miR-526b在胰腺癌中的表达及作用

Expression of miR-526b in pancreatic cancer and its function

目的:探讨mi R-526b在胰腺癌中的表达与作用。方法:用q RT-PCR法检测mi R-526b在52例胰腺癌和癌旁组织,以及在4种胰腺癌细胞系(Bx PC-3、SW1990、PANC-1和As PC-1)和正常胰腺导管上皮细胞系(HPDE6-C7)中的表达。将胰腺癌细胞分别转染mi R-526b模拟物、mi R-526b抑制物及阴性对照序列后,采用CCK-8、Transwell实验和流式细胞术分别测定细胞增殖、侵袭与凋亡情况。生物软件和双荧光素酶报告基因法分析mi R-526b潜在靶基因,并用Western blot和q RT-PCR法及相关性分析验证。结果:mi R-526b在胰腺癌组织中表达量明显低于癌旁组织,在4种胰腺癌细胞系中的表达量均明显低于人正常胰腺导管上皮细胞(均P<0.05)。胰腺癌细胞转染mi R-526b模拟物后,增殖能力明显降低、细胞凋亡率明显升高、侵袭能力明显减弱,而转染mi R-526b抑制物后则呈反向变化(均P<0.05)。分析结果显示XRCC5是mi R-526b靶基因;胰腺癌细胞转染mi R-526b模拟物后,XRCC5的m RNA和蛋白表达均明显下调,mi R-526b抑制物后则均明显上调(均P<0.05);胰腺癌组织中mi R-526b和XRCC5 m RNA表达水平呈显著负相关(r=-0.456,P<0.05)。结论:mi R-526b在胰腺癌中下调表达,mi R-526b低表达可促进胰腺癌细胞增殖、侵袭并抑制凋亡,机制可能与上调其靶基因XRCC5的表达有关。

Objective:To investigate the expression of mi R-526 b in pancreatic cancer and its effects.Methods:The expressions of mi R-526 b in 52 specimens of pancreatic cancer and adjacent tissue as well as in different pancreatic cancer cell lines(Bx PC-3,SW1990,PANC-1 and As PC-1)and normal pancreatic ductal epithelial cells(HPDE6-C7)were determined by q RT-PCR.In pancreatic cancer cells after transfection with mi R-526 b mimics,mi R-526 b inhibitors and negative control sequences,the proliferation,invasion and apoptosisability were examined by CCK-8,Transwell assay and flow cytometry,respectively.The potential target gene of mi R-526 b was analyzed by using biosoftware and dual-luciferase reporter assay,and then was verified by Western blot and q RT-PCR as well as correlation analysis.Results:The expression levels of mi R-526 b in pancreatic cancer tissue was significantly lower than that in adjacent tissue,and in each pancreatic cell line was significantly lower than that in normal pancreatic ductal epithelial cell line(all P<0.05).The proliferative ability was significantly decreased,the apoptotic rate was significantly increased and the invasion ability was significantly weakened in pancreatic cells transfected with mi R-526 b-mimics(all P<0.05),while the opposite changes occurred in those transfected with mi R-526 b inhibitors(all P<0.05).The results of analysis showed that XRCC5 was a potential target gene for mi R-526 b;in pancreatic cells,both m RNA and protein expressions of XRCC5 were down-regulated after transfection with mi R-526 b mimics,and were upregulated after transfection with mi R-526 b inhibitors(all P<0.05);there was a negative correlation between mi R-526 b XRCC5 m RNA in pancreatic cancer tissue(r=–0.456,P<0.05).Conclusion:The expression of mi R-526 b is down-regulated in pancreatic cancer,and the low expression of mi R-526 b can promote the proliferation and invasion and inhibit the apoptosis of pancreatic cancer cells.The mechanism may be related to the up-regulation of the expression of its target gene XRCC5.