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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.
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Objective To explore the effect of Latexin (Lxn) gene transfection on proliferation of CD13;MIAPaca-2 pancreatic cancer stem-like cells.Methods CD133+ MIAPaca-2 cells were isolated and sorted by magnetic activated cell sorting from pancreatic cancer MIAPaca-2 celt line.CD133+ MIAPaca-2 cells were cultured in serum-free medium and the capacity for proliferation,and tumorigenicity of CD133+ MIAPaca-2 cells was determined by the floating spheres test and tumor xenograft assays.The CD133+ MIAPaca-2 cells were transfected with Lxn plasmid (1,3,5 μg).After transfection,the protein and mRNA expression of Lxn in CD133+ and CD133+-MIAPaca-2 cells were detected by Western blotting and RT-PCR,respectively.Cell proliferation was assayed by CCK-8.Results CD133+ MIAPaca-2 cells were successfully isolated,and it grew into a ball-suspended way,the tumorigenicity rate in nude mice with subcutaneous injection 1 × 105 cancer cells was 100％.After Lxn plasmid transfection,the expression of Lxn in CD133+ MIAPaca-2 cells was increased in a dose dependent manner,the Lxn protein and mRNA expression of tumor cells transfected with 5 μg plasmid was 20.80 ±0.98,16.80± 2.73,which was significantly higher than that in non-transfected cells (1.02 ± 0.01,1.01 ± 0.01),and the difference between the two groups was statistically significant (P ＜ 0.05).After transfection,cellular proliferation activity also showed a transfection dose and culture time-dependent decrease,the inhibition rate of tumor cells transfected with 0.4 μg plasmid was 36.2％,which was significantly different from that in non-transfected cells (P ＜ 0.05).Conclusions CD133+ MIAPaca-2 pancreatic cancer cells have some characteristics of cancer stem cells.Lxn gene transfection can inhibit the proliferation of CD133+ MIAPaca-2 cells.
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Objective To study the effects of Lxn on CD133 + PANC-1 pancreatic cancer cells.Methods CD133 + PANC-1 cell were isolated by magnetic activated cell sorting (MACS).The properties of the CD133 + PANC-1 cells and Lxn effects on CD133 + PANC-1 cell proliferation in transplanted tumor in nude mice were determined by floating spheres test and tumor xenograft assays.Cell proliferation was assayed by Cell Counting Kit-8 (CCK-8).The Bcl-2,Bax protein and mRNA expression of CD133 + PANC-1 cells treated by Lxn were analyzed by Western blot and Quantitative real-time PCR (qRT-PCR).Results We successfully isolated the CD133 + PANC-1 cells and cultured in serum free medium,CD133 + PANC-1 cells formed sphere,while CD133-PANC-1 cells grew with adherence slowly and then underwent apoptotic process.CD133 + PANC-1 cells showed high tumorigenic in athymic BALB/c mice.Lxn suppressed the growth of transplanted tumor obviously.Compared with control group [(225.52 ± 34.09) mm3],tumor volume decreased significantly (P ＜ 0.05).Significant reduction in cell proliferation was observed in response to Lxn in PANC-1 CD133 + cells by CCK-8 assay with concentration and time dependent manners (P ＜ 0.05).Treated by Lxn,Bcl-2 expression decreased,Bax expression increased.Conclusions Lxn inhibits the proliferation of CD133 + PANC-1 cells probably through a mechanism down-regualting Bcl-2 and up-regulating Bax.