Figure 1.

Combined application of CTX and PP242 inhibits the proliferation of CRC cells. (A,B) EGFR wild-type Caco-2 cells (A) and HT-29 cells (B) were untreated or treated with 20 µg/mL CTX and 1 µmol/L PP242 alone or in combination for 96 h. Cell viability was determined by the CCK-8 assay and indicated by OD450. (C-F) Flow cytometry was used to detect the cell cycle of CRC cell lines. Caco-2 cells (C,E) and HT-29 cells (D,F) were untreated or treated with 20 µg/mL CTX and 1 µmol/L PP242 alone or in combination for 96 h. The relative numbers and proportions of cells in each group at G1, S, and G2 phases are shown in (C) and (D), respectively. The proportion of cells in S phase was used to assess cell division activity and displayed in (E) and (F). (G-J) Flow cytometry was used to detect the cell apotosis of CRC cell lines. Caco-2 cells (G,I) and HT-29 cells (H,J) were untreated or treated with 20 µg/mL CTX and 1 µmol/L PP242 alone or in combination for 96 h. Different apoptotic states of cells are shown in (G) and (H) and divided into four quadrants. The lower left quadrant, upper left quadrant, lower right quadrant, and upper right quadrant represent normal cells, necrotic cells, early apoptotic cells, and late apoptotic cells, respectively. The proportion of late apoptotic cells was used to assess the status of apoptotic cells and is displayed in (I) and (J). Each bar represents the mean ± SEM. All data were derived from at least three separate experiments. *, P<0.05; **, P<0.01; ***, P<0.001. CTX, cetuximab; CRC, colorectal cancer; EGFR, epidermal growth factor receptor; CCK-8, cell counting kit-8; OD450, optical density at 450 nm; SEM, standard error of mean.