The effect of DNA methyltransferase 3b (DNMT3b) stable knockdown on Adriamycin resistance of bladder cancer cell
10.3760/cma.j.cn112330-20241130-00527
- VernacularTitle:DNA甲基转移酶3b稳定低表达对膀胱癌细胞阿霉素耐药性的影响
- Author:
Ke CHEN
1
;
Jing XIE
1
;
Yingsheng LIN
1
;
Kefeng XIAO
1
;
Jinan GUO
1
Author Information
1. 深圳市人民医院泌尿外科南方科技大学第一附属医院 暨南大学第二临床医学院，深圳 518020
- Publication Type:Journal Article
- Keywords:
Bladder cancer;
DNA methyltransferase 3b;
Adriamycin;
Drug resistance
- From:
Chinese Journal of Urology
2025;46(6):455-461
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effect of stable low expression of DNA methyltransferase 3b（DNMT3b）on the adriamycin（ADM）resistance of wild-type bladder cancer cells BIU-87 and BIU-87/ADM-resistant cells（BIU-87/ADM）.Methods:Lentiviruses expressing DNMT3b siRNA and negative control siRNA were packaged. Stable DNMT3b-low-expressing BIU-87 cells（BIU-87-siRNA group），BIU-87/ADM cells（BIU-87/ADM-siRNA group），and corresponding control groups（BIU-87-NC group and BIU-87/ADM-NC group）were established via lentiviral infection. DNMT3b expression was detected by quantitative PCR and Western blot to validate siRNA interference efficiency. BIU-87-siRNA and BIU-87-NC cells were treated with 0.0125，0.025，0.05，0.1，and 0.2 mg/L ADM，while BIU-87/ADM-siRNA and BIU-87/ADM-NC cells were treated with 0.5，1，2，4，and 8 mg/L ADM. Cell survival rates were measured using the MTT assay to calculate the half-maximal inhibitory concentration（IC50）and relative reversal rate. Apoptosis was analyzed by flow cytometry. Expression of drug resistance-related genes（MRP1，P-gp and Survivin）was detected by quantitative PCR and Western blot. In vivo tumorigenesis experiments were performed by subcutaneously inoculating BIU-87-siRNA，BIU-87/ADM-siRNA，and control group cells into nude mice. Tumor sizes were measured on days 7，10，13，16，20，and 25 to plot growth curves and assess the effect of DNMT3b low expression on ADM resistance.Results:Quantitative PCR showed that the relative mRNA expression of DNMT3b in BIU-87-siRNA and BIU-87-NC groups were（0.32 ± 0.08） vs.（1.00±0.12）（ P < 0.01），and（0.30 ± 0.07） vs.（1.00 ± 0.11）in BIU-87/ADM-siRNA vs. BIU-87/ADM-NC groups（ P < 0.01）. Western blot confirmed significantly reduced DNMT3b protein levels in both siRNA groups（ P < 0.01）. After ADM treatment，BIU-87-siRNA cells exhibited lower survival rates compared to BIU-87-NC at 0.025，0.05，and 0.1 mg/L ADM（ P < 0.05），with IC50 values of（0.14 ± 0.02）mg/L vs.（0.18 ± 0.03）mg/L（ P > 0.05）. For BIU-87/ADM-siRNA cells，survival rates at 1，2，4，and 8 mg/L ADM were significantly lower than controls（ P < 0.05），with IC50 values of（7.10 ± 0.45）mg/L vs.（13.96 ± 1.20）mg/L and a relative reversal rate of 49.76%（ P < 0.01）. Apoptosis rates were significantly higher in siRNA groups（ P < 0.01）. mRNA and protein levels of MRP1，P-gp，and Survivin were reduced in both siRNA groups（ P < 0.05），except for P-gp protein in BIU-87-siRNA cells（ P > 0.05）. In vivo，tumor volumes in siRNA groups were significantly smaller than controls by day 25（ P < 0.05）. Conclusion:Stable low expression of DNMT3b reverses ADM resistance in bladder cancer BIU-87/ADM cells.
