Figure 1.

Establishment of a gemcitabine-resistant breast cancer cell line.

Notes: (A) Flow cytometry apoptosis analysis was performed in cultured 231 and 231/Gem cell lines harvested after 3 days of treatment with 35 μM gemcitabine. (B) Quantification of apoptosis for the 231/Gem cells and parental cells. **P<0.01. Columns are means of three independent experiments, bars are SD. (C) The half-maximal inhibitory concentration of 231 and 231/Gem was detected by CCK-8 under different concentrations of gemcitabine for 5 days.

Abbreviations: 231, human breast cancer cell line MDA-MB-231; 231/Gem, chemoresistant human breast cancer cell line MDA-MB-231/gemcitabine; CCK-8, Cell Counting Kit-8; FITC, fluorescein isothiocyanate; IC₅₀, half-maximal inhibitory concentration; SD, standard deviation.