Evaluating the landscape of gene cooperativity with receptor tyrosine kinases in liver tumorigenesis using transposon-mediated mutagenesis

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高压氧治疗对阿尔茨海默病大鼠海马内神经元凋亡及p38丝裂原蛋白激酶表达的影响

目的 评价高压氧治疗对阿尔茨海默病(alzheimer's disease,AD)大鼠海马内神经元凋亡及p38丝裂原蛋白激酶(p38 mitogenactivated protein kinases,p38MAPK)表达的影响. 方法 18只雄性SD大鼠,体重260 g～290 g,采用随机数字表法分为3组(每组6只):生理盐水组(NS组),海马区注射生理盐水;阿尔茨海默病组(AD组),海马区注射Aβ1-40;高压氧组(HBO组),海马区注射Aβ1-40,并于术后1 d～7d行每天1次的高压氧治疗.应用脑立体定位仪于大鼠海马区注射Aβ1-40制备AD模型.于术前1d和术后1、7、14、21 d行水迷宫行为学测试.于术后21 d水迷宫行为学测试结束后处死大鼠,采用苏木精-伊红染色(hematoxylin-eosin,HE)方法染色海马组织病理结构,TUNEL法标记检测凋亡细胞,免疫印迹法(Western bolt)法测定海马内p38MAPK蛋白磷酸化水平. 结果 术后21 d时,与NS组比较,AD组大鼠上台前路程和逃避潜伏期增加[(379±41)、(1 978±120) cm,(16.0±2.8)、(78.4±10.8)s](P＜0.05);与AD组比较,HBO组大鼠上台前路程和逃避潜伏期减少[(1978±120)、(1 246±96) cm,(78.4±10.8)、(51.7±6.2)s](P＜0.05).与NS组比较,AD组和HBO组大鼠海马组织细胞凋亡率[(6.3±13)％,(45.2±5.1)％]及p38MAPK蛋白磷酸化表达升高(0.16±0.06),(0.54±0.10)(P＜0.05);与AD组比较,HBO组海马组织细胞凋亡率[(45.2±5.1)％,(22.5±3.7)％]及p38 MAPK蛋白磷酸化表达下降[(0.54±0.10),(0.31±0.08)](P＜0.05).结论 高压氧治疗可有效缓解AD大鼠认知功能障碍,且能够抑制海马内神经元凋亡,其机制与降低p38MAPK的磷酸化水平有关.     

内源性信号通路在神经元轴突再生中的功能和机制研究

神经元内源性再生能力是神经元再生和功能恢复的关键。近年研究发现了多个调控轴突再生的内源性信号通路,其中丝裂原活化蛋白激酶（MAPK）信号通路和磷脂酰肌醇3-激酶/蛋白激酶B（PI3K/Akt）信号通路最具代表性。MAPK信号通路参与轴突损伤的感知、再生的启动和维持等过程,通过调节蛋白合成和细胞骨架来调控轴突再生;PI3K/Akt信号通路则通过调节损伤后神经元内相关基因的转录和翻译调控轴突再生。多种再生促进信号的共同作用能进一步提升轴突再生能力。本文综述了MAPK和PI3K/Akt信号通路在不同模式生物中调控轴突再生的研究进展,并展望了其在促进体内神经功能恢复上的重要作用。     

CD81-Receptor Associations — Impact for Hepatitis C Virus Entry and Antiviral Therapies

Tetraspanins are integral transmembrane proteins organized in microdomains displaying specific and direct interactions with other tetraspanins and molecular partners. Among them, CD81 has been implicated in a variety of physiological and pathological processes. CD81 also plays a crucial role in pathogen entry into host cells, including hepatitis C virus (HCV) entry into hepatocytes. HCV is a major cause of liver cirrhosis and hepatocellular carcinoma. HCV entry into hepatocytes is a complex process that requires the coordinated interaction of viral and host factors for the initiation of infection, including CD81, scavenger receptor BI, claudin-1, occludin, membrane-bound host cell kinases, Niemann-Pick C1 Like 1, Harvey rat sarcoma viral oncogene homolog (HRas), CD63 and transferrin receptor 1. Furthermore, recent data in HCV model systems have demonstrated that targeting critical components of tetraspanins and associated cell membrane proteins open new avenues to prevent and treat viral infection.     

转化生长因子β1/细胞外信号调节激酶/基质金属蛋白酶通路对腺样囊性癌侵袭和迁移的影响

目的 探讨转化生长因子β1/细胞外信号调节激酶/基质金属蛋白酶2(TGF-β1/ERKl/2/MMP-2)通路在腺样囊性癌(ACC)侵袭和迁移过程中的作用及机制.方法 以腺样囊性癌ACC-2细胞株为研究对象.用转化生长因子β1(TGF-β1)以及ERK通路抑制剂UO126处理ACC-2细胞.MTT检测ACC-2细胞的增殖情况,Transwell实验检测细胞迁移、侵袭能力,Westem blot蛋白印迹检测ACC-2细胞中ERKI/2的活化及MMP-2的表达情况,实时荧光定量聚合酶链反应检测ACC-2细胞中MMP-2的mRNA的表达情况.结果 TGF-β1及UO126干预后,ACC-2细胞增殖能力无明显变化;TGF-β1刺激可增强ACC-2细胞迁移、侵袭能力,增加ACC-2细胞p-ERKI/2和MMP-2蛋白以及MMP-2 mRNA的表达.而UO126阻断ERK磷酸化后,抑制了TGF-β1刺激的增强作用,ACC-2细胞的迁移、侵袭能力降低,MMP-2蛋白和mRNA的表达均下降.结论 TGF-β1/ERKl/2/MMP-2通路参与了人唾液腺ACC侵袭和迁移能力的调节.TGF-β1可通过上调ERK1/2,继而上调MMP-2,促进人唾液腺ACC细胞的侵袭和迁移能力,ERKl/2可能成为人唾液腺ACC侵袭防治的新靶点.     

How does ethanol induce apoptotic cell death of SK-N-SH neuroblastoma cells？

A body of evidence suggests that ethanol can lead to damage of neuronal cells. However, the mechanism underlying the ethanol-induced damage of neuronal cells remains unclear. The role of mitogen-activated protein kinases in ethanol-induced damage was investigated in SK-N-SH neuroblastoma cells. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide cell viability assay, DNA fragmentation detection, and flow cytometric analysis showed that ethanol induced apoptotic cell death and cell cycle arrest, characterized by increased caspase-3 activity, DNA fragmentation, nuclear disruption, and G1 arrest of cell cycle of the SK-N-SH neuroblastoma cells. In addition, western blot analysis indicated that ethanol induced a lasting increase in c-Jun N-terminal protein kinase activity and a transient increase in p38 kinase activity of the neuroblastoma cells. c-Jun N-terminal protein kinase or p38 kinase inhibitors significantly reduced the ethanol-induced cell death. Ethanol also increased p53 phosphorylation, followed by an increase in p21 tumor suppressor protein and a decrease in phospho-Rb （retinoblastoma） protein, leading to alterations in the expressions and activity of cyclin dependent protein kinases. Our results suggest that ethanol mediates apoptosis of SK-N-SH neuroblastoma cells by activating p53-related cell cycle arrest possibly through activation of the c-Jun N-terminal protein kinase-related cell death pathway.     

Systematic screen with kinases inhibitors reveals kinases play distinct roles in growth of osteoprogenitor cells

Cancer treatment-related bone loss has become growing problematic, especially in breast and prostate cancer treated with hormone/endocrine therapy, chemotherapy and radiotherapy. However, bone loss caused by targeted therapy in cancer patients is largely unknown yet. In present study, a kinase inhibitors screen was applied for MC3T3-E1, a murine osteoprogenitor cell line, and seven kinase inhibitors (GSK1838705A, PF-04691502, Dasatinib, Masitinib, GDC-0941, XL880 and Everolimus) were found to suppress the cell viability with dose- and time-dependent manner. The most interesting is that many kinase inhibitors (such as lapatinib, erlotinib and sunitinib) can promote MC3T3-E1 cell proliferation at 0.01 μM. 4 out of 7 inhibitors were selected to perform the functional study and found that they lead to cell cycle dysregulation, treatments of PF-04691502 (AKT inhibitor), Dasatinib (Src inhibitor) and Everolimus (mTOR inhibitor) lead to G1 arrest of MC3T3-E1 cells via downregulation of cyclin D1 and p-AKT, whereas XL880 (MET and VEGFR inhibitor) treatment results in increase of sub-G1 and G2/M phase by upregulation of p53 protein. Our work provides important indications for the comprehensive care of cancer patients treated with some targeted drugs.     

Randomized phase II study of sunitinib versus standard of care for patients with previously treated advanced triple-negative breast cancer

PurposeThis randomized, open-label phase II study compared the efficacy of sunitinib monotherapy with that of single-agent standard-of-care (SOC) chemotherapy in patients with previously treated advanced triple-negative breast cancer (TNBC).MethodsPatients with advanced TNBC, relapsed after anthracycline- and taxane-based chemotherapy, were randomized to receive either sunitinib (37.5 mg/day) or the investigator's choice of SOC therapy. Progression-free survival was the primary endpoint.ResultsMedian progression-free survival was 2.0 months with sunitinib and 2.7 months with SOC chemotherapy (one-sided P = 0.888). Median overall survival was not prolonged with sunitinib (9.4 months) compared with SOC chemotherapy (10.5 months; one-sided P = 0.839). The objective response rate was 3% with sunitinib and 7% with SOC chemotherapy (one-sided P = 0.962).ConclusionsSunitinib monotherapy did not improve efficacy compared with SOC chemotherapy in patients with previously treated advanced TNBC, for which identification of effective treatments and therapeutic targets remains an urgent need.Trial registrationNCT00246571.     

Caveolin-1下调细胞外调节蛋白激酶1/2抑制血管吻合口再狭窄

目的 探讨Caveolin-1对新西兰兔颈总动脉血管吻合口再狭窄的作用,以及与细胞外调节蛋白激酶(extracellular regulated protein kinases,ERK)的关系.方法 40只新西兰兔,随机分为正常对照组、手术组、空转染组和Caveolin-1转染组.行左侧颈总动脉血管端端吻合,并局部转染Caveolin-1质粒(转染组)或空质粒(空转染组).于术后第7天各组中分别取5只新西兰兔血管标本,用于Western blot和逆转录-聚合酶链反应(RT-PCR)检测蛋白和mRNA的表达;其余新西兰兔于术后28 d处死取颈总动脉,通过HE染色观察内膜增生情况,用Image-Pro Plus6.0软件测量内膜与中膜面积比值(IA/MA).结果 血管HE染色后测量内膜与中膜面积比值:Caveolin-1转染组的血管内膜/中膜面积比值较手术组降低约50％;与手术组比较,转染组Caveolin-1的mRNA和蛋白的表达明显升高,差异有统计学意义(t=36.59,P＜0.01);而在高表达Caveolin-1的血管吻合口上,ERK1/2的mRNA的表达以及蛋白质的活性都显著低于手术组(t值分别为:32.64和7.28,两者均P＜0.01).结论 Caveolin-1抑制吻合口再狭窄的作用可能与调节ERK1/2的活化有关.