miR-451a suppresses the development of breast cancer via targeted inhibition of CCND2

Extensive research has indicated that miRNAs are crucial for the occurrence and progression of cancers. miR-451a, involved in breast cancer (BC), is one of the miRNAs. This study focused on the mechanism by which miR-451a regulates BC. The levels of miR-451a in BC tissues and cell lines were examined using quantitative real-time polymerase chain reaction (qRT-PCR). Kaplan‒Meier analysis showed that this was intimately related to the patient's overall survival rate. Functional experiments revealed the negative effects of miR-451a on the abilities of BC cells to multiply (tested by Cell Counting Kit-8), migrate (tested by wound healing assay), and invade (tested by Transwell assay) and its positive effects on apoptosis (tested by flow cytometry). Western blotting indicated that the expression of tumor-related proteins was affected by miR-451a. Moreover, in vivo experiments suggested that tumor growth was clearly restrained by an miR-451a agonist in a xenograft tumor model. Bioinformatic analysis indicated that miR-451a directly targeted Cyclin D2 (CCND2), as demonstrated by the luciferase reporter assay. An opposite change in the level of CCND2 and miR-451a in BC was indicated by qRT-PCR, western blotting, and immunohistochemistry. Subsequently, functional experiments and western blotting analysis confirmed that CCND2 accelerated BC progression, which was regulated by miR-451a. Cumulatively, research on miR-451a may be valuable for BC treatment.     

依维莫司联合全反式维甲酸逆转急性早幼粒细胞白血病细胞耐药的研究

目的探讨依维莫司联合全反式维甲酸(简称维甲酸)逆转急性早幼粒细胞白血病(APL)细胞株NB4-R1耐药的作用。方法应用CD11b染色流式细胞术及硝基四唑氮蓝(NBT)还原实验检测两药联合应用对细胞分化的影响, 流式细胞术检测细胞周期情况, Annexin V/PI双染色检测细胞凋亡情况, 蛋白质印迹法检测自噬相关蛋白微管结合蛋白轻链3(LC3)、Beclin 1及早幼粒白血病-维甲酸受体融合蛋白(PML-RARα)、磷酸化核糖体S6激酶(P-P70S6K)、磷酸化4E结合蛋白1(P-4E-BP1) 等表达水平。结果与维甲酸组比较, 联用组能诱导耐药细胞株NB4-R1细胞的分化, 并将细胞增殖阻止在G ₁期而对细胞凋亡无明显影响。100 nmol/L依维莫司组、1μmol/L维甲酸组、联用组、对照组NB4-R1细胞培养48 h后分化百分率分别为(2.29±0.57)%、(17.06±2.65)%、(54.47±4.91)%、(2.54±0.53)%; 处于G ₁期的细胞百分率分别为(35.20±11.97)%、(33.54±6.25)%、(53.70±8.73)%、(27.40±6.01)%; 四组细胞凋亡细胞百分率分别为(2.30±0.14)%、(2.25±0.21)%、(2.40±0.28)%、(1.95±0.07)%。与维甲酸组比较, 联用组mTOR信号通路下游的P70S6K、4E-BP1分子磷酸化水平下降, LC3-II和Beclin 1的表达上调, 且能部分降解融合蛋白PML-RARα。 结论依维莫司联合维甲酸能诱导NB4-R1细胞分化, 且能阻滞细胞周期而不致细胞凋亡, 其机制可能与依维莫司联合维甲酸抑制mTOR信号通路激活自噬作用从而降解PML-RARα蛋白有关。     

Curcumin attenuates spatial memory impairment by anti-oxidative,anti-apoptosis,and anti-inflammatory mechanism against methamphetamine neurotoxicity in male Wistar rats: Histological and biochemical changes

ObjectiveMethamphetamine is used extensively around the world as a psychostimulant. The complications related to methamphetamine include methamphetamine-induced neurotoxicity, mainly involving intraneuronal processes, such as oxidative stress and excitotoxicity. Curcumin is effective against neuronal injury due to its antioxidant, anti-inflammatory effects. In this study, we examined the protective effects of curcumin against methamphetamine neurotoxicity.MethodsSixty male Wistar rats were divided into the following groups: control (n = 12), DMSO (n = 12), methamphetamine (n = 12), and methamphetamine + curcumin (100 and 200 mg/kg, respectively, intraperitoneal [IP]; n = 12). Neurotoxicity was induced by 40 mg/kg of methamphetamine administrated through 4 injections (4 × 10 mg/kg, q2h, IP). Curcumin (100 and 200 mg/kg) was administered at 7 days after the last methamphetamine injection. By using a Morris water maze task, the hippocampus-dependent memory and spatial learning were evaluated 1 day after the last curcumin injection. Then, the animal brains were isolated for biochemical measurements, as well as glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor protein-1(Iba-1) and caspase-3 immunohistochemical staining.ResultsThe current study demonstrated that administration of curcumin significantly attenuates spatial memory impairment (P < 0.01) following methamphetamine neurotoxicity. Curcumin caused a significant increase in the levels of superoxide dismutase and glutathione peroxidase (P < 0.05). However, it decreased tumor necrosis factor (TNF-α) (P < 0.05) and malondialdehyde (P < 0.01) levels as compared to the methamphetamine group. Also, curcumin significantly reduced Iba-1 (P < 0. 01), GFAP and caspase-3 positive cells in the hippocampus (P < 0.001).ConclusionCurcumin exerted neuroprotective effects on methamphetamine neurotoxicity because of its antioxidant and anti-inflammatory effect.     

Decellularized porcine conjunctiva as an alternative substrate for tissue-engineered epithelialized conjunctiva

PurposeThe long-term success of visual rehabilitation in patients with severe conjunctival scarring is reliant on the reconstruction of the conjunctiva with a suitable substitute. The purpose of this study is the development and investigation of a re-epithelialized conjunctival substitute based on porcine decellularized conjunctiva (PDC).MethodsPDC was re-epithelialized either with pre-expanded human conjunctival epithelial cells (PDC + HCEC) or with a human conjunctival explant placed directly on PDC (PDC + HCEx). Histology and immunohistochemistry were performed to evaluate epithelial thickness, proliferation (Ki67), apoptosis (Caspase 3), goblet cells (MUC5AC), and progenitor cells (CK15, ΔNp63, ABCG2). The superior construct (PDC + HCEx) was transplanted into a conjunctival defect of a rabbit (n = 6). Lissamine green staining verified the epithelialization in vivo. Orbital tissue was exenterated on day 10 and processed for histological and immunohistochemical analysis to examine the engrafted PDC + HCEx. A human-specific antibody was used to detect the transplanted cells.ResultsFrom day-14 in vitro onward, a significantly thicker epithelium and greater number of cells expressing Ki67, CK15, ΔNp63, and ABCG2 were noted for PDC + HCEx versus PDC + HCEC. MUC5AC-positive cells were found only in PDC + HCEx. The PDC + HCEx-grafted rabbit conjunctivas were lissamine-negative during the evaluation period, indicating epithelial integrity. Engrafted PDC + HCEx showed preserved progenitor cell properties and an increased number of goblet cells comparable to those of native conjunctiva.ConclusionPlacing and culturing a human conjunctival explant directly on PDC (PDC + HCEx) enables the generation of a stable, stratified, goblet cell-rich construct that could provide a promising alternative conjunctival substitute for patients with extensive conjunctival stem and goblet cell loss.     

超顺磁性氧化铁标记大鼠骨髓基质细胞经门静脉移植MRI活体示踪的研究

目的观察1．5T场强MRI联合动物专用线圈是否可以活体示踪经门静脉移植的纳米级超顺磁性氧化铁颗粒标记的骨髓基质细胞（bone marrow stromal cells BMSCs），为介人性门静脉骨髓基质细胞移植治疗终末期肝脏疾病的研究提供进一步的依据。方法供体大鼠5只，梯度密度离心分离BMSCs，纳米级超顺磁性氧化铁颗粒和脂质体转染BMSCs，体外经普鲁士蓝染色和HE染色确定细胞标记率。受体大鼠15只，分为5组，分别为对照组和纳米级超顺磁性氧化铁颗粒标记的骨髓基质细胞经门静脉移植人正常大鼠肝脏后2h、3d、7d及2周组。1．5T场强MRI联合动物专用线圈行T1W、T2W和T2＊序列扫描，观察肝脏信号改变情况，与对照组比较，并且与组织切片对照。结果纳米级超顺磁性氧化铁颗粒和脂质体转染BMSCs，细胞标记率〉95％。经门静脉移植人正常大鼠肝脏后，T2＊序列扫描显示经标记的BMSCs在肝内显示弥漫性的结节性低信号影，移植后2h到2周均可见到细胞在受体肝脏内存在，组织学切片显示信号缺失部位与铁颗粒标记细胞相一致。结论纳米级超顺磁性铁氧体颗粒标记的大鼠BMSCs经门静脉移植后可以通过1、5T场强行MRI活体示踪，为临床干细胞移植的应用提供可行的示踪方法。     

缺氧对乳腺癌细胞E-cadherin、cytokeratin、vimentin表达的影响

目的:研究体外缺氧对乳腺癌细胞系MCF7浸润能力及其细胞表面黏附分子E-cadherin和细胞骨架蛋白犤细胞角蛋白(cytokeratin)、波形蛋白(vimentin)犦表达的影响。方法:模拟体外缺氧环境,观察缺氧对乳腺癌细胞MCF7浸润穿透Matrigel的能力;以及采用半定量RT-PCR检测细胞表面黏附分子E-cadherin和cytokeratin、vimentin表达情况。结果:缺氧状态下MCF7细胞的浸润能力明显增强;且在缺氧条件下E-cadherin基因表达下降、cytokeratin、vimentin基因表达升高。结论:缺氧状态下MCF7细胞转移能力和其表面的E-cadherin基因、cytokeratin、vimentin基因表达存在一定关系。     

小颗粒致密低密度脂蛋白氧化特性及对血管内皮细胞脂质过氧化的影响

了解小颗粒致密低密度脂蛋白中抗氧化维生素含量、氧化特性 ,探讨其对血管内皮细胞脂质过氧化的影响。采用二次密度梯度超速离心的方法分离制备小颗粒致密低密度脂蛋白 ,高压液相色谱测定其抗氧化物质维生素A、E和 β 胡萝卜素 ;连续监测小颗粒致密低密度脂蛋白在 2 34nm的吸光度以测定其氧化敏感曲线 ;在血管内皮培养液中分别加入不同浓度的小颗粒致密低密度脂蛋白 ,培养后测定培养液丙二醛的浓度。实验成功分离小颗粒致密低密度脂蛋白 ,与大而轻低密度脂蛋白相比 ,维生素A、E和 β 胡萝卜素等抗氧化物质及总抗氧化能力明显减少 ,只有大而轻低密度脂蛋白的 6 5 %、39%和 2 4 % ,故小颗粒致密低密度脂蛋白氧化的延迟时间只有大而轻低密度脂蛋白的 37.5 % ,但硫代巴比妥酸反应物质值及氧化速率分别是大而轻低密度脂蛋白的 1 .7倍和 1 .2 8倍 ;培养液中丙二醛含量随加入脂蛋白的浓度和作用时间而增高 ,2 4h时小颗粒致密低密度脂蛋白 5 0mg组、1 0 0mg组、1 5 0mg组与相同剂量大而轻低密度脂蛋白组比较丙二醛显著增高 (P <0 .0 5 )。上述结果提示 :小颗粒致密低密度脂蛋白中抗氧化物质及抗氧化能力下降 ,氧化敏感性增高 ,并促进内皮细胞过氧化损伤     

胰腺导管癌中血管生成、细胞增殖指数、DNA倍性检测的临床意义

目的:探讨血管生成、细胞增殖指数、DNA倍性在胰腺导管癌发生、发展中的作用及临床意义。方法:对29例胰腺导管癌和7例慢性胰腺炎患者的石蜡包埋标本作苏木精鄄伊红(HE)染色,CD34、Ki67免疫组织化学染色,镜下计算微血管密度(MVD)及Ki67阳性细胞比例,同时用流式细胞仪(FCM)检测细胞核DNA倍性,计算异倍体出现率及S期比例,并结合临床病理资料对各项指标作相关分析。结果:胰腺导管癌和慢性胰腺炎都有较多的新生血管。MVD值在胰腺导管癌高、中、低分化3组之间差异无显著性。按肿瘤直径分为≤1.5cm、1.6～2.9cm、≥3cm3组,此3组间MVD值、Ki67阳性细胞百分率、DNA异倍体出现率及肿瘤周围有无浸润的差异都非常显著(P<0.01)。肿瘤越大,MVD值、Ki67阳性细胞百分率及DNA异倍体出现率越高。结论:胰腺导管癌的发生、发展伴血管生成和DNA合成增加,联合测定MVD、Ki67阳性细胞百分率、DNA倍型可能为胰腺导管癌临床预后预测提供辅助参考指标。     

Differential effects of cannabis extracts and pure plant cannabinoids on hippocampal neurones and glia

We have shown previously that the plant cannabinoid cannabidiol (CBD) elevates intracellular calcium levels in both cultured hippocampal neurones and glia. Here, we investigated whether the main psychotropic constituent of cannabis, Δ⁹-tetrahydrocannabinol (THC) alone or in combination with other cannabis constituents can cause similar responses, and whether THC affects the responses induced by CBD. Our experiments were performed with 1 μM pure THC (pTHC), with 1 μM pure CBD (pCBD), with a high-THC, low CBD cannabis extract (eTHC), with a high-CBD, low THC cannabis extract (eCBD), with a mixture of eTHC and eCBD (THC:CBD = 1:1) or with corresponding ‘mock extracts’ that contained only pTHC and pCBD mixed in the same proportion as in eTHC, eCBD or the 1:1 mixture of eTHC and eCBD.     

Stat3显性负性基因调控人结肠癌细胞增殖与凋亡的分子机制

目的 探讨转染Stat3（转录信号传导子和激活子3）显性负性基因Stat3β质粒阻断人结肠癌细胞系SW480细胞的Stat3信号传导通路对人结肠癌细胞增殖和凋亡的影响及可能的机制.方法 应用阳离子脂质体向人结肠癌细胞系SW480细胞中转染携带Stat3β基因的质粒,四唑盐法检测细胞增殖能力,流式细胞术检测细胞周期和细胞凋亡,反转录聚合酶链反应检测Stat3靶基因cyclinD1、bcl-xL mRNA表达情况.数据统计分析采用独立样本t检验.结果 转染Stat3β质粒36 h后,SW480细胞的增殖受到显著抑制（t=5.216,P=0.006）;G0/G1期的细胞比例由40.37%上升至67.25%,S期细胞由44.68%下降至31.23%;发生早期凋亡的细胞比例由5.34%上升至24.42%;同时cyclin D1、bcl-xLmRNA表达水平较对照组显著下降（t=5.228,P=0.010;t=3.517,P=0.025）.结论 转染携带Stat3β基因的质粒可以通过下调Stat3靶基因的表达抑制人结肠癌细胞的增殖,促进凋亡,为以Stat3为靶点的结肠癌基因治疗提供了实验基础.