TRISOMY 8 MOSAICISM: CELL CYCLE KINETICS AND ...

Pallister Killian patients with the absence or reduced level of i(12p) cells in metaphase
(Wenger et al. 1990; Thornberg Reeser and Wenger 1992). Cells exiting the cell cycle
and entering the GO phase is more likely a mechanism for our patient than apoptosis,
because cell death should not change the ratio of interphase to metaphase trisomy 8 cells,
whereas cells entering the GO phase would cease to continue with cell division and
therefore result in a decline of mitotic cells.
Conclusion
The trisomy 8 cell line as a whole is not delayed in going through the cell cycle,
which is evident in the statistical comparison shown in Table 4. However, a portion of
the cells are apparently exiting out of the cell cycle and no longer dividing, but not
undergoing apoptosis. This provides a selective growth advantage for the normal cells.
Exiting of trisomy 8 cells from the cell cycle will result in a decrease of the cell line over
time, which is supported in the literature (La Marche 1967; Mark and Bier 1997; Jordan
1998).
Further Studies
Further investigative measures would have to occur to determine the exact
mechanism causing the decrease of trisomy 8 cells in metaphase. Follow-up testing in
this case could not be performed to investigate each mechanism due to the patient
expiring and exhausting cell lines. However, in other cases, tissues could be examined
by tests including flow cytometry for apoptotic body identification (Felsher et al. 2000).
Also, DNA content measuring by fluorescence-activated cell analysis would identify
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