Fig. 1

Differential sensitivity of CRC cells to various antibiotics. A A pair of low (HT29 and HCT15) and high (HCT116 and Colo205) metastatic cells were treated with different classes of antibiotics at varying concentrations (0-200 µM) for 48h and changes in cell viability were measured by trypan blue staining. Graphs represent the relative percentage viability of CRC cells (low and high metastatic cells) after treatment with a chloramphenicol, b erythromycin, c linezolid, d tigecycline, and e tetracycline. Data represent the mean ± standard deviation (SD) of viability relative to their respective non-treated controls. Student’s t-test was used to calculate the significant difference in the viability of CRC cells, compared to the percentage viability of HT29 cells (one of the low metastatic cells) at the indicated concentrations. *P<0.05, **P<0.01 and ***P<0.001, ****P<0.0001.B After treatment with IC₅₀ concentrations of tigecycline and tetracycline for 48 h, bright field images of CRC cells were captured using an Olympus IX73 microscope. Representative images at total 100x magnification (100µm scale bar) are shown to indicate morphological differences at IC₅₀ concentrations, especially the dead rounded cells in high metastatic cells (right panel) compared with low metastatic CRC cells (left panel)