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ROLE OF OLIGOCHITOSANS IN REGULATION OF CELLULAR ACTIVITY AND LOCATION OF PYRUVATE KINASE (PK) ISOENZYME M2 THAT AFFECTS PROLIFERATION OF EHRLICH ASCITES TUMOR CELLS (EAT)

100%
Ignacak J., Wiśniewska-Wrona M., Pałka I., Niekraszewicz A.
Progress on Chemistry and Application of Chitin and its Derivatives
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2013
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vol. 18
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issue 18
67-76
EN
The pyruvate kinase isoenzyme M2 originating from the nucleoplasm and cytoplasm of tumor cells, with its highest affinity to the 2-phosphoenolpyruvate (2-PEP) and sensitivity to L-cysteine, contributes to an increased generation of energy as ATP, necessary for tumor cell proliferation. In the presence of L-cysteine, the isoenzyme M2 PK demonstrates the activity of histone kinase, transferring the phosphoryl group from 2-PEP to the ε-amine residue of the H1 histone lysine. Oligochitosans induce expression of the inducible nitric oxide synthase gene (iNOS), what results in an increased synthesis of nitric oxide, which reacts with L-cysteine and produces L-S-nitrosocysteine. Lack of L-cysteine contributes to inhibition of kinase activity of the H1 histone, an M2 PK isoenzyme. Decreased phosphorylation of the H1 histone contributes to inhibition of EAT cell proliferation. No effect on proliferation of normal cells that include the PK M1 isoenzyme has been observed in the presence of oligochitosans.
2
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ROLE OF OLIGOCHITOSANS IN REGULATION OF CELLULAR ACTIVITY AND LOCATION OF PYRUVATE KINASE (PK) ISOENZYME M2 THAT AFFECTS PROLIFERATION OF EHRLICH ASCITES TUMOR CELLS (EAT)

100%
Ignacak J., Wiśniewska-Wrona M., Pałka I., Niekraszewicz A.
Progress on Chemistry and Application of Chitin and its Derivatives
|
2013
|
vol. 18
|
issue 18
67-76
EN
The pyruvate kinase isoenzyme M2 originating from the nucleoplasm and cytoplasm of tumor cells, with its highest affinity to the 2-phosphoenolpyruvate (2-PEP) and sensitivity to L-cysteine, contributes to an increased generation of energy as ATP, necessary for tumor cell proliferation. In the presence of L-cysteine, the isoenzyme M2 PK demonstrates the activity of histone kinase, transferring the phosphoryl group from 2-PEP to the ε-amine residue of the H1 histone lysine. Oligochitosans induce expression of the inducible nitric oxide synthase gene (iNOS), what results in an increased synthesis of nitric oxide, which reacts with L-cysteine and produces L-S-nitrosocysteine. Lack of L-cysteine contributes to inhibition of kinase activity of the H1 histone, an M2 PK isoenzyme. Decreased phosphorylation of the H1 histone contributes to inhibition of EAT cell proliferation. No effect on proliferation of normal cells that include the PK M1 isoenzyme has been observed in the presence of oligochitosans.
3
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THE ROLE OF OLIGOCHITOSANS IN AKT KINASE REGULATION

88%
Ignacak J., Wiśniewska-Wrona M., Dulińska-Litewka J., Pałka I., Kucharska M.
Progress on Chemistry and Application of Chitin and its Derivatives
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2015
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vol. 20
73-81
EN
Among characteristic properties of cancers, there is their increased glycolytic activity.Contrary to normal cells, neoplastic cells use anaerobic glycolysis, even when a sufficient amount of oxygen is available. The intensity of the process is associated with a considerable demand for energy in the form of ATP. Akt, which - acting through the mTOR pathway - activates the HIF-1 factor, which in turn activates hexokinase that participates in glucose phosphorylation, stimulates the transport of glucose to cells via increasing glucose transporters (GLUT) and activates lactate dehydrogenase (which transforms pyruvate to lactate). Chitosan, as well as products of its degradation - oligochitosans - contribute to inhibiting the activity of the Akt kinase, and thus contribute to inhibiting excessive glycolytic activity of Ehrlich ascites tumor (EAT) cells and to decreasing proliferation of these cells.
4
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ROLE OF CHITOSAN OLIGOMERS IN REGULATION OF EHRLICH ASCITES TUMOR CELLS PROLIFERATION IN VITRO

88%
Ignacak J., Wiśniewska-Wrona M., Pałka I., Zagajewski J., Niekraszewicz A.
Progress on Chemistry and Application of Chitin and its Derivatives
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2011
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vol. 16
89 - 98
EN
Preliminary studies of proliferation of Ehrlich ascites tumor (EAT) cells and normal mammary gland epithelial cells have demonstrated the process to be inhibited by degradation products of microcrystalline chitosan, i.e. oligomers. Inhibition of proliferation has been also accompanied by a decreased activity of the M2 pyruvate kinase (PK) isoenzyme in nucleoplasm, what may indicate the role of this enzyme in regulation of tumor cell proliferation. Determinations of nitrogen oxide in tumor and normal cells point to a higher level of this endogenous effector in normal cells. An increase of nitrogen oxide levels in Ehrlich ascites tumor cells effected by chitosan oligomers may indicate increased nitrosylation, and particularly an increased amount of compounds containing sulfhydryl groups and their participation in regulation of nucleoplasm M2 PK isoenzyme activity. Chitosan oligomers have smaller molecules as compared to microcrystalline chitosan and for this reason appear to be more effective than the latter in acting upon the negatively charged cell membrane surfaces, thus contributing to proliferation inhibition.
5
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THE EFFECT OF CHITOSAN ON THE SYNTHESIS OF L-S-NITROSOCYSTEINE THAT PARTICIPATES IN THE REGULATION OF THE M2 PYRUVATE KINASE ISOENZYME ACTIVITY ASSOCIATED WITH EHRLICH ASCITES CELLS PROLIFERATION IN VITRO

88%
Ignacak J., Zagajewski J., Pałka I., Wiśniewska-Wrona M., Niekraszewicz A.
Progress on Chemistry and Application of Chitin and its Derivatives
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2010
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vol. 15
149 - 158
EN
L-S-nitrosocysteine formation in EAT tumor cells and normal CRL-1636 cells incubated with microcrystalline chitosan was confirmed by RP-HPLC. The metabolite was identified based on UV-VIS spectra. The formation of L-S-nitrosocysteine in EAT tumor cells contributes to decreasing the level of L-cysteine in these cells. L-cysteine as an effector of the bifunctional M2 isoenzyme of pyruvate kinase (PK) initiates its histone kinase activity, which is responsible for histone H1 phosphorylation. A decrease of L-cysteine level in EAT tumor cells contributes to lack of histone H1 phosphorylation by the M2 PK isoenzyme and by the same token to inhibition of EAT cell proliferation.
6
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INHIBITION OF EHRLICH ASCITES TUMOUR (EAT) CELLS PROLIFERATION THROUGH CHITOSAN-MEDIATED REGULATION OF ACTIVITY OF THE AKT PATHWAY

88%
Ignacak J., Wiśniewska-Wrona M., Dulińska-Litewka J., Pałka I., Kucharska M.
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EN
Isoenzyme M2 pyruvate kinase, which is a marker of cancer transformation, can take both tetramer (cytosol) and dimer (nucleus) forms. The former is responsible for ATP synthesis, and the latter demonstrates histone H1 kinase activity. Regulation of the expression of pyruvate kinase through which Akt controls the expression of genes involved in Ehrlich ascites tumour (EAT) cell proliferation, migration and death, also involves cross-talk with the other signalling pathways, transcription factors and co-regulatory proteins such as β-catenin and c-Myc. Treatment of EAT cells with chitosans significantly reduced their proliferation (by 45-60%), expression of nuclear β-catenin, c-Myc as well as cell migration. After 48–72 hours of treatment of the cell with oligochitosans, lower levels of p-Akt were detected. Simultaneously, decreased expression of isoenzyme M2 PK protein levels was observed. The dimeric form (nucleus) can participate in H1 histone phosphorylation, which contributes to increased EAT cell proliferation.
7
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THE ROLE OF CHITOSAN IN AKT KINASE REGULATION ACTIVITY

76%
Ignacak J., Wiśniewska-Wrona M., Dulińska-Litewka J., Pałka I., Kucharska M., Kazimierski J.
Progress on Chemistry and Application of Chitin and its Derivatives
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2016
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vol. 21
73-82
EN
A decrease in migration of tumor cells incubated with the investigated chitosan preparations was correlated with a decreased activity of MMP-2 and MMP-9 metalloproteinases, what significantly affected inhibition of tumor cell proliferation. In the investigations of the effects of various chitosan preparations on expression of PCNA, Akt and β-catenin in the normal human 184A1 cells and in breast carcinoma MCF7 cells evaluated at the protein level, significant differences in inhibition of expression of selected genes were noted in the tumor cells. Similarly as in the case of human cells, in mouse cells, the differences in expression of the investigated genes involved solely the Ehrlich carcinoma cells. In the presence of the investigated chitosan preparations, there was observed inhibition of expression of the N-cadherin, β-catenin, Akt and PCNA genes. In case of p21 protein, its level increased, similarly as in the human breast carcinoma cells, what may also be related to phosphorylation of the protein, its capture by the cytosol and prolonging its half-life as compared to the non-phosphorylated form. In case of the normal human 181A1 cells and mouse CRL 1636 cells, no significant alterations were noted in expression of the investigated genes in presence of the employed chitosan preparations.
8
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EFFECT OF OLIGOCHITOSANS ON EXPRESSION OF INOS GENE IN EHRLICH ASCITES TUMOUR IN VITRO

76%
Ignacak J., Wiśniewska-Wrona M., Dulińska-Litewka J., Pałka I., Zagajewski J., Niekraszewicz A.
Progress on Chemistry and Application of Chitin and its Derivatives
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2012
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vol. 17
141 - 148
EN
Oligochitosans obtained through degradation of macromolecules of chitosan with a high degree of deacetylation turned out to be biologically active, contributing to an increase of nitric oxide levels in Ehrlich ascites tumor (EAT) cells through inducing expression of the isoform of inducible nitric oxide synthase (iNOS) gene. An increase of NO levels in EAT cells in the presence of the investigated oligochitosans might contribute to nitrosylation of L-cysteine – an allosteric effector of the M2 isoenzyme of pyruvate kinase (PK), which switches the PK kinase activity, responsible for ATP synthesis, to the histone kinase activity that may participate in histone H1 phosphorylation. Lack of the histone activity of the PK M2 isoenzyme may contribute to decreased histone H1 phosphorylation and thus inhibit EAT cells proliferation.
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