Fig. 6
Overexpression of PRMT3 increases the sensitivity of pancreatic cancer cells to GAPDH blockage. a GFP- and GFP-PRMT3-ovexpressing PANC-1 cells were treated with indicated concentrations of GAPDH inhibitor, heptelidic acid, for 2 days, and the cell viability was investigated by MTT assay. Error bars, SEM. n = 3. *p < 0.05, **p < 0.01. b HPDE, PANC-1, and BxPC3 cells were treated with indicated concentrations of heptelidic acid for 2 days, and the viability was investigated by MTT assay. Error bars, SEM. n = 3. *p < 0.05, **p < 0.01, ***p < 0.001. N.S., not significant. c BxPC3 and L3.6pl cells with high endogenous expression of PRMT3 were exposed to various concentrations of heptelidic acid (between 0.05 and 2 μM) and oligomycin (between 1 and 40 μg/ml) for 48 h, and the viability was investigated by MTT assay. Combination index (CI) values were determined using the CalcuSyn software (Biosoft). CI values < 1.0 indicated a synergistic cytotoxic effect, and the CI of heptelidic acid and oligomycin in BxPC3 and L3.6pl is 0.30768 and 0.50318, respectively. d GFP- and GFP-PRMT3 overexpressing PANC-1 cells (1 × 106) were subcutaneously injected into the right flank of ASID mice. Tumor formation was monitored with digital calipers twice per week. Three weeks after injection, mice received PBS (control) and oligomycin (Oligo., 0.5 mg/kg) + heptelidic acid (H.A., 1 mg/kg) treatment. All of the mice received the drugs via tumor injection twice per week. One week after treatment, mice were sacrificed and tumor weight was measured. Error bars, SEM. n = 5. N.S., not significant. ***p < 0.001. e Apoptosis of tumor tissues was measured by TUNEL assay, and the images were captured by a fluorescence microscope (200× magnification). White arrows indicate TUNEL-positive cells. The percentage of cell death was determined by counting the number of TUNEL-positive cells in three independent fields. Quantitative result of TUNEL assay was analyzed. Data represented mean ± SEM. Obtained from 5 mice in each group. N.S., not significant. *p < 0.05