LncRNA MEG3靶向miR-181a-5p调控宫颈癌细胞放射敏感性

目的 研究LncRNA MEG3对宫颈癌细胞放射敏感性的影响,并探讨其作用机制。方法 运用qRT-PCR法检测放射抗性和放射敏感性宫颈癌细胞中LncRNA MEG3的表达;将过表达对照组(转染pcDNA 3.1)、过表达LncRNA MEG3组(转染pcDNA 3.1-LncRNA MEG3)、抑制miR-NC组(转染anti-miR-NC)、抑制miR-181a-5p组(转染anti-miR-181a-5p)、过表达LncRNA MEG3+过表达miR-NC组(共转染pcDNA 3.1-LncRNA MEG3和anti-miR-NC)、过表达LncRNA MEG3+过表达miR-181a-5p组(共转染pcDNA 3.1-LncRNA MEG3和anti-miR-181a-5p),均用脂质体法转染至SiHa细胞;克隆形成实验检测细胞的存活分数;流式细胞术检测细胞的凋亡率;双荧光素酶报告基因检测实验检测细胞的荧光活性;Western blot检测细胞中PTEN、p-Akt、Akt的蛋白表达。结果 与放射敏感组相比,放射抗性宫颈癌组织中LncRNA MEG3的表达明显降低(P<0.05),其表达量与宫颈癌细胞的放射敏感性呈正相关;过表达LncRNA MEG3、抑制miR-181a-5p均可显著增强宫颈癌细胞SiHa放射敏感性,促进凋亡(P<0.05);野生型LncRNA MEG3细胞的荧光活性受miR-181a-5p的抑制。过表达miR-181a-5p逆转了LncRNA MEG3对宫颈癌细胞放射增敏和促凋亡作用及对PTEN/Akt信号通路的调控。结论 长链非编码RNA LncRNA MEG3可增强宫颈癌细胞放射敏感性,其机制可能与靶向miR-181a-5p调控PTEN/Akt 信号通路有关,可为提高宫颈癌的预后提供新方向。     

低温等离子射频消融术联合顺铂注射液治疗喉癌的疗效观察

目的探讨低温等离子射频消融术联合顺铂注射液治疗喉癌的临床疗效及对患者血管内皮生长因子C(VEGF-C)和PTEN基因的影响。方法选取2017年1月至2018年8月间麻城市人民医院收治的150例喉癌患者,采用随机数表法分为观察组和对照组,每组75例。对照组患者采用喉镜下CO2激光切除术联合顺铂注射液治疗,观察组患者采用低温等离子射频消融术联合顺铂注射液治疗,比较两组患者的治疗效果、血清VEGF-C和PTEN及不良反应。结果观察组患者的临床疗效为72.0%,高于对照组患者的41.3%,差异有统计学意义(P<0.05)。治疗前,两组患者的血清VEGF-C和PTEN比较,差异无统计学意义(P>0.05)。治疗后,两组患者的血清VEGF-C和PTEN均下降,且观察组患者均低于对照组患者,差异均有统计学意义(均P<0.05)。观察组患者总生存时间及无瘤生存时间均高于对照组患者,差异均有统计学意义(均P<0.05)。两组患者的不良反应发生率比较,差异无统计学意义(P>0.05)。结论低温等离子射频消融术联合顺铂注射液治疗喉癌,可降低患者的VEGF-C和PTEN水平,治疗效果较好,建议临床推广。     

Notch1 contributes to TNF-α-induced proliferation and migration of airway smooth muscle cells through regulation of the Hes1/PTEN axis

Notch1 has been implicated in asthma pathogenesis. However, the function of Notch1 in regulating airway smooth muscle (ASM) cell proliferation and migration during airway remodeling of asthma remains unknown. Using an in vitro model induced by tumor necrosis factor (TNF)-α, we reported in this study that Notch1 participated in TNF-α-induced proliferation and migration of ASM cells. Our results demonstrated that Notch1 expression was significantly upregulated in ASM cells exposed to TNF-α. Notch1 inhibition significantly repressed TNF-α-induced ASM cell proliferation and migration, while Notch1 overexpression promoted the opposite effect. Moreover, Notch1 inhibition downregulated the expression of Notch-1 intracellular domain (NICD) and Hes1, while upregulated PTEN expression in TNF-α-exposed cells. Notably, Hes1 overexpression partially reversed the Notch1-inhibition-mediated inhibitory effect on TNF-α-induced ASM cell proliferation and migration. In addition, the promoting effect of Notch1 inhibition on PTEN expression was markedly abrogated by Hes1 overexpression. Overall, these findings demonstrated that Notch1 inhibition repressed TNF-α-induced ASM cell proliferation and migration by modulating the Hes1/PTEN signaling axis, a finding that highlights the involvement of Notch1/Hes1/PTEN in regulating airway remodeling of asthma.     

MicroRNA-181c provides neuroprotection in an intracerebral hemorrhage model

Apoptosis is an important factor during the early stage of intracerebral hemorrhage.MiR-181 c plays a key regulatory role in apoptosis.However,whether miR-181 c is involved in apoptosis of prophase cells after intracerebral hemorrhage remains unclear.Therefore,in vitro and in vivo experiments were conducted to test this hypothesis.In vivo experiments:collagenase type VII was injected into the basal ganglia of adult Sprague-Dawley rats to establish an intracerebral hemorrhage model.MiR-181 c mimic or inhibitor was injected in situ 4 hours after intracerebral hemorrhage.Neurological functional defects(neurological severity scores)were assessed 1,7,and 14 days after model establishment.Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and western blot assay were conducted 14 days after model establishment.In vitro experiments:PC12 cells were cultured under oxygen-glucose deprivation,and hemins were added to simulate intracerebral hemorrhage in vitro.MiR-181 c mimic or inhibitor was added to regulate miR-181 c expression.3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay,luciferase reporter system,and western blot assay were performed.Experimental results revealed differences in miR-181 c expression in brain tissues of both patients and rats with cerebral hemorrhage.In addition,in vitro experiments found that miR-181 c overexpression could upregulate the Bcl-2/Bax ratio to inhibit apoptosis,while inhibition of miR-181 c expression could reduce the Bcl-2/Bax ratio and aggravate apoptosis of cells.Regulation of apoptosis occurred through the phosphoinositide 3 kinase(PI3 K)/Akt pathway by targeting of phosphatase and tensin homolog deleted on chromosome ten(PTEN).Higher miR-181 c overexpression correlated with lower neurological severity scores,indicating better recovery of neurological function.In conclusion,miR-181 c affects the prognosis of intracerebral hemorrhage by regulating apoptosis,and these effects might be directly mediated and regulated by targeting of the PTEN\PI3 K/Akt pathway and Bcl-2/Bax ratio.Furthermore,these results indicated that miR-181 c played a neuroprotective role in intracerebral hemorrhage by regulating apoptosis of nerve cells,thus providing a potential target for the prevention and treatment of intracerebral hemorrhage.Testing of human serum was authorized by the Ethics Committee of China Medical University(No.2012-38-1)on February 20,2012.The protocol was registered with the Chinese Clinical Trial Registry(Registration No.ChiCTR-COC-17013559).The animal study was approved by the Institutional Animal Care and Use Committee of China Medical University(approval No.2017008)on March 8,2017.     

加味丹参饮通过PTEN/PI3K/Akt信号通路抑制IRI作用的研究

目的:探讨加味丹参饮预处理通过抑瘤基因/磷脂酰肌醇-3激酶/蛋白激酶B(PTEN/PI3K/Akt)信号通路对大鼠心肌缺血再灌注损伤(IRI)的保护作用及机制。方法:将75只雄性远交群(SD)大鼠随机分为5组:假手术组、模型组、加味丹参饮组、加味丹参饮+PI3K/Akt通路抑制剂(LY294002)组、LY294002组,采用结扎大鼠冠状动脉左前降支30min后再灌注60min的方法制备IRI模型。采用酶联免疫吸附测定(ELISA)法检测各组大鼠心肌肌钙蛋白I(c Tn I)表达;取心肌梗死边缘区心肌组织,采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记(TUNEL)法检测心肌凋亡指数,采用免疫组化法检测各组大鼠心肌组织Akt、PTEN的表达。结果:与假手术组比较,模型组c Tn I水平显著升高,大鼠心肌凋亡指数增加,PTEN、Akt表达均显著升高(P<0.05);与模型组比较,加味丹参饮组c Tn I水平均显著降低,Akt表达升高,心肌凋亡指数和PETN表达降低(P<0.05);与加味丹参饮组比较,加入抑制剂后,c Tn I水平均明显降低,Akt表达降低,PTEN表达升高(P<0.05)。结论:大鼠心肌缺血再灌注时,加味丹参饮可以通过降低PTEN表达,激活PI3K/Akt信号通路,抑制大鼠心肌细胞的凋亡,从而减轻心肌损伤,保护心肌。     

microRNA-21 mediates epithelial-mesenchymal transition of human hepatocytes via PTEN/Akt pathway

miR-21 has been shown to play fundamental role in diverse biological and pathological processes, including fibrotic diseases. In the present study, we investigated whether miR-21 regulated the fibrogenic epithelial-mesenchymal transition (EMT) in human hepatocytes QSG-7701 and explored underlying mechanisms. The results showed that treatment of QSG-7701 cells with pro-fibrogenic factor TGF-β₁ resulted in increased expression of miR-21 and promoted fibrogenic EMT in hepatocytes. Downregulation of miR-21 expression by transfection of anti-miR-21 into QSG-7701 cells inhibited fibrogenic EMT induced by TGF-β₁. Furthermore, overexpression of miR-21 alone also resulted in EMT-like transformation in QSG-7701 cells. TGF-β₁ treatment resulted in decreased PTEN and increased Akt phosphorylation and anti-miR-21 abolished this effect. Overexpression of miR-21 in QSG-7701 cells also downregulated PTEN and upregulated Akt phosphralation. Inhibition of Akt signaling by specific inhibitor Akt inhibitor IV blocked TGF-β₁ and miR-21-induced fibrogenic EMT. In summary, our results identify miR-21 as a key regulator of fibrogenic EMT in hepatocytes via PTEN/Akt pathway. Targeting miR-21 may provide a new therapeutic strategy against hepatic fibrosis.     

A Phase I Trial of IGF-1R Inhibitor Cixutumumab and mTOR Inhibitor Temsirolimus in Metastatic Castration-resistant Prostate Cancer

BackgroundDespite frequent PTEN (phosphatase and tensin homologue) loss and Akt/mammalian target of rapamycin (mTOR) signaling in prostate cancer, the disease is insensitive to single-agent mTOR inhibition. Insulin-like growth factor-1 receptor inhibition might mitigate the feedback inhibition by Torc1 inhibitors, suppressing downstream Akt activation and, thus, potentiating the antitumor activity of mTOR inhibition.Patients and MethodsIn the present phase I study, patients with metastatic castration-resistant prostate cancer received 6 mg/kg cixutumumab and 25 mg temsirolimus intravenously each week. The primary objective was safety and tolerability. Temsirolimus was decreased if ≥ 2 dose-limiting toxicities (DLTs) were observed in 6 patients. The correlative analyses included measurement of circulating tumor cells, [18F]-fluoro-2-deoxyglucose positron emission tomography, 16β-[18F]-fluoro-α-dihydrotestosterone positron emission tomography, and tumor biopsy.ResultsA total of 16 patients were enrolled across 3 cohorts (1, −1, −2). Two DLTs (grade 3 oral mucositis) were observed in cohort 1 (temsirolimus, 25 mg), and 1 DLT (grade 3 lipase) in cohort −1 (temsirolimus, 20 mg). The most common adverse events included hyperglycemia (100%; 31% grade 3), oral mucositis (63%; 19% grade 3), and diarrhea (44%; 0 grade 3). Low-grade pneumonitis occurred in 7 of 11 patients (44%; 0 grade 3), prompting the opening of a 3-weekly cohort (temsirolimus, 20 mg/kg), without pneumonitis events. No patient had a >50% decline in prostate-specific antigen from baseline. The best radiographic response was stable disease, with median study duration of 22 weeks (range, 7-63 weeks).ConclusionsDespite a strong scientific rationale for the combination, temsirolimus plus cixutumumab demonstrated limited antitumor activity and a greater than expected incidence of toxicity, including low-grade pneumonitis and hyperglycemia. Hence, the trial was stopped in favor of alternative androgen receptor/phosphatidylinositol 3-kinase–directed combinatorial therapies.