Potential Involvement of Calcineurin in Regulating the State of Differentiation and Apoptosis of HL-60 Cells During Methylprednisolone-TreatmentSerdar Bedii Omay1, Güray Saydam1, Hikmet Hakan Aydın2, Nur Selvi1, Gülperi Öktem3, Ulus Ali Sanlı1, Mahmut Tobu1, Filiz Büyükkeçec11Department Of Hematology And Oncology, Ege University School Of Medicine, İzmir, Turkey
2Department Of Biochemistry, Ege University School Of Medicine, İzmir, Turkey
3Department Of Histology And Embryology, Ege University School Of Medicine, İzmir, Turkey
To evaluate the role of calcineurin (protein phosphatase type 2B, PP2B) in methylprednisolone-induced differentiation and apoptosis of leukaemic cells, we have investigated the induction of apoptosis, calcineurin specific protein phosphatase activity and expression of regulatory and catalytic subunits of calcineurin and calmodulin after induction of HL-60 leukaemic cells with methylprednisolone. The cells underwent differentiation and apoptosis within 72 hours time period after methylprednisolone added to cell culture media. Before apoptosis occurred, the specific calcineurin enzyme activity revealed gradual increase during the differentiation process. However, immunoblots of catalytic and regulatory subunits of calcineurin showed no amplification in the amount of these cellular signaling mediators during methylprednisolone-induced differentiation and apoptosis but calmodulin expression gradually increased during the process. Significant increase in the specific calcineurin enzyme activity during differentiation and apoptosis might be crucial to the posttranslational modifications of calcineurin during methylprednisolone-induced differentiation. Keywords: Calcineurin, Methylprednisolone, Differentiation, Apoptosis, HL-60 cells.
HL-60 Hücrelerin Metilprednizolon Altında Apopitoz ve Farklılaşmasının Calcineurin ile DüzenlenmesiSerdar Bedii Omay1, Güray Saydam1, Hikmet Hakan Aydın2, Nur Selvi1, Gülperi Öktem3, Ulus Ali Sanlı1, Mahmut Tobu1, Filiz Büyükkeçec11Department Of Hematology And Oncology, Ege University School Of Medicine, İzmir, Turkey
2Department Of Biochemistry, Ege University School Of Medicine, İzmir, Turkey
3Department Of Histology And Embryology, Ege University School Of Medicine, İzmir, Turkey
Calcineurin`in (protein fosfataz tip 2B, PP2B) metilprednizolona bağlı lösemi hücre farklılaşması ve apopitozundaki rolünü anlamak amacı ile HL-60 lösemik hücrelerin metilprednizolon altında apopitozisi, calcineurin spesifik protein fosfataz aktivitesi ve calcineurin`in regülatör ve katalitik alt birimlerinin ve calmodulin`in ekspresyonunu inceledik. Hücre kültür ortamına metilprednizolon eklendikten sonraki 72 saatlik dönemde hücreler apopitoz ve farklılaşma gösterdiler. Apopitoz oluşmadan, farklılaşma döneminde spesifik calcineurin enzim aktivitesinde kademeli bir artış izlendi. Ancak bu sırada katalitik ve regülatör calcineurin alt birimlerinin immünblotlarında artış olmazken, calmodulin ekspresyonu giderek arttı. Metilprednizolona bağlı apopitoz ve farklılaşmada spesifik calcineurin enzim aktivitesinde belirgin artış olması calcineurin`in posttranslasyonel modifikasyonlarnda belirgin öneme sahip olabilir. Anahtar Kelimeler: Calcineurin, Metilprednizolon, Farklılaşma, Apopitoz, HL-60 hücreler
Serdar Bedii Omay, Güray Saydam, Hikmet Hakan Aydın, Nur Selvi, Gülperi Öktem, Ulus Ali Sanlı, Mahmut Tobu, Filiz Büyükkeçec. Potential Involvement of Calcineurin in Regulating the State of Differentiation and Apoptosis of HL-60 Cells During Methylprednisolone-Treatment. Turk J Hematol. 2003; 20(3): 143-151
Corresponding Author: Serdar Bedii Omay, Türkiye |
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