Expression of multiple isoforms of protein kinase C in normal human colon mucosa and colon tumors and decreased levels of protein kinase C β and η mRNAs in the tumors

1994 ◽  
Vol 11 (4) ◽  
pp. 197-203 ◽  
Author(s):  
Sadyuki Doi ◽  
Cebra Goldstein ◽  
Hubert Hug ◽  
I. Bernard Weinstein
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Human Colon ◽  
Colon Mucosa ◽  
Colon Tumors ◽  
Kinase C ◽  
Normal Human

scholarly journals Protein kinase C mediates mutant N-Ras–induced developmental abnormalities in normal human erythroid cells

Blood ◽  
2002 ◽  
Vol 100 (12) ◽  
pp. 4185-4192 ◽  
Author(s):  
Richard L. Darley ◽  
Lorna Pearn ◽  
Nader Omidvar ◽  
Marion Sweeney ◽  
Janet Fisher ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Myeloid Leukemia ◽  
Colony Growth ◽  
Developmental Abnormalities ◽  
Ras Mutations ◽  
Molecular Abnormalities ◽  
Kinase C ◽  
Poor Understanding ◽  
Normal Human

RAS mutations are one of the most frequent molecular abnormalities associated with myeloid leukemia and preleukemia, yet there is a poor understanding of how they contribute to the pathogenesis of these conditions. Here, we describe the consequences of ectopic mutant N-Ras (N-Ras*) expression on normal human erythropoiesis. We show that during early (erythropoietin [EPO]–independent) erythropoiesis, N-Ras* promoted the amplification of a phenotypically primitive but functionally defective subpopulation of CD34+ erythroblasts. N-Ras* also up-regulated the expression of megakaryocyte antigens on human erythroblasts. Although early erythroblasts expressing N-Ras* were able to respond to erythropoietin and generate mature progeny, this occurred with greatly reduced efficiency, probably explaining the poor colony growth characteristics of these cells. We further report that this oncogene promoted the expression and activation of protein kinase C (PKC) and that the effects of N-Ras* on erythropoiesis could be abrogated or attenuated by inhibition of PKC. Similarly, the effects of this oncogene could be partially mimicked by treatment with PKC agonist. Together, these data suggest that expression of N-Ras* is able to subvert the normal developmental cues that regulate erythropoiesis by activating PKC. This gives rise to phenotypic and functional abnormalities commonly observed in preleukemia, suggesting a direct link between RAS mutations and the pathogenesis of preleukemia.

Protein kinase C and casein kinase II activities in two human colon carcinoma cell lines, HT-29 and CaCo-2: Possible correlation with differentiation

1990 ◽  
Vol 10 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Ewa Rydell ◽  
Karl-Eric Magnusson ◽  
Anita Sjö ◽  
Krister Axelsson
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Colon Carcinoma ◽  
Carcinoma Cell ◽  
Human Colon ◽  
Human Colon Carcinoma Cell ◽  
Carcinoma Cell Lines ◽  
Kinase C ◽  
Human Colon Carcinoma ◽  
Ht 29

Protein kinase C (PK-C) and casein kinase II (CK-II) activities were studied in two human colon carcinoma cell lines (HT-29 and CaCO-2) undergoing differentiation in vitro resulting, in small-intestine-like cells. CaCo-2 cells, when grown under standard conditions, appear to undergo spontaneous differentiation. In these cells PK-C and CK-II activities were determined on day 5, 10 and 15. No significant differences in activities were seen either in PK-C or CK-II activity. HT-29 cells, when grown in glucose-free medium can be stimulated to undergo differentiation which is completed within 20 days. PK-C and CK-II activities were determined after 5, 10, 15, 20 and 25 days, respectively. PK-C activity rose from 7.9±3.5 pmole32P/mg protein/min at day 5 to 37.5±14.8 pmole32P/mg protein/min at day 20. After 25 days the activity was reduced to 20.0±7.8 pmole32P/mg protein/min. CK-II activity did not change significantly during day 5 to 20, but on day 25 there was a significant decrease in CK-II activity from 94.9±6.4 pmole32P/mg protein/min (day 20) to 62.6±3.9 pmole32P/mg protein/min (day 25) p=0.003. The results in this study indicate a role for PK-C and CK-II in cell growth and differentiation.

Apple Polyphenols Affect Protein Kinase C Activity and the Onset of Apoptosis in Human Colon Carcinoma Cells

2007 ◽  
Vol 55 (13) ◽  
pp. 4999-5006 ◽  
Author(s):  
Melanie Kern ◽  
Gudrun Pahlke ◽  
Kamal Kumar Balavenkatraman ◽  
Frank D. Böhmer ◽  
Doris Marko
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Colon Carcinoma ◽  
Human Colon ◽  
Carcinoma Cells ◽  
Colon Carcinoma Cells ◽  
Kinase C ◽  
Human Colon Carcinoma ◽  
Protein Kinase C Activity

Distinct protein kinase C isozymes signal mitogenesis and apoptosis in human colon cancer cells

1999 ◽  
Vol 117 (4) ◽  
pp. 848-857 ◽  
Author(s):  
Shaun G. Weller ◽  
Irene K. Klein ◽  
Robert C. Penington ◽  
William E. Karnes
Keyword(s):  
Colon Cancer ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cancer Cells ◽  
Human Colon ◽  
Colon Cancer Cells ◽  
Human Colon Cancer ◽  
Kinase C ◽  
Human Colon Cancer Cells

scholarly journals Expression and protein kinase C-dependent regulation of peptide/H+ co-transport system in the Caco-2 human colon carcinoma cell line

1994 ◽  
Vol 299 (1) ◽  
pp. 253-260 ◽  
Author(s):  
M Brandsch ◽  
Y Miyamoto ◽  
V Ganapathy ◽  
F H Leibach
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Line ◽  
Transport System ◽  
Carcinoma Cell ◽  
Human Colon ◽  
Human Colon Carcinoma Cell ◽  
Colon Carcinoma Cell Line ◽  
Kinase C ◽  
Human Colon Carcinoma

The characteristics of the transport of the dipeptide glycylsarcosine were studied in the human colon carcinoma cell line Caco-2 grown as a monolayer on impermeable plastic support. Transport of glycylsarcosine in these cells was found to be Na(+)-independent, but was stimulated by an inwardly directed H+ gradient. This H(+)-dependent transport of glycylsarcosine was inhibited by di- and tri-peptides and also by the beta-lactam antibiotic cephalexin, but was unaffected by the amino acids glycine and leucine. The transport system exhibited a Michaelis-Menten constant (Kt) of 1.1 +/- 0.1 mM for glycylsarcosine. The specific activity of the transport system in this cell line was found to be maximal when the cultures were confluent. Treatment of the cells with phorbol esters which activate protein kinase C resulted in a significant inhibition of the transport system. This inhibition was specific and could be blocked if treatment was done in the presence of staurosporine, an inhibitor of protein kinase C. Kinetic analysis revealed that the inhibition was associated with a decrease in the maximal velocity, the Kt remaining unaffected. The phorbol-ester-induced inhibition of the peptide-transport system was not prevented by co-treatment with cycloheximide, an inhibitor of cellular protein synthesis. In addition, there was no change in the intracellular pH following treatment with the phorbol ester, suggesting that the effect was not due to alterations in the transmembrane pH gradient. It is concluded that the peptide/H+ co-transport system, which is known to exist in the normal intestine, is expressed in Caco-2 cells and that the function of the transport system is under the regulatory control of protein kinase C.

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