FIGURE 5.

Prolonged inhibition of KMT1F is associated with chromosomal abnormalities. A, doxycyclin-inducible KMT1F depletion system. KMT1F expression was assayed in Zeocin-resistant cell populations and isolated clones by reverse transcription-PCR (Fig. S2). Three days after induction, KMT1F expression is significantly decreased in A9 and A7 clones, which were selected for further analysis (60 and 80%, compared with noninduced cells, respectively). B, abnormal metaphase figure count comparison. Between 2500 and 3000 cells were analyzed in A7 and A9 mock treated (−) or doxycyclin-induced (+) cells, and 30, 219, 130, and 242 metaphase figures were respectively analyzed. Upon induction an increased number of cells with aberrant nuclear morphology or nuclei containing multipolar spindles is observed. Significant differences are indicated with asterisks (*, doxycyclin versus mock induced in A7 and A9; p values (<0.001) were determined using a t test). C, the percentages of hyperploid (>2n) and tetraploid (4n) cells were estimated in A9 cells induced or not with doxycyclin for 8 days.