scholarly journals The protein kinase C-η isoform induces proliferation in glioblastoma cell lines through an ERK/Elk-1 pathway

Oncogene ◽  
2006 ◽  
Vol 26 (20) ◽  
pp. 2885-2893 ◽  
Author(s):  
R M Uht ◽  
S Amos ◽  
P M Martin ◽  
A E Riggan ◽  
I M Hussaini
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Lines ◽  
Glioblastoma Cell ◽  
Kinase C ◽  
Glioblastoma Cell Lines

The identification of four protein kinase C isoforms in human glioblastoma cell lines: PKC alpha, gamma, epsilon, and zeta

1994 ◽  
Vol 81 (5) ◽  
pp. 734-740 ◽  
Author(s):  
Haiguang Xiao ◽  
David A. Goldthwait ◽  
Timothy Mapstone
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Lines ◽  
Glioblastoma Cell ◽  
Kinase C ◽  
Normal Human ◽  
Pkc Ζ ◽  
Glial Cell Cultures ◽  
Glioblastoma Cell Lines

✓ Levels of protein kinase C (PKC) isoforms in eight human glioblastoma cell lines and two normal human glial cell cultures were determined. Earlier studies identified PKC-α and PKC-γ in these cell lines but PKC-β was not present. In this study, PKC-ϵ and PKC-ζ are demonstrated immunologically in these cell lines and also in two normal human glial cell cultures. Protein kinase C-δ was not present. When levels of the four isoforms in the tumor cells were compared to levels in the normal cells, no increase was observed in PKC-α or PKC-γ, but PKC-ϵ was elevated three to 30 times in six of the eight tumors, and PKC-ζ was elevated approximately two times in all of the tumors. Incubation of cell line A172 with phorbol ester for 6 hours resulted in a 48-fold maximum increase in the nuclear PKC-ϵ and a sevenfold increase in the plasma membrane fraction with no change in the cytoplasmic fraction. A similar incubation for 4 hours produced a 0.5- to onefold increase of PKC-ζ in cytoplasmic, nuclear, and plasma membrane fractions. Other researchers have shown that overexpression of PKC-ϵ in fibroblasts results in tumorigenesis, and that blocking PKC-ζ function inhibits deoxyribonucleic acid synthesis. These data suggest that alteration in the expression of PKC-ϵ and PKC-ζ could be a factor in the conversion of normal glial cells to glioblastomas.

scholarly journals Nanog expression is negatively regulated by protein kinase C activities in human cancer cell lines

2013 ◽  
Vol 34 (7) ◽  
pp. 1497-1509 ◽  
Author(s):  
Wing-Keung Chu ◽  
Pei-Min Dai ◽  
Hsin-Lun Li ◽  
Chia-Chu Pao ◽  
Jan-Kan Chen
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Lines ◽  
Cancer Cell ◽  
Human Cancer ◽  
Cancer Cell Lines ◽  
Human Cancer Cell ◽  
Human Cancer Cell Lines ◽  
Nanog Expression ◽  
Kinase C

scholarly journals Differential responsiveness of intestinal epithelial cells to 1,25-dihydroxyvitamin D3--role of protein kinase C

2001 ◽  
Vol 169 (1) ◽  
pp. 145-151 ◽  
Author(s):  
HJ Armbrecht ◽  
MA Boltz ◽  
TL Hodam ◽  
VB Kumar
Keyword(s):  
Vitamin D ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Lines ◽  
Phorbol Esters ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
Vitamin D Receptors ◽  
Kinase C ◽  
Crypt Cells

Non-transformed rat intestinal epithelial cell (IEC) lines were used to study the action of 1,25-dihydroxyvitamin D(3) (1,25(OH)2D) in the intestine. The capacity of 1,25(OH)2D to increase the expression of the cytochrome P450 component of the vitamin D 24-hydroxylase (CYP24) was determined in IEC-6 and IEC-18 cell lines. In IEC-6 cells, which are derived from crypt cells isolated from the whole small intestine, 1,25(OH)2D markedly increased expression of CYP24 protein and mRNA within 12 h. In contrast, in IEC-18 cells, which are derived from crypt cells from the ileum only, 1,25(OH)2D did not increase expression of CYP24 until 24-48 h. The maximal levels of CYP24 mRNA seen in the IEC-18 cells were only 31% of the maximal levels seen in the IEC-6 cells. In the presence of 1,25(OH)2D, phorbol esters rapidly increased CYP24 mRNA levels in IEC-18 cells from almost undetectable to levels seen in IEC-6 cells. Protein kinase inhibitors abolished the stimulation by 1,25(OH)2D and by phorbol esters in both cell lines. Stimulation of mRNA levels by phorbol esters required new protein synthesis but stimulation by 1,25(OH)2D did not. These studies demonstrated that the rapid action of 1,25(OH)2D in IEC-6 cells is related to the activation of protein kinase C, an event which is missing in the IEC-18 cells. This differential response to 1,25(OH)2D probably takes place at a post-receptor site, since the number of vitamin D receptors in each cell line was found to be similar.

scholarly journals Regulation of epidermal-growth-factor-receptor signal transduction by cis-unsaturated fatty acids. Evidence for a protein kinase C-independent mechanism

1991 ◽  
Vol 278 (3) ◽  
pp. 679-687 ◽  
Author(s):  
X Casabiell ◽  
A Pandiella ◽  
F F Casanueva
Keyword(s):  
Signal Transduction ◽  
Fatty Acids ◽  
Protein Kinase C ◽  
Oleic Acid ◽  
Growth Factor ◽  
Protein Kinase ◽  
Epidermal Growth Factor ◽  
Cell Lines ◽  
Kinase C ◽  
Epidermal Growth

The effect of acute treatment with non-esterified fatty acids (NEFA) on transmembrane signalling has been investigated in three different cell lines. In EGFR T17 cells, pretreatment with cis-unsaturated (oleic and palmitoleic acids) NEFA, but not with saturated or trans-unsaturated NEFA, inhibited the epidermal-growth-factor (EGF)-induced increases in cytosolic [Ca2+], membrane potential and Ins(1,4,5)P3 generation. The blocking effect was found to be time- and dose-dependent and rapidly reversible after washout. However, oleic acid treatment did not block either binding of 125I-EGF to its receptor or EGF-induced autophosphorylation of the EGF receptor. The mechanism of action of NEFA could not be attributed to protein kinase C activation, since (i) down-regulation of the enzyme by long-term treatment with phorbol esters did not prevent blockade by oleic acid, and (ii) the effects of acutely administered phorbol ester and oleic acid were additive. In this cell line, signalling at bradykinin and bombesin receptors was also impaired by oleic acid. In A431 cells, oleic acid also blocked signal transduction at the EGF and B2 bradykinin receptors. Finally, in PC12 cells, oleic acid blocked the Ca2+ influx mediated by the activation of B2 bradykinin receptors. In conclusion: (1) NEFA block signal transduction by interfering with receptor-phospholipase C or phospholipase C-substrate interaction without preventing ligand binding; (2) NEFA do not act by a protein kinase C-mediated mechanism; (3) the effect of NEFA is dependent on their configuration rather than hydrophobicity or chain length; (4) this effect is evident in several different cell lines and receptor systems.

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