AKT1 Oncogene in Carcinogenesis

描述：（改编自研究者摘要）我们以前 证明AKT 1是真正的人类v-akt对应物，最近 在前列腺原发性肿瘤中检测到频繁升高的AKT 1激酶活性， 乳房和卵巢。我们还观察到激活的AKT 1可以转化NIH 313 细胞并诱导膜皱褶，DN-AKT 1抑制ras 转型此外，两种阿基1 -相互作用蛋白已被发现。 其中一个是含有4个AKT 1磷酸化位点的APciB 和3个SH 3结构域，另一个是蛋白酶体b亚基（PMSB 4），其具有 AKT 1磷酸化位点。AKT 1在体外和体内磷酸化APaB和PSMB 4 vivo.此外，APaB与PAK 1激酶结合，并增强AKT 1诱导的细胞凋亡。 存活和细胞生长。我们还表明，阿基使p21 WAFI磷酸化， 并消除p21对CDK 4/6和cdc 2激酶的抑制作用。激活AKT 1 覆盖p5 3诱导的Gi停搏。根据这些数据，我们假设， 激活的AKT 1及其相关蛋白与PAK 1和p21相互作用， WAFi通路有助于控制恶性转化，细胞 周期进展和细胞骨架重组。因此，AKT 1可能是 有价值的肿瘤标志物和治疗干预的关键靶点， 人类癌症这个项目的广泛的长期目标是阐明 AKT 1蛋白的正常细胞功能，并确定其重要性 人类癌症中AKT 1通路的紊乱。具体目标是：1. 确定AKT 1激活的临床病理学意义和作用 在前列腺癌和乳腺癌中。这将通过（a）检查AKT 1 在大量的原发性前列腺癌和乳腺癌中激活， 将AKT 1活化与临床病理学特征相关联，和（B）产生 前列腺特异性，probasin启动子驱动的AKTJ转基因小鼠，以确定 如果激活的AKT 1的过度表达是致瘤的。2.定义交互 AKT 1和两个潜在的重要信号伴侣之间的关系， 酵母双杂交系统我们将研究（a）AKT的影响 1-AKT 1细胞存活途径的相互作用蛋白，包括PAK 1 活化，Bad磷酸化，NFiB活化，细胞色素c释放， （B）AKT的作用 1-相互作用蛋白对AKT 1致癌活性的影响，以及（c） AKT 1及其相关蛋白之间的结合结构域 信号3.检测p21的AKT 1磷酸化对细胞周期的影响 控制这将通过检查AKT 1诱导的细胞凋亡的影响来实现。 （a）p21的亚细胞定位和p21结合 细胞周期蛋白/CDK复合物的能力，（B）细胞周期蛋白/CDK活性，（c）Gi的组装 细胞周期蛋白CDK复合物和PCNA结合活性，以及（d）p21诱导的细胞周期 逮捕了4.确定AKT 1作为癌症干预的关键目标。这 将通过检查（a）直接抑制AKT 1的作用来完成 （B）DN-AKT 1和活化的AKT 1对癌细胞生长的影响， 化疗药物的敏感性，和（c）潜在的AKT 1抑制剂， 特异性和体外和体内抑制肿瘤细胞生长的能力。

DESCRIPTION: (Adapted from the investigator's abstract) We previously demonstrated that AKT1 is the true human counterpart of v-akt and recently detected frequent elevated AKT1 kinase activity in primary tumors of prostate, breast and ovary. We have also observed that activated AKT1 transforms NIH 313 cells and induces membrane ruffling and that DN-AKT1 inhibits ras transformation. In addition, two AKI 1 -interation proteins have been identified, one of which is APciB that contains 4 AKT 1 phosphorylation sites and 3 SH3 domains, and the other is a proteasome b-subunit (PMSB4) that has an AKT1 phosphotylation site. AKT1 phosphorylates APaB and PSMB4 in vitro and in vivo. Moreover, APaB binds to PAK 1 kinase and enhances AKT1-induced cell survival and cell growth. We have also shown that AKI I phosphorylates p21 WAFI and abrogates p21 inhibitory effect on CDK4/6 and cdc2 kinases. Activated AKT1 overrides p5 3-induced Gi arrest. Based on these data, we hypothesize that that activated AKT1 and its associated proteins are cross-talk with PAK1 and p21 WAFi pathways to contribute to the control of malignant transformation, cell cycle progression and cytoskeleton reorganization. Thus, AKT1 could be a valuable tumor marker and a critical target for therapeutic intervention in human cancer. The broad, long-term objective of this project is to elucidate the normal cellular function of the AKT1 protein and determine the importance of perturbations of AKT1 pathway in human cancers. The specific aims are: 1. Determine the clinicopathologic significance and the role of AKT1 activation in prostate and breast cancer. This will be accomplished by (a) examining AKT1 activation in a large series of primary prostate and breast carcinomas and correlating AKT1 activation with clinicopathologic features, and (b) creating prostate-specific, probasin promoter-driven AKTJ transgenic mice to ascertain if overexpression of activated AKT1 is tumorigenic. 2. Define the interaction between AKT1 and two potentially important signaling partners identified by the yeast two-hybrid system. We will examine (a) the effects of AKT 1-interaction proteins on AKT1 cell survival pathway, including PAK1 activation, Bad phosphorylation, NFiB activation, cytochrome c release, cytoskeleton reorganization, and p27 degradation, (b) the effects of AKT 1-interaction proteins on AKT1 oncogenic activity, and (c) the importance of the binding domains between AKT1 and its associated proteins in AKT1 signaling. 3. Examine the effects of AKT1 phosphorylation of p21 on cell cycle control. This will be accomplished by examining the effects of AKT1-induced p21 phosphorylation on (a) subcellular localization of p21 and p21 binding ability to cyclinlCDK complexes, (b) cyclinlCDK activity, (c) assembly of Gi cyclinlCDK complexes and PCNA binding activity, and (d) p21-induced cell cycle arrest. 4. Determine AKT1 as a critical target for cancer intervention. This will be accomplished by examining (a) the effects of direct inhibition of AKT1 on cancer cell growth, (b) the effects of DN-AKT1 and activated AKT1 on sensitivity of chemotherapeutic drugs, and (c) potential AKT1 inhibitors' specificity and ability to inhibit tumor cell growth in vitro and in vivo.