OBJECTIVE: To probe into the inhibitory effect of emodin combined with raltitrexed on the proliferation of pancreatic cancer PANC-1 cell line and its effect on angiotensin converting enzyme 2（ACE2） and angiotensin Ⅱ（AngⅡ）. METHODS: The PANC-1 cells were divided into control group（treated with 0.1% DMSO）

raltitrexed group（treated with raltitrexed）

emodin group（treated with emodin） and combination group（treated with emodin combined with raltitrexed）. The methyl thiazolyl tetrazolium method（MTT） was used to detect the effect of emodin

raltitrexed and drug combination on the proliferative capacity of PANC-1 cells; the enzyme linked immunosorbent assay was used to measure the interleukin（IL） 6

IL-1β and tumor necrosis factor α（TNF-α） levels in cell supernate; the Annexin-V FITC/PI double-staining method method was used to detect the cell apoptosis in the emodin group

raltitrexed group and combination group; the Western blotting and immunofluorescence methods was used to detect the expression of ACE2 and AngⅡ protein in each group. RESULTS: The MTT result showed that the inhibition rates of emodin group（100 μmol/L）

raltitrexed group（40 μmol/L） and combination group on PANC-1 cells were respectively 46.73%

42.39% and 68.71%

the differences were statistically significant compared with the control group（P<0.05）. The IL-6

IL-1β and TNF-α levels in the supernate of PANC-1 cells were significantly lower in the emodin group

raltitrexed group and combined group than those in the control group

while those of raltitrexed group were significantly lower than the emodin group

and those of the combination group were significantly lower than the emodin group and raltitrexed group

with statistically significant differences（P<0.05）. The PANC-1 cell apoptosis rates of the emodin group

raltitrexed group and combination group were significantly higher than that of the control group

with statistically significant difference（P<0.01）. The Western blotting and immunofluorescence method confirmed that the expression of ACE2 in PANC-1 cells was higher and the expression of AngⅡ in PANC-1 cells was lower in the emodin group

raltitrexed group and combination group than those in the control group

with statistically significant differences（P<0.001）

the expression of ACE2 was the highest and the expression of AngⅡ was the lowest in the combination group. CONCLUSIONS: Single use of emodin or raltitrexed can effectively inhibit the proliferation of pancreatic cancer PANC-1 cells

increase ACE2 level and decrease AngⅡ level

which has the effect of promoting apoptosis of tumor cells

while the combination of two drugs has a synergistic effect.