Fig. 5

Effect of H5B14-based ADCs on cancer stem cell-derived spheroid formation, cellular viability, and ALDH expression. a Inhibitory effect of H5B14-based ADCs on spheroid formation by pancreatic cancer cells. Spheroid formation from ASPC-1, BxPC3, and L3.6pl cells were performed as previously described [5, 29]. H5B14-MMAE or H5B14-DCM was added after initiation of cell culture. The number of spheroids was counted 40 days after ADC treatment. Scale bar: 50 μM. b Death of pancreatic stem-like cells mediated by H5B14-based ADCs. PAC^SL cells with RON⁺/CD44⁺/ESA⁺ phenotypes were treated in triplicate with different amounts of H5B14-MMAE or H5B14-DCM for 72 h. Cell death was determined by the trypan blue exclusion assay [1]. c and d Inhibitory effect of H5B14-based ADCs on pancreatic cancer cells expressing ALDH. FG cells expressing a relatively high level of ALDH were used as the model. After treatment of cells with H5B14-MMAE or H5B14-DCM for 48 h, the percentages of FG cells expressing ALDH were determined by using the ALDEFLUOR™ Kit according to the manufacture’s instruction. Results shown here are from one of two experiments with similar results