胃癌SGC7901/DDP细胞microRNA的表达谱分析及其在耐药逆转中的作用

 目的：分析胃癌SGC7901/DDP细胞microRNA表达谱及其耐药特性,研究筛选出的microRNA-200c对SGC7901/DDP细胞耐药的影响。方法：采用MTT法检测细胞的药物敏感性;应用microRNA芯片进行表达谱分析;运用生物信息学对筛选出的microRNA进行靶点预测和生物学进程分析。采用实时荧光定量RT-PCR检测microRNA-200c的表达;采用细胞转染分析microRNA-200c对SGC7901/DDP细胞药物敏感性的影响。结果：SGC7901/DDP细胞对顺铂、阿霉素、5-氟脲嘧啶及紫杉醇的IC50均显著高于SGC7901细胞(P<0.05)。与SGC7901细胞相比,SGC7901/DDP细胞中表达上调和下调超过2倍的microRNA分别有5和14个。microRNA高低表达组预测的靶点均广泛参与信号传导、细胞周期、分化、凋亡、增殖等生物学进程。实时荧光定量RT-PCR分析证实microRNA-200c在SGC7901/DDP细胞中的表达显著降低(P<0.05),microRNA-200c能够显著降低SGC7901/DDP细胞对顺铂、阿霉素、5-氟脲嘧啶及紫杉醇的IC50(P<0.05)。结论：SGC7901/DDP细胞的多药耐药特性可能与microRNA表达谱的改变有关,其耐药表型的逆转可能与microRNA-200c的表达有关。     

Fas基因转导逆转胃癌耐药细胞的作用及其机制分析

目的　 观察Fas基因转导人胃癌耐药细胞SGC790 1/VCR对化疗药物的敏感性 ,并初步探讨其机制。方法　 以流式细胞仪检测Fas基因转导和对照胃癌细胞在细胞周期中的分布 ;用MTT实验检查癌细胞对多种药物的敏感性 ;用免疫细胞化学染色法检测胃癌细胞P 糖蛋白 (P gp)和拓扑异构酶II(TopoII)的表达。结果　与胃癌细胞SGC790 1和pBK SGC790 1/VCR相比较 ,Fas SGC790 1/VCR在G2期减少 ,S期增多 ,并出现明显的凋亡峰 ;Fas SGC790 1/VCR对DDP ,MMC和 5 Fu的敏感性增加 ,但对VCR和DOX的敏感性无明显变化 ;SGC790 1,pBK SGC790 1/VCR和Fas SGC790 1/VCRTopoII的表达无明显差别 ;Fas SGC790 1/VCRP gp的表达水平明显低于 pBK SGC790 1/VCR ,仅显示弱阳性。 结论　Fas基因可在一定程度上逆转人胃癌耐药细胞SGC790 1/VCR的多药耐药性 (MDR) ,其涉及的相关机制可能是增强细胞对凋亡诱导剂的敏感性 ,以及降低细胞P gp的表达水平     

PPZ与5-FU对胃癌细胞生长、自我更新能力的影响及相互作用

目的 探讨泮托拉唑（PPZ）、5-氟尿嘧啶（5-FU）在调控胃癌细胞及胃癌干细胞生长、自我更新能力中的影响及其相互作用。方法 将SGC-7901和HGC-27细胞分为3组实验:5-Fu处理组、PPZ处理组和5-Fu+PPZ组。通过细胞成球实验检测PPZ加药前后胃癌细胞系（SGC7901、HGC-27）中胃癌细胞及胃癌干细胞自我更新能力的变化,观察PPZ对胃癌细胞系成球能力干扰情况;MTT法检测PPZ、5-FU对胃癌细胞及胃癌干细胞增殖能力的影响,观察PPZ对5-FU药物敏感性的调节作用。结果 PPZ加入后胃癌细胞系（SGC7901、HGC-27）和胃癌干细胞系（SGC7901-SP、 HGC-27-SP）自我更新率比PPZ加入前的自我更新率下降（P＜0.01）;PPZ、5-FU对胃癌细胞（SGC7901、HGC-27）增殖均有抑制作用,而5-Fu+PPZ联合组抑制最为明显,抑制增殖的作用在24 h开始出现,96 h最低,均低于0 h。PPZ对胃癌干细胞（SGC7901-SP、HGC-27-SP）增殖均有抑制作用,在48 h逐渐明显;加入PPZ后,胃癌干细胞（SGC7901-SP、HGC-27-SP）两个细胞系酶标仪检测到的吸光值在48 h、72 h、96 h时均下降。72 h和96 h时,加与不加PPZ的吸光值比较,统计学意义显著（P＜0.01）。不同浓度（0~50 μg/ml）5-FU对胃癌干细胞（SGC7901-SP、HGC-27-SP）增殖抑制的差异不显著;而加入PPZ 100 μg/ml后,随着5-FU浓度的增加增殖抑制作用逐渐增强,在40~50 μg/ml浓度的5-FU对胃癌干细胞（SGC7901-SP、HGC-27-SP）增殖抑制更加明显;加入PPZ 后,40 μg/ml及50 μg/ml浓度的5-FU作用下胃癌干细胞（SGC7901-SP、HGC-27-SP）酶标仪检测到的吸光值均降低。结论 PPZ能有效抑制胃癌细胞及胃癌干细胞的自我更新能力,抑制其增殖,并可提高其对5-FU的化疗敏感性。PPZ有望成为逆转胃癌耐药的一类联合治疗药物应用于临床。     

ER-α36和miR-143介导胃癌细胞的侵袭

 目的：探讨雌激素受体α36（ER-α36）与胃癌细胞侵袭之间的关联及其作用机制。方法：用高浓度和低浓度17β-雌二醇作用人胃癌细胞SGC7901,检测细胞侵袭能力和ER-α36蛋白表达变化;构建稳定转染低表达ER-α36和高表达ER-α36的SGC7901细胞系,在检测其侵袭能力的变化同时进行microRNA测序。结果：高浓度17β-雌二醇刺激SGC7901细胞后,细胞的侵袭能力减弱,ER-α36的蛋白减少;低浓度17β-雌二醇刺激细胞后的效应相反;高表达ER-α36的SGC7901细胞的侵袭能力要明显高于低表达ER-α36和对照组的SGC7901细胞;高表达ER-α36的SGC7901细胞miR-143的表达显著下降,低表达ER-α36的SGC7901细胞miR-143的表达显著上升。结论：ER-α36的表达与胃癌的侵袭相关,此机制可能与miR-143的调控有关。     

上皮间质转化在胃癌SGC7901细胞向胃癌干细胞转化过程中的作用

BACKGROUND: Studies have found that epithelial-mesenchymal transition is closely related with tumor invasion, metastasis, and drug resistance, but studies on the role of epithelial-mesenchymal transition in the transformation process of gastric cancer cells SGC7901 to gastric cancer stem-like cells are rarely reported. OBJECTIVE: To explore the effect of epithelial-mesenchymal transition in the transformation process of gastric cancer cells SGC7901 to gastric cancer stem-like cells. METHODS: Vincristine-induced SGC7901 cells were cultured and screened to prepare gastric cancer stem-like cells. CD44 phenotype, morphological changes, stem cell-related markers, and epithelial-mesenchymal transition related molecules were detected. RESULTS AND CONCLUSION: After passage, vincristine-induced SGC7901 cells presented with morphological changes, and clonal cell spheres generated after serum-free suspension culture. Meanwhile, the proportion of SGC7901 cells positive for CD44 was decreased. Expression levels of SOX2, OCT4, Snail1 mRNA, Twist mRNA and Vimentin mRNA were significantly higher in the gastric cancer stem-like cells than SGC7901 cells, but the expression level of E-caderin was lower in the gastric cancer stem-like cells than SGC7901 cells. These findings indicate that gastric cancer cells SGC7901 can be successfully transformed into gastric cancer stem-like cells, and the epithelial-mesenchymal transition is involved in this transforming progress.       

miR-140在人胃癌组织中的表达及对SGC-7901胃癌细胞功能的影响

 目的: 研究microRNA-140(miR-140)在人胃癌和正常胃组织中的表达水平,以及调控miR-140表达后对SGC-7901胃癌细胞功能的影响。方法: 采用实时荧光定量PCR检测miR-140在人胃癌和正常胃组织中的表达水平;将miR-140 mimics(miR-140上调表达)和miR-140 inhibitors(miR-140下调表达)分别通过脂质体转染至人胃癌SGC-7901细胞中,同时设置未转染对照组(control组)和miRNA无义序列转染对照组(NC组)。实时荧光定量PCR检测转染后各组细胞中miR-140的表达变化;MTT方法检测各组细胞的生长活力和顺铂(DDP)作用下的生长抑制率;流式细胞术检测各组的细胞周期和凋亡率;Transwell实验检测各组细胞侵袭能力;Western blot检测各组细胞中组蛋白脱乙酰酶4(HDAC4)蛋白表达。结果: miR-140在人胃癌组织中表达水平显著低于正常胃组织(P<0.05)。与control和NC组相比,miR-140 mimics组中SGC-7901细胞活力和侵袭能力下降,细胞周期被阻滞,DDP作用下细胞生长抑制率和凋亡率上升,且HDAC4蛋白表达下调,差异均有统计学意义(P<0.05);而miR-140 inhibitors组中SGC-7901细胞活力和侵袭能力上升,细胞周期被促进,DDP作用下细胞生长抑制率和凋亡率下降,且HDAC4蛋白表达上调,差异均有统计学意义(P<0.05)。结论: miR-140在胃癌组织中低表达,可作为抑癌因子调控胃癌细胞活力、细胞周期变化、凋亡、侵袭并通过下调HDAC4发挥作用。miR-140可能作为胃癌诊断和治疗的新靶点。     

Reversal of P‐glycoprotein‐mediated multi‐drug resistance by the E3 ubiquitin ligase Cbl‐b in human gastric adenocarcinoma cells

P‐glycoprotein (P‐gp)‐mediated multi‐drug resistance (MDR) is a major barrier to the effective chemotherapy of many cancers. Recent studies have shown that inhibition of the PI3K/Akt signalling pathway can reverse P‐gp‐mediated MDR. We investigated the expression of activated Akt (p‐Akt) in 124 human gastric carcinoma tissue samples. Ubiquitous p‐Akt expression was recorded in the majority (88/124). There was a significant correlation between p‐Akt expression and the expression of P‐gp. In the adriamycin‐resistant MDR gastric carcinoma cell line SGC7901/ADR, p‐Akt expression was increased in comparison with the parental cell line SGC7901. Treatment of SGC7901/ADR cells with the PI3K inhibitor LY294002 reduced the expression of both p‐Akt and P‐gp. To explore the role of ubiquitin ligase Cbl‐b in this regulatory pathway, SGC7901/ADR cells were transfected with a plasmid overexpressing wild‐type Cbl‐b. This down‐regulated the expression of both p‐Akt and P‐gp. Furthermore, resistance to chemotherapeutic drugs was partially reversed. These results demonstrate an important role for Cbl‐b in reversing P‐gp‐mediated gastric cancer MDR through suppression of the PI3K/Akt signalling pathway and the down‐regulation of P‐gp expression. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

微小RNA-98-5p靶向调控核糖核苷酸还原酶小亚基M2调控宫颈癌细胞顺铂的耐药性

目的 探讨微小RNA（miR)-98-5p对顺铂(DDP)耐药宫颈癌细胞顺铂敏感性的调控及其机制。 方法 用脂质体法将DDP+miR-NC组（转染miR-NC）、DDP+miR-98-5p组（转染miR-98-5p mimics）、DDP+si-NC组（转染si-NC）、DDP+si-核糖核苷酸还原酶小亚基M2（RRM2）组（转染si-RRM2）、DDP+miR-98-5p+pcDNA组（共转染miR-98-5p mimics和pcDNA）、DDP+miR-98-5p+pcDNA-RRM2组（共转染miR-98-5p mimics和pcDNA-RRM2）转染至HeLa/DDP组细胞;Real-time PCR、Western blotting、CCK-8、迁移实验（Transwell）和双荧光素酶报告基因检测细胞中miR-98-5p、RRM2、细胞周期蛋白D1（cyclin D1）、P21、基因金属蛋白酶（MMP）-2、MMP-9的表达、细胞的抑制率、半数抑制浓度（IC50）、迁移和侵袭及荧光活性。 结果 与HeLa组细胞相比,HeLa/DDP组细胞中miR-98-5p表达显著降低,RRM2表达显著升高,IC₅₀值显著升高（P<0.05）;过表达miR-98-5p或抑制RRM2可明显抑制HeLa/DDP细胞的增殖、迁移和侵袭,下调cyclin D1、MMP-2、MMP-9蛋白,上调P21蛋白;miR-98-5p明显抑制野生型RRM2细胞的荧光活性,并且过表达RRM2反转了miR-98-5p对HeLa/DDP细胞增殖、迁移侵袭的抑制作用。 结论 MiR-98-5p可抑制顺铂耐药宫颈癌细胞的增殖、迁移和侵袭,增强对顺铂的敏感性,其机制与靶向RRM2相关,将可为顺铂耐药宫颈癌细胞的治疗提供方向。     

miR-199a-3p targets ETNK1 to promote invasion and migration in gastric cancer cells and is associated with poor prognosis

PurposeTo investigate the prognostic significance of miR-199a-3p and its role in invasion and metastasis in gastric cancer.MethodsmiR-199a-3p expression in 436 formalin-fixed and 39 frozen gastric cancer tissues was investigated by in situ hybridization and RT-PCR, respectively. The role of miR-199a-3p in the migration and invasion of gastric cancer cells was determined in overexpression and inhibitor studies using transwell assays and the SGC-7901, BGC-823 and MGC-803 gastric cancer cells lines. The effect of miR-199a-3p expression on ethanolamine kinase 1 (ETNK1) levels was determined by western botting.ResultsmiR-199a-3p was significantly up-regulated in AGS, SGC-7901, BGC-823 and MGC-803 gastric cancer cells, when compared with GES-1 non-malignant gastric epithelial cells. In situ hybridization studies revealed that human non-tumor gastric mucosa samples were negative for miR-199a-3p expression, while 162 of 436 (37.16%) cases of gastric cancer demonstrated positive expression. miR-199a-3p overexpression was associated with tumor size, Lauren classification, depth of invasion, lymph node and distant metastasis, TNM stage and prognosis. In patients with I, II and III stage tumors, high miR-199a-3p expression was associated with a significantly lower 5-year survival rate. miR-199a-3p overexpression was associated with increased cell migration and invasion. ETNK1 expression was inhibited following miR-199a-3p overexpression in BGC-823 and SGC-7901 cells, and elevated following miR-199a-3p suppression in MGC-803 cells.ConclusionmiR-199a-3p is highly expressed in gastric cancer, and correlates with invasion, metastasis and prognosis. miR-199a-3p regulates the invasion and migration of gastric cancer cells by targeting ETNK1. Consequently, miR-199a-3p may serve as a prognostic indicator in gastric cancer.     

Integrin β1对胃癌细胞SGC7901多药耐药性的影响

目的:探究整合素β1(integrinβ1)对胃癌多药耐药性的影响及可能的作用机制。方法:Western blot法及q PCR实验检测胃癌细胞株SGC-7901及胃癌耐药细胞株SGC-7901/DDP中integrinβ1的表达情况。采用integrinβ1反义寡核苷酸转染,敲减胃癌耐药细胞株SGC-7901/DDP中integrinβ1的表达,CCK-8法检测细胞活力,流式细胞术检测细胞凋亡,Western blot法检测integrinβ1、Bcl-2/Bax、cleaved caspase-3/caspase-3、细胞色素C(CytC)和p-AKT/AKT的蛋白水平。结果:耐药细胞株SGC7901/DDP中integrinβ1的mRNA及蛋白表达水平均明显高于亲本细胞株;并且在亲本细胞株SGC7901中加入顺铂、长春新碱及5-氟尿嘧啶等化疗药物刺激后,integrinβ1的蛋白表达水平明显升高。敲减integrinβ1的表达可诱导胃癌耐药细胞SGC7901/DDP的凋亡,增加细胞对化疗药物的敏感性;此外下调Bcl-2/Bax、p-AKT~(Ser473)和p-AKT~(Thr308)的蛋白水平,同时促进线粒体Cyt-C的释放,上调cleaved caspase-3的蛋白水平。结论:敲减胃癌顺铂耐药细胞SGC7901/DDP的integrinβ1表达可恢复细胞对化疗药物的敏感性,促进细胞经线粒体路径的凋亡,其机制可能与抑制AKT的磷酸化,阻断该信号通路有关。     

MicroRNA-301b-3p accelerates the growth of gastric cancer cells by targeting zinc finger and BTB domain containing 4

MicroRNAs (miRNAs) have been found to be aberrantly expressed and exert essential roles in the tumorigenesis and progression of gastric cancer (GC). miR-301b-3p has been recognized as a cancer-related miRNA in lung cancer, bladder cancer and hepatocellular carcinoma. However, the function of miR-301b-3p in GC progression and its underlying mechanism have not been studied yet. In this study, we found that miR-301b-3p expression was up-regulated in GC tissues compared to adjacent noncancerous tissues. Furthermore, the elevated levels of miR-301b-3p were detected in GC cell lines (SGC-7901, AGS, MKN-45 and MGC-803) as compared with GES-1 cells. Interestingly, GC tissues from patients with tumor size ≥ 5 cm and advanced tumor stages showed obvious higher levels of miR-301b-3p compared to matched controls. Functionally, miR-301b-3p knockdown prominently inhibited cell proliferation, and induced cell cycle arrest at G1 phase and apoptosis in MGC-803 cells. Meanwhile, ectopic expression of miR-301b-3p conversely regulated these biological behaviors of MKN-45 cells. Next, we found that miR-301b-3p knockdown increased, whereas miR-301b-3p overexpression reduced the expression of zinc finger and BTB domain containing 4 (ZBTB4) in GC cells. Accordingly, luciferase reporter assay identified ZBTB4 as a direct target of miR-301b-3p. ZBTB4 overexpression markedly restrained the growth of MGC-803 cells. More importantly, ZBTB4 silencing partially reversed miR-301b-3p knockdown-induced tumor suppressive effects on MGC-803 cells. In conclusion, we firstly revealed that miR-301-3p was highly expressed in GC and contributed to tumor progression via attenuating ZBTB4, which might provide a novel molecular-targeted strategy for GC treatment.     

藤黄酸增强人胃癌SGC7901/DDP细胞对顺铂的敏感性

目的 探讨藤黄酸（GA）对人胃癌SGC7901/DDP细胞顺铂敏感性的影响及其分子机制。方法 采用顺铂（DDP）浓度梯度递增法构建人胃癌顺铂耐药株SGC7901/DDP细胞,采用细胞计数盒-8（CCK-8）法检测藤黄酸和顺铂对SGC7901/DDP细胞的毒性作用,采用Chou-Talalay中效分析法定量评价藤黄酸和顺铂的联合作用效果,采用流式细胞术检测细胞凋亡,采用Western blotting方法检测Bcl-2、Bax、Survivin、多药耐药相关蛋白2（MRP2）、磷酸化氨基末端蛋白激酶（p-JNK）（Thr183/Tyr185）和JNK的蛋白水平。结果 藤黄酸与顺铂各自单独作用48 h的IC₅₀分别为2.94 μmmol/L和39.76 μmmol/L;当抑制率超过20%时,两者联合应用呈协同效应;藤黄酸可协同增强顺铂诱导的细胞凋亡（P<0.05）,下调Survivin和MRP2蛋白水平（P<0.05）,上调Bax蛋白水平（P<0.05）,抑制JNK磷酸化（P<0.05）;JNK特异性抑制剂SP600125可下调MRP2蛋白水平（P<0.05）。结论 藤黄酸可增强人胃癌SGC7901/DDP细胞对顺铂的敏感性,这可能与藤黄酸通过抑制JNK信号通路下调MRP2蛋白表达,以及上调Bax蛋白表达和下调Survivin蛋白表达有关。     

miR-129-5p attenuates cell proliferation and epithelial mesenchymal transition via HMGB1 in gastric cancer

Background

The miR-129-5p has been reported to be aberrant expression and exert vital roles in tumor progression of various malignancies. However, the effects on EMT in gastric cancer and its precise molecular mechanism in gastric cancer remain unclear.

反义人钙周期素结合蛋白编码基因转染对胃癌细胞多药耐药性的影响

目的 研究hCacyBP编码基因在胃癌多药耐药机制中的作用。方法 采用Northern杂交，检测SGC7901细胞及SGC7901／ADR细胞中hCacyBP mRNA表达水平的差异。将hCacyBP cDNA克隆到pcDNA3.1中，构建反义核酸真核表达载体pcDNA3.1/hCacyBP-，并转染耐阿霉素人胃癌细胞，用RT－PCR检测转染细胞中hCacyBP mRNA水平的变化。用MTT比色法和FCM，分别检测SGC7901／ADR细胞，pcDNA3.1/hCacyBP-和pcDNA3.1分别转染的SGC7901／ADR细胞，对ADR的药物敏感性和胞内ADR的蓄积浓度。结果 Northern杂交证实，SGC7901／ADR细胞中hCacyBP mRNA表达的水平显著高于SGC7901细胞。成功地构建了pcDNA3.1/hCacyBP-。以pcDNA3.1/hCacyBP-转染的SGC791／ADR细胞中hCacyBP mRNA的表达水平，显著低于空载体转染及未转染的SGC791／ADR细胞。MTT检测表明，转染pcDNA3.1/hCacyBP-细胞，对ADR的药物敏性较空载体转染及未转染的SGC7901／ADR细胞有所增高，生存率较后两者为低。FCM显示，转染pcDNA3.1/hCacyBP-的SGC7901／ADR细胞，转染pcDNA3.1及未转染的SGC7901／ADR细胞内ADR的蓄积浓度，分别为6．72，5．62和5．54。结论 hCacyBP编码基因对胃癌细胞的MDR有一定的影响，CacyBP可能是一种胃癌细胞MDR中的重要分子。     

lncRNA MALAT1靶向调控miR-146b-5p影响膀胱癌细胞侵袭和迁移

目的:探讨长链非编码RNA(lncRNA)肺腺癌转移相关转录因子1(MALAT1)靶向微小RNA-146b-5p(miR-146b-5p)影响膀胱癌细胞侵袭和迁移的机制。方法:在膀胱癌BIU-87细胞中转染MALAT1 siRNA,以real-time PCR方法测定转染效果,Transwell法测定侵袭及迁移能力,Western blot法检测细胞中上皮-间充质转化(EMT)相关蛋白波形蛋白(vimentin)、上皮型钙黏蛋白(E-cadherin)和迁移侵袭相关蛋白基质金属蛋白酶-2(MMP-2)蛋白表达的变化。生物信息学软件预测MALAT1与miR-146b-5p有靶向互补位点,利用双萤光素酶报告系统鉴定靶向关系。用real-time PCR方法检测下调MALAT1后BIU-87细胞中miR-146b-5p表达的变化。将MALAT1 siRNA和miR-146b-5p inhibitor共转染至BIU-87细胞中,用上述方法分析细胞侵袭、迁移及vimentin、E-cadherin和MMP-2蛋白表达的变化。结果:转染MALAT1 siRNA可明显下调BIU-87细胞中MALAT1的表达水平(P<0.05)。敲减MALAT1表达后,BIU-87细胞的侵袭和迁移能力下降,细胞中vimentin和MMP-2蛋白水平降低,E-cadherin蛋白水平升高。MALAT1靶向调控miR-146b-5p的表达,敲减MALAT1的表达可以提高BIU-87细胞中miR-146b-5p的水平。miR-146b-5p inhibitor可以明显逆转敲减MALAT1的表达对BIU-87细胞侵袭、迁移能力和vimentin、E-cadherin、MMP-2蛋白表达的影响。结论:下调MALAT1可靶向促进miR-146b-5p表达,抑制膀胱癌细胞侵袭、迁移能力和EMT。     

miR-194-5p inhibits SLC40A1 expression to induce cisplatin resistance in ovarian cancer

BackgroundmiR-194-5p has been associated with drug resistance in many cancers. However, the role of miR-194-5p in cisplatin resistance in ovarian cancer is still unclear.Materials and methodsTo study the role and mechanism of miR-194-5p in cisplatin resistance, qRT-PCR was performed to determine the expression of miR-194-5p and SLC40A1 in ovarian cancer. Cell Counting Kit-8 (CCK8) assay was used to analyse cell viability after cisplatin treatment. Dual-luciferase reporter gene assay was performed to examine the relationship between miR-194-5p and SLC40A1. The genes downstream of SLC40A1 were investigated through bioinformatics analysis.ResultsCompared to cisplatin-sensitive ovarian cancer cells, higher miR-194-5p expression and lower SLC40A1 expression were found in cisplatin-resistant ovarian cancer cells. Moreover, this study demonstrated that over-expression of miR-194-5p inhibited SLC40A1 expression, and knockdown of miR-194-5p promoted SLC40A1 expression. In addition, dual-luciferase reporter gene assay further confirmed the negative correlation between miR-194-5p and SLC40A1. Furthermore, we found that over-expression of miR-194-5p resulted in cisplatin resistance. When miR-194-5p and SLC40A1 were simultaneously up-regulated, cisplatin sensitivity increased, while down-regulation of miR-194-5p sensitised ovarian cancer cells to cisplatin. However, when miR-194-5p and SLC40A1 were simultaneously down-regulated, cisplatin sensitivity was decreased. These data suggested that miR-194-5p inhibited SLC40A1 expression to induce cisplatin resistance. In addition, bioinformatics analysis indicated a positive correlation of SLC40A1 with hephaestin (HEPH), and homeostatic iron regulator (HFE). However, we found that HEPH and HFE were associated with cisplatin resistance, suggesting that their role in drug resistance is induced by miR-194-5p/SLC40A1.ConclusionIn conclusion, we found that miR-194-5p inhibited SLC40A1 expression to induce cisplatin resistance in ovarian cancer. This study suggests that miR-194-5p could be a potential therapeutic target and a prognostic biomarker for ovarian cancer, with important implications for future research.     

甲基莲心碱对耐长春新碱人胃癌细胞多药耐药性的逆转

目的:研究甲基莲心碱(Nef)逆转耐长春新碱人胃癌细胞多药耐药性(MDR)的作用及机制。方法:采用噻唑蓝(MTT)比色法检测长春新碱(VCR)的细胞毒性;PI染色流式细胞计数测定VCR诱导细胞凋亡;间接免疫荧光流式细胞术检测细胞P-gp和MRP的表达。结果:Nef(5、10μmol·L^-1)对人胃癌细胞(SGC7901)和耐长春新碱人胃癌细胞(SGC7901/VCR)无显著毒性作用,VCR对敏感株SGC7901的IC₅₀为0.06mg·L^-1,而对MDR细胞株SGC7901/VCR的IC₅₀为2.32mg·L^-1,SGC7901/VCR较SGC7901对VCR耐药39倍,Nef(2.5、5、10μmol·L^-1)能使VCR对SGC7901/VCR细胞的IC₅₀从2.32mg·L^-1依次下降至0.34、0.12、0.05mg·L^-1,逆转倍数分别为6.8、18.1、43.8。Nef(2.5、5、10μmol·L^-1)能降低SGC7901/VCR细胞对VCR的凋亡抗性,其作用强于维拉帕米(VRP)。SGC7901/VCR细胞较SGC7901细胞高表达P-gp、MRP,Nef(10μmol·L^-1)处理24h后,SGC7901/VCR细胞P-gp、MRP的表达明显低下。结论:Nef具有逆转耐长春新碱人胃癌细胞的MDR作用,其作用机理与下调P-pg和MRP表达有关。     

MicroRNA-146b-5p suppresses cholangiocarcinoma cells by targeting TRAF6 and modulating p53 translocation

BackgroundIn view of the poor prognosis and high mortality of cholangiocarcinoma, there is a need for new therapeutic strategies. This study aims to reveal the biological function of miR-146b-5p in cholangiocarcinoma cell and its possible mechanism.MethodsThe expression level and prognostic information on miR-146b-5p in cholangiocarcinoma were obtained in TCGA database. The biological function of miR-146b-5p on proliferation and vitality of cholangiocarcinoma cell HUCCT-1 was examined by EdU and MTT assay, and the apoptosis of HUCCT-1 cells transfected with miR-146b-5p mimic, mimic control, inhibitor, inhibitor control was detected by flow cytometry analysis. The western blot was done to evaluate the effect of miR-146b-5p targeting substrate and the expression of p53 in whole-cell protein and mitochondria fractions.ResultsOur finding revealed that miR-146b-5p expression in patients with CHOL was lower than the normal group(p＜0.001). MiR-146b-5p expression was down-regulated in human cholangiocarcinoma HUCCT-1 and RBE cells compared to normal control HIBEC and other cancer cells. The miR-146b-5p mimic could inhibit HUCCT-1 cell proliferation (p＜0.05) and promote HUCCT-1 cell apoptosis significantly (p＜0.05). The results of western blot showed that miR-146b-5p mimic could directly target TRAF6 3′UTR region and up-regulate the expression of p53 in mitochondria and miR-146b-5p inhibitor could down-regulated the level of p53 in mitochondria.ConclusionMiR-146b-5p is a cholangiocarcinoma suppressor by inhibiting cell proliferation and promoting cell apoptosis with targeting TRAF6, possibly via modulating p53 translocation to mitochondria.