:DNA, Antisense; D018808:Transcription Factor AP-1; C496628:PRKCA protein, human; C496630:Prkca protein, mouse; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D051571:Protein Kinase C-alpha