Inhibitory effect of nafamostat mesylate on cell viability of endocrine-resistant estrogen receptor-positive breast cancer. (A) IC50 values of H184, parental MCF7, MCF7-TamR, and MCF7-FulR cells for NM. (B) Analysis of the viability of H184, parental MCF7, MCF7-TamR and -FulR cells treated with various doses of NM for 72 and 96 h, using MTT assays. (C) Analysis of growth of MCF7-TamR (upper) and MCF7-FulR (lower) cells, assessed using colony formation assays. (D) Quantitative analysis of colony formation assays for NM-treated MCF7-TamR (left) and MCF7-FulR (right) cells. Data are represented as the mean ± SEM for biological triplicate experiments. ⁎#P < 0.01, compared with the results for untreated H184, parental MCF7, MCF7-FulR, and MCF7-TamR cells.