ACE2、PRR和AT2R在肾癌干细胞中的表达

Expression of ACE2,PRR and AT2R in Renal Carcinoma Stem Cells

目的探讨肾素-血管紧张素系统(renin-angiotensin system,RAS)成分在肾透明细胞癌(renal clear cell carcinoma,RCCC)中的肿瘤干细胞(cancer stem cells,CSCs)上的表达情况,为RAS抑制剂治疗RCCC提供理论依据。方法选出既有石蜡标本又有新鲜冷冻标本的RCCC组织样本。对样本的RAS成分:肾素(Renin)、肾素原受体(prorenin receptor,PRR)、血管紧张素转换酶(angiotensin-converting enzyme,ACE)、血管紧张素转换酶2(angiotensin-converting enzyme 2,ACE2)和血管紧张素II受体(angiotensin II receptor,AT2R)行免疫组化染色。用OCT4或KLF4作为CSCs标志物分别和以上RAS成分进行免疫荧光共染色或免疫组化双染色。采用Western Blot和RT-qPCR技术定量研究RCCC组织样本中这些RAS组分的蛋白和基因表达情况。结果免疫组化染色显示,35份RCCC样本中分别有31份、33份和33份表达肾素、PRR和ACE2。所有35份样本均表达AT2R,ACE只在正常组织血管的内皮细胞中表达。双免疫组化双染色显示ACE2定位于KLF4+CSCs上,肾素不表达在CSCs上。免疫荧光染色显示PRR和AT2R定位于OCT4+CSCs上。Western Blot证实除了肾素外,以上RAS的蛋白成分都有表达。RT-qPCR显示了所有RAS组分的转录表达,但AT2R未见表达。结论RCCC中CSCs表达PRR、ACE2和AT2R,通过靶向CSCs调控RAS可能成为一种新的治疗RCCC的方法。

Objective To investigate the expression of renin-angiotensin system(RAS)components on cancer stem cells(CSCs)in renal clear cell carcinoma(RCCC)and to provide a theoretical basis for RAS inhibitors to treat RCCC survival of patients.Methods RCCC tissue samples with both paraffin and fresh frozen specimens were selected.Immunohistochemical staining was performed for RAS components of renin,prorenin receptor(PRR),angiotensin-converting enzyme(ACE),angiotensin-converting enzyme 2(ACE2)and angiotensin II receptor(AT2R).OCT4 or KLF4 were used as CSCs markers for immunofluorescence co-staining or immunohistochemical double staining with the above RAS components.Western Blot and RT-qPCR were used to quantitatively study the protein and gene expressions of these RAS components in RCCC tissue samples.Results Immunohistochemical staining showed that 31,33 and 33 of 35 RCCC samples expressed renin,PRR and ACE2,respectively.All 35 samples expressed AT2R,while ACE was only expressed in endothelial cells of blood vessels in normal tissue.Double immunohistochemical staining showed that ACE2 was located on KLF4+CSCs,while renin was not expressed on CSCs.Immunofluorescence staining showed that PRR and AT2R were located on OCT4+CSCs.Western Blot confirmed that all the protein components of RAS were expressed except renin.RT-qPCR showed transcriptional expression of all RAS components,but no expression of AT2R.Conclusion In RCCC,CSCs expressed PRR,ACE2 and AT2R.Regulation of RAS by targeting CSCs may be a new therapeutic approach for RCCC.