A-549 (non-small cell lung carcinoma), DU145 (androgen-independent prostate cancer), and KB (nasopharyngeal carcinoma) cell lines were obtained from the Lineberger Comprehensive Cancer Center (UNC-CH). KBvin (vincristine-resistant KB) cell line was a generous gift of Professor Y.-C. Cheng, Yale University. Cells were cultured in RPMI 1640 medium containing 25 mM HEPES and 2 mM L-glutamine (Mediatech), supplemented with 10 % heat-inactivated fetal bovine serum (Hyclone), 100 IU penicillin, 100 μg/mL streptomycin, and 0.25 μg/mL amphotericin B (Mediatech) in 5 % CO2 and 95 % air at 37 °C.
Antiproliferative activity was determined by the sulfo-rhodamine B (SRB) colorimetric assay as previously described (Nakagawa-Goto et al., 2011 (link)). In brief, cells (3–5 × 103 cells/well) were seeded in 96-well plates filled with culture medium containing various concentrations of sample and incubated for 72 h. At the end of the exposure period, cells were fixed with cold 50 % trichloroacetic acid followed by staining with 0.04 % SRB (Sigma Chemical Co.). The absorbance of solubilized SRB was measured at 515 nm on a Microplate Reader ELx800 (Bio-Tek Instruments, Winooski, VT) with Gen5 software. All results are representative of three or more experiments.
Antiproliferative activity was determined by the sulfo-rhodamine B (SRB) colorimetric assay as previously described (Nakagawa-Goto et al., 2011 (link)). In brief, cells (3–5 × 103 cells/well) were seeded in 96-well plates filled with culture medium containing various concentrations of sample and incubated for 72 h. At the end of the exposure period, cells were fixed with cold 50 % trichloroacetic acid followed by staining with 0.04 % SRB (Sigma Chemical Co.). The absorbance of solubilized SRB was measured at 515 nm on a Microplate Reader ELx800 (Bio-Tek Instruments, Winooski, VT) with Gen5 software. All results are representative of three or more experiments.
