Table 2

Luria-Delbrück fluctuation analysis of paclitaxel-resistant Calu3 cells

PlateFluctuation groupControl group
PaclitaxelBexarotene + paclitaxelPaclitaxel
Colonies/plateColonies/plateColonies/plate
Total colonies46122
Mean3.1*0.80.1
Variance9.41.20.1
Mutation rate1.7 × 10-73.4 × 10-8NA
  • NOTE. Individual populations at 1000 cells per flask were allowed to expand in either the culture medium or in 1 μmol/L bexarotene until confluence. The total cell population from each flask was seeded onto separated 96-well plates and exposed to 100 nmol/L paclitaxel. Cells grown in 1 μmol/L bexarotene during expansion period were treated with combination of 100 nmol/L paclitaxel and 1 μmol/L bexarotene. Treatment was continued for 7 days. The surviving clones were counted 3 weeks later. Control group used the bulk populations of cells (15 × 106 cells at 1 × 106 cells per plate) from mass cultures prior to drug selection.

  • * P < 0.05 versus control group.

  • Abbreviation: NA, not applicable.