In vitro study on the improvements of Latexin on the chemosensitivity in gemcitabine-resistant pancreatic cancer cells and potential mechanism / 中华胰腺病杂志

ABSTRACT

Objective To observe the effect of Latexin treatment on the chemoresistance in gemcitabine-resistant pancreatic cancer cell line SW1990, and explore the potential mechanism.Methods Gemcitabine-resistant pancreatic cancer cell line SWl990/GZ was induced and established by increasing gemcitabine dosage intermittently.IC50 of gemcitabine in SW1990 cells and SWl990/GZ cells pre and post Latexin treatment at the dosage of 10, 20 and 40 ng/μl for 48 h was evaluated using CCK-8 assay.The mRNA and protein expression of Latexin gene in SW1990 and SW1990/GZ cells were evaluated using qRT-PCR and Western blot, and the expression of Shh and Gli1 in 40 ng/μl Latexin treated SW1990 and SW1990/GZ cells for 48 h.Results A gemcitabine-resistant pancreatic cancer cell line SWl990/GZ was obtained successfully, which can grow stably and passage in the media containing 150 μmol/L gemcitabine.The IC50 values of gemcitabine in SW1990 cells and SWl990/GZ cells were (3.8±0.4)μmol/L and(226.52±13.61)μmol/L, respectively, and the later was greatly higher than the former, which was statistically different (P=0.000).The drug resistance indexes (RI) was 59.6.After treated with different concentrations of Latexin(10,20,40 ng/μl), the IC50 of SW1990 cells was (3.0±0.4)μmol/L, (2.5±0.3)μmol/L and (1.8±0.3)μmol/L, respectively,and the IC50 of SW1990/GZ cells was(113.08±5.01)μmol/L,(70.26±2.31)μmol/L and (42.12±1.31)μmol/L, respectively.Compared with the untreated cells,the IC50 of gemcitabine in 20,40 ng/μl Latexin treated cells was obviously decreased, and the differences were statistically significant (P<0.05).Compared with the SW1990 cells,the expression of Latexin in SW1990/GZ cells was obviously decreased.RI were 37.7, 28.1 and 23.1,respectively.mRNA relative expression of Latexin in SW1990 and SW1990/GZ cells were 0.85±0.08 and 0.31±0.07, and protein relative expression were 0.49±0.09 and 0.13±0.05, and Latexin expression in SW1990/GZ was obviously lower than that in SW1990 cells and the difference was statistically significant (P<0.05).After being treated by 40 ng/μl Latexin, SHH mRNA in SW1990/GZ cells decreased from 0.89±0.09 (control cells) to 0.53±0.06, Gli1 mRNA decreased from 0.58±0.06 to 0.35±0.05, Shh protein decreased from 0.72±0.09 to 0.35±0.06,Gli1 protein level decreased from 0.78±0.08 to 0.28±0.03, and all the differences were statistically significant (P<0.05 or 0.01).Conclusions Latexin can significantly improve the chemosensitivity in gemcitabine-resistant pancreatic cancer cells, and the potential mechanism may be related to the inhibition of sonic hedgehog pathway activation.