miR-1271-5p在胃癌组织的表达及对胃癌AGS细胞生物学行为的影响

目的 探讨miR-1271-5p在胃癌组织和细胞中的表达及其对胃癌细胞增殖、侵袭和迁移的影响。方法 收集2011年6月至2014年6月广西医科大学附属肿瘤医院90例手术切除胃癌组织及相应癌旁组织。采用qRT-PCR法检测胃癌组织及相应癌旁组织,人胃癌细胞系（SGC-7901、MGC-803、AGS）和人正常胃黏膜上皮细胞系GES1中miR-1271-5p的表达情况。利用瞬时转染法将miR-1271-5p mimics（过表达miR-1271-5p组）和miR-NC（阴性对照组）分别转染胃癌AGS细胞,建立过表达miR-1271-5p的胃癌AGS细胞系,然后采用CCK-8法检测转染后的胃癌AGS细胞增殖能力,平板克隆形成实验检测细胞克隆形成能力,Transwell实验检测细胞迁移和侵袭能力。结果 miR-1271-5p在胃癌组织和胃癌细胞（SGC-7901、MGC-803、AGS）中的表达均低于相应癌旁组织及人正常胃黏膜上皮GES1细胞（均P<0.01）。与阴性对照组相比,过表达miR-1271-5p组胃癌AGS细胞增殖活力降低（P<0.01）,细胞集落形成数减少（P<0.01）,迁移和侵袭细胞数量亦减少（P<0.01）。结论 miR-1271-5p在胃癌组织和细胞中低表达,上调miR-1271-5p可抑制胃癌AGS细胞的增殖、迁移和侵袭。     

miR-9-5p靶向FGF9抑制胃癌细胞迁移侵袭的作用机制

目的:探讨miR-9-5p在胃癌组织中的表达及对胃癌细胞株SGC7901、AGS细胞迁移和侵袭影响的作用机制。方法:real-time PCR和Western blot检测癌旁组织、胃癌组织及其细胞系中miR-9-5p和FGF9的表达；Transwell小室检测过表达miR-9-5p或敲除FGF9对SGC7901和AGS细胞迁移和侵袭能力的影响；TargetScan在线分析、双荧光素酶报告基因和Western blot实验验证miR-9-5p和FGF9的靶向关系；将转染后的SGC7901细胞分为对照（NC）组和实验（miR-9-5p）组接种于裸鼠右侧腋窝皮下，观察记录裸鼠成瘤情况并绘制生长曲线。结果:与癌旁组织相比，胃癌组织及其细胞系中miR-9-5p表达下调、FGF9表达上调（P＜0.05）；过表达miR-9-5p或敲除FGF9能抑制SGC7901、AGS细胞迁移和侵袭；TargetScan在线分析、双荧光素酶报告基因和Western blot实验表明miR-9-5p能调控FGF9表达；miR-9-5p组细胞成瘤速度较NC组慢（P＜0.05），肿瘤体积及重量小（P＜0.05）。结论:miR-9-5p在胃癌组织中表达下调，过表达miR-9-5p可抑制FGF9表达，从而抑制胃癌细胞的迁移和侵袭，减缓肿瘤生长。     

miR-369-5p抑制肝细胞癌细胞增殖、迁移及侵袭

目的:探讨miR-369-5p在肝细胞癌（hepatocellular carcinoma,HCC）中的表达情况、临床意义,观察miR-369-5p对HCC细胞增殖、迁移及侵袭的影响及其作用机制。方法:实时定量PCR检测miR-369-5p在HCC组织与相应癌旁组织、正常肝细胞（L02）与HCC细胞系中的表达情况;CCK-8实验检测MHCC-97H及HCCLM3细胞增殖能力;Transwell实验检测MHCC-97H及HCCLM3细胞迁移及侵袭能力;Targetscan数据库预测p21活化激酶4（p21 activated kinase 4,PAK4）为miR-369-5p下游靶基因;用双荧光素酶实验检测荧光素酶活性;蛋白免疫印迹试验检测MHCC-97H及HCCLM3细胞中PAK4的蛋白表达水平。结果:miR-369-5p在HCC组织及细胞系中均明显低表达,低表达miR-369-5p与肿瘤大小、TNM分期、微血管浸润相关;在MHCC-97H及HCCLM3细胞中过表达miR-369-5p抑制细胞的增殖、迁移及侵袭能力;通过生物信息学工具预测PAK4是miR-369-5p的下游靶基因;在MHCC-97H及HCCLM3细胞中过表达miR-369-5p下调PAK4蛋白的表达。结论:在HCC中miR-369-5p表达下调且其低表达与HCC恶性病理特征有关,在HCC中过表达miR-369-5p可通过下调PAK4表达抑制细胞增殖、迁移及侵袭。     

miR-875-5p通过靶向USF2抑制胃癌细胞的增殖、迁移和侵袭

目的:探讨miR-875-5p对胃癌细胞增殖、迁移和侵袭的影响及其机制。方法:采用qPCR法检测胃癌细胞BGC-823、HGC-27、MGC-803、SGC-7901、AGS、MKN-45和胃黏膜上皮细胞GES-1中miR-875-5p的表达水平。利用脂质体转染技术,分别将miR-875-5p模拟物/抑制剂(mimic/inhibitor)及其阴性对照质粒(miR-NC/Anti-miR-NC)转染至AGS细胞/MKN-45细胞,构建过表达/抑制miR-875-5p的细胞模型,空白对照组(Control组)不转染。通过CCK-8、克隆形成、Transwell等实验分别检测miR-875-5p表达变化对细胞增殖、克隆形成、迁移和侵袭的影响。采用双荧光素酶报告基因实验验证miR-875-5p与上游刺激因子2(USF2)的靶向关系,WB实验验证miR-875-5p对USF2的调控作用并检测USF2蛋白的表达。构建MKN-45细胞裸鼠移植瘤模型,验证miR-875-5p过表达对MKN-45细胞成瘤能力的影响。结果:miR-875-5p在6种胃癌细胞中表达水平显著低于胃黏膜上皮细胞GES-1(均P<0.01)。与Control组和miR-NC组相比,miR-875-5p mimic组AGS细胞的增殖、克隆形成率、迁移和侵袭细胞数,以及USF2蛋白的表达均显著降低(P<0.05或P<0.01);miR-875-5p inhibitor组MKN-45细胞的增殖、克隆形成率、迁移和侵袭细胞数,以及USF2蛋白的表达均显著提高(P<0.05或P<0.01)。双荧光素酶报告基因实验证明,miR-875-5p能够直接靶向USF2基因。体内成瘤实验结果表明,过表达miR-875-5p显著抑制MKN-45细胞移植瘤的生长(均P<0.01)。结论:miR-875-5p通过靶向USF2抑制胃癌细胞的增殖、迁移和侵袭。     

miRNA-335基因启动子区甲基化与胃癌细胞不良生物学行为的关系

目的:探讨miR-335基因启动子区异常甲基化状态对胃癌细胞系中miR-335表达水平的影响,以及miR-335基因启动子区甲基化状态对胃癌细胞侵袭,迁移,以及增殖能力的影响。方法:1株永生化胃黏膜上皮细胞系(GES-1)和4株胃癌细胞系(SGC-7901,MKN-45,BGC-823和AGS)。实时荧光定量PCR(qRT-PCR)检测胃癌细胞株miR-335及CRKL的表达水平。甲基化特异性PCR(MSP)方法检测胃癌细胞株miR-335的基因启动子区甲基化状态。应用MTT方法检测恢复miR-335表达对胃癌细胞增殖能力的影响,Transwell侵袭迁移实验及划痕愈合实验分析恢复miR-335表达对胃癌细胞系侵袭及迁移能力的影响。结果:MSP实验结果表明,MKN-45、SGC-7901和BGC-823细胞系均存在基因启动子区异常的高甲基化状态,AGS细胞系基因启动子区亦呈部分高甲基化状态。去甲基药物5-aza-2′-deoxycytidine处理后胃癌细胞miR-335的表达水平可升高2~3倍。Transwell侵袭迁移实验及划痕愈合实验表明miR-335表达水平恢复后SGC-7901细胞的侵袭和迁移能力明显降低。MTT实验结果表明5-aza-2′-deoxycytidine处理后的SGC-7901细胞系与对照组相比,增殖能力显著降低。结论:miR-335启动子区的异常高甲基化状态抑制了miR-335在胃癌细胞系中的表达,恢复miR-335的表达水平可以抑制胃癌细胞的增殖,迁移和侵袭能力。miR-335为胃癌的肿瘤抑制因子。     

miR-542-5p对卵巢癌细胞SKOV3恶性生物学行为的影响

目的:探讨miR-542-5p对卵巢癌细胞系SKOV3的增殖、迁移、侵袭、凋亡等恶性生物学行为的影响。方法:应用miR-542-5p mimics和mimics阴性对照 (mimics NC)分别转染卵巢癌细胞SKOV3。采用MTT实验、划痕试验、Transwell实验和流式细胞术检测过表达miR-542-5p对SKOV3细胞增殖、迁移、侵袭、凋亡的影响。结果:过表达miR-542-5p后,SKOV3细胞的增殖能力较阴性对照和正常SKOV3细胞明显降低（P<0.05）;Transwell实验和划痕实验显示,过表达miR-542-5p后,细胞的迁移和侵袭能力较阴性对照组明显下降（P<0.05）;流式细胞术结果显示,过表达miR-542-5p后,SKOV3细胞的凋亡率较阴性对照组升高,而对细胞周期无影响。结论:过表达miR-542-5p可以抑制卵巢癌细胞SKOV3的体外增殖、迁移和侵袭能力,诱导细胞凋亡。提示miR-542-5p在卵巢癌恶性生物学进程中可能发挥重要作用。     

miR-21通过靶向SOX2增强胃癌细胞的迁移能力

目的:探讨miR-21在胃癌细胞系中对SOX2的调控作用及其对胃癌细胞迁移的影响。方法:在胃癌细胞系AZ-521、AGS中通过转染miR-21 mimic或者miR-21 antagomir构建miR-21过表达和低表达模型,RT-qPCR检测转染效果,并通过蛋白免疫印迹法检测SOX2在转染细胞中表达的变化。构建miR-21双荧光素酶报告基因,在工具细胞HEK293T中检验miR-21是否通过直接结合SOX2的3′-UTR区域来对其实现调控。应用Transwell迁移实验检测miR-21及SOX2对胃癌细胞迁移能力的影响。结果:miR-21直接结合于SOX2的3′-UTR区域来抑制SOX2在胃癌细胞系中的表达。迁移实验发现上调miR-21或者下调SOX2都能促进胃癌细胞的迁移。结论:miR-21可促进胃癌细胞的迁移能力,其机制可能通过抑制SOX2的表达而实现。     

miR-486-5p对胃癌细胞株SGC7901生物学行为的影响

背景与目的：既往研究表明微小RNA-486-5p(miR-486-5p)在多种肿瘤的进展中起重要作用,但其在胃癌中作用的研究较少,本研究旨在探讨miR-486-5p对胃癌细胞株SGC7901增殖、凋亡及迁移能力的影响。方法：使用实时定量PCR(quantification real-time PCR,qRT-PCR)检测胃癌细胞株SGC7901及胃黏膜上皮细胞GES-1中miR-486-5p的表达,构建miR-486-5p过表达质粒,使用脂质体法瞬时转染胃癌细胞株SGC7901,qRT-PCR检测转染细胞后miR-486-5p的表达丰度,噻唑蓝(MTT)法及流式细胞仪检测细胞的增殖及凋亡情况,Transwell小室迁移实验检测细胞的迁移能力。结果：miR-486-5p在SGC7901细胞中表达明显下调,SGC7901细胞转染miR-486-5p过表达质粒后,miR-486-5p表达明显上调,细胞增殖、迁移能力降低,凋亡率增高,差异均有统计学意义(P<0.05)。结论：miR-486-5p可抑制胃癌细胞株SGC7901的增殖和迁移。     

MiR-144-5p在胃癌中的表达及其生物学功能

摘 要：［目的］ 探讨miR-144-5p在胃癌组织和细胞中的表达及生物学功能。［方法］ 采用qRT-PCR 检测miR-144-5p在胃癌组织和细胞系中的表达水平,并验证miR-144-5p mimics的转染效率;分别采用CCK-8法、克隆形成实验、流式细胞仪、Transwell实验检测miR-144-5p mimics对胃癌细胞AGS和HGC-27增殖、克隆形成能力、细胞周期和侵袭能力的影响。［结果］ MiR-144-5p在胃癌组织的表达水平明显低于癌旁组织（0.607±0.257 vs 1.000±0.360,t=5.616,P<0.001）。MiR-144-5p低表达与胃癌患者的肿瘤浸润深度、淋巴结转移、远处转移、TNM分期显著相关（P<0.05）。MiR-144-5p在胃癌细胞SNU-1、HGC-27、SGC-7901、KATO Ⅲ及AGS中表达水平显著低于正常人胃黏膜上皮细胞GES-1（F=12.17,P<0.001）。转染miR-144-5p mimics后,AGS（t=4.902,P=0.001）和HGC-27（t=4.154,P=0.003）细胞中miR-144-5p的表达水平显著增高;AGS和HGC-27细胞的增殖能力、克隆形成能力、侵袭能力均被抑制（P<0.05）,G1期细胞比例增加、而S期的细胞比例减少（P<0.05）。［结论］ MiR-144-5p在胃癌组织和细胞中表达降低,与胃癌患者的TNM分期较晚和胃癌细胞恶性程度较高有关,提示miR-144-5p在胃癌的恶性进程中起重要作用。     

沉默ERK5对胃癌SGC-7901、BGC-823细胞生物学功能的影响

目的 探讨沉默细胞外信号调节激酶5（extracellular signal regulated kinase 5,ERK5）对胃癌细胞SGC-7901、BGC-823生物学功能的影响。方法 实时荧光定量PCR法（qRT-PCR）检测人胃癌细胞株和人胃黏膜上皮细胞株ERK5 mRNA的表达水平。应用短发荚RNA（shRNA）干扰技术沉默胃癌细胞SGC-7901、BGC-823中ERK5的表达。CCK-8法检测ERK5沉默后胃癌细胞的生长能力,平板克隆实验检测细胞克隆形成能力,Transwell 实验检测细胞侵袭和迁移能力,流式细胞仪检测细胞凋亡和周期分布。结果 与胃黏膜上皮细胞GES-1相比,胃癌细胞SGC-7901、BGC-823、AGS、HGC-27中ERK5 mRNA均呈高表达,相对表达量分别为2.696±0.501、1.865±0.185、1.793±0.137和1.530±0.093（P<0.05）。ERK5-shRNA有效沉默胃癌细胞SGC-7901、BGC-823中ERK5的表达水平,沉默效率分别为（74.4±1.5）%和（69.1±3.9）%,差异有统计学意义（P<0.05）。沉默 ERK5的表达能有效抑制胃癌细胞增殖、克隆形成、迁移和侵袭能力（P<0.05）,而促进胃癌细胞凋亡（P<0.05）,并诱导细胞周期阻滞于G0/G1期。结论 沉默ERK5可显著抑制胃癌细胞SGC-7901、BGC-823的生长侵袭,促进细胞凋亡,ERK5可能是胃癌治疗的潜在靶点。     

miR-106a靶向调控TIMP2对人胃癌细胞增殖、转移及EMT的影响

目的 探讨微小RNA-106a(miR-106a)在人胃癌组织中的表达及其与癌细胞增殖、转移的关系。方法 收集人胃癌和配对癌旁福尔马林固定-石蜡包埋样本共50对,Real-time PCR法检测miR-106a在人胃癌组织中的表达;培养人低分化胃癌细胞系SGC-7901、BGC-823、MKN-45和永生化人胃黏膜上皮细胞GES-1,Real-time PCR法检测miR-106a在人胃癌细胞中的表达;MTT法检测细胞增殖,Transwell法检测细胞迁移和侵袭,生物信息学和双荧光素酶法鉴定miR-106a靶基因,Western blot检测靶蛋白TIMP2、MMP2、MMP9、E-cadherin、N-cadherin表达。结果 Real-time PCR检测显示,与癌旁组织比较,miR-106a在人胃癌组织中高表达,差异有统计学意义(P＜0.001);与GES-1细胞比较,miR-106a在人胃癌细胞SGC-7901、BGC-823、MKN-45中普遍高表达,差异有统计学意义(P＜0.001)。MTT检测显示抑制miR-106a后胃癌细胞SGC-7901、BGC-823增殖能力下降(P＜0.01)。Transwell显示胃癌细胞BGC-823迁移、侵袭能力下降(P＜0.001)。双荧光素酶法显示TIMP2野生型报告基因与miR-106a mimic共转后,其荧光素酶活性较miR-106a NC组明显下降(P＜0.001),但TIMP2突变型报告基因无明显变化。Western blot显示抑制miR-106a后TIMP2表达升高,MMP2、MMP9表达下降,E-cadherin表达升高,N-cadherin表达下降。结论 miR-106a在人胃癌中的高表达可能通过靶向TIMP2而影响癌细胞的增殖、转移和上皮-间质转化。     

幽门螺杆菌感染诱导微小RNA?181c对胃癌细胞增殖和侵袭的影响

目的探讨幽门螺杆菌(Hp)感染诱导微小RNA-181c(miR-181c)对胃癌细胞增殖、侵袭和迁移的影响。方法采用实时定量PCR(QPCR)检测Hp感染人正常胃黏膜GES-1细胞和胃癌细胞(BGC-823、SGC-7901、AGS)的miR-181c水平。采用脂质体向SGC-7901细胞转染miR-181c抑制物(Inhibitor组)或阴性对照序列(NC组),另取未转染的细胞为对照组;转染48 h后采用QPCR检测miR-181c水平,活细胞计数(CCK-8)法、划痕实验和Transwell小室实验检测细胞增殖活力、划痕愈合率和穿膜细胞数以评估细胞增殖、迁移和侵袭能力,QPCR和Western blotting检测Bcl-2、基质金属蛋白酶(MMP)-9和神经型钙黏蛋白(N-cad)水平。结果QPCR检测结果显示Hp感染后各细胞的miR-181水平较感染前均升高(P<0.05),GES-1、BGC-823、SGC-7901和AGS细胞Hp感染后的miR-181c水平分别为感染前的4.37、1.63、3.25和2.09倍。与对照组和NC组相比,Inhibitor组SGC-7901细胞的miR-181c水平和转染48、72 h后的增殖活力降低(P<0.05);Inhibitor组SGC-7901细胞的划痕愈合率和穿膜细胞数量分别为(21.679±3.762)%和(128.056±21.463)个,低于对照组的(65.004±2.309)%和(325.07±34.082)个及NC组的(65.675±2.914)%和(328.035±31.391)个,差异有统计学意义(P<0.05);与对照组和NC组相比,Inhibitor组的Bcl-2、MMP-9和N-cad水平均降低(P<0.05)。对照组和NC组上述指标的差异无统计学意义(P>0.05)。结论Hp感染可升高胃癌细胞的miR-181c水平,下调该miR-181c水平对增殖、侵袭和迁移具有明显抑制作用,为Hp感染的胃癌治疗提供了新的靶点。     

MicroRNA 495 Inhibits Proliferation and Metastasis and Promotes Apoptosis by Targeting Twist1 in Gastric Cancer Cells

Recently, microRNAs (miRNAs) have been reported to participate in multiple biological processes. However, the effects of miR-495 on gastric cancer (GC) remain unclear. The purpose of this study was to explore the functions of miR-495 in GC cell proliferation, metastasis, and apoptosis. SGC-7901 and BGC-823 cell lines were transfected with miR-495 mimic, miR-495 inhibitor, and negative controls (mimic control and inhibitor control). The expressions of miR-495, cell viability, migration, apoptosis, and apoptosis-related factors were examined by qRT-PCR, trypan blue staining, Transwell, flow cytometry, and Western blot, respectively. Simultaneously, key factor expression levels of EMT were detected by qRT-PCR and Western blot. The direct target of miR-495 was confirmed by dual-luciferase assay. Additionally, sh-Twist1, pc-Twist1, and corresponding controls were transfected into SGC-7901 and BGC-823 cells, and the protein levels of EMTassociated factors were detected by Western blot. miR-495 was downregulated in GC cells. miR-495 expression level was effectively overexpressed or suppressed in SGC-7901 and BGC-823 cells. Overexpression of miR-495 significantly decreased cell viability and migration, increased apoptosis, and inhibited the EMT process. Suppression of miR-495 showed contrary results. Twist1 was clarified as a target gene of miR-495, and Twist1 silencing obviously reduced the promoting effect of miR-495 suppression on these biological processes. Twist1 silencing significantly blocked the EMT process in both SGC-7901 and BGC-823 cells. miR-495 inhibited proliferation and metastasis and promoted apoptosis by targeting Twist1 in GC cells. These data indicated that miR-495 might be a novel antitumor factor of GC and provide a new method for the treatment of GC.     

Curcumin inhibits cell growth and induces cell apoptosis through upregulation of miR-33b in gastric cancer

In this work, the in vitro experiments about biological mechanisms of curcumin were conducted using the gastric cancer cell lines SGC-7901 and BGC-823. After 24-h exposure to curcumin at the concentrations of 5, 10, 15, 20, and 40 μmol/L, two cells showed the decreased proliferation and increased apoptosis abilities. Real-time PCR, Cell Counting Kit-8 (CCK-8) assay, western blotting, and cell apoptosis assay were used to further study the underlying mechanisms of curcumin. The first stage of our studies showed that curcumin affected the expression of miR-33b, which, in turn, affected the expression of the X-linked inhibitor of apoptosis protein (XIAP) messenger RNA (mRNA). Next, curcumin was also identified to regulate the proliferation and apoptosis of SGC-7901 and BGC-823 cells. Further bioinformatics analysis and luciferase reporter assays proved that XIAP was one of the target genes of miR-33b. In the next stage, SGC-7901 and BGC-823 cells were treated with 20 μL curcumin, miR-33b mimics, and small interfering RNA (siRNA) of XIAP, respectively. The results showed that curcumin had similar effects on cell growth and apoptosis as the upregulation of miR-33b and the upregulation of the siRNA of XIAP. The results that followed from the restore experiments showed that curcumin affected cell growth and apoptosis presumably by upregulating the XIAP targeting in gastric cancer. Collectively, our results indicate that curcumin-miR-33b-XIAP coupling might be an important mechanism by which curcumin induces the apoptosis of SGC-7901 and BGC-823 cells.

     

Down-regulation of miR-212 expression by DNA hypermethylation in human gastric cancer cells

There has been few report discussing the expression and function of miR-212 in gastric cancer (GC). The aim of this pilot study was to investigate the expression of miR-212 in both gastric cancer tissues and gastric cancer cells and further explores the possible reasons for this change and the impact on the development of gastric cancer. qRT-PCR was used to detect the expression of miR-212 in primary GC tissues, adjacent normal tissues, gastric cancer cell lines BGC-823, SGC-7901, MKN-45, and normal gastric mucosa cell line GES. The expression of miR-212 was evaluated before and after treatment with methylation inhibitor-5-Aza-2'-deoxycitidine (5-Aza-dC), finally anti-miRNA and dual luciferase reporter assay were used to prove that MYC is a target gene of miR-212. The results showed that a significant reduction of miR-212 expression in GC tissues was observed compared to that in normal tissues (P = 0.002). At the same time, miR-212 expression level in normal gastric mucosa cell line GES was higher than that of in gastric cancer cell lines BGC-823, SGC-7901, and MKN-45 (P = 0.015, 0.008, 0.044, respectively). Computer sequence analysis showed the hypermethylation of CpG islands(CPI) in the promoter regions of miR-212 led to the lower expression of miR-212 in gastric cell strains (BGC-823 and SGC-7901). MiR-212 expression was significantly recovered after treatment with methylation inhibitor 5-Aza-dC (P = 0.016, 0.000, 0.015, respectively). Then, the results of AMOs transfection and dual luciferase reporter assay showed that Myc is a target of miR-212, which will be helpful to verify the function of miR-212 in carcinogenesis. The conclusion could be deduced from the study that decreased expression of miR-212 may be due to hypermethylation of CPI in gastric cancer cells, and miR-212 might act on the progression of gastric cancer through the potential target gene Myc.     

铂类药物对胃癌细胞生物学行为和MDR1表达的影响

目的 研究顺铂（CDDP）和奥沙利铂（L-OHP）对人胃癌细胞株生长的抑制作用,进而分析两种铂类不同的作用机制。方法 用不同浓度（IC10、IC30、IC50）的CDDP和L-OHP分别作用胃癌细胞株（BGC-823和SGC-7901）24、48、72h,应用MTT比色法检测细胞的增殖抑制率;采用RT-PCR法检测MDR1基因表达量。IC30浓度的两种铂类药物作用于胃癌细胞48h后,用流式细胞术分析细胞凋亡,细胞划痕实验评价细胞迁移能力。结果 两种铂类药物作用后,胃癌细胞BGC-823和SGC-7901的增殖受到抑制,呈时间和剂量依赖,L-OHP的量效变化更明显。两种铂类药物作用后,MDR1呈上升趋势,随着浓度增加和（或）时间的延长,表达增强。BGC-823细胞的凋亡率增加较SGC-7901细胞明显,L-OHP组的细胞凋亡率高于CDDP组;BGC-823细胞的增殖迁移较SGC-7901细胞慢而距离短,CDDP作用后细胞的增殖迁移较L-OHP作用后快而距离长。结论 L-OHP诱导胃癌细胞凋亡及抑制细胞迁移侵袭的能力均强于CDDP。胃癌对两种铂类药的耐药机制可能与其诱导MDR1表达上调有关。     

MicroRNA-181a Functions as an Oncomir in Gastric Cancer by Targeting the Tumour Suppressor Gene ATM

Based on our previous experiments, this study is to further investigate the functional significance of miR-181a and its target gene in gastric cancer. Expression of miR-181a was detected by qRT-PCR in three normal gastric tissues and three human gastric cancer cell lines (SGC-7901, MGC-803, and BGC-823 cells). After transfection with miR-181a inhibitor, proliferation, apoptosis, migration, and invasion of the SGC-7901 cells were evaluated. Ataxia-telangiectasia mutation (ATM) was predicted as a target gene of miR-181a with bioinformatics analysis, and was verified by lucifersae reporter assay. Expression of ATM protein in HEK293T cells and tissues was measured by Western Blot. Expression of ATM mRNA in HEK293T cells was measured by RT-PCR. Compared with three non-tumour tissues, the expression of miR-181a in three gastric cancer cells was significantly increased by 26.68, 14.83 and 14.96 folds; Compared with Negative Control(NC) and blank groups, transfection of miR-181a inhibitor led to inhibition of SGC7901 cell proliferation, invasion, and migration as well as promotion of apoptosis. A luciferase reporter assay demonstrated that ATM was a direct target of miR-181a, miR-181a mimics transfection down regulated ATM mRNA and protein expression. There was inverse correlation between miR-181a and ATM protein expression in gastric cancer and normal gastric tissues. Our study demonstrates that over-expression of miR-181a might be involved in development of gastric cancer by promoting proliferation and inhibiting apoptosis probably through directly targeting ATM. miR-181a modulation may be a potential strategy for the development of miRNA-based therapy of gastric cancer.