A somatostatin analogue induces translocation of Ku 86 autoantigen from the cytosol to the nucleus in colon tumour cells.
Flow cytometric and electron microscopic immunocytochemical studies have been performed in HT-29 human colon tumour cells in vitro, to determine and localise p86 Ku protein, which is a regulatory subunit of DNA-dependent kinase and a specific binding site for somatostatin. We have demonstrated that HT-29 cells contain p86 Ku and that the distribution between the cytoplasm and the nucleus is even. After administration of the somatostatin analogues Sandostatin and TT-232 to HT-29 cells, the p86 Ku content of the cytoplasmic compartment decreased in the first 4 h. An increase in the content of this protein in the nuclear compartment was observed at hour 1 followed by a decrease at hour 4 after treatment. Quantitative differences between the two analogues have been observed in this respect. The practical significance of these findings is discussed.
Tóvári
J
J
First Institute of Pathology and Experimental Cancer Research, Semmelweis University of Medicine, Budapest, Hungary.
Szende
B
B
Bocsi
J
J
Falaschi
A
A
Simoncsits
A
A
Pongor
S
S
Erchegyi
J
J
Steták
A
A
Kéri
G
G
D034961:Antigens, Nuclear; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001324:Autoantigens / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects / Q000276:immunology; D002467:Cell Nucleus / Q000276:immunology / Q000378:metabolism*; D003600:Cytosol / Q000276:immunology / Q000378:metabolism*; D004265:DNA Helicases; D004268:DNA-Binding Proteins / Q000378:metabolism*; D019073:HT29 Cells; D006801:Humans; D000072200:Ku Autoantigen; D009687:Nuclear Proteins / Q000378:metabolism*; D015282:Octreotide / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000494:pharmacology*; D013004:Somatostatin / Q000031:analogs & derivatives
D034961:Antigens, Nuclear; D000970:Antineoplastic Agents; D001324:Autoantigens; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010456:Peptides, Cyclic; C094462:TT2-32; D013004:Somatostatin; D004265:DNA Helicases; C106893:XRCC5 protein, human; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen; D015282:Octreotide