RNAi-mediated knockdown of protein kinase C-alpha inhibits cell migration in MM-RU human metastatic melanoma cell line.
Protein kinase C (PKC) is a multigene family of serine/threonine protein kinases involved in cell signaling pathways of proliferation and motility. PKC interacts with Rho GTPases in the regulation of the actin cytoskeleton. The PKC-alpha isozyme binds the Rho GTPase cdc42, and both are coordinated with the Rac-phosphatidylinositol-3 kinase (PI3K) signaling pathway in melanoma cell invasion and migration on extracellular matrix proteins. To further define the role of PKC-alpha in melanoma cell migration, we tested the effect of PDBu and Ca dependent activation of PKC-alpha as well as treatment with the PKC-alpha inhibitors calphostin C and Go6976. Furthermore, we transfected siRNA targeted against PKC-alpha into human melanoma cells and performed time-lapse analysis of cell migration followed by western immunoblotting. We found that significant enhancement of cell migration at 0.5 h after PDBu treatment directly correlated with Ca dependent activation of PKC-alpha and was inhibited by the PKC-alpha inhibitor calphostin C. PKC-alpha siRNA transfection nearly abrogated PKC-alpha expression and significantly reduced melanoma cell migration compared with siRNA controls. These findings provide further evidence that PKC-alpha plays an important role in melanoma cell migration and may have implications in therapies designed to disrupt melanoma cell motility by alteration of PKC-alpha signaling.
Byers
Hugh Randolph
HR
Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts 02118, USA. hrbyers@acs.bu.edu
Boissel
Sandrine J S
SJ
Tu
Chi
C
Park
Hee-Young
HY
D017209:Apoptosis; D002227:Carbazoles / Q000494:pharmacology; D045744:Cell Line, Tumor; D002465:Cell Movement; D005109:Extracellular Matrix / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008545:Melanoma / Q000378:metabolism / Q000473:pathology*; D009281:Naphthalenes / Q000494:pharmacology; D009362:Neoplasm Metastasis; D020033:Protein Isoforms; D051571:Protein Kinase C-alpha / Q000235:genetics* / Q000502:physiology; D034622:RNA Interference; D013997:Time Factors; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism
D002227:Carbazoles; D009281:Naphthalenes; D020033:Protein Isoforms; C081021:Go 6976; D051571:Protein Kinase C-alpha; D020764:cdc42 GTP-Binding Protein; C058819:calphostin C