高糖诱导前列腺上皮细胞微小RNA的差异表达及miR-301a的促增殖作用

Aberrant expression of microRNAs induced by high glucose and the influence of miR-301a on the proliferation of prostatic epithelial cells

目的检测高糖刺激下微小RNA（miRNA）在前列腺组织及细胞中的差异表达，探讨高血糖对前列腺影响的分子机制。方法将成年雄性SD大鼠随机分为对照组和高血糖组（〉300mg／d1），应用miRNA芯片技术检测两组间miRNA表达谱的差异，并通过实时定量聚合酶链反应（qRT—PCR）方法验证；以qRT．PCR检测差异表达的miRNAs在高糖（50mmoL／L）培养的RWPE-1细胞中的表达；噻唑蓝（MTT）比色法检测转染miRNAs和／或高糖（25～50mmol／L）培养的RWPE—1的增殖。结果高血糖组大鼠前列腺组织中4个miRNA上调（miR-1862．405倍、miR-301a2．202倍、miR-3652．093倍、miR-1932．317倍），2个miRNA下调（miR-4340．298倍、miR-3610．386倍），差异均有统计学意义（P〈0．05）；高糖培养下，RWPE-1细胞中各miRNAs的表达趋势与之一致。MTT实验中25mmol／L组、50mmol／L组、miR-301a转染组的细胞吸光度（A）值分别为起始的175％、197％、188％，与对照组（122％）比较差异有统计学意义（P〈0．05）；50mmol／L高糖联合miR-301a抑制物转染组的A值为起始的143％，与50mmol／L组比较差异有统计学意义（P〈0．05）。结论体内外高糖条件均可引起前列腺miRNA表达谱变化，高糖通过miR-301a对前列腺上皮细胞的增殖有明显促进作用。

Objective To study the aberrant expression of miRNAs implicated in the prostate un- der high-glucose treatment and to uncover the molecular impact of hyperglycemia exerted on the prostate. Methods A hyperglycemia rat model was induced by intraperitoneal injection of streptozotocin on male Sprague-Dawley rats. MicroRNA array was taken to detect the different expression of miRNAs in prostate tissues of rats, with quantitative real time polymerase chain reaction （qRT-PCR） adapted to confirm the al- teration. Furthermore, these changes were also investigated in the human prostate epithelial cell line RWPE-1 in vitro. Methyl thiazol tetrazolium （MTF） assay was performed to evaluate the influence of high glucose （25-50 mmo]/L） and/or miRNAs transfeetion on the proliferation of RWPE-1. Results Com- pared to the control, four miRNAs were significantly up-regulated （miR-186 240.5%, miR-301a 220. 2% , miR-365 209. 3% , miR-193 231.7% ）in the hyperglycemia group （P 〈 0.05 ）, while two miR- NAs （ miR-434 29. 8% , miR-361 38.6% ） were obviously down-regulated （P 〈 0. 05）. These changes were consistent with the qRT-PCR results in RWPE-1 cells cultured in high-glucose condition. MTT assay showed the cellular absorbance values （A values ） of high-glucose groups and miR-301a-transfeeted group increased by 75 % , 97 % and 88% respectively at the 48th hour, while 22% for the control （ P 〈 0. 05）. Meanwhile, the A value of the 50 mmol/L group with miR-301 a-inhibitor transfected was significantly less than that of the 50 mmol/L group （P 〈 0. 05 ）. Conclusion Differential expression of miRNAs could be induced in prostate by high-glucose condition both in vitro and in vivo. Hyperglycemia and miR-301a have positive effect on prostatic epithelium proliferation.