Figure 2

ND-PTX induces apoptosis through active caspase 3 and PARP cleavage in CRC cells. (a) RKO cells were left treated with or without 0.1–1 μg/mL ND-PTX for 48 h. The cellular sub-G1 fractions were analyzed by flow cytometry. (b) The sub-G1 fractions of cell population were quantified. (c) Apoptosis levels were determined by Annexin V-FITC and PI staining using flow cytometry. The population of Annexin V⁺/PI⁻ cells represents cells undergoing early apoptosis (lower right), whereas the fraction of Annexin V⁺/PI⁺ cells are those undergoing late apoptosis (upper right). (d) The percentage of total apoptosis (early and late apoptosis) cells was quantified. Results were obtained from three experiments and the bar represents the mean ± S.E. *p < 0.05 and **p < 0.01 indicate significant differences between untreated and ND-PTX samples. (e) RKO cells were left treated with or without 0.1–1 μg/mL ND-PTX for 48 h. At the end of treatment, the total protein extracts were collected and subjected to western blot. The representative western blot data were shown from one of three separate experiments with similar findings.