Intracellular delivery of protein kinase C‐α or ε isoform‐specific antibodies promotes acquisition of a morphologically differentiated phenotype in neuroblastoma cells

Leli, Ubaldo; Parker, Peter J.; Shea, Thomas B.

doi:10.1016/0014-5793(92)80334-d

Cited by 46 publications

(21 citation statements)

References 29 publications

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“…The 6 isoform is found in intact vessels and cultured cells but is lost from cells during transformation. The expression of PKC-E appears to increase with the state of dedifferentiation of the cells, in accordance with the observation [25] that down-regulation of PKC-& promotes neuroblastoma cell differentiation.…”

Section: Resultssupporting

confidence: 88%

Expression of protein kinase C isoforms in smooth muscle cells in various states of differentiation

1994

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We analysed the expression of protein kinase C (PKC) isoforms in smooth muscle cells (SMC) in various states of differentiation, using Western blots and thermocycle amplification of mRNA. SMC isolated from intact tissues express three isoforms of PKC, namely a, 6, and c. Following cell culture, SMC additionally express mRNA for PKC-E, but significant amounts of the corresponding protein were not detected. Transformed SMC, such as the cell line DDT, MF-2, express both mRNA and protein for PKC-E, lack the 6 isoenyzme, whilst maintaining the expression of the a and < isoforms. Thus PKCd and E isoenzyme expression appears to vary with the state of differentiation of these cells, with PKC-E expression increasing as the cells become proliferative.

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Section: Resultssupporting

confidence: 88%

Expression of protein kinase C isoforms in smooth muscle cells in various states of differentiation

1994

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“…Western blot analysis (Figure 1) confirmed the specific down-regulation of the target isoform and the maintenance of the expression levels for other isoforms including PKCe and PKCd, in accordance with the pattern shown in previous experiments using these cell lines. 15,16 The cellular model was also chosen because SH-SY5Y cells express muscarinic receptors of the m1 and m3 subtype, 17,18 and this characteristic makes the cell line suitable for the characterization of PKC-dependent and receptormediated APP metabolism without further manipulation. These cells secrete sAPPa, which can be detected by either the 22C11 or 6E10 monoclonal antibodies, with the same SDS gel band pattern.…”

Section: Resultsmentioning

confidence: 99%

Role of protein kinase Cα in the regulated secretion of the amyloid precursor protein

et al. 2003

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Protein kinase C (PKC) has a key role in the signal transduction machinery involved in the regulation of amyloid precursor protein (APP) metabolism. Direct and indirect receptor-mediated activation of PKC has been shown to increase the release of soluble APP (sAPPa) and reduce the secretion of b-amyloid peptides. Experimental evidence suggests that specific isoforms of PKC, such as PKCa and PKCe, are involved in the regulation of APP metabolism. In this study, we characterized the role of PKCa in the regulated secretion of APP using wild-type SH-SY5Y neuroblastoma cells and cells transfected with a plasmid expressing PKCa antisense cDNA. Cells expressing antisense PKCa secrete less sAPPa in response to phorbol esters. In contrast, carbachol increases the secretion of sAPPa to similar levels in wild-type cells and in cells transfected with antisense PKCa by acting on APP metabolism through an indirect pathway partially involving the activation of PKC. These results suggest that the direct PKC-dependent activation of the APP secretory pathway is compromised by reduced PKCa expression and a specific role of this isoform in these mechanisms. On the other hand, indirect pathways that are also partially dependent on the mitogen-activated protein kinase signal transduction mechanism remain unaffected and constitute a redundant, compensatory mechanism within the APP secretory pathway.

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“…As mentioned above, with the neuroblastoma cells Neuro-2a and SHSY-5Y the involvement of PKC a and E in differentiation has been shown (Leli et al, 1992;Minana et al, 1990;Wada et al, 1989). Recently Watanabe et al (1992) showed that overexpression of PKC 6 in Chinese hamster ovary cells prevents cell division after PMA stimulation and causes the appearance of dikaryotic cells.…”

Section: Pkc Isozymes In Subcellular Fractionsmentioning

confidence: 93%

Differential nuclear localization of protein kinase C isoforms in neuroblastoma × glioma hybrid cells

Beckmann

Lindschau

Haller

et al. 1994

European Journal of Biochemistry

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The protein kinase C (PKC) a, p and E isoforms have distinct nuclear localizations in neuroblastoma X glioma hybrid cells NG 108-15. We found by immunoblotting that PKC a, pII, 6 and E are the predominant isoforms in these cells. In contrast to other neuronal cell lines, none of these isoforms is down-regulated during differentiation.Confocal immunofluorescence microscopy revealed that in undifferentiated cells PKC a is located in the cytoplasm and in the nucleus excluding nucleoli. In differentiated cells PKC a was almost exclusively located in the cytoplasm. Stimulation of the cells with phorbol ester resulted in translocation to the plasma membrane. PKC PII was not detectable in the nuclei. PKC 6 was found in the nucleoli and in the cytoplasm, in differentiated cells particularly in the neurites. Phorbol ester failed to induce a translocation to other compartments. PKC E was localized with the nuclear-pore complexes at the nuclear envelope. In differentiated cells after stimulation with phorbol ester, partial translocation to the plasma membrane was observed.Protein kinase C (PKC) plays a key role in many signaltransduction pathways and cellular processes (for review see Nishizuka, 1986;Lester and Epand, 1992). Ten isoforms of PKC are found in mammals, showing characteristic patterns of expression in different tissues. Four isoforms (called PKC A forms), PKC a, PI, pII and 7, are phospholipid and Ca2+ dependent in contrast to the B forms such as PKC 6, E and cwhich are Ca2+ independent (Stabel and Parker, 1991). After an increase of intracellular Ca2+ levels the PKC A isoforms were shown to be translocated to the plasma membrane. Binding to the plasma membrane via phospholipids enables activation by the second messenger diacylglycerol (Huang, 1989).There is evidence that members of the PKC family respond differently to various combinations of Caz+ and phospholipid-degradation products. This could be one of the reasons for distinct intracellular distribution and activation patterns (Asaoka et al., 1992).Several investigators have observed translocation to other cell compartments including the cell nucleus in addition to the plasma membrane. With fibroblast cells, Leach et al. (1992) observed translocation of PKC a to the cell nucleus after treatment with phorbol ester or a-thrombin. In promyelocytic leukemia (HL 60) cells, stimulation with the PKC activator bryostatin leads to a selective translocation of PKC P but not PKC a to the nucleus (Hocevar and Fields, 1991).In liver, PKC BI1 was found in the nuclei (Rogue et al., 1990 found PKC a and PKC y as the 'membrane inserted' and constitutively active form.The current view is that each cell type expresses a specific set of PKC isoforms, which are localized and regulated in a cell-specific manner. It is not yet understood how this differential expression, localization, and regulation is achieved. The specific localizations of PKC isoforms imply specific functions for each cell type. Due to the known effects of PKC activation on nuclear events (induction of proli...

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Intracellular delivery of protein kinase C‐α or ε isoform‐specific antibodies promotes acquisition of a morphologically differentiated phenotype in neuroblastoma cells

Cited by 46 publications

References 29 publications

Expression of protein kinase C isoforms in smooth muscle cells in various states of differentiation

Expression of protein kinase C isoforms in smooth muscle cells in various states of differentiation

Role of protein kinase Cα in the regulated secretion of the amyloid precursor protein

Differential nuclear localization of protein kinase C isoforms in neuroblastoma × glioma hybrid cells

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