Multiple centrosomal microtubule organising centres and increased microtubule stability are early features of VP-16-induced apoptosis in CCRF-CEM cells.
Microtubular reorganisation contributing to apoptotic morphology occurs in normal and neoplastic cells undergoing apoptosis induced by cytotoxic drugs [1-3]. The aim of this study was to correlate the changes in the microtubules (MTs) with behavior of the centrosome in apoptotic cells, and to see whether post-translational changes in tubulin occurred with the emergence of apoptotic MT bands. Apoptosis was induced in the human T-cell leukaemia line (CCRF-CEM) by treatment with 17 microM etoposide over a 4 h period. The time course of changes was assessed using flow cytometry (FCM) and immunocytochemistry in cells labelled for a centrosomal antigen (CSP-alpha) or alpha-tubulins. One hour following treatment we observed multiple centrosomal microtubule organising centres (MTOCs) associated with the nucleus and the transient appearance of a subset of stable MTs detected with an antibody specific for acetylated alpha-tubulin, as the bands of MTs which lobulate the nucleus are formed. The altered properties of the MTs thus reflect changes in function as apoptosis progresses.
Pittman
S
S
Children's Cancer Research Institute, Sydney Children's Hospital, Australia.
Geyp
M
M
Fraser
M
M
Ellem
K
K
Peaston
A
A
Ireland
C
C
D000941:Antigens / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D018385:Centrosome / Q000276:immunology; D053938:DNA Fragmentation; D005047:Etoposide / Q000494:pharmacology*; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D008870:Microtubules; D014404:Tubulin / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000941:Antigens; D014404:Tubulin; D005047:Etoposide