VEGFR-3(261bp) A B A:VEGFR-3siRNA/PEI转染LEPCs48h各组VEGFR-3mRNA的表达。B:统计学结果siRNA a组、siRNA b组、siRNA c组与空白转染组和阴性转染组比较有统计学意义,#P<0.05,*P<0.01,siRNAa组与siRNAb组、siRNAc组比有统计学意义P<0.05 图1 半定量RTPCR结果分析 2.2.2 Western blot检测结果分析 转染各组细胞VEGFR-3蛋白表达结果显示,空白与阴性转染组之间无差异siRNA a组、siRNA b组、siRNA c组与空白转染组和阴性转染组比较均有显著差异,其中siRNA a组抑制效率最高(图2)。此结果在蛋白水平上符合半定量RT-PCR的实验结果。 空白 阴性 a b c VEGFR-3165KD β-actin 43KD C D C:VEGFR-3siRNA/PEI转染LEPCs72h各组VEGFR-3蛋白的表达。D:统计学结果siRNA a组、siRNA b组、siRNA c组与空白转染组和阴性转染组比较有统计学意义,#P<0.05,*P<0.01,siRNAa组与siRNAb组、siRNAc组比有统计学意义,P<0.05 图2 Westem blot 检测结果 3 讨论 在肿瘤转移过程中,肿瘤细胞可经新生的淋巴管转移[11],抑制肿瘤淋巴管新生对肿瘤治疗至关重要。LEPCs参与肿瘤淋巴管新生已成为研究热点[12]。LEPCs可迁移和定居到肿瘤,参与肿瘤淋巴管新生[3,13-14]。关于LEPCs参与淋巴管新生的机制尚未完全明确。本实验在体外将VEGFR-3siRNA转染入LEPCs。裸siRNA分子易降解且靶向性差,目前多采用借助载体给药,阳离子聚合物具有较低的免疫原性和细胞毒性多被应用于研究[15]。PEI是一种被广泛用于DNA和siRNA等的阳离子聚合物载体,通过形成纳米粒包裹siRNA后给药[16]。 本研究采用分子量为25KDa的PEI为载体介导VEGFR-3siRNA的转染,成功转染VEGFR-3siRNA进入LEPCs内,用RT-PCR和Western blot检测mRNA和蛋白质表达,证实了VEGFR-3siRNA对靶基因VEGFR-3的沉默效果。说明通过利用RNAi技术能够在体外靶向抑制LEPCs VEGFR-3的表达,进而干扰VEGF-C/VEGFR-3信号途径,抑制其分化和淋巴管新生。如果以体外实验结果作为基础,将VEGFR-3siRNA导入LEPCs并靶向于肿瘤,可能会抑制淋巴管新生引起的肿瘤转移。 [参考文献] [1] Wang H,Tan Y,Zhang M,et al.Vascular endothelial growth factor-C induced differentiation of CD34+ CD133+ VEGFR-3 EPCs towards lymphatic endothelial cells[J].Jpn J Lymphol,2005,28(2):71-73. [2] Salven P,Mustjoki S,Alitalo R,et al.VEGFR-3 and CD133 identify a population of CD 34+ lymphatic/vascular endothelial precursor cells[J].Blood,2003,101(1):168-172. [3] Norrmén C,Tammela T,Petrova TV. et al. Biological basis of therapeutic lymphangiogenesis. Circulation[J].2011,123:1335-1351. [4] Tan YZ,Wang HJ,Zhang MH,et al.CD34+ VEGFR-3+ progenitor cells have a potential to differentiate towards lymphaticendothelial cells[J]. Cell Mol Med,2014,18(3):422-433. [5] Religa P,Cao R,Bjorndahl M,et al. Presence of bone marrow derived circulating progenitor endothelial cells in the newly formed lymphatic vessels[J].Blood,2005,106(13): 4184-4190. [6] Bogos K,Renyi-Vamos F,Dobos J,et al.High VEGFR-3-positive circulating lymphatic/vascular endothelial progenitor cell level is associated with poor prognosis in human small cell lung cancer[J].Clin Cancer Res,2009,15(5):1741-1746. [7] 王海杰,谭玉珍.淋巴管内皮祖细胞在淋巴管新生中的作用及其机制[J].解剖科学进展,2011,17(6):593-596. [8] González-González M,Rito-Palomares M,Méndez Quintero O. Partition behavior of CD133(+) stem cells from human umbilical cord blood in aqueous two-phase systems: In route to establish novel stem cell primary recovery strategies[J].Biotechnol Prog,2014,30(3):700-707. [9] Wu JH,Wang HJ,Tan YZ. et al.Characterization of rat very small embryonic-like stem cells and cardiac repair after cell transplantation for myocardial infarction[J].Stem Cells Dev,2012,21(8):1367-1379. [10] Zhang DY,Wang HJ,Tan YZ.Wnt/β-catenin signaling induces the aging of mesenchymal stem cells through the DNA damage response and the p53/p21 pathway[J].PLoS One,2011,6(6):e21397. [11] Moore XL,LU J,Sun L,et al.Endothelial progenitor cells “homing”specificity to brain tumors[J].Gene Theraphy,2004,11(10):811-818. [12] 王海杰,谭玉珍.淋巴管新生及其在疾病发生和治疗中的意义[J].解剖学报,2007,38(2): 250-252. [13] Hiasa K,Ishibashi M,Ohtani K,et al.Gene transfer of stromal cell-derived factor-1:enhances ischemic vasculogenesis and angiogenesis via vascular endothelial growth factor/endothelial nitric oxide synthase-related pathway[J].Circulation,2004,109(20):2454-2461. [14] Ingber DE. Mechanical signaling and the cellular response to extracellular matrix in angiogenesis and cardiovascular physiology[J].CireRes,2002:92(10):877-887. [15] Pecot CV,Calin GA,Coleman RL,et al.RNA interference in the clinic: challenges and future directions[J].Nat Rev Cancer,2011,11(1):59-67. [16] Goldsmith M,Mizrahy S,Peer D.Grand challenges in modulating the immune response with RNAi nanomedicines[J].Nanomedicine,2011,6(10):1771-1785. |