Inhibition of human malignant glioma cell motility and invasion in vitro by hypericin, a potent protein kinase C inhibitor

Bisindolylmaleimide I (BIM-I) is a competitive pan protein kinase C inhibitor with anti-inflammatory and anti-metastatic properties, suggested to treat inflammatory diseases and various cancer entities. However, despite its therapeutic potential, BIM-I has two major drawbacks, i.e., it has a poor water solubility, and it binds the human ether-à-go-go-related gene (hERG) ion channels, potentially causing deadly arrhythmias. In this case, a targeted delivery of BIM-I is imperative to minimize peripheral side effects. To circumvent these drawbacks BIM-I was encapsulated into nanoparticles prepared from poly(lactic-co-glycolic acid) (PLGA) functionalized by the near-infrared dye DY-635. DY-635 served as an active targeting moiety since it selectively binds the OATP1B1 and OATP1B3 transporters that are highly expressed in liver and cancer cells. PLGA-DY-635 (BIM-I) nanoparticles were produced by nanoprecipitation and characterized using dynamic light scattering, analytical ultracentrifugation, and cryogenic transmission electron microscopy. Particle sizes were found to be in the range of 20 to 70 nm, while a difference in sizes between the drug-loaded and unloaded particles was observed by all analytical techniques. In vitro studies demonstrated that PLGA-DY-635 (BIM-I) NPs prevent the PKC activation efficiently, proving the efficacy of the inhibitor after its encapsulation, and suggesting that BIM-I is released from the PLGA-NPs. Ultimately, our results present a feasible formulation strategy that improved the cytotoxicity profile of BIM-I and showed a high cellular uptake in the liver as demonstrated in vivo by intravital microscopy investigations.

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Evidence that interleukin-1 and phorbol esters activate NF-kappa B by different pathways: role of protein kinase C.

Cell Regulation ◽

10.1091/mbc.2.4.329 ◽

1991 ◽

Vol 2 (4) ◽

pp. 329-335 ◽

Cited By ~ 46

Author(s):

K Bomsztyk ◽

J W Rooney ◽

T Iwasaki ◽

N A Rachie ◽

S K Dower ◽

...

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Cell Line ◽

Phorbol Esters ◽

Interleukin 1 ◽

Interleukin 2 ◽

Nf Kappa B ◽

Kinase C ◽

Protein Kinase C Inhibitor

Nuclear factor kappa B (NF-kappa B) is a ubiquitous transcription factor that affects expression of many genes, including immunoglobulin kappa (kappa), the interleukin-2 receptor alpha chain, and two genes in HIV-1. NF-kappa B can be activated by a number of stimuli, including pharmacological stimulation of protein kinase C by phorbol 12-myristate 13-acetate (PMA) and treatment in vitro with either protein kinase C or protein kinase A. This has lead to the proposal that these kinases are key enzymes in the physiological activation of NF-kappa B as well. We have used a murine B cell line, 70Z/3, and T cell line, EL-4 6.1 C10, to study the activation of NF-kappa B by two physiological activators, interleukin-1 alpha (IL-1) and lipopolysaccharide (LPS). There are four reasons to propose that these agents activate pathways that do not include protein kinase C as a major component in these cell lines. First, the protein kinase C inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7) strongly inhibited PMA-induced activation of NF-kappa B in 70Z/3 cells but had no effect on NF-kappa B activated by IL-1 or LPS. Second, depletion of protein kinase C by prolonged growth of 70Z/3 in PMA abrogated the capacity of the cells to activate NF-kappa B in response to further PMA treatment. However, these same cells activated NF-kappa B normally after either IL-1 or LPS treatment. Third, IL-1 effectively activated NF-kappa B in EL-4 6.1 C10 cells, but PMA did not. Fourth, interferon-gamma is a potent activator of protein kinase C in 70Z/3 cells, but is completely inactive in the mobilization of NF-kappa B. These results suggest that the physiological inducers IL-1 and LPS activate NF-kappa B by pathways independent of protein kinase C in both 70Z/3 and EL-4 6.1 C10 cells.

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Blocking of glioma proliferation in vitro and in vivo and potentiating the effects of BCNU and cisplatin: UCN-01, a selective protein kinase C inhibitor

Journal of Neurosurgery ◽

10.3171/jns.1996.84.6.1024 ◽

1996 ◽

Vol 84 (6) ◽

pp. 1024-1032 ◽

Cited By ~ 47

Author(s):

Ian F. Pollack ◽

Stephanie Kawecki ◽

John S. Lazo

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Cell Lines ◽

Glioma Cell ◽

Significant Activity ◽

Inhibition Of Proliferation ◽

Kinase C ◽

Glioma Cell Lines

✓ Seven-hydroxystaurosporine (UCN-01) is a derivative of the nonselective protein kinase inhibitor staurosporine that exhibits significant selectivity for protein kinase C (PKC) in comparison to a variety of other intracellular kinases and appears to be well tolerated in vivo at concentrations sufficient to achieve effective inhibition of PKC. Because recent studies have indicated that the proliferation of malignant gliomas may result from activation of PKC-mediated pathways and, conversely, may be inhibited by blocking PKC, the authors examined the efficacy of this agent as an inhibitor of proliferation in three established and three low-passage malignant glioma cell lines in vitro. A striking inhibition of proliferation was produced by UCN-01 in each of the cell lines, with a median effective concentration of 20 to 100 nM, which correlated with the median in vitro PKC inhibitory concentration of 20 to 60 nM for this agent in the U-87 and SG-388 glioma cell lines. Inhibition-recovery studies of clonogenic activity indicated that UCN-01 had both cytostatic and cytotoxic effects on the treated cells. Proliferation resumed after short-term (6- and 24-hour) exposures to this agent; in contrast, with longer exposures, recovery of proliferative activity was severely compromised. In addition, UCN-01 enhanced the inhibition of glioma cell proliferation achieved with conventional chemotherapeutic agents, exhibiting synergistic effects with cisplatin and additive effects with 1,3-bis(2-chloroethyl)-1-nitrosourea. In vivo studies in which UCN-01 was administered by continuous intraperitoneal infusion in subcutaneous and intracranial intraparenchymal nude rat models demonstrated significant activity against U-87 glioma xenografts at dose levels that were well tolerated. It is concluded that UCN-01 is an effective agent for the inhibition of glioma proliferation in vitro and in vivo and has potential for clinical applicability in the treatment of human gliomas.

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Protein kinase C inhibitor as a potent inhibitor of accelerated repopulation during radiotherapy:I. growth inhibitory, cytotoxic, and indirect radiosensitizing effects of a staurosporine derivative (UCN-01) in vitro

Radiation Oncology Investigations ◽

10.1002/roi.2970030205 ◽

1995 ◽

Vol 3 (2) ◽

pp. 64-71 ◽

Cited By ~ 1

Author(s):

Muneyasu Urano ◽

Regina Reynolds ◽

James Begley

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Potent Inhibitor ◽

Kinase C ◽

Growth Inhibitory ◽

Accelerated Repopulation ◽

Protein Kinase C Inhibitor

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The β-Specific Protein Kinase C Inhibitor Ruboxistaurin (LY333531) Suppresses Glucose-Induced Adhesion of Human Monocytes to Endothelial Cells in Vitro

Journal of Diabetes Science and Technology ◽

10.1177/193229680700100620 ◽

2007 ◽

Vol 1 (6) ◽

pp. 929-934 ◽

Cited By ~ 3

Keyword(s):

Endothelial Cells ◽

Protein Kinase C ◽

Protein Kinase ◽

Specific Protein ◽

Human Monocytes ◽

Kinase C ◽

Protein Kinase C Inhibitor ◽

Specific Protein Kinase

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Contrasting effects of the protein kinase C inhibitor, staurosporine, on cytokine and phorbol ester stimulation of fructose 2,6-bisphosphate and prostaglandin E production by fibroblasts in vitro. Comparative studies using interleukin-1α, tumour necrosis factor α, transforming growth factor β, interferon-γ and 12-O-tetradecanoylphorbol 13-acetate

Biochemical Journal ◽

10.1042/bj2690573 ◽

1990 ◽

Vol 269 (3) ◽

pp. 573-577 ◽

Cited By ~ 25

Author(s):

D J Taylor ◽

J M Evanson ◽

D E Woolley

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Transforming Growth Factor ◽

Dermal Fibroblasts ◽

Tnf Alpha ◽

Prostaglandin E ◽

Kinase C ◽

Protein Kinase C Inhibitor ◽

Necrosis Factor

It is known that both interleukin-1 alpha (IL-1 alpha) and 12-O-tetradecanoylphorbol 13-acetate (TPA) promote increases in intracellular levels of the glycolytic regulatory metabolite fructose 2,6-bisphosphate [Fru(2,6)P2] and in the production of prostaglandin E (PGE) by subcultured rheumatoid synovial cells (RSC) and human dermal fibroblasts in vitro. We report here that the protein kinase C inhibitor staurosporine enhanced the IL-1 alpha-induced increase in [Fru(2,6)P2] and PGE production by RSC, whereas in similar concentrations (3-30 nM) this inhibitor decreased the TPA-induced stimulation of these parameters. Staurosporine produced a similar enhancement of the response to IL-1 alpha by normal human dermal fibroblasts. The increased PGE production provoked by tumour necrosis factor alpha (TNF alpha) in RSC was also augmented by staurosporine, but, in contrast, the increases in cellular [Fru(2,6)P2] induced by transforming growth factor beta (TGF beta) and interferon-gamma (IFN-gamma) were diminished. Thus the protein kinase C inhibitor staurosporine discriminates not only between the effects produced by IL-1 alpha and TPA, but also between those of IL-1 alpha and two other cytokines (but not between IL-1 alpha and TNF alpha). These findings suggest that IL-1 alpha and probably TNF alpha act via an intracellular mechanism different from that mediating the action of TPA, TGF-beta and IFN-gamma, and provide evidence that staurosporine is capable of amplifying the IL-1 signal.

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Inhibition of Neutrophil Apoptosis by Verotoxin 2 Derived from Escherichia coli O157:H7

Infection and Immunity ◽

10.1128/iai.67.11.6203-6205.1999 ◽

1999 ◽

Vol 67 (11) ◽

pp. 6203-6205 ◽

Cited By ~ 36

Author(s):

Jiajia Liu ◽

Tohru Akahoshi ◽

Takeshi Sasahana ◽

Hidero Kitasato ◽

Rie Namai ◽

...

Keyword(s):

Escherichia Coli ◽

Protein Kinase C ◽

Protein Kinase ◽

Neutrophil Apoptosis ◽

Escherichia Coli O157 ◽

Significant Delay ◽

Kinase C ◽

Protein Kinase C Inhibitor

ABSTRACT In order to evaluate the pathological role of verotoxin 2 (VT2), we investigated the effects of VT2 on neutrophil apoptosis in vitro. The results showed that VT2 caused a significant delay in spontaneous neutrophil apoptosis and that the effect was abrogated by a protein kinase C inhibitor. These data indicate that longer survival of neutrophils may aggravate neutrophil-mediated tissue damage in VT2-associated diseases.

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