沉默Bmi-1表达对K562/ADM细胞体内外增殖能力的影响

目的:观察沉默Bmi-1表达对慢性髓系白血病阿霉素耐药细胞株-K562/ADM细胞增殖的影响并初步探讨其分子机制。方法:将Bmi-1小干扰RNA(siRNA)序列转染到K562/ADM细胞中降低其Bmi-1的表达;采用MTT法、软琼脂集落形成实验、裸鼠成瘤实验检测沉默Bmi-1表达对K562/ADM细胞体内外增殖能力的影响;应用Western blot检测Bmi-1、PTEN、p-AKT等蛋白表达;免疫组织化学实验分析Bmi-1和Ki-67的表达情况。结果:Bmi-1基因的沉默能够抑制K562/ADM细胞的增殖活性、集落形成及裸鼠成瘤能力;Bmi-1基因沉默后,干扰组PTEN表达明显升高,而p-AKT活性明显下降;p-AKT抑制剂-LY294002处理K562/ADM细胞后,p-AKT表达降低,集落形成及裸鼠成瘤能力相比K562/ADM细胞降低;PTEN抑制剂-Bpv处理K562/ADM-S1细胞后,PTEN的表达降低,而p-AKT表达、集落形成及裸鼠成瘤能力得以重塑;Bmi-1基因沉默使得肿瘤组织中Bmi-1与Ki-67表达均下降。结论:Bmi-1基因有可能参与了对K562/ADM的体内外增殖能力的调控,PTEN/pAKT信号通路可能涉及其中。     

Expression and significance of leptin receptor,p-STAT3 and p-AKT in diffuse large B-cell lymphoma

We investigated the expression and clinical significance of leptin receptor (OBR), p-STAT3 and p-AKT in patients with diffuse large B-cell lymphoma (DLBCL) by immunohistochemical analysis. Immunohistochemistry revealed high expression of OBR, p-STAT3 and p-AKT in 45.0% (36/80), 28.8% (23/80) and 18.8% (15/80) cases of DLBCL, respectively, and minimal staining in 100% (20/20) cases of RLH (P < 0.05). Compared with GCB group, the non-GCB group had higher p-STAT3 expression rate (21/57 vs. 2/23, P < 0.01). The expression of OBR was positively related with that of p-STAT3 and p-AKT in DLBCL patients (P < 0.05). Our data suggest that OBR stimulates the JAK/STAT and PI3K/AKT signaling pathway and induces the phosphorylation of STAT3 and AKT. This may be involved in carcinogenesis and prognosis of DLBCL. The specific inhibitions could interfere in the combination of leptin with OBR and obstruct the JAK/STAT and PI3K/AKT signaling pathways, which could lead to new research and treatment strategies for DLBCL treatment.     

电针对局灶脑缺血/再灌注大鼠骨髓及外周血CD34~+内皮祖细胞的影响

目的:观察电针对局灶脑缺血/再灌注大鼠骨髓及外周血CD 34+内皮祖细胞(EPCs)数量、磷酸化蛋白激酶B(p-AKT)表达的影响,探讨电针动员骨髓CD 34+EPCs入血,促进脑缺血修复的机制。方法:雄性SD大鼠随机分为假手术组、模型组、电针组。采用线栓法制备局灶脑缺血/再灌注大鼠模型,局灶脑缺血2h后将各组分为再灌注12、24、48h3个时间点,每个时间点12只大鼠。取大鼠"百会"穴及左侧"四关"穴("合谷"/"太冲")为电针穴位,刺激时间30min,每日1次。采用神经行为学评分法评价大鼠神经功能缺损情况,流式细胞术检测骨髓及外周血CD 34+EPCs数量,Western blot法检测骨髓p-AKT蛋白的表达。结果:模型组再灌注后各时间点均有不同程度的神经功能缺损,电针可明显改善大鼠再灌注后48h神经功能评分(P0.05)。与假手术组比较,模型组各时间点骨髓及外周血CD 34+EPCs数量及骨髓p-AKT蛋白的表达明显增多(P0.01,P0.05);与模型组比较,电针组再灌注后各时间点外周血CD 34+EPCs数量及骨髓p-AKT蛋白的表达亦明显增多(P0.05,P0.01),同时电针组再灌注后12、24h骨髓CD 34+EPCs数量相对模型组明显上调(P0.05,P0.01)。结论:电针可上调局灶脑缺血/再灌注大鼠骨髓及外周血CD 34+EPCs数量,促进骨髓CD 34+EPCs动员入血,其作用可能与电针进一步激活骨髓磷脂酰肌醇-3-激酶/AKT通路相关。     

结直肠癌中p-AKT和PTEN蛋白的表达及其临床意义

目的探讨磷酸化AKT(p-AKT)和PTEN蛋白在结直肠癌中的表达及其临床意义。方法应用免疫组化PV-9000两步法检测80例结直肠癌手术切除标本和20例癌旁正常组织中p-AKT、PTEN蛋白的表达,分析两者与临床病理特征的关系。结果 p-AKT蛋白在结直肠癌中表达的阳性率(71.25%)显著高于癌旁正常组织(10.00%,P0.05);而PTEN蛋白在结直肠癌中表达的阳性率(45.00%)与癌旁正常组织(100.00%,P0.05)相比具有统计学意义的降低,二者的表达与肿瘤的分化程度、TNM分期、浆膜浸润、淋巴结转移具有明显相关性(P0.05),并且p-AKT与PTEN蛋白的表达呈显著负相关(r=-0.314,P=0.005)。结论 p-AKT和PTEN蛋白的表达可能与结直肠癌的发生、发展密切相关。联合检测二者的表达,对判断结直肠癌的恶性程度及预后具有重要的临床意义。     

信号转导蛋白AKT在非小细胞肺癌中的表达及意义

目的 分析非小细胞肺癌（NSCLC）中信号转导蛋白AKT的活化状态磷酸化AKT（P—AKT）的表达及意义。方法 应用免疫组织化学的方法，检测80例NSCLC组织及35例良性肺病变组织标本中P—AKT的表达，并与临床病理因素进行相关性分析。结果 P—AKT在NSCLC中高表达，阳性率为78．8％，而在良性肺病变组织中不表达（P〈0．05），P—AKT在不同年龄、性别、TNM分期、组织分化以及淋巴结转移与无淋巴结转移组均高表达，组间对比差异无统计学意义（P〉0．05）。结论 在NSCLC中存在AKT的活化，P—AKT参与肺癌的发生和发展。AKT的活化在NSCLC中不仅是一个频发事件，而且是一个普遍事件。针对AKT的靶位点治疗有可能对各期、各型NSCLC产生治疗作用。     

Scriptaid,a Novel Histone Deacetylase Inhibitor,Protects Against Traumatic Brain Injury via Modulation of PTEN and AKT Pathway: Scriptaid Protects Against TBI via AKT

Traumatic brain injury (TBI) is a leading cause of motor and cognitive deficits in young adults for which there is no effective therapy. The present study characterizes the protective effect of a new histone deacetylase inhibitor, Scriptaid (Sigma-Aldrich Corporation, St. Louis, MO), against injury from controlled cortical impact (CCI). Scriptaid elicited a dose-dependent decrease in lesion size at 1.5 to 5.5 mg/kg and a concomitant attenuation in motor and cognitive deficits when delivered 30 minutes postinjury in a model of moderate TBI. Comparable protection was achieved even when treatment was delayed to 12 h postinjury. Furthermore, the protection of motor and cognitive functions was long lasting, as similar improvements were detected 35 days postinjury. The efficacy of Scriptaid (Sigma-Aldrich Corporation) was manifested as an increase in surviving neurons, as well as the number/length of their processes within the CA3 region of the hippocampus and the pericontusional cortex. Consistent with other histone deacetylase inhibitors, Scriptaid treatment prevented the decrease in phospho-AKT (p-AKT) and phosphorylated phosphatase and tensin homolog deleted on chromosome 10 (p-PTEN) induced by TBI in cortical and CA3 hippocampal neurons. Notably, the p-AKT inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 attenuated the impact of Scriptaid, providing mechanistic evidence that Scriptaid functions partly by modulating the prosurvival AKT signaling pathway. As Scriptaid offers long-lasting neuronal and behavioral protection, even when delivered 12 h after controlled cortical impact, it is an excellent new candidate for the effective clinical treatment of TBI.

Electronic supplementary material

The online version of this article (doi:10.1007/s13311-012-0157-2) contains supplementary material, which is available to authorized users.     

Quercetin suppresses HeLa cells by blocking PI3K/Akt pathway

To explore the effect of quercetin on the proliferation and apoptosis of HeLa cells, HeLa cells were incubated with quercetin at different concentrations. Cell viability was evaluated by MTT assay, cell apoptosis was detected by Annexin- V/PI double labeled cytometry and DNA ladder assay. Cell cycle was flow cytometrically determined and the morphological changes of the cells were ob- served under a fluorescence microscope after Hoechst 33258 staining and the apoptosis-related pro- teins in the HeLa cells were assessed by Western blotting. The results showed that quercetin signifi- cantly inhibited the growth of HeLa cells and induced obvious apoptosis in vitro in a time- and dose-dependent manner. Moreover, quercetin induced apoptosis of HeLa cells in cell cycle-dependent manner because quercetin could induce arrest of HeLa cells at G0/G1 phase. Quercetin treatment down-regulated the expression of the PI3K and p-Akt. In addition, quercetin could down-regulate ex- pression of bcl-2, up-regulate Bax, but exerted no effect on the overall expression of Akt. We are led to conclude that quercetin induces apoptosis via PI3k/Akt pathways, and quercetin has potential to be used as an anti-tumor agent against human cervix oancer.     

Gas1 inhibits cell proliferation and induces apoptosis of human primary gliomas in the absence of Shh

Growth arrest specific1 (Gas1) is a protein expressed during development and when cells arrest their growth. The potential of Gas1 as an adjuvant in the treatment of cancer, and its role as a tumor suppressor have also been proposed. In this work we are addressing the molecular mechanisms by which Gas1 induces cell arrest and apoptosis of cancer cells, using primary cultures of human gliomas as a model. We had previously demonstrated the structural relationship between Gas1 and the α receptors for the Glial-cell line-Derived Neurotrophic Factor (GDNF) family of ligands, and showed that Gas1 acts by inhibiting the intracellular signaling induced by GDNF. There are also reports indicating that Gas1 positively cooperates with Sonic Hedgehog (Shh) during embryonic development and in this paper we analyzed the potential interactions between Gas1 and Shh. We show that human gliomas do not express Shh, whereas GDNF and the molecular components necessary to transduce its signaling are present in human gliomas. Furthermore, the over-expression of Gas1 induces cell arrest, apoptosis and prevents the activation of Akt, a crucial mediator of survival and cellular proliferation pathways. In the present work, we present evidence demonstrating that Gas1 exerts its effects inhibiting cell growth and inducing apoptosis of glioma cells in the absence of Shh.     

DATS对缝线诱导的大鼠角膜新生血管的影响及机制研究

目的：探讨二烯丙基三硫化物(diallyl trisulfide，DATS)抑制缝线诱导的大鼠角膜新生血管(corneal neovascularization，CNV)的生长情况，检测大鼠新生血管化角膜中VEGF、p-AKT 的表达量，初步探讨其抑制CNV的可能机制。

方法：缝线法诱导大鼠CNV模型，随机分为A组：含DMSO的生理盐水对照组(10只)； B组：25μmol/L DATS治疗组(10只)； C组：50μmol/L DATS治疗组(10只)； D组：100μmol/L DATS治疗组(10只)； E组：200μmol/L DATS治疗组(10只)。缝线后第7d裂隙灯下观察各组CNV的生长情况并计算面积。缝线后第14d取各组大鼠角膜组织行HE 染色，光镜下观察各组角膜病理组织形态，并采用RT-PCR 法检测VEGF mRNA 的表达情况，Western-blot 法检测VEGF、p-AKT蛋白表达情况。

结果：C、D、E组的CNV面积分别与A组比较，差异均有统计学意义(P<0.05)。HE切片显示，与A组相比，B、C、D组角膜水肿、新生血管、炎症细胞浸润情况逐渐减轻。与A组相比，B、C、D、E组的VEGF mRNA 的表达水平均降低，差异均有统计学意义(P<0.05)。与A组相比，C、D、E组的VEGF、p-AKT蛋白的表达逐渐下降，差异均有统计学意义(P<0.05)。

结论：DATS 能够抑制缝线诱导的大鼠CNV的形成，其机制可能与抑制VEGF的表达及使得p-AKT的失活有关。     

BRMS1、整合素β1及p-AKT在卵巢癌组织中的表达及临床意义

目的研究乳腺癌转移抑制因子1（BRMS1）、整合素β1、p-AKT在卵巢癌中的表达及其与临床病理特征的关系。方法应用免疫组织化学法检测卵巢癌、良性肿瘤及其卵巢组织中BRMS1、整合素β1、p-AKT的表达。结果 BRMS1在卵巢癌中阳性表达率降低（P〈0.01）,其表达与卵巢癌转移相关,与组织学分级无关。整合素β1及p-AKT在卵巢癌中的阳性表达率升高（P〈0.01）,其表达与卵巢癌病理分期、分化程度有关（P〈0.05）。BRMS1与整合素β1及p-AKT在卵巢癌组织中表达呈负相关（r=-0.59,r=-0.50,P〈0.05）。结论卵巢癌中BRMS1有可能通过抑制整合素β1/AKT通路,抑制肿瘤转移。