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.
Jiang
Xiao-Hua
XH
Department of Gastroenterology, Rui-jin Hospital, Shanghai, P.R. China.
Tu
Shui-Ping
SP
Cui
Jian-Tao
JT
Lin
Marie C M
MC
Xia
Harry H X
HH
Wong
Wai Man
WM
Chan
Annie On-On
AO
Yuen
Man Fung
MF
Jiang
Shi-Hu
SH
Lam
Shiu-Kum
SK
Kung
Hsiang-Fu
HF
Soh
Jae Won
JW
Weinstein
I Bernard
IB
Wong
Benjamin Chun-Yu
BC
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