Zinc protoporphyrin IX enhances chemotherapeutic response of hepatoma cells to cisplatin

Figure 1 Liver cancer cell lines showed divergent heme oxygenase-1 expression levels, which were associated with variable susceptibility to chemotherapy. In Western blotting, high levels of heme oxygenase (HO)-1 protein were detected in HepG2 cell line, whereas other cell lines revealed lower expression (A) HepG2 > 97H > SMMC7721. Cell viability was assessed 48 h after application of cis-diaminedichloroplatinum (cisplatin; CDDP) via MTT assay. All cell lines showed dose-dependent growth inhibition upon treatment with CDDP. The HepG2 cell line, with the highest HO-1 expression, was significantly more chemoresistant to CDDP than the other cell lines with lower HO-1 expression (B).