PKB/Akt Activation and Cell Survival with HIV-1 Tat

HIV-1 Tat 的 PKB/Akt 激活和细胞存活

• 批准号: 7052884
• 负责人: FELIPE SAMANIEGO
• 金额: $ 12.6万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-12 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7052884
• 关键词: AIDS related neoplasm /cancer; Kaposi' s sarcoma; SDS polyacrylamide gel electrophoresis; apoptosis; athymic mouse; biological signal transduction; cell line; clinical research; genetically modified animals; growth factor receptors; human immunodeficiency virus 1; immunoprecipitation; integrins; laboratory mouse; neoplastic growth; phosphorylation; protein kinase; terminal nick end labeling; transcription factor; transfection; vascular endothelial growth factors; virus protein

DESCRIPTION (provided by applicant): No convincing explanation exists for the aggressive growth of Kaposi's sarcoma (KS) in the estimated 8 million people worldwide afflicted with both this disease and human immunodeficiency virus type 1 (HIV-1). Human herpesvirus 8 (HHV-8) is required for the development of KS but is insufficient to cause it unless a second factor, such as HIV-1, is present. The HIV-1 transactivator of transcription (Tat) protein is implicated in KS because it stimulates the invasive and proliferative properties of KS cells and endothelial cells (ECs) in cultures and in tat transgenic mice. In preliminary studies, we found that Tat activates phosphatidylinositol 3'-kinase (PI3K) and Akt, the latter is a key regulator in tumorigenesis and cell survival. We found that immobilized Tat and physiologic levels of Tat in solution promoted the survival of KS SLK cells. It is not known how Tat promotes cell survival or to what extent this effect promotes growth of KS. We hypothesize that HIV-1 Tat activates Akt and promotes cell survival. Our preliminary studies with Tat and our exclusive faf transgenic mice lines will enable us to evaluate Tat's role in PI3K-Akt activation and cell survival. Specific Aim 1. Determine to what extent Tat activates Akt In vitro, and identify the signaling pathway Tat uses to promote cell survival. We will characterize Tat-related Akt phosphorylation and Akt kirtase activity in HHV-8 infected dermal microvasculature endothelial (HHV8-OMVE) cells. We will map the active moiety in Tat by using peptides, truncated Tat mutants, and antibodies. We will target the PI3K-Akt pathway with drugs (LY294002 and Perifosine) and PI3K-AM dominant-negative mutants to determine the role of this pathway in Tat-related cell survival. Specific Aim 2. Determine to what extent Tat activates Akt In vivo and promotes tumor growth by analyzing Tatexpressing cells In nude mice and tat transgenic mice. Tat of different sizes will be expressed and mapped on Tat domains critical to Akt phosphorylation. We will also test designed PISK-Akt inhibitors (LY294002 and Perifosine) and candidate anticancer agents for their role in blocking this pathway and reversing tumor growth. Successful completion of these studies will help identify a novel property of Tat that stimulates a survival mechanism anticipated to play a major role in KS and HHV8-DMVE cells. This research plan will establish the potential of drugs designed to interrupt this pathway implicated in KS and perhaps in other cancers associated with HIV-1 infection.

描述（由申请人提供）： 对于卡波西肉瘤（KS）的积极增长，在全球大约800万人患有这种疾病和人类免疫缺陷病毒1型（HIV-1）的人中，没有令人信服的解释。人类疱疹病毒8（HHV-8）是开发KS所必需的，但除非存在第二个因素（例如HIV-1），否则不足以引起它。 HIV-1转录（TAT）蛋白的HIV-1反式激活剂与KS有关，因为它刺激了培养物和TAT转基因小鼠中KS细胞和内皮细胞（EC）的侵入性和增殖性能。在初步研究中，我们发现TAT激活磷脂酰肌醇3'-激酶（PI3K）和AKT，后者是肿瘤发生和细胞存活中的关键调节剂。我们发现溶液中TAT的TAT固定水平和生理水平促进了KS SLK细胞的存活。尚不清楚TAT如何促进细胞存活，或在多大程度上促进KS的生长。我们假设HIV-1 TAT激活AKT并促进细胞存活。我们对TAT和我们独家FAF转基因小鼠系的初步研究将使我们能够评估TAT在PI3K-AKT激活和细胞存活中的作用。 具体目标1。确定TAT在体外激活AKT的程度，并确定TAT用来促进细胞存活的信号传导途径。我们将表征与HHV-8感染的皮肤微瘤内皮（HHV8-OMVE）细胞中与TAT相关的AKT磷酸化和Akt Kirtase活性。我们将使用肽，TAT突变体和抗体绘制TAT中的活性部分。我们将使用药物（LY294002和Perifosine）和PI3K-AM显性阴性突变体靶向PI3K-AKT途径，以确定该途径在TAT相关细胞存活中的作用。 具体目的2。确定TAT在多大程度上激活了体内Akt，并通过分析裸鼠和TAT转基因小鼠的Tatexpress细胞来促进肿瘤的生长。不同尺寸的TAT将在对Akt磷酸化至关重要的TAT结构域上表达和映射。我们还将测试设计设计的Pisk-Akt抑制剂（LY294002和Perifosine）和候选抗癌药，以在阻断这一途径和逆转肿瘤生长中的作用。 这些研究的成功完成将有助于确定TAT的新型特性，该特性刺激了预计在KS和HHV8-DMVE细胞中起主要作用的生存机制。该研究计划将建立旨在中断与KS有关的途径以及与HIV-1感染相关的其他癌症的潜力。

项目成果

FAS-antisense 1 lncRNA and production of soluble versus membrane Fas in B-cell lymphoma.

• DOI: 10.1038/leu.2014.126
• 发表时间: 2014-12
• 期刊: Leukemia
• 影响因子: 11.4
• 作者: Sehgal L;Mathur R;Braun FK;Wise JF;Berkova Z;Neelapu S;Kwak LW;Samaniego F
• 通讯作者: Samaniego F

Targeting nucleolin for better survival in diffuse large B-cell lymphoma.

• DOI: 10.1038/leu.2017.215
• 发表时间: 2018-03
• 期刊: Leukemia
• 影响因子: 11.4
• 作者: Jain N;Zhu H;Khashab T;Ye Q;George B;Mathur R;Singh RK;Berkova Z;Wise JF;Braun FK;Wang X;Patel K;Xu-Monette ZY;Courty J;Young KH;Sehgal L;Samaniego F
• 通讯作者: Samaniego F