Table 2.

Effects of 2ME2 on microtubule dynamics in living cells at the mitotic IC50

Control2ME2 mitotic IC50 (1.2 μmol/L)Percentage change (%)
Variable
    Growth rate (μm/min)12.3 ± 3.89.1 ± 4.4−26
    Growth duration (min)0.33 ± 0.220.23 ± 0.17−30
    Growth length (μm)4.1 ± 3.31.8 ± 1.4−57
    Shortening rate (μm/min)30.6 ± 12.233.3 ± 14.4NS
    Shortening duration (min)0.18 ± 0.090.18 ± 0.08NC
    Shortening length (μm)6.0 ± 4.26.1 ± 3.8NC
    Pause duration (min)0.26 ± 0.230.31 ± 0.26NS
    Catastrophe frequency/MT/min1.8 ± 1.01.0 ± 1.0−41
    Rescue frequency/MT/min4.8 ± 3.14.0 ± 3.3−17
    Catastrophe frequency/MT/μm0.41 ± 0.400.44 ± 0.44NS
    Rescue frequency/MT/μm0.18 ± 0.160.16 ± 0.19NS
    Dynamicity/MT (μm/min)11.6 ± 4.36.6 ± 3.2−43
Percentage (%) of time spent:
    Growing40.027.7−12
    Shortening22.913.8−9
    Paused37.158.5+21
MTs/cells49/865/15
  • NOTE: Values are the mean ± SD except for percentage of time spent in each phase, which represents the behavior of the entire population of microtubules. Values in bold type are statistically significant at ≥99% confidence level by Student's t test.

  • Abbreviations: MT, microtubule; NC, no change; NS, not significant.