Figure 2

ICD induces apoptosis in SP cells. (A) Cell proliferation was analyzed by BrdU assay in MHCC-97L and PLC/PRF/5 SP cells after treatment with ICD and DXR. (B) Representative flow cytometry histograms of SP and non-SP cells, in which G2/M arrest was induced by ICD treatment for 12, 24 and 48 h. The level of G2/M arrest in SP cells was more significant than the arrest in non-SP cells. (C) FACS analysis revealed that exposing MHCC-97L SP cells to ICD for 48 h induced apoptosis. Early apoptotic cells refer to cells labeled only by annexin V; late apoptotic cells refer to cells that have both signals of 7-AAD and annexin V (defined according to the manual of PE Annexin V Apoptosis Detection Kit from BD Biosciences). (D) Western blot of caspases in MHCC-97L SP and non-SP cells after treatment with 150 µg/mL ICD for 24 h. (E) Western blot of apoptosis proteins, which localized on the cellular and mitochondrial membranes in MHCC-97L SP and non-SP cells treated with 150 µg/mL ICD for 24 h.