Fatty Acid Synthase Regulates Proliferation and Migration of Colorectal Cancer Cells Via HER2-PI3K/Akt Signaling Pathway

Recent evidence suggests that fatty acid synthase mediating de novo fatty acid synthesis plays a crucial role in the carcinogenesis process of various cancers. Moreover, HER2 and related PI3K/Akt signaling pathway, which links intimately with cellular metabolism, influence cancer biological behavior. However, it remains unknown whether malignant phenotype of colorectal cancer cells is regulated by the HER2-PI3K/Akt-FASN signaling pathway. In this study, Caco-2 cells were selected for functional characterization, and treated with ZSTK474, followed by RT-qPCR and Western blot assays examining PI3K, Akt, HER2, and FASN expression. The MTT and colony formation assays were used to assess proliferation. The migration was investigated by transwell, apoptosis, and cell-cycle analysis. We found that the blockade of PI3K/Akt signaling pathway by ZSTK474 treatment led to downregulation of PI3K, Akt, HER2, and FASN expression. The proliferation was decreased upon treatment which was consistent with an increased percentage of G(1) arrested cells instead of apoptosis. The migration of Caco-2 cells was also impaired by ZSTK474 treatment. Inhibition of HER2-PI3K/Akt signaling pathway suppresses FASN expression of Caco-2 cells, and inhibition of FASN expression changes malignant phenotype of Caco-2 cells.     

Inhibitory effect of liquiritigenin on migration via downregulation proMMP-2 and PI3K/Akt signaling pathway in human lung adenocarcinoma A549 cells

Liquiritigenin (LQ) is a flavanone extracted from Glycyrrhizae, which has multiple biological effects, such as antiinflammation and anticancer. This study is the first to investigate the effect of LQ on the migration of human lung adenocarcinoma A549 cells in vitro. First, LQ exhibited inhibitory effects on the adhesion and migration of A549 cells in the absence of cytotoxicity. Gelatin zymography and Western blot analysis showed that LQ significantly reduced the expression of promatrix metalloproteinase-2 (proMMP-2) in A549 cells in terms of both activity and protein level. Second, LQ inhibited the phosphorylation of Akt and activated the phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2). Furthermore, the treatment of inhibitors specific for Akt (LY294002) and ERK1/2 (U0126) to A549 cells resulted in reduced activity of proMMP-2. These results suggested that the inhibition on proMMP-2 expression by LQ may be through suppression on PI3K/Akt signaling pathway, which in turn led to the inhibition of lung adenocarcinoma A549 cells migration. However, activation of ERK might not be involved in the regulation of proMMP-2. Taken together, LQ may be considered as a potential interfering agent of cancer progression.     

PI3K/Akt信号通路对胃癌细胞SGC7901细胞化疗效果的影响

目的运用磷脂酰肌醇3-激酶抑制剂(phosphatidylinositol 3-kinases,PI3-K)LY294002[2-(4-吗啉基)-8-苯基-4氢-1-苯并吡喃-4-酮]作用于胃癌细胞系SGC7901,探讨抑制PI3K/Akt信号转导通路对胃癌细胞化疗敏感性的影响。方法采用MTT比色法,流式细胞术检测5-FU、DDP及ADM单独或联合PI3K抑制剂LY294002对人胃癌细胞SGC7901的抑制率、凋亡率。并分析单独及联合应用LY294002对SGC7901细胞周期的影响。Western-blot检测单独及联合化疗药后P-Akt蛋白在SGC7901细胞中的表达水平。结果单独使用化疗药5-FU、DDP及ADM均可抑制SGC7901细胞增殖、诱导其凋亡。当化疗药与抑制剂联合应用,对细胞的抑制作用明显增强,促凋亡作用增强,与对照组比较(P0.05)。细胞周期同步分析显示,单独用药均可将SGC7901细胞阻滞于G0/G1期。联合使用抑制剂使处于G0/G1期细胞增加。Western blot显示化疗药上调P-Akt蛋白的表达,联合使用抑制剂后SGC7901细胞P-Akt蛋白的表达与未使用抑制剂比较减弱,差异有统计学意义(P0.05)。结论阻断PI3K/Akt信号通路可提高化疗药5-FU、DDP及ADM对胃癌细胞株SGC7901的抑制率,凋亡率并使阻滞于G0/G1期细胞增多;LY294002通过阻断PI3K/Akt信号通路,抑制P-Akt蛋白表达,增强化疗药的敏感性;LY294002阻断PI3K/Akt信号通路对5-FU、DDP、ADM治疗胃癌有一定的协同或增强作用。     

Involvement of the PI3K/Akt/Nrf2 Signaling Pathway in Resveratrol-Mediated Reversal of Drug Resistance in HL-60/ADR Cells

Resistance to chemotherapy drugs, such as adriamycin (ADR), is a common problem in acute myeloid leukemia (AML) patients. We hypothesized that the natural compound resveratrol (Res) may reverse AML drug resistance through the PI3K/Akt/Nrf2 pathway. We investigated the in vitro effect of Res using human promyelocytic leukemia cells (HL-60) and the ADR-resistant cell line (HL-60/ADR) and treated with either Res or ADR?+?Res. Cellular proliferation inhibition rate, auto-fluorescence intensity of ADR in HL-60/ADR cells and HL-60 cells, mRNA expression of Nrf2 and the drug-resistant gene MRP1, and protein expression of PI3K, Akt, p-Akt, Nrf2, and MRP1 were measured. Results showed ADR?+?Res had a more significant inhibitory effect than ADR alone on HL-60/ADR cells. Auto-fluorescence intensity of ADR in HL-60/ADR cells treated with ADR?+?Res significantly increased. No difference of the auto-fluorescence intensity of ADR was observed in HL-60 cells treated with ADR and ADR?+?Res. mRNA expression of Nrf2 and MRP1 significantly decreased in HL-60/ADR cells treated with both Res and ADR?+?Res; protein expression of PI3K, p-Akt, Nrf2, and MRP1 significantly decreased in HL-60/ADR cells treated with PI3K inhibitor, Res and ADR?+?Res. In conclusion, Res reverses the drug resistance of AML HL-60/ADR cells through regulation of the PI3K/Akt/Nrf2 signaling pathway and MRP1 expression.     

Activation of PI3K/Akt Signaling Pathway in Rat Hypothalamus Induced by an Acute Oral Administration of D-Pinitol

D-Pinitol (DPIN) is a natural occurring inositol capable of activating the insulin pathway in peripheral tissues, whereas this has not been thoroughly studied in the central nervous system. The present study assessed the potential regulatory effects of DPIN on the hypothalamic insulin signaling pathway. To this end we investigated the Phosphatidylinositol-3-kinase (PI3K)/Protein Kinase B (Akt) signaling cascade in a rat model following oral administration of DPIN. The PI3K/Akt-associated proteins were quantified by Western blot in terms of phosphorylation and total expression. Results indicate that the acute administration of DPIN induced time-dependent phosphorylation of PI3K/Akt and its related substrates within the hypothalamus, indicating an activation of the insulin signaling pathway. This profile is consistent with DPIN as an insulin sensitizer since we also found a decrease in the circulating concentration of this hormone. Overall, the present study shows the pharmacological action of DPIN in the hypothalamus through the PI3K/Akt pathway when giving in fasted animals. These findings suggest that DPIN might be a candidate to treat brain insulin-resistance associated disorders by activating insulin response beyond the insulin receptor.     

Endothelium-Dependent Relaxation Effect of Apocynum venetum Leaf Extract via Src/PI3K/Akt Signalling Pathway

Botanical herbs are consumed globally not only as an essential diet but also as medicines or as functional/recreational food supplements. The extract of the Apocynum venetum leaves (AVLE), also known as Luobuma, exerts its antihypertensive effect via dilating the blood vessels in an endothelium- and concentration-dependent manner with optimal effect seen at as low as 10 µg/mL. A commercial Luoboma “antihypertensive tea” is available commercially in the western province of China. The present study seeks to investigate the underlying cellular mechanisms of the nitric oxide (NO)-releasing property of AVLE in rat aortas and human umbilical vein endothelial cells (HUVECs). Endothelium-dependent relaxation induced by AVLE was assessed in organ chambers in the presence or absence of polyethyleneglycol catalase (PP2, 20 µM; inhibitor of Src kinase), wortmannin (30 nM) and {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 (20 µM; PI3 (phosphatidylinositol3)-Kinase inhibitor), N^G-nitro-l-arginine (L-NAME, 100 µM; endothelial NO synthase inhibitor (eNOS)) and ODQ (1 µM; soluble guanylyl cyclase inhibitor). Total nitrite and nitrate (NOx) level and protein expression of p-Akt and p-eNOS were measured. AVLE-induced endothelium-dependent relaxation was reduced by PP2, wortmannin and {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 and abolished by L-NAME and ODQ. AVLE significantly increased total NO_x level in rat aortas and in HUVECs compared to control. It also instigated phosphorylation of Akt and eNOS in cultured HUVECs in a concentration-dependent manner and this was markedly suppressed by PP2, wortmannin and {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002. AVLE also inhibited superoxide generated from both NADPH oxidase and xanthine/xanthine oxidase system. Taken together, AVLE causes endothelium-dependent NO mediated relaxations of rat aortas through Src/PI3K/Akt dependent NO signalling pathway and possesses superoxide scavenging activity.     

砷对PI3K/AKT信号通路调节效应的Meta分析

目的系统评价砷(arsenic,As)对PI3K/AKT信号通路的多种调节效应,为揭示砷毒性作用机制提供理论依据。方法 2名研究者独立地评价中国知网、维普、万方、Cochrane、Embase、PubMed、Web of Science等数据库的文献质量,提取资料并进行交叉核对。对纳入的研究结果采用RevMan 5. 3和Stata 12. 0进行Meta分析。结果在体外实验中,与对照组相比,砷干预组PI3K、P-AKT水平均低于对照组,PTEN水平高于对照组,差异有统计学意义(Z分别为3. 01、3. 15和1. 97,P<0. 05);亚组分析发现,长时间(>24 h)砷干预组PTEN水平高于对照组,PI3K和P-AKT(ser473)水平均低于对照组,短时间(≤24 h)砷干预组P-AKT水平低于对照组,差异有统计学意义(Z分别为2. 06、2. 34、2. 92和2. 79,P<0. 05)。高浓度(≥3μmol/L)砷干预组PI3K及P-AKT水平均低于对照组,差异有统计学意义(Z分别为2. 46和3. 34,P<0. 05)。砷与PI3K抑制剂联合处理后的AKT、P-AKT及P-AKT(ser473)的表达比砷干预组下降更为明显。在体内实验中,砷干预组PI3K、P-AKT水平均低于对照组,差异有统计学意义(Z分别为2. 40、4. 25,P<0. 05);亚组分析可见,长时间(>14 d)砷干预组P-AKT水平,短时间(≤14 d)砷干预组PI3K、P-AKT、AKT水平均低于对照组,差异有统计学意义(Z分别为3. 01、4. 04、3. 67和2. 17,P<0. 05)。高浓度(>3 mg/kg)砷干预组PI3K、P-AKT,低浓度(≤3 mg/kg)砷干预组AKT、P-AKT水平均低于对照组,差异有统计学意义(Z分别为4. 04、3. 00、4. 33和2. 35,P<0. 05)。凋亡指标分析显示,砷干预后,凋亡相关蛋白Bax、Cytochrome C、Caspase3、Caspase9、PARP和Apoptosis rate表达水平较对照组均增加,差异有统计学意义(Z分别为3. 34、2. 47、2. 05、2. 36、2. 21和3. 16,P<0. 05),Bcl-2蛋白表达水平与对照组相比下降(Z=2. 05,P<0. 05)。结论砷可以通过抑制PI3K/AKT信号通路诱导细胞的调亡,其作用受到剂量、作用时间的影响。     

砷对PI3K/AKT信号通路调节效应的Meta分析

目的系统评价砷(arsenic,As)对PI3K/AKT信号通路的多种调节效应,为揭示砷毒性作用机制提供理论依据。方法 2名研究者独立地评价中国知网、维普、万方、Cochrane、Embase、PubMed、Web of Science等数据库的文献质量,提取资料并进行交叉核对。对纳入的研究结果采用RevMan 5. 3和Stata 12. 0进行Meta分析。结果在体外实验中,与对照组相比,砷干预组PI3K、P-AKT水平均低于对照组,PTEN水平高于对照组,差异有统计学意义(Z分别为3. 01、3. 15和1. 97,P<0. 05);亚组分析发现,长时间(>24 h)砷干预组PTEN水平高于对照组,PI3K和P-AKT(ser473)水平均低于对照组,短时间(≤24 h)砷干预组P-AKT水平低于对照组,差异有统计学意义(Z分别为2. 06、2. 34、2. 92和2. 79,P<0. 05)。高浓度(≥3μmol/L)砷干预组PI3K及P-AKT水平均低于对照组,差异有统计学意义(Z分别为2. 46和3. 34,P<0. 05)。砷与PI3K抑制剂联合处理后的AKT、P-AKT及P-AKT(ser473)的表达比砷干预组下降更为明显。在体内实验中,砷干预组PI3K、P-AKT水平均低于对照组,差异有统计学意义(Z分别为2. 40、4. 25,P<0. 05);亚组分析可见,长时间(>14 d)砷干预组P-AKT水平,短时间(≤14 d)砷干预组PI3K、P-AKT、AKT水平均低于对照组,差异有统计学意义(Z分别为3. 01、4. 04、3. 67和2. 17,P<0. 05)。高浓度(>3 mg/kg)砷干预组PI3K、P-AKT,低浓度(≤3 mg/kg)砷干预组AKT、P-AKT水平均低于对照组,差异有统计学意义(Z分别为4. 04、3. 00、4. 33和2. 35,P<0. 05)。凋亡指标分析显示,砷干预后,凋亡相关蛋白Bax、Cytochrome C、Caspase3、Caspase9、PARP和Apoptosis rate表达水平较对照组均增加,差异有统计学意义(Z分别为3. 34、2. 47、2. 05、2. 36、2. 21和3. 16,P<0. 05),Bcl-2蛋白表达水平与对照组相比下降(Z=2. 05,P<0. 05)。结论砷可以通过抑制PI3K/AKT信号通路诱导细胞的调亡,其作用受到剂量、作用时间的影响。     

氟化钠对人成骨肉瘤Saos-2细胞PI3K/Akt信号表达及凋亡的影响

目的观察氟化钠(NaF)对人成骨肉瘤Saos-2细胞磷脂酰肌醇-3-激酶/蛋白激酶B(PI3K/Akt)信号表达及凋亡的影响。方法采用成组设计,按NaF剂量将Saos-2细胞分为0(对照)、5、10、20、40 mg/L染氟组(n=3)。体外培养24、48 h后收集细胞,采用蛋白免疫印迹(Western blot)法检测PI3K、Akt和线粒体凋亡途径相关分子Forkhead转录因子(FoxO)1的蛋白表达,采用流式细胞仪检测Saos-2细胞的凋亡水平。结果体外培养24、48 h时,各组Saos-2细胞PI3K、Akt蛋白表达比较,差异均无统计学意义(P均>0.05)。24 h时,5、10、20、40 mg/L染氟组磷酸化PI3K(p-PI3K)蛋白表达(0.40±0.06、0.45±0.02、0.37±0.06、0.32±0.06)均高于对照组(0.28±0.04,P均<0.05);48 h时,5、10 mg/L染氟组p-PI3K蛋白表达(0.46±0.06、0.58±0.03)均高于对照组(0.29±0.04,P均<0.05),而40 mg/L染氟组(0.21±0.03)低于对照组(P<0.05)。24 h时,5、10、20 mg/L染氟组磷酸化Akt(p-Akt)蛋白表达(0.27±0.01、0.30±0.03、0.27±0.03)均高于对照组(0.20±0.02,P均<0.05);48 h时,5、10 mg/L染氟组p-Akt蛋白表达(0.42±0.04、0.60±0.02)均高于对照组(0.27±0.01,P均<0.05),而40 mg/L组(0.18±0.02)低于对照组(P<0.05)。24 h时,10、20、40 mg/L染氟组FoxO1蛋白表达(0.38±0.07、0.41±0.06、0.47±0.08)均高于对照组(0.34±0.04,P均<0.05);48 h时,5、10、20、40 mg/L染氟组FoxO1蛋白表达(0.36±0.08、0.37±0.10、0.54±0.04、0.73±0.04)均高于对照组(0.28±0.04,P均<0.05)。24、48 h时,对照组和5、10、20、40 mg/L染氟组细胞凋亡率分别为(2.867±0.583)%、(3.647±0.035)%、(3.773±0.095)%、(5.440±0.325)%、(7.203±0.476)%,(3.707±0.286)%、(4.023±0.241)%、(4.970±0.368)%、(12.473±0.949)%、(19.387±1.892)%。24 h时,40 mg/L染氟组凋亡水平高于对照组(P<0.05);48 h时,20、40 mg/L染氟组凋亡水平均高于对照组(P均<0.05)。结论氟可以直接激活成骨细胞内的PI3K/Akt信号通路,进而产生抗凋亡作用。     

PI3K/AKT/Bcl-2通路在吡格列酮保护缺血再灌注损伤心肌细胞中作用的研究

目的 研究吡格列酮对缺血再灌注损伤心肌细胞的保护作用机制中PI3K/AKT/Bcl-2信号通路的作用.方法 取Wistar大鼠乳鼠心室肌细胞进行体外培养,缺氧、复氧各3 h后建立缺血再灌注损伤细胞模型.采用免疫细胞化学染色法检测细胞内Bcl-2蛋白含量,采用Western-bloting检测细胞内Bcl-2蛋白表达水平.结果 免疫细胞化学染色法及Western-bloting结果均显示：与Ⅰ组比较,P组Bcl-2表达明显增加（P〈0.05）;与P组比较,P＋Ly组Bcl-2表达明显减少（P〈0.05）.结论 吡格列酮减轻心肌缺血再灌注损伤保护机制与其激活PI3K/AKT/ Bcl-2信号通路有关.     

蓝莓对大鼠肝纤维化PI3K-Akt信号通路影响

目的 观察磷脂酰肌醇-3激酶/蛋白激酶（PI3K/Akt）信号通路在猪血清所致的免疫性大鼠肝组织纤维化中作用及蓝莓影响。方法 60只健康雄性SD大鼠随机分为对照组、模型组、蓝莓原浆低、中、高剂量组（每天灌胃给予0.25、0.50、1.00 mL/100 g）及复方鳖甲软肝片组（每天灌胃0.054 g/100 g）,每组10只,除对照组外,其余各组均采用每周二、五腹腔注射猪血清复制大鼠肝纤维化模型,共12周;测定大鼠肝脏指数及血清丙氨酸转氨酶（ALT）、谷草转氨酶（AST）,观察肝组织病理学改变,采用免疫组织化学、Western blot法检测肝组织Akt1、磷酸化Akt1（p-Akt1）表达。结果 与对照组比较,模型组大鼠肝脏指数（0.58±0.02）明显升高（P<0.01）,肝纤维化明显;与模型组比较,蓝莓高剂量组大鼠肝指数（0.37±0.06）明显降低（P<0.01）,肝纤维化程度明显减轻;与对照组比较,模型组大鼠肝组织中Akt1、p-Akt1 蛋白表达量[分别为（0.99±0.09）、（0.81±0.06）]明显增加（P<0.01）;与模型组比较,蓝莓高、中剂量组大鼠肝组织中Akt1、p-Akt1 蛋白表达量[分别为（0.39±0.13）、（0.42±0.15）与（0.44±0.06）、（0.43±0.12）]明显下调（P<0.01）。结论 蓝莓对大鼠免疫性肝纤维化发生发展过程具有干预作用,其机制可能与PI3K/Akt信号通路激活有关。     

PI3K/Akt信号通路在虾青素调节LX-2细胞活化中作用

目的 探讨磷脂酰肌醇3-激酶/蛋白激酶B（PI3K/Akt）信号通路在虾青素调节人肝星状细胞（LX-2细胞）活化中的作用。方法 实验设对照组、低、中、高剂量虾青素组（5、10、20 μmol/L）、抑制剂组（25 μmol/L LY294002）、抑制剂+虾青素组（25 μmol/L LY294002+20 μmol/L虾青素）,作用48 h后检测LX-2细胞中α-平滑肌肌动蛋白（α-SMA）和Ⅰ型胶原（col1a1）mRNA表达水平、各组细胞Akt及其磷酸化水平。结果 与对照组比较,虾青素组LX-2细胞中α-SMA和col1a1 mRNA表达明显降低,并呈剂量依赖关系（P<0.05）;与对照组比较,抑制剂组LX-2细胞中磷酸化Akt水平（0.42±0.05）、α-SMA和col1a1 mRNA表达水平[分别为（0.23±0.05）、（0.35±0.06）]均明显降低（P<0.05）;与对照组比较,虾青素组LX-2细胞中磷酸化Akt水平（0.60±0.07）、α-SMA和col1a1 mRNA表达水平[分别为（0.48±0.07）、（0.61±0.04）]均明显降低（P<0.05）;与抑制剂组比较,抑制剂+虾青素组LX-2细胞中磷酸化Akt水平（0.18±0.04）、α-SMA和col1a1 mRNA表达水平[分别为（0.11±0.05）、（0.20±0.03）]均明显降低（P<0.05）。结论 虾青素可通过PI3K/Akt信号通路抑制肝星状细胞活化,发挥抗非酒精性脂肪肝纤维化作用。     

Promising Anticancer Activities of Alismatis rhizome and Its Triterpenes via p38 and PI3K/Akt/mTOR Signaling Pathways

The flowering plant genus Alisma, which belongs to the family Alismataceae, comprises 11 species, including Alisma orientale, Alisma canaliculatum, and Alisma plantago-aquatica. Alismatis rhizome (Ze xie in Chinese, Takusha in Japanese, and Taeksa in Korean, AR), the tubers of medicinal plants from Alisma species, have long been used to treat inflammatory diseases, hyperlipidemia, diabetes, bacterial infection, edema, oliguria, diarrhea, and dizziness. Recent evidence has demonstrated that its extract showed pharmacological activities to effectively reverse cancer-related molecular targets. In particular, triterpenes naturally isolated from AR have been found to exhibit antitumor activity. This study aimed to describe the biological activities and plausible signaling cascades of AR and its main compounds in experimental models representing cancer-related physiology and pathology. Available in vitro and in vivo studies revealed that AR extract possesses anticancer activity against various cancer cells, and the efficacy might be attributed to the cytotoxic and antimetastatic effects of its alisol compounds, such as alisol A, alisol B, and alisol B 23-acetate. Several beneficial functions of triterpenoids found in AR might be due to p38 activation and inhibition of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathways. Moreover, AR and its triterpenes inhibit the proliferation of cancer cells that are resistant to chemotherapy. Thus, AR and its triterpenes may play potential roles in tumor attack, as well as a therapeutic remedy alone and in combination with other chemotherapeutic drugs.     

Rapamycin抑制PI3K/AKT/mTOR信号通路对胃癌MGC-803细胞影响

目的 探讨rapamycin作用于胃癌细胞株MGC-803后对细胞生长影响及其作用机制。方法 体外培养胃癌细胞株MGC-803,使用不同浓度rapamycin干预MGC-803细胞。采用MTT法检测细胞增殖变化;实时荧光定量PCR（QPCR）检测关键基因的表达;蛋白印迹法（WB）检测相关蛋白的表达;流式细胞术检测细胞周期及凋亡的变化。结果 与对照组相比,rapamycin对胃癌MGC-803细胞的增殖活性有明显的抑制作用,呈现出剂量依赖性（P<0.05）。Rapamycin显著抑制PI3K、AKT、mTOR、4EBP、P70S6K基因的mRNA表达,差异有统计学意义（P<0.05）;Rapamycin能抑制p-mTOR、p-P70S6K蛋白的表达;Rapamycin将细胞周期阻滞在G0/G1期,并诱导细胞凋亡（P<0.05）。结论 靶向mTOR抑制剂rapamycin可通过调控PI3K/AKT/mTOR信号通路进而调控胃癌细胞的生长。     

氯化锂对缺氧后神经干细胞PI3K/Akt信号通道活性的影响

目的 探讨氯化锂对缺氧后神经干细胞(NSCs)磷脂酰肌醇-3-羟激酶/蛋白激酶B(PI3K/Akt)信号通道活性的影响。方法 分离培养新生SD乳鼠(SD)NSCs,建立缺氧NSCs模型。正常对照组NSCs加无血清培养基,单纯缺氧组仅缺氧,生理盐水干预组缺氧后加生理盐水,三组氯化锂干预组分别加入氯化锂至所需的浓度。免疫组织化学技术检测各组Akt /P-Akt阳性细胞表达。结果 缺氧NSCs形态不规则,胞体肿胀,甚至出现细胞膜破裂,数量减少,折光性减弱;缺氧NSCs死亡数较未缺氧NSCs明显增多、活性明显降低(P均<0.05)。1 mM氯化锂干预组P-Akt表达较单纯缺氧组、生理盐水干预组及5 mM氯化锂干预组强,较3 mM氯化锂干预组弱。3 mM 氯化锂干预组P-Akt表达较1 mM 、5 mM氯化锂干预组强。3 mM氯化锂干预组P-Akt阳性细胞数较单纯缺氧组、生理盐水干预组、1 mM、5 mM氯化锂干预组明显增多(P<0.05)。结论 氯化锂激活缺氧后NSCs PI3K/Akt信号通路。     

前列腺癌细胞DU145同步化诱导的DNA损伤反应通路和PI3K/Akt通路对凋亡抑制因子基因API2(BIRC3)mRNA表达的影响

目的探讨在前列腺癌细胞DU145同步化培养后引起的DNA损伤反应通路和PI3K/AKT通路对凋亡抑制因子(IAP)基因API2(BIRC3)mRNA表达的影响,同时分析API2基因所在染色体是否存在特异性的异常。方法采用无血清的饥饿培养法使细胞同步在G0期;分别用含羞草碱(mimosine)、胸腺嘧啶(thymidine)和噻氨酯哒唑(nocodazole)使细胞同步在G1期、S期和G2/M期并引起DNA损伤反应,同时加入PI3K的特异性抑制剂ly294002以阻止PI3K/AKT通路。通过RT-PCR半定量法检测API2 mRNA在各个细胞周期相的表达情况。通过细胞遗传学的常规G式显带法,分析凋亡抑制因子基因所在的染色体是否存在特异性的异常。结果 mimosine同步化的G0/G1期细胞达到了78.04%,thymidine同步化的S期细胞达到62.19%,nocodazole同步化的G2/M 60.5%。API2基因位于染色体11q22-q23,存在易位,如t(11;12)(q;q)。API2mRNA的表达,非同步化的ly294002组分别与同步化的mimosine+ly294002组、nocodazole+ly294002组和thymidine+ly294002组比较,差异均有统计学意义(P<0.05)。结论前列腺癌细胞株DU145存在某些染色体的结构和数目异常,这些异常可能影响某些基因的表达。药物的同步化激活了DNA损伤反应通路和生存信号通路,再通过PI3K/Akt通路,而不是通过P53通路,在细胞周期的某个时相调控API2(BIRC3)mRNA的表达。     

子宫内膜组织中PTEN表达与Akt信号通路的相关性

目的:探讨抑癌基因PTEN与子宫内膜癌发生、发展的关系及与Akt信号传导通路的相关性。方法:应用半定量逆转录聚合酶链反应(RT-PCR)方法和Western-blot方法测定24例子宫内膜癌、10例子宫内膜非典型增生、10例子宫内膜增殖症和10例正常子宫内膜组织PTENmRNA和蛋白水平的表达及Akt磷酸化水平的变化;免疫组织化学SP法检测增生期内膜31例(增生期组),分泌期内膜30例(分泌期组),内膜增殖症71例(增殖症组),非典型增生内膜25例(非典型增生组),子宫内膜癌73例(内膜癌组)组织中PTEN蛋白水平的表达,将结果与各病例的组织学类型、组织学分级、肌层浸润深度和临床分期等生物学行为进行相关性分析。结果:PTEN在增生期组、分泌期组、增殖症组、非典型增生组、内膜癌组的免疫组化染色强度分别为:3.39±0.15、1.90±0.21、3.34±0.29、0.62±0.11、0.74±0.19,mRNA相对含量在正常内膜、增殖症、非典型增生及内膜癌组中分别为2.45±0.51、2.32±0.32、0.46±0.11、0.35±0.13。在转录和蛋白水平子宫内膜腺癌组和癌前病变组中PTEN的表达明显低于内膜增殖症组和正常子宫内膜组(P<0.0001)。PTEN蛋白表达与组织学类型、组织学分级和临床分期有关(P<0.05),与子宫内膜癌肌层浸润深度无关(P>0.05)。Western-blot结果显示,phospho-Akt表达水平在PTEN表达阴性病例中明显升高,与PTEN表达呈负相关(r=-0.8973,P<0.0001)。结论:PTEN表达缺失是子宫内膜癌发生的早期事件;PTEN蛋白表达缺失导致Akt信号传导通路持续活化参与了子宫内膜癌的发生、发展。     

PI3K/Akt/mTOR信号传导通路在肿瘤的研究进展

PI3K/Akt/mTOR信号传导通路是哺乳动物细胞内非常重要的信号传导通路之一,它通过影响其下游多种效应分子的活化状态,发挥在细胞内抑制凋亡、促进增殖的作用.最新研究表明PI3K/Akt/mTOR信号传导通路与包括肝癌、结肠癌、肺癌、乳腺癌等多种肿瘤的发生发展密切相关,且PI3K/Akt/mTOR信号传导通路的研究在肿瘤的治疗中同样发挥着重要的作用.因此文章将PI3K/Akt/mTOR信号通路的组成、分子机制、功能、及其在肿瘤治疗中的应用前景等方面的研究进展作一综诉.     

SDF-1和PI3K/Akt通路对卵巢癌CAOV3细胞增殖和侵袭能力的影响研究

目的:探讨基质细胞衍生因子-1(SDF-1)通过磷脂酰肌醇3激酶/蛋白激酶B(PI3K/Akt)信号传导通路对卵巢癌CAOV3细胞增殖和侵袭能力的影响及其作用机制.方法:将卵巢癌CAOV3细胞分为对照组(未给药),实验组1(100 ng/ml SDF-1),实验组2(50 μmol/L PI3K/Akt信号传导通路抑制剂LY294002)和实验组3(50 μmol/L LY294002,作用0.5h后加入100 ng/ml SDF-1).采用MTT法检测卵巢癌CAOV3细胞经不同药物处理后24、48和72 h的细胞增殖能力.采用Transwell体外细胞侵袭实验和Western Blot法检测经不同药物处理48h后卵巢癌CAOV3细胞的侵袭能力、Akt磷酸化程度和基质金属蛋白酶-9(MMP-9)水平.结果:SDF-1可以明显促进卵巢癌CAOV3细胞的增殖和侵袭(P＜0.05),LY294002可以抑制卵巢癌CAOV3细胞的增殖和侵袭(P＜0.05);实验组3卵巢癌CAOV3细胞的增殖和侵袭能力与实验组2比较差异无统计学意义(P＞0.05).结论:SDF-1能够通过PI3K/Akt信号传导通路诱导MMP-9蛋白表达上调,增强卵巢癌细胞的增殖和侵袭能力;应用LY294002阻断PI3 K/Akt信号传导通路可显著抑制SDF-1对人卵巢癌CAOV3细胞增殖和侵袭的促进作用.