Photodynamic treatment (ALA-PDT) suppresses the expression of the oncogenic Bcr-Abl kinase and affects the cytoskeleton organization in K562 cells.
K562 is the chronic myelogenous leukemia (CML)-derived cell line that expresses high levels of chimeric oncoprotein Bcr-Abl. The deregulated (permanent) kinase activity of Bcr-Abl leads to continuous proliferation of K562 cells and their resistance to the apoptosis promotion by conventional drugs. The photodynamic treatment (PDT) based on the application of 5-aminolevulinic acid (ALA) and irradiation with blue light (ALA-PDT) resulted in the suppression of K562 cells proliferation. It was followed by a necrosis-like cell death [K. Kuzelová, D. Grebenová, M. Pluskalová, I. Marinov, Z. Hrkal, J. Photochem. Photobiol. B 73 (2004) 67-78]. ALA-PDT led to the perturbation of the Hsp90/p23 multichaperone complex of which the Bcr-Abl is the client protein. Bcr-Abl protein was suppressed whereas the bcr-abl mRNA level was not affected. Further on, we observed several changes in the cytoskeleton organization. We detected ALA-PDT-mediated disruption of filamental actin structure using FITC-Phalloidin staining. In connection with this we uncovered certain cytoskeleton organizing proteins involved in the cell response to the treatment. Among these proteins, Septin2, which plays a role in maintaining actin bundles, was suppressed. Another one, PDZ-LIM domain protein 1 (CLP36) was altered. This protein acts as an adaptor molecule for LIM-kinase which phosphorylates and thus inactivates cofilin. Cofilin was indeed dephosphorylated and could thus be activated and operate as an actin-depolymerizing factor. We propose the scheme of molecular response of K562 cells to ALA-PDT.
Department of Cellular Biochemistry, Institute of Hematology and Blood Transfusion, U Nemocnice 1, 12880 Prague 2, Czech Republic. pluskalm@uhkt.cz
Michaela
M
Pluskalová
Gabriela
G
Peslová
Dana
D
Grebenová
Petr
P
Halada
Zbynek
Z
Hrkal
D000622:Aminolevulinic Acid / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D003599:Cytoskeleton / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D004268:DNA-Binding Proteins / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate; D016044:Fusion Proteins, bcr-abl; D005786:Gene Expression Regulation; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D020014:K562 Cells / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D060588:LIM Domain Proteins; D008027:Light; D054461:Lim Kinases; D008565:Membrane Proteins; D008840:Microfilament Proteins / Q000378:metabolism; D018832:Molecular Chaperones / Q000378:metabolism; D015513:Oncogene Proteins / Q000378:metabolism; D010590:Phalloidine / Q000737:chemistry; D017319:Photosensitizing Agents / Q000494:pharmacology; D011494:Protein Kinases / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014157:Transcription Factors
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D018841:HSP90 Heat-Shock Proteins; C484572:LDB2 protein, human; D060588:LIM Domain Proteins; C065072:LMO1 protein, human; D008565:Membrane Proteins; D008840:Microfilament Proteins; D018832:Molecular Chaperones; D015513:Oncogene Proteins; C484659:PDZK1 protein, human; D017319:Photosensitizing Agents; D012333:RNA, Messenger; D014157:Transcription Factors; D010590:Phalloidine; D000622:Aminolevulinic Acid; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D016044:Fusion Proteins, bcr-abl; C515892:LIMK1 protein, human; D054461:Lim Kinases; D016650:Fluorescein-5-isothiocyanate