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6th ESACP Congress, Heidelberg, April 7-11, 1999 |
A040
The aim of this study was to investigate the development of microcells
in the human sarcoma cell line HT - 1080 after interference with
thiophosphamidum. We found that damaged interphase macrocells located at
the projection of the nucleolus may form one or several microcells. The
micronuclei of the microcells intensively incorporate the thymidine
analogue 5 - bromo - 2 - deoxyuridine and strongly express argyrophilic
nucleolar organiser region proteins. At an early phase of the development,
the micronuclei contain fragmented DNA, but in subsequent phases, the
micronuclei accumulate polymeric DNA, simultaneously with an increase
in their size. After desintegration of the damaged macrocell, the microcells
appear in the intercellular space. The microcells can enter mitosis and they
strongly express the lung resistance protein. The microcells showed a strong
cytochemical staining for NADF-diaphorase, NAD-diaphorase, non-specific
esterase and acid phosphatase activity. Electron microscopic observations
suggest coiled bodies to be involved in the development of the microcells.
Since the observed path of microcell formation differs from apoptotic cell
fragmentation into apoptotic bodies, we propose a new term for this microcell
development: sporosis. We suggest that self-renewal of the tumour stem cells
is likely based on sporosis.
MICROCELLS IN THE HUMAN SARCOMA CELL LINE HT-1080
Buikis I, Harju L, Freivalds T
Latvian Institute of Experimental and Clinical Medicine,
Riga, Latvia